From 1d04cbf5844ebac8c7eea25a0eaa6eec65f12939 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Tue, 7 Jan 2014 14:58:51 -0700
Subject: [PATCH 01/89] Enable harmony proxies

I want to use these in the pane-models branch, so it will be helpful
if they are enabled in atom stable since it's an atom-shell level
setting.
---
 src/browser/atom-application.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/browser/atom-application.coffee b/src/browser/atom-application.coffee
index 5b480d2f2..3e9aacc18 100644
--- a/src/browser/atom-application.coffee
+++ b/src/browser/atom-application.coffee
@@ -107,7 +107,7 @@ class AtomApplication
 
   # Private: Configures required javascript environment flags.
   setupJavaScriptArguments: ->
-    app.commandLine.appendSwitch 'js-flags', '--harmony_collections'
+    app.commandLine.appendSwitch 'js-flags', '--harmony_collections --harmony-proxies'
 
   # Private: Enable updates unless running from a local build of Atom.
   checkForUpdates: ->

From c99e211144be9fc5c56e33b04c6f9669c015510e Mon Sep 17 00:00:00 2001
From: Corey Johnson & Nathan Sobo <cj+nathan@github.com>
Date: Tue, 7 Jan 2014 15:42:23 -0700
Subject: [PATCH 02/89] Store Pane items in PaneModel

---
 package.json          |  3 ++-
 src/pane-model.coffee |  5 +++++
 src/pane.coffee       | 14 ++++++++------
 3 files changed, 15 insertions(+), 7 deletions(-)
 create mode 100644 src/pane-model.coffee

diff --git a/package.json b/package.json
index f9cca4db8..d438072a5 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,8 @@
     "temp": "0.5.0",
     "text-buffer": "0.9.0",
     "underscore-plus": "0.6.1",
-    "theorist": "~0.7.0"
+    "theorist": "~0.7.0",
+    "delegato": "~0.4.0"
   },
   "packageDependencies": {
     "atom-dark-syntax": "0.10.0",
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
new file mode 100644
index 000000000..fd0c1e6ce
--- /dev/null
+++ b/src/pane-model.coffee
@@ -0,0 +1,5 @@
+{Model} = require 'theorist'
+
+module.exports =
+class PaneModel extends Model
+  constructor: ({@items}) ->
diff --git a/src/pane.coffee b/src/pane.coffee
index d976a95f0..234a50048 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -2,7 +2,9 @@
 {$, View} = require './space-pen-extensions'
 _ = require 'underscore-plus'
 Serializable = require 'serializable'
+Delegator = require 'delegato'
 
+PaneModel = require './pane-model'
 PaneRow = require './pane-row'
 PaneColumn = require './pane-column'
 
@@ -15,6 +17,7 @@ PaneColumn = require './pane-column'
 module.exports =
 class Pane extends View
   Serializable.includeInto(this)
+  Delegator.includeInto(this)
 
   @version: 1
 
@@ -22,18 +25,17 @@ class Pane extends View
     @div class: 'pane', tabindex: -1, =>
       @div class: 'item-views', outlet: 'itemViews'
 
+  @delegatesProperty 'items', toProperty: 'model'
+
   activeItem: null
-  items: null
-  viewsByItem: null      # Views without a setModel() method are stored here
 
   # Private:
   initialize: (args...) ->
     if args[0]?.items # deserializing
-      {@items, activeItemUri, @focusOnAttach} = args[0]
+      {items, activeItemUri, @focusOnAttach} = args[0]
+      @model = new PaneModel({items})
     else
-      @items = args
-
-    @items ?= []
+      @model = new PaneModel(items: args)
 
     @handleItemEvents(item) for item in @items
 

From 14175d80eff417199db42ca2b8f73f69be333407 Mon Sep 17 00:00:00 2001
From: Corey Johnson & Nathan Sobo <cj+nathan@github.com>
Date: Tue, 7 Jan 2014 15:46:17 -0700
Subject: [PATCH 03/89] Move Pane::activeItem to PaneModel

---
 src/pane-model.coffee | 2 ++
 src/pane.coffee       | 4 +---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index fd0c1e6ce..6f5948466 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -2,4 +2,6 @@
 
 module.exports =
 class PaneModel extends Model
+  activeItem: null
+
   constructor: ({@items}) ->
diff --git a/src/pane.coffee b/src/pane.coffee
index 234a50048..f441b63b0 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -25,9 +25,7 @@ class Pane extends View
     @div class: 'pane', tabindex: -1, =>
       @div class: 'item-views', outlet: 'itemViews'
 
-  @delegatesProperty 'items', toProperty: 'model'
-
-  activeItem: null
+  @delegatesProperties 'items', 'activeItem', toProperty: 'model'
 
   # Private:
   initialize: (args...) ->

From 25c099f3a227c3f4e987493f04c51a452535f2f7 Mon Sep 17 00:00:00 2001
From: Corey Johnson & Nathan Sobo <cj+nathan@github.com>
Date: Tue, 7 Jan 2014 17:23:29 -0700
Subject: [PATCH 04/89] Serialize the items and activeItem via PaneModel

This necessitates setting the ::activeView based on the model's
::activeItem instead of doing it in ::showItem.
---
 spec/pane-container-spec.coffee |  2 +-
 spec/pane-spec.coffee           |  6 +++---
 src/pane-model.coffee           | 21 +++++++++++++++++++--
 src/pane.coffee                 | 28 +++++++++++++++-------------
 4 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index 13ff182f6..4dc770c16 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -16,7 +16,7 @@ describe "PaneContainer", ->
       serialize: -> { deserializer: 'TestView', @name }
       getUri: -> path.join(temp.dir, @name)
       save: -> @saved = true
-      isEqual: (other) -> @name is other.name
+      isEqual: (other) -> @name is other?.name
 
     container = new PaneContainer
     pane1 = new Pane(new TestView('1'))
diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index 6851bb8f4..fd6339cab 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -13,7 +13,7 @@ describe "Pane", ->
     initialize: ({@id, @text}) ->
     serialize: -> { deserializer: 'TestView', @id, @text }
     getUri: -> @id
-    isEqual: (other) -> @id == other.id and @text == other.text
+    isEqual: (other) -> other? and @id == other.id and @text == other.text
 
   beforeEach ->
     atom.deserializers.add(TestView)
@@ -558,12 +558,12 @@ describe "Pane", ->
         pane2 = pane1.splitRight()
         expect(container.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
         expect(pane2.items).toEqual []
-        expect(pane2.activeItem).toBe null
+        expect(pane2.activeItem).toBeUndefined()
 
         pane3 = pane2.splitRight()
         expect(container.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0], pane3[0]]
         expect(pane3.items).toEqual []
-        expect(pane3.activeItem).toBe null
+        expect(pane3.activeItem).toBeUndefined()
 
     describe "splitLeft(items...)", ->
       it "builds a row if needed, then appends a new pane before itself", ->
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 6f5948466..b91edb0e6 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -1,7 +1,24 @@
+{find, compact} = require 'underscore-plus'
 {Model} = require 'theorist'
+Serializable = require 'serializable'
 
 module.exports =
 class PaneModel extends Model
-  activeItem: null
+  Serializable.includeInto(this)
 
-  constructor: ({@items}) ->
+  @properties
+    activeItem: null
+
+  constructor: ({@items, @activeItem}) ->
+    @items ?= []
+    @activeItem ?= @items[0]
+
+  serializeParams: ->
+    items: compact(@items.map((item) -> item.serialize?()))
+    activeItemUri: @activeItem?.getUri?()
+
+  deserializeParams: (params) ->
+    {items, activeItemUri} = params
+    params.items = items.map (itemState) -> atom.deserializers.deserialize(itemState)
+    params.activeItem = find params.items, (item) -> item.getUri?() is activeItemUri
+    params
diff --git a/src/pane.coffee b/src/pane.coffee
index f441b63b0..a463b4ac6 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -27,11 +27,12 @@ class Pane extends View
 
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
 
+  previousActiveItem: null
+
   # Private:
   initialize: (args...) ->
-    if args[0]?.items # deserializing
-      {items, activeItemUri, @focusOnAttach} = args[0]
-      @model = new PaneModel({items})
+    if args[0]?.model?
+      {@model, @focusOnAttach} = args[0]
     else
       @model = new PaneModel(items: args)
 
@@ -39,8 +40,7 @@ class Pane extends View
 
     @viewsByItem = new WeakMap()
 
-    unless activeItemUri? and @showItemForUri(activeItemUri)
-      @showItem(@items[0]) if @items.length > 0
+    @subscribe @model.$activeItem, 'value', @onActiveItemChanged
 
     @command 'pane:save-items', @saveItems
     @command 'pane:show-next-item', @showNextItem
@@ -66,13 +66,12 @@ class Pane extends View
     @on 'focusin', => @makeActive()
 
   deserializeParams: (params) ->
-    params.items = _.compact(params.items.map (itemState) -> atom.deserializers.deserialize(itemState))
+    params.model = PaneModel.deserialize(params.model)
     params
 
   serializeParams: ->
-    items: _.compact(@items.map (item) -> item.serialize?())
+    model: @model.serialize()
     focusOnAttach: @is(':has(:focus)')
-    activeItemUri: @getActivePaneItem()?.getUri?()
 
   # Private:
   afterAttach: (onDom) ->
@@ -146,20 +145,23 @@ class Pane extends View
 
   # Public: Focuses the given item.
   showItem: (item) ->
-    return if !item? or item is @activeItem
+    if item?
+      @addItem(item)
+      @model.activeItem = item
 
-    if @activeItem
-      @activeItem.off? 'title-changed', @activeItemTitleChanged
+  onActiveItemChanged: (item) =>
+    @previousActiveItem?.off? 'title-changed', @activeItemTitleChanged
+    @previousActiveItem = item
+
+    return unless item?
 
     isFocused = @is(':has(:focus)')
-    @addItem(item)
     item.on? 'title-changed', @activeItemTitleChanged
     view = @viewForItem(item)
     @itemViews.children().not(view).hide()
     @itemViews.append(view) unless view.parent().is(@itemViews)
     view.show() if @attached
     view.focus() if isFocused
-    @activeItem = item
     @activeView = view
     @trigger 'pane:active-item-changed', [item]
 

From cd97de76fcdf19dcc776734721fb965f4af532d0 Mon Sep 17 00:00:00 2001
From: Corey Johnson & Nathan Sobo <cj+nathan@github.com>
Date: Tue, 7 Jan 2014 17:28:50 -0700
Subject: [PATCH 05/89] :lipstick:

---
 src/pane.coffee | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/pane.coffee b/src/pane.coffee
index a463b4ac6..cd31b67b1 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -40,7 +40,12 @@ class Pane extends View
 
     @viewsByItem = new WeakMap()
 
+    @handleEvents()
+
+  handleEvents: ->
     @subscribe @model.$activeItem, 'value', @onActiveItemChanged
+    @subscribe this, 'focus', => @activeView?.focus(); false
+    @subscribe this, 'focusin', => @makeActive()
 
     @command 'pane:save-items', @saveItems
     @command 'pane:show-next-item', @showNextItem
@@ -62,8 +67,6 @@ class Pane extends View
     @command 'pane:split-down', => @splitDown(@copyActiveItem())
     @command 'pane:close', => @destroyItems()
     @command 'pane:close-other-items', => @destroyInactiveItems()
-    @on 'focus', => @activeView?.focus(); false
-    @on 'focusin', => @makeActive()
 
   deserializeParams: (params) ->
     params.model = PaneModel.deserialize(params.model)

From 2938a8e65022e23a6ddc67a2088ac9cc3678716d Mon Sep 17 00:00:00 2001
From: Corey Johnson & Nathan Sobo <cj+nathan@github.com>
Date: Tue, 7 Jan 2014 17:47:42 -0700
Subject: [PATCH 06/89] Move item-oriented methods to PaneModel

---
 src/pane-model.coffee | 48 ++++++++++++++++++++++++++++-
 src/pane.coffee       | 70 ++++++++-----------------------------------
 2 files changed, 60 insertions(+), 58 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index b91edb0e6..8b0be5d62 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -1,4 +1,4 @@
-{find, compact} = require 'underscore-plus'
+{find, compact, clone} = require 'underscore-plus'
 {Model} = require 'theorist'
 Serializable = require 'serializable'
 
@@ -22,3 +22,49 @@ class PaneModel extends Model
     params.items = items.map (itemState) -> atom.deserializers.deserialize(itemState)
     params.activeItem = find params.items, (item) -> item.getUri?() is activeItemUri
     params
+
+  # Public: Returns all contained views.
+  getItems: ->
+    clone(@items)
+
+  # Public: Switches to the next contained item.
+  showNextItem: =>
+    index = @getActiveItemIndex()
+    if index < @items.length - 1
+      @showItemAtIndex(index + 1)
+    else
+      @showItemAtIndex(0)
+
+  # Public: Switches to the previous contained item.
+  showPreviousItem: =>
+    index = @getActiveItemIndex()
+    if index > 0
+      @showItemAtIndex(index - 1)
+    else
+      @showItemAtIndex(@items.length - 1)
+
+  # Public: Returns the index of the currently active item.
+  getActiveItemIndex: ->
+    @items.indexOf(@activeItem)
+
+  # Public: Switch to the item associated with the given index.
+  showItemAtIndex: (index) ->
+    @showItem(@itemAtIndex(index))
+
+  # Public: Focuses the given item.
+  showItem: (item) ->
+    if item?
+      @addItem(item)
+      @activeItem = item
+
+  # Public: Add an additional item at the specified index.
+  addItem: (item, index=@getActiveItemIndex() + 1) ->
+    return if item in @items
+
+    @items.splice(index, 0, item)
+    @emit 'item-added', item, index
+    item
+
+  # Public: Returns the item at the specified index.
+  itemAtIndex: (index) ->
+    @items[index]
diff --git a/src/pane.coffee b/src/pane.coffee
index cd31b67b1..0e3a7496d 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -26,6 +26,8 @@ class Pane extends View
       @div class: 'item-views', outlet: 'itemViews'
 
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
+  @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
+    'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex', toProperty: 'model'
 
   previousActiveItem: null
 
@@ -36,20 +38,20 @@ class Pane extends View
     else
       @model = new PaneModel(items: args)
 
-    @handleItemEvents(item) for item in @items
-
+    @onItemAdded(item) for item in @items
     @viewsByItem = new WeakMap()
-
     @handleEvents()
 
   handleEvents: ->
     @subscribe @model.$activeItem, 'value', @onActiveItemChanged
+    @subscribe @model, 'item-added', @onItemAdded
+
     @subscribe this, 'focus', => @activeView?.focus(); false
     @subscribe this, 'focusin', => @makeActive()
 
-    @command 'pane:save-items', @saveItems
-    @command 'pane:show-next-item', @showNextItem
-    @command 'pane:show-previous-item', @showPreviousItem
+    @command 'pane:save-items', => @saveItems()
+    @command 'pane:show-next-item', => @showNextItem()
+    @command 'pane:show-previous-item', => @showPreviousItem()
 
     @command 'pane:show-item-1', => @showItemAtIndex(0)
     @command 'pane:show-item-2', => @showItemAtIndex(1)
@@ -111,47 +113,9 @@ class Pane extends View
     nextIndex = (panes.indexOf(this) + 1) % panes.length
     panes[nextIndex]
 
-  # Public: Returns all contained views.
-  getItems: ->
-    new Array(@items...)
-
-  # Public: Switches to the next contained item.
-  showNextItem: =>
-    index = @getActiveItemIndex()
-    if index < @items.length - 1
-      @showItemAtIndex(index + 1)
-    else
-      @showItemAtIndex(0)
-
-  # Public: Switches to the previous contained item.
-  showPreviousItem: =>
-    index = @getActiveItemIndex()
-    if index > 0
-      @showItemAtIndex(index - 1)
-    else
-      @showItemAtIndex(@items.length - 1)
-
   getActivePaneItem: ->
     @activeItem
 
-  # Public: Returns the index of the currently active item.
-  getActiveItemIndex: ->
-    @items.indexOf(@activeItem)
-
-  # Public: Switch to the item associated with the given index.
-  showItemAtIndex: (index) ->
-    @showItem(@itemAtIndex(index))
-
-  # Public: Returns the item at the specified index.
-  itemAtIndex: (index) ->
-    @items[index]
-
-  # Public: Focuses the given item.
-  showItem: (item) ->
-    if item?
-      @addItem(item)
-      @model.activeItem = item
-
   onActiveItemChanged: (item) =>
     @previousActiveItem?.off? 'title-changed', @activeItemTitleChanged
     @previousActiveItem = item
@@ -168,23 +132,15 @@ class Pane extends View
     @activeView = view
     @trigger 'pane:active-item-changed', [item]
 
+  onItemAdded: (item, index) =>
+    if typeof item.on is 'function'
+      @subscribe item, 'destroyed', => @destroyItem(item)
+    @trigger 'pane:item-added', [item, index]
+
   # Private:
   activeItemTitleChanged: =>
     @trigger 'pane:active-item-title-changed'
 
-  # Public: Add an additional item at the specified index.
-  addItem: (item, index=@getActiveItemIndex() + 1) ->
-    return if _.include(@items, item)
-
-    @items.splice(index, 0, item)
-    @trigger 'pane:item-added', [item, index]
-    @handleItemEvents(item)
-    item
-
-  handleItemEvents: (item) ->
-    if _.isFunction(item.on)
-      @subscribe item, 'destroyed', => @destroyItem(item)
-
   # Public: Remove the currently active item.
   destroyActiveItem: =>
     @destroyItem(@activeItem)

From 1a487db29f2c3e0eed915136c80ef59259de9bc7 Mon Sep 17 00:00:00 2001
From: Corey Johnson & Nathan Sobo <cj+nathan@github.com>
Date: Tue, 7 Jan 2014 17:55:56 -0700
Subject: [PATCH 07/89] Move item removal events to PaneModel

---
 src/pane-model.coffee | 12 ++++++++++++
 src/pane.coffee       | 22 +++++++---------------
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 8b0be5d62..8d3f13d40 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -65,6 +65,18 @@ class PaneModel extends Model
     @emit 'item-added', item, index
     item
 
+  # Public:
+  removeItem: (item) ->
+    index = @items.indexOf(item)
+    @removeItemAtIndex(index) if index >= 0
+
+  # Public: Just remove the item at the given index.
+  removeItemAtIndex: (index) ->
+    item = @items[index]
+    @showNextItem() if item is @activeItem and @items.length > 1
+    @items.splice(index, 1)
+    @emit 'item-removed', item, index
+
   # Public: Returns the item at the specified index.
   itemAtIndex: (index) ->
     @items[index]
diff --git a/src/pane.coffee b/src/pane.coffee
index 0e3a7496d..7f1f6056c 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -27,7 +27,8 @@ class Pane extends View
 
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
   @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
-    'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex', toProperty: 'model'
+    'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex',  'removeItem', 'removeItemAtIndex',
+    toProperty: 'model'
 
   previousActiveItem: null
 
@@ -45,6 +46,7 @@ class Pane extends View
   handleEvents: ->
     @subscribe @model.$activeItem, 'value', @onActiveItemChanged
     @subscribe @model, 'item-added', @onItemAdded
+    @subscribe @model, 'item-removed', @onItemRemoved
 
     @subscribe this, 'focus', => @activeView?.focus(); false
     @subscribe this, 'focusin', => @makeActive()
@@ -137,6 +139,10 @@ class Pane extends View
       @subscribe item, 'destroyed', => @destroyItem(item)
     @trigger 'pane:item-added', [item, index]
 
+  onItemRemoved: (item, index) =>
+    @cleanupItemView(item)
+    @trigger 'pane:item-removed', [item, index]
+
   # Private:
   activeItemTitleChanged: =>
     @trigger 'pane:active-item-title-changed'
@@ -214,20 +220,6 @@ class Pane extends View
   saveItems: =>
     @saveItem(item) for item in @getItems()
 
-  # Public:
-  removeItem: (item) ->
-    index = @items.indexOf(item)
-    @removeItemAtIndex(index) if index >= 0
-
-  # Public: Just remove the item at the given index.
-  removeItemAtIndex: (index) ->
-    item = @items[index]
-    @activeItem.off? 'title-changed', @activeItemTitleChanged if item is @activeItem
-    @showNextItem() if item is @activeItem and @items.length > 1
-    _.remove(@items, item)
-    @cleanupItemView(item)
-    @trigger 'pane:item-removed', [item, index]
-
   # Public: Moves the given item to a the new index.
   moveItem: (item, newIndex) ->
     oldIndex = @items.indexOf(item)

From 5837b7cfda0007fec005f7e3c29a5226ffd16427 Mon Sep 17 00:00:00 2001
From: Corey Johnson & Nathan Sobo <cj+nathan@github.com>
Date: Tue, 7 Jan 2014 18:39:39 -0700
Subject: [PATCH 08/89] Move methods related to item movement to PaneModel

---
 src/pane-model.coffee | 26 +++++++++++++++++++-------
 src/pane.coffee       | 34 ++++++++++++----------------------
 2 files changed, 31 insertions(+), 29 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 8d3f13d40..605ed3a14 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -27,6 +27,10 @@ class PaneModel extends Model
   getItems: ->
     clone(@items)
 
+  # Public: Returns the item at the specified index.
+  itemAtIndex: (index) ->
+    @items[index]
+
   # Public: Switches to the next contained item.
   showNextItem: =>
     index = @getActiveItemIndex()
@@ -66,17 +70,25 @@ class PaneModel extends Model
     item
 
   # Public:
-  removeItem: (item) ->
+  removeItem: (item, detach) ->
     index = @items.indexOf(item)
-    @removeItemAtIndex(index) if index >= 0
+    @removeItemAtIndex(index, detach) if index >= 0
 
   # Public: Just remove the item at the given index.
-  removeItemAtIndex: (index) ->
+  removeItemAtIndex: (index, detach) ->
     item = @items[index]
     @showNextItem() if item is @activeItem and @items.length > 1
     @items.splice(index, 1)
-    @emit 'item-removed', item, index
+    @emit 'item-removed', item, index, detach
 
-  # Public: Returns the item at the specified index.
-  itemAtIndex: (index) ->
-    @items[index]
+  # Public: Moves the given item to a the new index.
+  moveItem: (item, newIndex) ->
+    oldIndex = @items.indexOf(item)
+    @items.splice(oldIndex, 1)
+    @items.splice(newIndex, 0, item)
+    @emit 'item-moved', item, newIndex
+
+  # Public: Moves the given item to another pane.
+  moveItemToPane: (item, pane, index) ->
+    pane.addItem(item, index)
+    @removeItem(item, true)
diff --git a/src/pane.coffee b/src/pane.coffee
index 7f1f6056c..13f1fc087 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -28,7 +28,7 @@ class Pane extends View
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
   @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
     'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex',  'removeItem', 'removeItemAtIndex',
-    toProperty: 'model'
+    'moveItem', 'moveItemToPane', toProperty: 'model'
 
   previousActiveItem: null
 
@@ -47,6 +47,7 @@ class Pane extends View
     @subscribe @model.$activeItem, 'value', @onActiveItemChanged
     @subscribe @model, 'item-added', @onItemAdded
     @subscribe @model, 'item-removed', @onItemRemoved
+    @subscribe @model, 'item-moved', @onItemMoved
 
     @subscribe this, 'focus', => @activeView?.focus(); false
     @subscribe this, 'focusin', => @makeActive()
@@ -139,10 +140,13 @@ class Pane extends View
       @subscribe item, 'destroyed', => @destroyItem(item)
     @trigger 'pane:item-added', [item, index]
 
-  onItemRemoved: (item, index) =>
-    @cleanupItemView(item)
+  onItemRemoved: (item, index, detach) =>
+    @cleanupItemView(item, detach)
     @trigger 'pane:item-removed', [item, index]
 
+  onItemMoved: (item, newIndex) =>
+    @trigger 'pane:item-moved', [item, newIndex]
+
   # Private:
   activeItemTitleChanged: =>
     @trigger 'pane:active-item-title-changed'
@@ -220,20 +224,6 @@ class Pane extends View
   saveItems: =>
     @saveItem(item) for item in @getItems()
 
-  # Public: Moves the given item to a the new index.
-  moveItem: (item, newIndex) ->
-    oldIndex = @items.indexOf(item)
-    @items.splice(oldIndex, 1)
-    @items.splice(newIndex, 0, item)
-    @trigger 'pane:item-moved', [item, newIndex]
-
-  # Public: Moves the given item to another pane.
-  moveItemToPane: (item, pane, index) ->
-    @isMovingItem = true
-    pane.addItem(item, index)
-    @removeItem(item)
-    @isMovingItem = false
-
   # Public: Finds the first item that matches the given uri.
   itemForUri: (uri) ->
     _.detect @items, (item) -> item.getUri?() is uri
@@ -247,24 +237,24 @@ class Pane extends View
       false
 
   # Private:
-  cleanupItemView: (item) ->
+  cleanupItemView: (item, detach) ->
     if item instanceof $
       viewToRemove = item
     else if viewToRemove = @viewsByItem.get(item)
       @viewsByItem.delete(item)
 
     if @items.length > 0
-      if @isMovingItem and item is viewToRemove
+      if detach and item is viewToRemove
         viewToRemove?.detach()
-      else if @isMovingItem and viewToRemove?.setModel
+      else if detach and viewToRemove?.setModel
         viewToRemove.setModel(null) # dont want to destroy the model, so set to null
         viewToRemove.remove()
       else
         viewToRemove?.remove()
     else
-      if @isMovingItem and item is viewToRemove
+      if detach and item is viewToRemove
         viewToRemove?.detach()
-      else if @isMovingItem and viewToRemove?.setModel
+      else if detach and viewToRemove?.setModel
         viewToRemove.setModel(null) # dont want to destroy the model, so set to null
 
       @parent().view().removeChild(this)

From 626e22e4aec924446b48813b054732a029a60597 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Tue, 7 Jan 2014 18:45:18 -0700
Subject: [PATCH 09/89] Avoid exceptions when a live editor is compared with a
 destroyed one

---
 src/editor.coffee | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/editor.coffee b/src/editor.coffee
index cff06ddfc..c144aa10d 100644
--- a/src/editor.coffee
+++ b/src/editor.coffee
@@ -174,7 +174,8 @@ class Editor extends Model
   # Returns a {Boolean}.
   isEqual: (other) ->
     return false unless other instanceof Editor
-    @buffer.getPath() == other.buffer.getPath() and
+    @isAlive() == other.isAlive() and
+      @buffer.getPath() == other.buffer.getPath() and
       @getScrollTop() == other.getScrollTop() and
       @getScrollLeft() == other.getScrollLeft() and
       @getCursorScreenPosition().isEqual(other.getCursorScreenPosition())

From a379d47230853a501555573ec8a37f63c5c76cb7 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 11:12:27 -0700
Subject: [PATCH 10/89] Move methods related to item destruction and saving to
 PaneModel

---
 src/pane-model.coffee |  84 +++++++++++++++++++++++++++++++++++
 src/pane.coffee       | 100 +++++-------------------------------------
 2 files changed, 96 insertions(+), 88 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 605ed3a14..ef236a655 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -1,4 +1,5 @@
 {find, compact, clone} = require 'underscore-plus'
+{dirname} = require 'path'
 {Model} = require 'theorist'
 Serializable = require 'serializable'
 
@@ -92,3 +93,86 @@ class PaneModel extends Model
   moveItemToPane: (item, pane, index) ->
     pane.addItem(item, index)
     @removeItem(item, true)
+
+  # Public: Remove the currently active item.
+  destroyActiveItem: ->
+    @destroyItem(@activeItem)
+    false
+
+  # Public: Remove the specified item.
+  destroyItem: (item, options) ->
+    @emit 'before-item-destroyed', item
+    if @promptToSaveItem(item)
+      @emit 'item-destroyed', item
+      @removeItem(item, options)
+      item.destroy?()
+      true
+    else
+      false
+
+  # Public: Remove and delete all items.
+  destroyItems: ->
+    @destroyItem(item) for item in @getItems()
+
+  # Public: Remove and delete all but the currently focused item.
+  destroyInactiveItems: ->
+    @destroyItem(item) for item in @getItems() when item isnt @activeItem
+
+  # Public: Prompt the user to save the given item.
+  promptToSaveItem: (item) ->
+    return true unless item.shouldPromptToSave?()
+
+    uri = item.getUri()
+    chosen = atom.confirm
+      message: "'#{item.getTitle?() ? item.getUri()}' has changes, do you want to save them?"
+      detailedMessage: "Your changes will be lost if you close this item without saving."
+      buttons: ["Save", "Cancel", "Don't Save"]
+
+    switch chosen
+      when 0 then @saveItem(item, -> true)
+      when 1 then false
+      when 2 then true
+
+  # Public: Saves the currently focused item.
+  saveActiveItem: =>
+    @saveItem(@activeItem)
+
+  # Public: Save and prompt for path for the currently focused item.
+  saveActiveItemAs: =>
+    @saveItemAs(@activeItem)
+
+  # Public: Saves the specified item and call the next action when complete.
+  saveItem: (item, nextAction) ->
+    if item.getUri?()
+      item.save?()
+      nextAction?()
+    else
+      @saveItemAs(item, nextAction)
+
+  # Public: Prompts for path and then saves the specified item. Upon completion
+  # it also calls the next action.
+  saveItemAs: (item, nextAction) ->
+    return unless item.saveAs?
+
+    itemPath = item.getPath?()
+    itemPath = dirname(itemPath) if itemPath
+    path = atom.showSaveDialogSync(itemPath)
+    if path
+      item.saveAs(path)
+      nextAction?()
+
+  # Public: Saves all items in this pane.
+  saveItems: =>
+    @saveItem(item) for item in @getItems()
+
+  # Public: Finds the first item that matches the given uri.
+  itemForUri: (uri) ->
+    find @items, (item) -> item.getUri?() is uri
+
+  # Public: Focuses the first item that matches the given uri.
+  showItemForUri: (uri) ->
+    if item = @itemForUri(uri)
+      @showItem(item)
+      true
+    else
+      false
diff --git a/src/pane.coffee b/src/pane.coffee
index 13f1fc087..54cc64cf4 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -1,6 +1,4 @@
-{dirname} = require 'path'
 {$, View} = require './space-pen-extensions'
-_ = require 'underscore-plus'
 Serializable = require 'serializable'
 Delegator = require 'delegato'
 
@@ -28,7 +26,9 @@ class Pane extends View
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
   @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
     'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex',  'removeItem', 'removeItemAtIndex',
-    'moveItem', 'moveItemToPane', toProperty: 'model'
+    'moveItem', 'moveItemToPane', 'destroyItem', 'destroyItems', 'destroyActiveItem',
+    'destroyInactiveItems', 'saveActiveItem', 'saveActiveItemAs', 'saveItem', 'saveItemAs',
+    'saveItems', 'itemForUri', 'showItemForUri', 'promptToSaveItem', toProperty: 'model'
 
   previousActiveItem: null
 
@@ -48,6 +48,8 @@ class Pane extends View
     @subscribe @model, 'item-added', @onItemAdded
     @subscribe @model, 'item-removed', @onItemRemoved
     @subscribe @model, 'item-moved', @onItemMoved
+    @subscribe @model, 'before-item-destroyed', @onBeforeItemDestroyed
+    @subscribe @model, 'item-destroyed', @onItemDestroyed
 
     @subscribe this, 'focus', => @activeView?.focus(); false
     @subscribe this, 'focusin', => @makeActive()
@@ -147,95 +149,17 @@ class Pane extends View
   onItemMoved: (item, newIndex) =>
     @trigger 'pane:item-moved', [item, newIndex]
 
+  onBeforeItemDestroyed: (item) =>
+    @unsubscribe(item) if typeof item.off is 'function'
+    @trigger 'pane:before-item-destroyed', [item]
+
+  onItemDestroyed: (item) =>
+    @getContainer()?.itemDestroyed(item)
+
   # Private:
   activeItemTitleChanged: =>
     @trigger 'pane:active-item-title-changed'
 
-  # Public: Remove the currently active item.
-  destroyActiveItem: =>
-    @destroyItem(@activeItem)
-    false
-
-  # Public: Remove the specified item.
-  destroyItem: (item, options) ->
-    @unsubscribe(item) if _.isFunction(item.off)
-    @trigger 'pane:before-item-destroyed', [item]
-
-    if @promptToSaveItem(item)
-      @getContainer()?.itemDestroyed(item)
-      @removeItem(item, options)
-      item.destroy?()
-      true
-    else
-      false
-
-  # Public: Remove and delete all items.
-  destroyItems: ->
-    @destroyItem(item) for item in @getItems()
-
-  # Public: Remove and delete all but the currently focused item.
-  destroyInactiveItems: ->
-    @destroyItem(item) for item in @getItems() when item isnt @activeItem
-
-  # Public: Prompt the user to save the given item.
-  promptToSaveItem: (item) ->
-    return true unless item.shouldPromptToSave?()
-
-    uri = item.getUri()
-    chosen = atom.confirm
-      message: "'#{item.getTitle?() ? item.getUri()}' has changes, do you want to save them?"
-      detailedMessage: "Your changes will be lost if you close this item without saving."
-      buttons: ["Save", "Cancel", "Don't Save"]
-
-    switch chosen
-      when 0 then @saveItem(item, -> true)
-      when 1 then false
-      when 2 then true
-
-  # Public: Saves the currently focused item.
-  saveActiveItem: =>
-    @saveItem(@activeItem)
-
-  # Public: Save and prompt for path for the currently focused item.
-  saveActiveItemAs: =>
-    @saveItemAs(@activeItem)
-
-  # Public: Saves the specified item and call the next action when complete.
-  saveItem: (item, nextAction) ->
-    if item.getUri?()
-      item.save?()
-      nextAction?()
-    else
-      @saveItemAs(item, nextAction)
-
-  # Public: Prompts for path and then saves the specified item. Upon completion
-  # it also calls the next action.
-  saveItemAs: (item, nextAction) ->
-    return unless item.saveAs?
-
-    itemPath = item.getPath?()
-    itemPath = dirname(itemPath) if itemPath
-    path = atom.showSaveDialogSync(itemPath)
-    if path
-      item.saveAs(path)
-      nextAction?()
-
-  # Public: Saves all items in this pane.
-  saveItems: =>
-    @saveItem(item) for item in @getItems()
-
-  # Public: Finds the first item that matches the given uri.
-  itemForUri: (uri) ->
-    _.detect @items, (item) -> item.getUri?() is uri
-
-  # Public: Focuses the first item that matches the given uri.
-  showItemForUri: (uri) ->
-    if item = @itemForUri(uri)
-      @showItem(item)
-      true
-    else
-      false
-
   # Private:
   cleanupItemView: (item, detach) ->
     if item instanceof $

From ee9b78afb6e5561135361e8e742ab653b7e1501e Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 11:14:02 -0700
Subject: [PATCH 11/89] Move copyActiveItem to PaneModel

---
 src/pane-model.coffee | 4 ++++
 src/pane.coffee       | 7 ++-----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index ef236a655..94cb78d82 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -176,3 +176,7 @@ class PaneModel extends Model
       true
     else
       false
+
+  # Private:
+  copyActiveItem: ->
+    @activeItem.copy?() ? atom.deserializers.deserialize(@activeItem.serialize())
diff --git a/src/pane.coffee b/src/pane.coffee
index 54cc64cf4..f9bb2b25c 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -28,7 +28,8 @@ class Pane extends View
     'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex',  'removeItem', 'removeItemAtIndex',
     'moveItem', 'moveItemToPane', 'destroyItem', 'destroyItems', 'destroyActiveItem',
     'destroyInactiveItems', 'saveActiveItem', 'saveActiveItemAs', 'saveItem', 'saveItemAs',
-    'saveItems', 'itemForUri', 'showItemForUri', 'promptToSaveItem', toProperty: 'model'
+    'saveItems', 'itemForUri', 'showItemForUri', 'promptToSaveItem', 'copyActiveItem',
+    toProperty: 'model'
 
   previousActiveItem: null
 
@@ -260,10 +261,6 @@ class Pane extends View
   getContainer: ->
     @closest('.panes').view()
 
-  # Private:
-  copyActiveItem: ->
-    @activeItem.copy?() ? atom.deserializers.deserialize(@activeItem.serialize())
-
   # Private:
   remove: (selector, keepData) ->
     return super if keepData

From 2acde6a727f71a90554790112c761ddff6bbf06d Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 11:20:15 -0700
Subject: [PATCH 12/89] Call `super` in constructor to assign PaneModel
 properties

The theorist model superclass constructor will automatically assign
all declared properties, or substitute the specified default value if
no param key is present for that property.
---
 src/pane-model.coffee | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 94cb78d82..c39174083 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -8,10 +8,11 @@ class PaneModel extends Model
   Serializable.includeInto(this)
 
   @properties
+    items: -> []
     activeItem: null
 
-  constructor: ({@items, @activeItem}) ->
-    @items ?= []
+  constructor: ->
+    super
     @activeItem ?= @items[0]
 
   serializeParams: ->

From c281eb9596a48532bc28b7ca171bb6b80fe2776a Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 11:23:06 -0700
Subject: [PATCH 13/89] Move serialization of focus into PaneModel

---
 src/pane-model.coffee | 8 ++++++++
 src/pane.coffee       | 8 +++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index c39174083..def6d3a6c 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -10,6 +10,7 @@ class PaneModel extends Model
   @properties
     items: -> []
     activeItem: null
+    focused: false
 
   constructor: ->
     super
@@ -18,6 +19,7 @@ class PaneModel extends Model
   serializeParams: ->
     items: compact(@items.map((item) -> item.serialize?()))
     activeItemUri: @activeItem?.getUri?()
+    focused: @focused
 
   deserializeParams: (params) ->
     {items, activeItemUri} = params
@@ -25,6 +27,12 @@ class PaneModel extends Model
     params.activeItem = find params.items, (item) -> item.getUri?() is activeItemUri
     params
 
+  focus: ->
+    @focused = true
+
+  blur: ->
+    @focused = false
+
   # Public: Returns all contained views.
   getItems: ->
     clone(@items)
diff --git a/src/pane.coffee b/src/pane.coffee
index f9bb2b25c..8896d95bd 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -32,11 +32,13 @@ class Pane extends View
     toProperty: 'model'
 
   previousActiveItem: null
+  focusOnAttach: false
 
   # Private:
   initialize: (args...) ->
     if args[0]?.model?
-      {@model, @focusOnAttach} = args[0]
+      {@model} = args[0]
+      @focusOnAttach = @model.focused
     else
       @model = new PaneModel(items: args)
 
@@ -53,7 +55,8 @@ class Pane extends View
     @subscribe @model, 'item-destroyed', @onItemDestroyed
 
     @subscribe this, 'focus', => @activeView?.focus(); false
-    @subscribe this, 'focusin', => @makeActive()
+    @subscribe this, 'focusin', => @makeActive(); @model.focus()
+    @subscribe this, 'focusout', => @model.blur()
 
     @command 'pane:save-items', => @saveItems()
     @command 'pane:show-next-item', => @showNextItem()
@@ -82,7 +85,6 @@ class Pane extends View
 
   serializeParams: ->
     model: @model.serialize()
-    focusOnAttach: @is(':has(:focus)')
 
   # Private:
   afterAttach: (onDom) ->

From 7eba9d3a23c6cad4a33f18433dbd58208c7b43f8 Mon Sep 17 00:00:00 2001
From: probablycorey <cj@github.com>
Date: Wed, 8 Jan 2014 13:39:58 -0800
Subject: [PATCH 14/89] Use flexbox to arrange panes

---
 src/pane-axis.coffee       |  8 -------
 src/pane-column.coffee     | 21 -----------------
 src/pane-container.coffee  |  8 -------
 src/pane-row.coffee        | 21 -----------------
 src/pane.coffee            | 10 ---------
 static/panes.less          | 41 +++++++++++++++++++++++++++++----
 static/workspace-view.less | 46 --------------------------------------
 7 files changed, 37 insertions(+), 118 deletions(-)

diff --git a/src/pane-axis.coffee b/src/pane-axis.coffee
index e256c58be..c2edc63c1 100644
--- a/src/pane-axis.coffee
+++ b/src/pane-axis.coffee
@@ -18,7 +18,6 @@ class PaneAxis extends View
 
   addChild: (child, index=@children().length) ->
     @insertAt(index, child)
-    @getContainer()?.adjustPaneDimensions()
 
   removeChild: (child) ->
     parent = @parent().view()
@@ -47,7 +46,6 @@ class PaneAxis extends View
     else
       primitiveRemove(child)
 
-    container.adjustPaneDimensions()
     Pane = require './pane'
     container.trigger 'pane:removed', [child] if child instanceof Pane
 
@@ -68,9 +66,3 @@ class PaneAxis extends View
 
   insertChildAfter: (child, newChild) ->
     newChild.insertAfter(child)
-
-  horizontalChildUnits: ->
-    $(child).view().horizontalGridUnits() for child in @children()
-
-  verticalChildUnits: ->
-    $(child).view().verticalGridUnits() for child in @children()
diff --git a/src/pane-column.coffee b/src/pane-column.coffee
index 522e54ca7..5fe964c33 100644
--- a/src/pane-column.coffee
+++ b/src/pane-column.coffee
@@ -11,24 +11,3 @@ class PaneColumn extends PaneAxis
 
   className: ->
     "PaneColumn"
-
-  adjustDimensions: ->
-    totalUnits = @verticalGridUnits()
-    unitsSoFar = 0
-    for child in @children()
-      child = $(child).view()
-      childUnits = child.verticalGridUnits()
-      child.css
-        width: '100%'
-        height: "#{childUnits / totalUnits * 100}%"
-        top: "#{unitsSoFar / totalUnits * 100}%"
-        left: 0
-
-      child.adjustDimensions()
-      unitsSoFar += childUnits
-
-  horizontalGridUnits: ->
-    Math.max(@horizontalChildUnits()...)
-
-  verticalGridUnits:   ->
-    _.sum(@verticalChildUnits())
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index 4ecda8359..623c1baf5 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -127,14 +127,6 @@ class PaneContainer extends View
       return pane if view?
     null
 
-  adjustPaneDimensions: ->
-    if root = @getRoot()
-      root.css(width: '100%', height: '100%', top: 0, left: 0)
-      root.adjustDimensions()
-
   removeEmptyPanes: ->
     for pane in @getPanes() when pane.getItems().length == 0
       pane.remove()
-
-  afterAttach: ->
-    @adjustPaneDimensions()
diff --git a/src/pane-row.coffee b/src/pane-row.coffee
index 2c9b7774a..3a8e8d7bc 100644
--- a/src/pane-row.coffee
+++ b/src/pane-row.coffee
@@ -11,24 +11,3 @@ class PaneRow extends PaneAxis
 
   className: ->
     "PaneRow"
-
-  adjustDimensions: ->
-    totalUnits = @horizontalGridUnits()
-    unitsSoFar = 0
-    for child in @children()
-      child = $(child).view()
-      childUnits = child.horizontalGridUnits()
-      child.css
-        width: "#{childUnits / totalUnits * 100}%"
-        height: '100%'
-        top: 0
-        left: "#{unitsSoFar / totalUnits * 100}%"
-
-      child.adjustDimensions()
-      unitsSoFar += childUnits
-
-  horizontalGridUnits: ->
-    _.sum(@horizontalChildUnits())
-
-  verticalGridUnits: ->
-    Math.max(@verticalChildUnits()...)
diff --git a/src/pane.coffee b/src/pane.coffee
index 8896d95bd..e2cd866cb 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -202,15 +202,6 @@ class Pane extends View
   viewForActiveItem: ->
     @viewForItem(@activeItem)
 
-  # Private:
-  adjustDimensions: -> # do nothing
-
-  # Private:
-  horizontalGridUnits: -> 1
-
-  # Private:
-  verticalGridUnits: -> 1
-
   # Public: Creates a new pane above with a copy of the currently focused item.
   splitUp: (items...) ->
     @split(items, 'column', 'before')
@@ -248,7 +239,6 @@ class Pane extends View
     switch side
       when 'before' then parent.insertChildBefore(this, newPane)
       when 'after' then parent.insertChildAfter(this, newPane)
-    @getContainer().adjustPaneDimensions()
     newPane.makeActive()
     newPane.focus()
     newPane
diff --git a/static/panes.less b/static/panes.less
index 33fdbe91a..38981bd5b 100644
--- a/static/panes.less
+++ b/static/panes.less
@@ -3,8 +3,41 @@
 // Pane-items are things that go inside a pane. Like the UI-Demo, the
 // settings-view, the archive-view, the image-view. Etc. Basically a non-
 // editor resource with a tab.
-.pane-item {
-  overflow: auto;
-  color: @text-color;
-  background-color: @pane-item-background-color;
+.panes {
+  display: -webkit-flex;
+  -webkit-flex: 1;
+
+  .column {
+    display: -webkit-flex;
+    -webkit-flex: 1;
+    -webkit-flex-direction: column;
+  }
+
+  .row {
+    display: -webkit-flex;
+    -webkit-flex: 1;
+    -webkit-flex-direction: row;
+  }
+
+  .pane {
+    display: -webkit-flex;
+    -webkit-flex: 1;
+    -webkit-flex-flow: column;
+
+    .pane-item {
+      color: @text-color;
+      background-color: @pane-item-background-color;
+    }
+
+    .item-views {
+      -webkit-flex: 1;
+      display: -webkit-flex;
+      min-height: 0;
+    }
+
+    .item-views > * {
+      -webkit-flex: 1;
+      min-width: 0;
+    }
+  }
 }
diff --git a/static/workspace-view.less b/static/workspace-view.less
index ae0afcf56..55fdbd03b 100644
--- a/static/workspace-view.less
+++ b/static/workspace-view.less
@@ -39,49 +39,3 @@ h6 {
     -webkit-flex-flow: column;
   }
 }
-
-.panes {
-  position: relative;
-  -webkit-flex: 1;
-
-  .column {
-    position: absolute;
-    top: 0;
-    bottom: 0;
-    left: 0;
-    right: 0;
-    overflow-y: hidden;
-  }
-
-  .row {
-    position: absolute;
-    top: 0;
-    bottom: 0;
-    left: 0;
-    right: 0;
-    overflow-x: hidden;
-    margin: 0;
-  }
-
-  .pane {
-    position: absolute;
-    display: -webkit-flex;
-    -webkit-flex-flow: column;
-    top: 0;
-    bottom: 0;
-    left: 0;
-    right: 0;
-    box-sizing: border-box;
-  }
-
-  .pane .item-views {
-    -webkit-flex: 1;
-    display: -webkit-flex;
-    min-height: 0;
-  }
-
-  .pane .item-views > * {
-    -webkit-flex: 1;
-    min-width: 0;
-  }
-}

From 6f766acac8ba8d2b304b43555364790952d9b64f Mon Sep 17 00:00:00 2001
From: probablycorey <cj@github.com>
Date: Wed, 8 Jan 2014 14:30:33 -0800
Subject: [PATCH 15/89] Rename .row and .column to .pane-row and .pane-column

Bootstrap's .row and .column css was influencing our pane rows and
columns.
---
 src/pane-column.coffee | 2 +-
 src/pane-row.coffee    | 2 +-
 static/panes.less      | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/pane-column.coffee b/src/pane-column.coffee
index 5fe964c33..4a89e0a6a 100644
--- a/src/pane-column.coffee
+++ b/src/pane-column.coffee
@@ -7,7 +7,7 @@ module.exports =
 class PaneColumn extends PaneAxis
 
   @content: ->
-    @div class: 'column'
+    @div class: 'pane-column'
 
   className: ->
     "PaneColumn"
diff --git a/src/pane-row.coffee b/src/pane-row.coffee
index 3a8e8d7bc..76106ab61 100644
--- a/src/pane-row.coffee
+++ b/src/pane-row.coffee
@@ -7,7 +7,7 @@ PaneAxis = require './pane-axis'
 module.exports =
 class PaneRow extends PaneAxis
   @content: ->
-    @div class: 'row'
+    @div class: 'pane-row'
 
   className: ->
     "PaneRow"
diff --git a/static/panes.less b/static/panes.less
index 38981bd5b..3aac5db27 100644
--- a/static/panes.less
+++ b/static/panes.less
@@ -7,13 +7,13 @@
   display: -webkit-flex;
   -webkit-flex: 1;
 
-  .column {
+  .pane-column {
     display: -webkit-flex;
     -webkit-flex: 1;
     -webkit-flex-direction: column;
   }
 
-  .row {
+  .pane-row {
     display: -webkit-flex;
     -webkit-flex: 1;
     -webkit-flex-direction: row;

From d908c8b02606db15cf0bd4b6b796953a19c1c382 Mon Sep 17 00:00:00 2001
From: probablycorey <cj@github.com>
Date: Wed, 8 Jan 2014 14:31:46 -0800
Subject: [PATCH 16/89] Use absolute divs to limit repaints on keypresses

---
 src/pane.coffee   |  3 ++-
 static/panes.less | 14 ++++++++++++--
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/pane.coffee b/src/pane.coffee
index e2cd866cb..fee6294e2 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -21,7 +21,8 @@ class Pane extends View
 
   @content: (wrappedView) ->
     @div class: 'pane', tabindex: -1, =>
-      @div class: 'item-views', outlet: 'itemViews'
+      @div class: 'flexbox-repaint-hack', =>
+        @div class: 'item-views', outlet: 'itemViews'
 
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
   @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
diff --git a/static/panes.less b/static/panes.less
index 3aac5db27..238cdb4a0 100644
--- a/static/panes.less
+++ b/static/panes.less
@@ -20,9 +20,19 @@
   }
 
   .pane {
-    display: -webkit-flex;
+    position: relative;
     -webkit-flex: 1;
-    -webkit-flex-flow: column;
+
+    .flexbox-repaint-hack {
+      display: -webkit-flex;
+      -webkit-flex-flow: column;
+
+      position: absolute;
+      top: 0;
+      right: 0;
+      bottom: 0;
+      left: 0;
+    }
 
     .pane-item {
       color: @text-color;

From 196942d1267312f1ef6069709257bed2b2406803 Mon Sep 17 00:00:00 2001
From: probablycorey <cj@github.com>
Date: Wed, 8 Jan 2014 16:31:56 -0800
Subject: [PATCH 17/89] Rename .row and .column in pane specs

---
 spec/pane-container-spec.coffee | 12 ++++++------
 spec/pane-spec.coffee           | 22 +++++++++++-----------
 2 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index 4dc770c16..cd2f7264e 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -124,19 +124,19 @@ describe "PaneContainer", ->
   describe "serialization", ->
     it "can be serialized and deserialized, and correctly adjusts dimensions of deserialized panes after attach", ->
       newContainer = atom.deserializers.deserialize(container.serialize())
-      expect(newContainer.find('.row > :contains(1)')).toExist()
-      expect(newContainer.find('.row > .column > :contains(2)')).toExist()
-      expect(newContainer.find('.row > .column > :contains(3)')).toExist()
+      expect(newContainer.find('.pane-row > :contains(1)')).toExist()
+      expect(newContainer.find('.pane-row > .pane-column > :contains(2)')).toExist()
+      expect(newContainer.find('.pane-row > .pane-column > :contains(3)')).toExist()
 
       newContainer.height(200).width(300).attachToDom()
-      expect(newContainer.find('.row > :contains(1)').width()).toBe 150
-      expect(newContainer.find('.row > .column > :contains(2)').height()).toBe 100
+      expect(newContainer.find('.pane-row > :contains(1)').width()).toBe 150
+      expect(newContainer.find('.pane-row > .pane-column > :contains(2)').height()).toBe 100
 
     xit "removes empty panes on deserialization", ->
       # only deserialize pane 1's view successfully
       TestView.deserialize = ({name}) -> new TestView(name) if name is '1'
       newContainer = atom.deserializers.deserialize(container.serialize())
-      expect(newContainer.find('.row, .column')).not.toExist()
+      expect(newContainer.find('.pane-row, .pane-column')).not.toExist()
       expect(newContainer.find('> :contains(1)')).toExist()
 
   describe "pane-container:active-pane-item-changed", ->
diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index fd6339cab..53e3073ed 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -4,7 +4,7 @@ Pane = require '../src/pane'
 path = require 'path'
 temp = require 'temp'
 
-describe "Pane", ->
+fdescribe "Pane", ->
   [container, view1, view2, editor1, editor2, pane] = []
 
   class TestView extends View
@@ -545,23 +545,23 @@ describe "Pane", ->
       it "builds a row if needed, then appends a new pane after itself", ->
         # creates the new pane with a copy of the active item if none are given
         pane2 = pane1.splitRight(pane1.copyActiveItem())
-        expect(container.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
+        expect(container.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
         expect(pane2.items).toEqual [editor1]
         expect(pane2.activeItem).not.toBe editor1 # it's a copy
 
         pane3 = pane2.splitRight(view3, view4)
         expect(pane3.getItems()).toEqual [view3, view4]
-        expect(container.find('.row .pane').toArray()).toEqual [pane[0], pane2[0], pane3[0]]
+        expect(container.find('.pane-row .pane').toArray()).toEqual [pane[0], pane2[0], pane3[0]]
 
       it "builds a row if needed, then appends a new pane after itself ", ->
         # creates the new pane with a copy of the active item if none are given
         pane2 = pane1.splitRight()
-        expect(container.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
+        expect(container.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
         expect(pane2.items).toEqual []
         expect(pane2.activeItem).toBeUndefined()
 
         pane3 = pane2.splitRight()
-        expect(container.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0], pane3[0]]
+        expect(container.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0], pane3[0]]
         expect(pane3.items).toEqual []
         expect(pane3.activeItem).toBeUndefined()
 
@@ -569,37 +569,37 @@ describe "Pane", ->
       it "builds a row if needed, then appends a new pane before itself", ->
         # creates the new pane with a copy of the active item if none are given
         pane2 = pane.splitLeft(pane1.copyActiveItem())
-        expect(container.find('.row .pane').toArray()).toEqual [pane2[0], pane[0]]
+        expect(container.find('.pane-row .pane').toArray()).toEqual [pane2[0], pane[0]]
         expect(pane2.items).toEqual [editor1]
         expect(pane2.activeItem).not.toBe editor1 # it's a copy
 
         pane3 = pane2.splitLeft(view3, view4)
         expect(pane3.getItems()).toEqual [view3, view4]
-        expect(container.find('.row .pane').toArray()).toEqual [pane3[0], pane2[0], pane[0]]
+        expect(container.find('.pane-row .pane').toArray()).toEqual [pane3[0], pane2[0], pane[0]]
 
     describe "splitDown(items...)", ->
       it "builds a column if needed, then appends a new pane after itself", ->
         # creates the new pane with a copy of the active item if none are given
         pane2 = pane.splitDown(pane1.copyActiveItem())
-        expect(container.find('.column .pane').toArray()).toEqual [pane[0], pane2[0]]
+        expect(container.find('.pane-column .pane').toArray()).toEqual [pane[0], pane2[0]]
         expect(pane2.items).toEqual [editor1]
         expect(pane2.activeItem).not.toBe editor1 # it's a copy
 
         pane3 = pane2.splitDown(view3, view4)
         expect(pane3.getItems()).toEqual [view3, view4]
-        expect(container.find('.column .pane').toArray()).toEqual [pane[0], pane2[0], pane3[0]]
+        expect(container.find('.pane-column .pane').toArray()).toEqual [pane[0], pane2[0], pane3[0]]
 
     describe "splitUp(items...)", ->
       it "builds a column if needed, then appends a new pane before itself", ->
         # creates the new pane with a copy of the active item if none are given
         pane2 = pane.splitUp(pane1.copyActiveItem())
-        expect(container.find('.column .pane').toArray()).toEqual [pane2[0], pane[0]]
+        expect(container.find('.pane-column .pane').toArray()).toEqual [pane2[0], pane[0]]
         expect(pane2.items).toEqual [editor1]
         expect(pane2.activeItem).not.toBe editor1 # it's a copy
 
         pane3 = pane2.splitUp(view3, view4)
         expect(pane3.getItems()).toEqual [view3, view4]
-        expect(container.find('.column .pane').toArray()).toEqual [pane3[0], pane2[0], pane[0]]
+        expect(container.find('.pane-column .pane').toArray()).toEqual [pane3[0], pane2[0], pane[0]]
 
     it "lays out nested panes by equally dividing their containing row / column", ->
       container.width(520).height(240).attachToDom()

From 99a67ca1ab343a6d8dc2d207f4dbc25a57625595 Mon Sep 17 00:00:00 2001
From: probablycorey <cj@github.com>
Date: Wed, 8 Jan 2014 16:37:57 -0800
Subject: [PATCH 18/89] Remove focused spec

---
 spec/pane-spec.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index 53e3073ed..00364ac77 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -4,7 +4,7 @@ Pane = require '../src/pane'
 path = require 'path'
 temp = require 'temp'
 
-fdescribe "Pane", ->
+describe "Pane", ->
   [container, view1, view2, editor1, editor2, pane] = []
 
   class TestView extends View

From ad60594c138e2b8f1cb63cd63b8a1aad51969340 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 12:10:58 -0700
Subject: [PATCH 19/89] Add mixto module

---
 package.json | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/package.json b/package.json
index e390b9700..5e3ca675f 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,8 @@
     "text-buffer": "0.12.0",
     "underscore-plus": "0.6.1",
     "theorist": "~0.7.0",
-    "delegato": "~0.4.0"
+    "delegato": "~0.4.0",
+    "mixto": "~0.4.0"
   },
   "packageDependencies": {
     "atom-dark-syntax": "0.10.0",

From 101326a130cc3943646eaa435c47ec954c51d789 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 12:11:21 -0700
Subject: [PATCH 20/89] Upgrade theorist to 0.9.0 for sequences

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 5e3ca675f..e23497b3e 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
     "temp": "0.5.0",
     "text-buffer": "0.12.0",
     "underscore-plus": "0.6.1",
-    "theorist": "~0.7.0",
+    "theorist": "~0.9.0",
     "delegato": "~0.4.0",
     "mixto": "~0.4.0"
   },

From bb595ab08a5726deb6ea1a74d98685518e4941af Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 13:06:21 -0700
Subject: [PATCH 21/89] Start adding PaneAxisModel

---
 src/pane-axis-model.coffee | 21 +++++++++++++++++++++
 src/pane-axis.coffee       | 24 ++++++++++++++++++------
 src/pane.coffee            |  2 +-
 3 files changed, 40 insertions(+), 7 deletions(-)
 create mode 100644 src/pane-axis-model.coffee

diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
new file mode 100644
index 000000000..cacade828
--- /dev/null
+++ b/src/pane-axis-model.coffee
@@ -0,0 +1,21 @@
+{Model, Sequence} = require 'theorist'
+
+module.exports =
+class PaneAxisModel extends Model
+  constructor: (params) ->
+    @children = Sequence.fromArray(params?.children ? [])
+
+  addChild: (child, index=@children.length) ->
+    @children.splice(index, 0, child)
+
+  removeChild: (child) ->
+    index = @children.indexOf(child)
+    @children.splice(index, 1) unless index is -1
+
+  insertChildBefore: (currentChild, newChild) ->
+    index = @children.indexOf(currentChild)
+    @children.splice(index, 0, newChild)
+
+  insertChildAfter: (currentChild, newChild) ->
+    index = @children.indexOf(currentChild)
+    @children.splice(index + 1, 0, newChild)
diff --git a/src/pane-axis.coffee b/src/pane-axis.coffee
index c2edc63c1..61d29cda9 100644
--- a/src/pane-axis.coffee
+++ b/src/pane-axis.coffee
@@ -1,5 +1,6 @@
 Serializable = require 'serializable'
 {$, View} = require './space-pen-extensions'
+PaneAxisModel = require './pane-axis-model'
 
 ### Internal ###
 module.exports =
@@ -7,6 +8,11 @@ class PaneAxis extends View
   Serializable.includeInto(this)
 
   initialize: ({children}={}) ->
+    @model = new PaneAxisModel
+    @model.children.on 'changed', ({index, removedValues, insertedValues}) =>
+      @onChildRemoved(child, index) for child in removedValues
+      @onChildAdded(child, index) for child in insertedValues
+
     @addChild(child) for child in children ? []
 
   serializeParams: ->
@@ -16,10 +22,16 @@ class PaneAxis extends View
     params.children = params.children.map (childState) -> atom.deserializers.deserialize(childState)
     params
 
-  addChild: (child, index=@children().length) ->
-    @insertAt(index, child)
+  addChild: (child, index) ->
+    @model.addChild(child, index)
 
   removeChild: (child) ->
+    @model.removeChild(child)
+
+  onChildAdded: (child, index) =>
+    @insertAt(index, child)
+
+  onChildRemoved: (child) =>
     parent = @parent().view()
     container = @getContainer()
     childWasInactive = not child.isActive?()
@@ -61,8 +73,8 @@ class PaneAxis extends View
   getActivePane: ->
     @find('.pane.active').view() ? @find('.pane:first').view()
 
-  insertChildBefore: (child, newChild) ->
-    newChild.insertBefore(child)
+  insertChildBefore: (currentChild, newChild) ->
+    @model.insertChildBefore(currentChild, newChild)
 
-  insertChildAfter: (child, newChild) ->
-    newChild.insertAfter(child)
+  insertChildAfter: (currentChild, newChild) ->
+    @model.insertChildAfter(currentChild, newChild)
diff --git a/src/pane.coffee b/src/pane.coffee
index fee6294e2..b44b59680 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -223,7 +223,7 @@ class Pane extends View
   split: (items, axis, side) ->
     PaneContainer = require './pane-container'
 
-    parent = @parent().view()
+    parent = @parentModel ? @parent().view()
     unless parent.hasClass(axis)
       axis = @buildPaneAxis(axis)
       if parent instanceof PaneContainer

From eb7f3ff5af9d5406eb51b4cbfb466a7e7412f8d7 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 14:55:22 -0700
Subject: [PATCH 22/89] Support splitting at the model layer

Splitting in the view will need to be removed and mapped to splits in
the model.
---
 spec/pane-model-spec.coffee     | 79 +++++++++++++++++++++++++++++++++
 src/pane-axis-model.coffee      | 13 ++++--
 src/pane-container-model.coffee | 14 ++++++
 src/pane-model.coffee           | 23 ++++++++++
 4 files changed, 126 insertions(+), 3 deletions(-)
 create mode 100644 spec/pane-model-spec.coffee
 create mode 100644 src/pane-container-model.coffee

diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
new file mode 100644
index 000000000..d27d1da25
--- /dev/null
+++ b/spec/pane-model-spec.coffee
@@ -0,0 +1,79 @@
+PaneModel = require '../src/pane-model'
+PaneAxisModel = require '../src/pane-axis-model'
+PaneContainerModel = require '../src/pane-container-model'
+
+describe "PaneModel", ->
+  describe "split methods", ->
+    [pane1, container] = []
+
+    beforeEach ->
+      pane1 = new PaneModel(items: ["A"])
+      container = new PaneContainerModel(root: pane1)
+
+    describe "::splitLeft(params)", ->
+      describe "when the parent is the container root", ->
+        it "replaces itself with a row and inserts a new pane to the left of itself", ->
+          pane2 = pane1.splitLeft(items: ["B"])
+          pane3 = pane1.splitLeft(items: ["C"])
+          expect(container.root.orientation).toBe 'horizontal'
+          expect(container.root.children).toEqual [pane2, pane3, pane1]
+
+      describe "when the parent is a column", ->
+        it "replaces itself with a row and inserts a new pane to the left of itself", ->
+          pane1.splitDown()
+          pane2 = pane1.splitLeft(items: ["B"])
+          pane3 = pane1.splitLeft(items: ["C"])
+          row = container.root.children[0]
+          expect(row.orientation).toBe 'horizontal'
+          expect(row.children).toEqual [pane2, pane3, pane1]
+
+    describe "::splitRight(params)", ->
+      describe "when the parent is the container root", ->
+        it "replaces itself with a row and inserts a new pane to the right of itself", ->
+          pane2 = pane1.splitRight(items: ["B"])
+          pane3 = pane1.splitRight(items: ["C"])
+          expect(container.root.orientation).toBe 'horizontal'
+          expect(container.root.children).toEqual [pane1, pane3, pane2]
+
+      describe "when the parent is a column", ->
+        it "replaces itself with a row and inserts a new pane to the right of itself", ->
+          pane1.splitDown()
+          pane2 = pane1.splitRight(items: ["B"])
+          pane3 = pane1.splitRight(items: ["C"])
+          row = container.root.children[0]
+          expect(row.orientation).toBe 'horizontal'
+          expect(row.children).toEqual [pane1, pane3, pane2]
+
+    describe "::splitUp(params)", ->
+      describe "when the parent is the container root", ->
+        it "replaces itself with a column and inserts a new pane above itself", ->
+          pane2 = pane1.splitUp(items: ["B"])
+          pane3 = pane1.splitUp(items: ["C"])
+          expect(container.root.orientation).toBe 'vertical'
+          expect(container.root.children).toEqual [pane2, pane3, pane1]
+
+      describe "when the parent is a row", ->
+        it "replaces itself with a column and inserts a new pane above itself", ->
+          pane1.splitRight()
+          pane2 = pane1.splitUp(items: ["B"])
+          pane3 = pane1.splitUp(items: ["C"])
+          column = container.root.children[0]
+          expect(column.orientation).toBe 'vertical'
+          expect(column.children).toEqual [pane2, pane3, pane1]
+
+    describe "::splitDown(params)", ->
+      describe "when the parent is the container root", ->
+        it "replaces itself with a column and inserts a new pane below itself", ->
+          pane2 = pane1.splitDown(items: ["B"])
+          pane3 = pane1.splitDown(items: ["C"])
+          expect(container.root.orientation).toBe 'vertical'
+          expect(container.root.children).toEqual [pane1, pane3, pane2]
+
+      describe "when the parent is a row", ->
+        it "replaces itself with a column and inserts a new pane below itself", ->
+          pane1.splitRight()
+          pane2 = pane1.splitDown(items: ["B"])
+          pane3 = pane1.splitDown(items: ["C"])
+          column = container.root.children[0]
+          expect(column.orientation).toBe 'vertical'
+          expect(column.children).toEqual [pane1, pane3, pane2]
diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index cacade828..fcbe4d2cf 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -2,15 +2,22 @@
 
 module.exports =
 class PaneAxisModel extends Model
-  constructor: (params) ->
-    @children = Sequence.fromArray(params?.children ? [])
+  constructor: ({@orientation, children}) ->
+    @children = Sequence.fromArray(children ? [])
+    @children.onEach (child) => child.parent = this
 
   addChild: (child, index=@children.length) ->
     @children.splice(index, 0, child)
 
   removeChild: (child) ->
     index = @children.indexOf(child)
-    @children.splice(index, 1) unless index is -1
+    throw new Error("Removing non-existent child") if index is -1
+    @children.splice(index, 1)
+
+  replaceChild: (oldChild, newChild) ->
+    index = @children.indexOf(oldChild)
+    throw new Error("Replacing non-existent child") if index is -1
+    @children.splice(index, 1, newChild)
 
   insertChildBefore: (currentChild, newChild) ->
     index = @children.indexOf(currentChild)
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
new file mode 100644
index 000000000..f421d9b3b
--- /dev/null
+++ b/src/pane-container-model.coffee
@@ -0,0 +1,14 @@
+{Model} = require 'theorist'
+
+module.exports =
+class PaneContainerModel extends Model
+  @properties
+    root: null
+
+  constructor: ->
+    super
+    @subscribe @$root, (root) => root?.parent = this
+
+  replaceChild: (oldChild, newChild) ->
+    throw new Error("Replacing non-existent child") if oldChild isnt @root
+    @root = newChild
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index def6d3a6c..d12376eb9 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -2,6 +2,7 @@
 {dirname} = require 'path'
 {Model} = require 'theorist'
 Serializable = require 'serializable'
+PaneAxisModel = require './pane-axis-model'
 
 module.exports =
 class PaneModel extends Model
@@ -189,3 +190,25 @@ class PaneModel extends Model
   # Private:
   copyActiveItem: ->
     @activeItem.copy?() ? atom.deserializers.deserialize(@activeItem.serialize())
+
+  splitLeft: (params) ->
+    @split('horizontal', 'before', params)
+
+  splitRight: (params) ->
+    @split('horizontal', 'after', params)
+
+  splitUp: (params) ->
+    @split('vertical', 'before', params)
+
+  splitDown: (params) ->
+    @split('vertical', 'after', params)
+
+  split: (orientation, side, params) ->
+    if @parent.orientation isnt orientation
+      @parent.replaceChild(this, new PaneAxisModel({orientation, children: [this]}))
+
+    newPane = new @constructor(params)
+    switch side
+      when 'before' then @parent.insertChildBefore(this, newPane)
+      when 'after' then @parent.insertChildAfter(this, newPane)
+    newPane

From f031a9706d03ff19e2135ac6234409d02921baec Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 18:46:21 -0700
Subject: [PATCH 23/89] Support unsplitting in the model layer

---
 spec/pane-model-spec.coffee | 28 ++++++++++++++++++++++++++++
 src/pane-axis-model.coffee  | 13 ++++++++++++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index d27d1da25..6117091ce 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -77,3 +77,31 @@ describe "PaneModel", ->
           column = container.root.children[0]
           expect(column.orientation).toBe 'vertical'
           expect(column.children).toEqual [pane1, pane3, pane2]
+
+  describe "::destroy()", ->
+    [pane1, container] = []
+
+    beforeEach ->
+      pane1 = new PaneModel(items: ["A"])
+      container = new PaneContainerModel(root: pane1)
+
+    describe "if the pane's parent has more than two children", ->
+      it "removes the pane from its parent", ->
+        pane2 = pane1.splitRight()
+        pane3 = pane2.splitRight()
+
+        expect(container.root.children).toEqual [pane1, pane2, pane3]
+        pane2.destroy()
+        expect(container.root.children).toEqual [pane1, pane3]
+
+    describe "if the pane's parent has two children", ->
+      it "replaces the parent with its last remaining child", ->
+        pane2 = pane1.splitRight()
+        pane3 = pane2.splitDown()
+
+        expect(container.root.children[0]).toBe pane1
+        expect(container.root.children[1].children).toEqual [pane2, pane3]
+        pane3.destroy()
+        expect(container.root.children).toEqual [pane1, pane2]
+        pane2.destroy()
+        expect(container.root).toBe pane1
diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index fcbe4d2cf..b8edfbbc5 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -4,7 +4,15 @@ module.exports =
 class PaneAxisModel extends Model
   constructor: ({@orientation, children}) ->
     @children = Sequence.fromArray(children ? [])
-    @children.onEach (child) => child.parent = this
+
+    @children.onEach (child) =>
+      child.parent = this
+      @subscribe child, 'destroyed', => @removeChild(child)
+
+    @children.onRemoval (child) => @unsubscribe(child)
+
+    @when @children.$length.becomesLessThan(2), 'reparentLastChild'
+    @when @children.$length.becomesLessThan(1), 'destroy'
 
   addChild: (child, index=@children.length) ->
     @children.splice(index, 0, child)
@@ -26,3 +34,6 @@ class PaneAxisModel extends Model
   insertChildAfter: (currentChild, newChild) ->
     index = @children.indexOf(currentChild)
     @children.splice(index + 1, 0, newChild)
+
+  reparentLastChild: ->
+    @parent.replaceChild(this, @children[0])

From 8efcb1abfa4a0edece4e1574d25e1c868d79ab82 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 18:49:50 -0700
Subject: [PATCH 24/89] Remove pane splitting/unsplitting logic from view

There's still some failing specs around focus management, but it's
getting closer.
---
 src/pane-axis-model.coffee      | 20 +++++++++++
 src/pane-axis.coffee            | 64 +++++++++------------------------
 src/pane-container-model.coffee | 11 ++++++
 src/pane-container.coffee       | 36 ++++++++++++-------
 src/pane-model.coffee           |  4 +++
 src/pane.coffee                 | 61 +++++++------------------------
 6 files changed, 88 insertions(+), 108 deletions(-)

diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index b8edfbbc5..824727815 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -1,7 +1,14 @@
 {Model, Sequence} = require 'theorist'
+Serializable = require 'serializable'
+
+PaneRow = null
+PaneColumn = null
 
 module.exports =
 class PaneAxisModel extends Model
+  atom.deserializers.add(this)
+  Serializable.includeInto(this)
+
   constructor: ({@orientation, children}) ->
     @children = Sequence.fromArray(children ? [])
 
@@ -14,6 +21,19 @@ class PaneAxisModel extends Model
     @when @children.$length.becomesLessThan(2), 'reparentLastChild'
     @when @children.$length.becomesLessThan(1), 'destroy'
 
+  deserializeParams: (params) ->
+    params.children = params.children.map (childState) -> atom.deserializers.deserialize(childState)
+    params
+
+  serializeParams: ->
+    children: @children.map (child) -> child.serialize()
+
+  getViewClass: ->
+    if @orientation is 'vertical'
+      PaneColumn ?= require './pane-column'
+    else
+      PaneRow ?= require './pane-row'
+
   addChild: (child, index=@children.length) ->
     @children.splice(index, 0, child)
 
diff --git a/src/pane-axis.coffee b/src/pane-axis.coffee
index 61d29cda9..bdee142ad 100644
--- a/src/pane-axis.coffee
+++ b/src/pane-axis.coffee
@@ -1,68 +1,36 @@
 Serializable = require 'serializable'
 {$, View} = require './space-pen-extensions'
 PaneAxisModel = require './pane-axis-model'
+Pane = null
 
 ### Internal ###
 module.exports =
 class PaneAxis extends View
-  Serializable.includeInto(this)
+  initialize: (@model) ->
+    @subscribe @model.children.onRemoval @onChildRemoved
+    @subscribe @model.children.onEach @onChildAdded
 
-  initialize: ({children}={}) ->
-    @model = new PaneAxisModel
-    @model.children.on 'changed', ({index, removedValues, insertedValues}) =>
-      @onChildRemoved(child, index) for child in removedValues
-      @onChildAdded(child, index) for child in insertedValues
+    @onChildAdded(child) for child in children ? []
 
-    @addChild(child) for child in children ? []
-
-  serializeParams: ->
-    children: @children().views().map (child) -> child.serialize()
-
-  deserializeParams: (params) ->
-    params.children = params.children.map (childState) -> atom.deserializers.deserialize(childState)
-    params
+  viewForModel: (model) ->
+    viewClass = model.getViewClass()
+    model._view ?= new viewClass(model)
 
   addChild: (child, index) ->
-    @model.addChild(child, index)
+    @model.addChild(child.model, index)
 
   removeChild: (child) ->
-    @model.removeChild(child)
+    @model.removeChild(child.model)
 
   onChildAdded: (child, index) =>
-    @insertAt(index, child)
+    view = @viewForModel(child)
+    @insertAt(index, view)
 
   onChildRemoved: (child) =>
-    parent = @parent().view()
-    container = @getContainer()
-    childWasInactive = not child.isActive?()
-
-    primitiveRemove = (child) =>
-      node = child[0]
-      $.cleanData(node.getElementsByTagName('*'))
-      $.cleanData([node])
-      this[0].removeChild(node)
-
-    # use primitive .removeChild() dom method instead of .remove() to avoid recursive loop
-    if @children().length == 2
-      primitiveRemove(child)
-      sibling = @children().view()
-      siblingFocused = sibling.is(':has(:focus)')
-      sibling.detach()
-
-      if parent.setRoot?
-        parent.setRoot(sibling, suppressPaneItemChangeEvents: childWasInactive)
-      else
-        parent.insertChildBefore(this, sibling)
-        parent.removeChild(this)
-      sibling.focus() if siblingFocused
-    else
-      primitiveRemove(child)
-
-    Pane = require './pane'
-    container.trigger 'pane:removed', [child] if child instanceof Pane
-
-  detachChild: (child) ->
-    child.detach()
+    view = @viewForModel(child)
+    view.detach()
+    Pane ?= require './pane'
+    @getContainer()?.trigger 'pane:removed', [view] if view instanceof Pane
 
   getContainer: ->
     @closest('.panes').view()
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index f421d9b3b..1aa975cd7 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -1,7 +1,11 @@
 {Model} = require 'theorist'
+Serializable = require 'serializable'
 
 module.exports =
 class PaneContainerModel extends Model
+  atom.deserializers.add(this)
+  Serializable.includeInto(this)
+
   @properties
     root: null
 
@@ -9,6 +13,13 @@ class PaneContainerModel extends Model
     super
     @subscribe @$root, (root) => root?.parent = this
 
+  deserializeParams: (params) ->
+    params.root = atom.deserializers.deserialize(params.root)
+    params
+
+  serializeParams: (params) ->
+    root: @root?.serialize()
+
   replaceChild: (oldChild, newChild) ->
     throw new Error("Replacing non-existent child") if oldChild isnt @root
     @root = newChild
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index 623c1baf5..bc5f0e2f4 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -1,18 +1,26 @@
 Serializable = require 'serializable'
 {$, View} = require './space-pen-extensions'
 Pane = require './pane'
+PaneContainerModel = require './pane-container-model'
 
 # Private: Manages the list of panes within a {WorkspaceView}
 module.exports =
 class PaneContainer extends View
   Serializable.includeInto(this)
-  atom.deserializers.add(this)
+
+  @deserialize: (state) ->
+    new this(PaneContainerModel.deserialize(state.model))
 
   @content: ->
     @div class: 'panes'
 
-  initialize: ({root}={}) ->
-    @setRoot(root)
+  initialize: (params) ->
+    if params instanceof PaneContainerModel
+      @model = params
+    else
+      @model = new PaneContainerModel({root: params?.root?.model})
+
+    @subscribe @model.$root, 'value', @onRootChanged
 
     @subscribe this, 'pane:attached', (event, pane) =>
       @triggerActiveItemChange() if @getActivePane() is pane
@@ -26,15 +34,15 @@ class PaneContainer extends View
     @subscribe this, 'pane:active-item-changed', (event, item) =>
       @triggerActiveItemChange() if @getActivePaneItem() is item
 
+  viewForModel: (model) ->
+    viewClass = model.getViewClass()
+    model._view ?= new viewClass(model)
+
   triggerActiveItemChange: ->
     @trigger 'pane-container:active-pane-item-changed', [@getActivePaneItem()]
 
   serializeParams: ->
-    root: @getRoot()?.serialize()
-
-  deserializeParams: (params) ->
-    params.root = atom.deserializers.deserialize(params.root)
-    params
+    model: @model.serialize()
 
   ### Public ###
 
@@ -71,11 +79,15 @@ class PaneContainer extends View
   getRoot: ->
     @children().first().view()
 
-  setRoot: (root, {suppressPaneItemChangeEvents}={}) ->
-    @empty()
+  setRoot: (root) ->
+    @model.root = root?.model
+
+  onRootChanged: (root) =>
+    @children().detach()
     if root?
-      @append(root)
-      root.makeActive?()
+      view = @viewForModel(root)
+      @append(view)
+      view.makeActive?()
 
   removeChild: (child) ->
     throw new Error("Removing non-existant child") unless @getRoot() is child
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index d12376eb9..9b42aaf87 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -3,9 +3,11 @@
 {Model} = require 'theorist'
 Serializable = require 'serializable'
 PaneAxisModel = require './pane-axis-model'
+Pane = null
 
 module.exports =
 class PaneModel extends Model
+  atom.deserializers.add(this)
   Serializable.includeInto(this)
 
   @properties
@@ -28,6 +30,8 @@ class PaneModel extends Model
     params.activeItem = find params.items, (item) -> item.getUri?() is activeItemUri
     params
 
+  getViewClass: -> Pane ?= require './pane'
+
   focus: ->
     @focused = true
 
diff --git a/src/pane.coffee b/src/pane.coffee
index b44b59680..540cbf9f9 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -19,6 +19,9 @@ class Pane extends View
 
   @version: 1
 
+  @deserialize: (state) ->
+    new this(PaneModel.deserialize(state.model))
+
   @content: (wrappedView) ->
     @div class: 'pane', tabindex: -1, =>
       @div class: 'flexbox-repaint-hack', =>
@@ -37,11 +40,12 @@ class Pane extends View
 
   # Private:
   initialize: (args...) ->
-    if args[0]?.model?
-      {@model} = args[0]
+    if args[0] instanceof PaneModel
+      @model = args[0]
       @focusOnAttach = @model.focused
     else
       @model = new PaneModel(items: args)
+      @model._view = this
 
     @onItemAdded(item) for item in @items
     @viewsByItem = new WeakMap()
@@ -203,52 +207,13 @@ class Pane extends View
   viewForActiveItem: ->
     @viewForItem(@activeItem)
 
-  # Public: Creates a new pane above with a copy of the currently focused item.
-  splitUp: (items...) ->
-    @split(items, 'column', 'before')
+  splitLeft: (items...) -> @model.splitLeft({items})._view
 
-  # Public: Creates a new pane below with a copy of the currently focused item.
-  splitDown: (items...) ->
-    @split(items, 'column', 'after')
+  splitRight: (items...) -> @model.splitRight({items})._view
 
-  # Public: Creates a new pane left with a copy of the currently focused item.
-  splitLeft: (items...) ->
-    @split(items, 'row', 'before')
+  splitUp: (items...) -> @model.splitUp({items})._view
 
-  # Public: Creates a new pane right with a copy of the currently focused item.
-  splitRight: (items...) ->
-    @split(items, 'row', 'after')
-
-  # Private:
-  split: (items, axis, side) ->
-    PaneContainer = require './pane-container'
-
-    parent = @parentModel ? @parent().view()
-    unless parent.hasClass(axis)
-      axis = @buildPaneAxis(axis)
-      if parent instanceof PaneContainer
-        @detach()
-        axis.addChild(this)
-        parent.setRoot(axis)
-      else
-        parent.insertChildBefore(this, axis)
-        axis.addChild(this)
-      parent = axis
-
-    newPane = new Pane(items...)
-
-    switch side
-      when 'before' then parent.insertChildBefore(this, newPane)
-      when 'after' then parent.insertChildAfter(this, newPane)
-    newPane.makeActive()
-    newPane.focus()
-    newPane
-
-  # Private:
-  buildPaneAxis: (axis) ->
-    switch axis
-      when 'row' then new PaneRow()
-      when 'column' then new PaneColumn()
+  splitDown: (items...) -> @model.splitDown({items})._view
 
   # Private:
   getContainer: ->
@@ -257,13 +222,13 @@ class Pane extends View
   # Private:
   remove: (selector, keepData) ->
     return super if keepData
-    @parent().view().removeChild(this)
 
-  # Private:
-  beforeRemove: ->
     if @is(':has(:focus)')
       @getContainer().focusNextPane() or atom.workspaceView?.focus()
     else if @isActive()
       @getContainer().makeNextPaneActive()
 
+    @parent().view().removeChild(this) unless keepData
     item.destroy?() for item in @getItems()
+
+    super

From 1a5e10c1d2a439d4cc38d855910b630c7eef5641 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Wed, 8 Jan 2014 19:05:35 -0700
Subject: [PATCH 25/89] Focus the new pane when splitting

---
 spec/pane-model-spec.coffee | 5 +++++
 src/pane-model.coffee       | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index 6117091ce..db6bdac48 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -78,6 +78,11 @@ describe "PaneModel", ->
           expect(column.orientation).toBe 'vertical'
           expect(column.children).toEqual [pane1, pane3, pane2]
 
+    it "focuses the new pane, even if the current pane isn't focused", ->
+      expect(pane1.focused).toBe false
+      pane2 = pane1.split()
+      expect(pane2.focused).toBe true
+
   describe "::destroy()", ->
     [pane1, container] = []
 
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 9b42aaf87..be9b651cb 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -1,4 +1,4 @@
-{find, compact, clone} = require 'underscore-plus'
+{find, compact, clone, extend} = require 'underscore-plus'
 {dirname} = require 'path'
 {Model} = require 'theorist'
 Serializable = require 'serializable'
@@ -211,7 +211,7 @@ class PaneModel extends Model
     if @parent.orientation isnt orientation
       @parent.replaceChild(this, new PaneAxisModel({orientation, children: [this]}))
 
-    newPane = new @constructor(params)
+    newPane = new @constructor(extend({focused: true}, params))
     switch side
       when 'before' then @parent.insertChildBefore(this, newPane)
       when 'after' then @parent.insertChildAfter(this, newPane)

From 4e99d003ee7afb1fef5e267e1af1f25d60c139a5 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 09:53:14 -0700
Subject: [PATCH 26/89] Add Focusable mixin and FocusContext

Focusable objects have ::focus and ::blur methods and a ::focused
property. Focusable objects can be assigned a ::focusContext, and the
::focused property will only be true for at most one object with the
same context.
---
 spec/focusable-spec.coffee | 36 ++++++++++++++++++++++++++++++++++++
 src/focus-context.coffee   |  5 +++++
 src/focusable.coffee       | 18 ++++++++++++++++++
 3 files changed, 59 insertions(+)
 create mode 100644 spec/focusable-spec.coffee
 create mode 100644 src/focus-context.coffee
 create mode 100644 src/focusable.coffee

diff --git a/spec/focusable-spec.coffee b/spec/focusable-spec.coffee
new file mode 100644
index 000000000..0cb26b908
--- /dev/null
+++ b/spec/focusable-spec.coffee
@@ -0,0 +1,36 @@
+{Model} = require 'theorist'
+Focusable = require '../src/focusable'
+FocusContext = require '../src/focus-context'
+
+describe "Focusable mixin", ->
+  it "ensures that only a single model is focused for a given focus manager", ->
+    class Item extends Model
+      Focusable.includeInto(this)
+
+    focusContext = new FocusContext
+    item1 = new Item({focusContext})
+    item2 = new Item({focusContext})
+    item3 = new Item({focusContext})
+
+    expect(focusContext.focusedObject).toBe null
+    expect(item1.focused).toBe false
+    expect(item2.focused).toBe false
+    expect(item3.focused).toBe false
+
+    item1.focus()
+    expect(focusContext.focusedObject).toBe item1
+    expect(item1.focused).toBe true
+    expect(item2.focused).toBe false
+    expect(item3.focused).toBe false
+
+    item2.focus()
+    expect(focusContext.focusedObject).toBe item2
+    expect(item1.focused).toBe false
+    expect(item2.focused).toBe true
+    expect(item3.focused).toBe false
+
+    item2.blur()
+    expect(focusContext.focusedObject).toBe null
+    expect(item1.focused).toBe false
+    expect(item2.focused).toBe false
+    expect(item3.focused).toBe false
diff --git a/src/focus-context.coffee b/src/focus-context.coffee
new file mode 100644
index 000000000..e52b0487f
--- /dev/null
+++ b/src/focus-context.coffee
@@ -0,0 +1,5 @@
+{Model} = require 'theorist'
+
+module.exports =
+class FocusContext extends Model
+  @property 'focusedObject', null
diff --git a/src/focusable.coffee b/src/focusable.coffee
new file mode 100644
index 000000000..6441a74eb
--- /dev/null
+++ b/src/focusable.coffee
@@ -0,0 +1,18 @@
+Mixin = require 'mixto'
+
+module.exports =
+class Focusable extends Mixin
+  @included: ->
+    @property 'focusContext'
+    @behavior 'focused', ->
+      @$focusContext
+        .flatMapLatest((context) -> context?.$focusedObject)
+        .map((focusedObject) => focusedObject is this)
+
+  focus: ->
+    throw new Error("Object must be assigned a focusContext to be focus") unless @focusContext
+    @focusContext.focusedObject = this
+
+  blur: ->
+    throw new Error("Object must be assigned a focusContext to be blurred") unless @focusContext
+    @focusContext.focusedObject = null if @focused

From 2317c6835e9bfaa920b7cd6197644629261a934f Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 10:41:48 -0700
Subject: [PATCH 27/89] At the model layer: Focus next pane when a focused pane
 is destroyed

This incorporates the Focusable mixin into PaneModel and ensures that
all panes in the same pane container share a single focus context.
---
 spec/pane-model-spec.coffee     | 12 +++++++++++-
 src/pane-axis-model.coffee      | 18 +++++++++++++++--
 src/pane-container-model.coffee | 34 ++++++++++++++++++++++++++++++++-
 src/pane-model.coffee           | 17 ++++++++++-------
 4 files changed, 70 insertions(+), 11 deletions(-)

diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index db6bdac48..794507ba5 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -80,7 +80,7 @@ describe "PaneModel", ->
 
     it "focuses the new pane, even if the current pane isn't focused", ->
       expect(pane1.focused).toBe false
-      pane2 = pane1.split()
+      pane2 = pane1.splitRight()
       expect(pane2.focused).toBe true
 
   describe "::destroy()", ->
@@ -110,3 +110,13 @@ describe "PaneModel", ->
         expect(container.root.children).toEqual [pane1, pane2]
         pane2.destroy()
         expect(container.root).toBe pane1
+
+    describe "if the pane is focused", ->
+      it "shifts focus to the next pane", ->
+        pane2 = pane1.splitRight()
+        pane3 = pane2.splitRight()
+        pane2.focus()
+        expect(pane2.focused).toBe true
+        expect(pane3.focused).toBe false
+        pane2.destroy()
+        expect(pane3.focused).toBe true
diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index 824727815..d23e93493 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -1,4 +1,6 @@
 {Model, Sequence} = require 'theorist'
+{flatten} = require 'underscore-plus'
+Delegator = require 'delegato'
 Serializable = require 'serializable'
 
 PaneRow = null
@@ -8,15 +10,24 @@ module.exports =
 class PaneAxisModel extends Model
   atom.deserializers.add(this)
   Serializable.includeInto(this)
+  Delegator.includeInto(this)
+
+  @delegatesMethod 'focusNextPane', toProperty: 'parent'
+
+  @property 'focusContext'
 
   constructor: ({@orientation, children}) ->
     @children = Sequence.fromArray(children ? [])
 
-    @children.onEach (child) =>
+    @subscribe @$focusContext, (focusContext) =>
+      child.focusContext = focusContext for child in @children
+
+    @subscribe @children.onEach (child) =>
       child.parent = this
+      child.focusContext = @focusContext
       @subscribe child, 'destroyed', => @removeChild(child)
 
-    @children.onRemoval (child) => @unsubscribe(child)
+    @subscribe @children.onRemoval (child) => @unsubscribe(child)
 
     @when @children.$length.becomesLessThan(2), 'reparentLastChild'
     @when @children.$length.becomesLessThan(1), 'destroy'
@@ -34,6 +45,9 @@ class PaneAxisModel extends Model
     else
       PaneRow ?= require './pane-row'
 
+  getPanes: ->
+    flatten(@children.map (child) -> child.getPanes())
+
   addChild: (child, index=@children.length) ->
     @children.splice(index, 0, child)
 
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index 1aa975cd7..d4029886e 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -1,5 +1,7 @@
 {Model} = require 'theorist'
 Serializable = require 'serializable'
+{find} = require 'underscore-plus'
+FocusContext = require './focus-context'
 
 module.exports =
 class PaneContainerModel extends Model
@@ -8,10 +10,13 @@ class PaneContainerModel extends Model
 
   @properties
     root: null
+    focusContext: -> new FocusContext
 
   constructor: ->
     super
-    @subscribe @$root, (root) => root?.parent = this
+    @subscribe @$root.filterDefined(), (root) =>
+      root.parent = this
+      root.focusContext = @focusContext
 
   deserializeParams: (params) ->
     params.root = atom.deserializers.deserialize(params.root)
@@ -23,3 +28,30 @@ class PaneContainerModel extends Model
   replaceChild: (oldChild, newChild) ->
     throw new Error("Replacing non-existent child") if oldChild isnt @root
     @root = newChild
+
+  getPanes: ->
+    @root?.getPanes() ? []
+
+  getFocusedPane: ->
+    find @getPanes(), (pane) -> pane.focused
+
+  focusNextPane: ->
+    panes = @getPanes()
+    if panes.length > 1
+      currentIndex = panes.indexOf(@getFocusedPane())
+      nextIndex = (currentIndex + 1) % panes.length
+      panes[nextIndex].focus()
+      true
+    else
+      false
+
+  focusPreviousPane: ->
+    panes = @getPanes()
+    if panes.length > 1
+      currentIndex = panes.indexOf(@getFocusedPane())
+      previousIndex = currentIndex - 1
+      previousIndex = panes.length - 1 if previousIndex < 0
+      panes[previousIndex].focus()
+      true
+    else
+      false
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index be9b651cb..ed3a5e8de 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -3,17 +3,18 @@
 {Model} = require 'theorist'
 Serializable = require 'serializable'
 PaneAxisModel = require './pane-axis-model'
+Focusable = require './focusable'
 Pane = null
 
 module.exports =
 class PaneModel extends Model
   atom.deserializers.add(this)
   Serializable.includeInto(this)
+  Focusable.includeInto(this)
 
   @properties
     items: -> []
     activeItem: null
-    focused: false
 
   constructor: ->
     super
@@ -32,11 +33,7 @@ class PaneModel extends Model
 
   getViewClass: -> Pane ?= require './pane'
 
-  focus: ->
-    @focused = true
-
-  blur: ->
-    @focused = false
+  getPanes: -> [this]
 
   # Public: Returns all contained views.
   getItems: ->
@@ -132,6 +129,10 @@ class PaneModel extends Model
   destroyInactiveItems: ->
     @destroyItem(item) for item in @getItems() when item isnt @activeItem
 
+  # Private: Called by model superclass
+  destroyed: ->
+    @parent.focusNextPane() if @focused
+
   # Public: Prompt the user to save the given item.
   promptToSaveItem: (item) ->
     return true unless item.shouldPromptToSave?()
@@ -211,8 +212,10 @@ class PaneModel extends Model
     if @parent.orientation isnt orientation
       @parent.replaceChild(this, new PaneAxisModel({orientation, children: [this]}))
 
-    newPane = new @constructor(extend({focused: true}, params))
+    newPane = new @constructor(params)
     switch side
       when 'before' then @parent.insertChildBefore(this, newPane)
       when 'after' then @parent.insertChildAfter(this, newPane)
+
+    newPane.focus()
     newPane

From 466868e63919d6fabb8d75caca930fd348c1908f Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 10:47:07 -0700
Subject: [PATCH 28/89] Fix access to undefined root property

The ::filterDefined transform unfortunately doesn't prevent an undefined
initial value when applied to behaviors.
---
 src/pane-container-model.coffee | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index d4029886e..10ab34292 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -14,9 +14,10 @@ class PaneContainerModel extends Model
 
   constructor: ->
     super
-    @subscribe @$root.filterDefined(), (root) =>
-      root.parent = this
-      root.focusContext = @focusContext
+    @subscribe @$root, (root) =>
+      if root?
+        root.parent = this
+        root.focusContext = @focusContext
 
   deserializeParams: (params) ->
     params.root = atom.deserializers.deserialize(params.root)

From af3ca5709409b9bf2d0b5db1ff6adaee7010e7b9 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 15:43:05 -0700
Subject: [PATCH 29/89] Make focus state distinct until changed on Focusable
 objects

---
 src/focusable.coffee | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/focusable.coffee b/src/focusable.coffee
index 6441a74eb..69c966896 100644
--- a/src/focusable.coffee
+++ b/src/focusable.coffee
@@ -8,6 +8,7 @@ class Focusable extends Mixin
       @$focusContext
         .flatMapLatest((context) -> context?.$focusedObject)
         .map((focusedObject) => focusedObject is this)
+        .distinctUntilChanged()
 
   focus: ->
     throw new Error("Object must be assigned a focusContext to be focus") unless @focusContext

From 5309d5f24d17c0cc808eecdb50de470890272fe0 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 15:46:32 -0700
Subject: [PATCH 30/89] Add ability to suppress blur on all focusable objects
 in a focus context

When a view receives a 'focusout' event, we relay that to the model by
calling ::blur. This is great for when users initiate the change in
focus, but 'focusout' events can *also* be caused by elements being
temporarily detached from the DOM.

The ::suppressBlur method gives the ability to ignore blur calls during
a certain operation. This is helpful, for example, when we want to
detach a model and reattach it somewhere else without changing its focus
state.
---
 src/focus-context.coffee | 10 ++++++++++
 src/focusable.coffee     | 13 +++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/focus-context.coffee b/src/focus-context.coffee
index e52b0487f..c17514471 100644
--- a/src/focus-context.coffee
+++ b/src/focus-context.coffee
@@ -3,3 +3,13 @@
 module.exports =
 class FocusContext extends Model
   @property 'focusedObject', null
+
+  blurSuppressionCounter: 0
+
+  isBlurSuppressed: ->
+    @blurSuppressionCounter > 0
+
+  suppressBlur: (fn) ->
+    @blurSuppressionCounter++
+    fn()
+    @blurSuppressionCounter--
diff --git a/src/focusable.coffee b/src/focusable.coffee
index 69c966896..c046e7cd2 100644
--- a/src/focusable.coffee
+++ b/src/focusable.coffee
@@ -12,8 +12,17 @@ class Focusable extends Mixin
 
   focus: ->
     throw new Error("Object must be assigned a focusContext to be focus") unless @focusContext
-    @focusContext.focusedObject = this
+    unless @focused
+      @suppressBlur =>
+        @focusContext.focusedObject = this
 
   blur: ->
     throw new Error("Object must be assigned a focusContext to be blurred") unless @focusContext
-    @focusContext.focusedObject = null if @focused
+    if @focused and not @focusContext.isBlurSuppressed()
+      @focusContext.focusedObject = null
+
+  suppressBlur: (fn) ->
+    if @focusContext?
+      @focusContext.suppressBlur(fn)
+    else
+      fn()

From a67f0d4d5704b31454db8eaf547bcb7cf43e251e Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 15:53:52 -0700
Subject: [PATCH 31/89] Make PaneModel::items an observable sequence

---
 src/pane-model.coffee | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index ed3a5e8de..6d310c47c 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -1,6 +1,6 @@
 {find, compact, clone, extend} = require 'underscore-plus'
 {dirname} = require 'path'
-{Model} = require 'theorist'
+{Model, Sequence} = require 'theorist'
 Serializable = require 'serializable'
 PaneAxisModel = require './pane-axis-model'
 Focusable = require './focusable'
@@ -16,10 +16,22 @@ class PaneModel extends Model
     items: -> []
     activeItem: null
 
-  constructor: ->
+  constructor: (params) ->
     super
+
+    @items = Sequence.fromArray(params?.items ? [])
     @activeItem ?= @items[0]
 
+    @subscribe @items.onEach (item) =>
+      if typeof item.on is 'function'
+        @subscribe item, 'destroyed', => @removeItem(item)
+
+    @subscribe @items.onRemoval (item, index) =>
+      @unsubscribe item
+      @emit 'item-removed', item, index
+
+    @when @items.$length.becomesLessThan(1), 'destroy'
+
   serializeParams: ->
     items: compact(@items.map((item) -> item.serialize?()))
     activeItemUri: @activeItem?.getUri?()
@@ -37,7 +49,7 @@ class PaneModel extends Model
 
   # Public: Returns all contained views.
   getItems: ->
-    clone(@items)
+    @items.slice()
 
   # Public: Returns the item at the specified index.
   itemAtIndex: (index) ->

From 2965d2e9742ec1f7fc695087404de6235d13e0d1 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 16:01:52 -0700
Subject: [PATCH 32/89] Bind Pane view's focus to focus state on the model
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

It's a bit tricky… we don't want to blur the model when focusing the
pane's active view causes a focusout event on the pane, so we use
::suppressBlur on the model to prevent it from blurring as the focus
is transferred.
---
 src/pane.coffee | 40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/src/pane.coffee b/src/pane.coffee
index 540cbf9f9..0121c8d36 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -36,13 +36,11 @@ class Pane extends View
     toProperty: 'model'
 
   previousActiveItem: null
-  focusOnAttach: false
 
   # Private:
   initialize: (args...) ->
     if args[0] instanceof PaneModel
       @model = args[0]
-      @focusOnAttach = @model.focused
     else
       @model = new PaneModel(items: args)
       @model._view = this
@@ -51,6 +49,9 @@ class Pane extends View
     @viewsByItem = new WeakMap()
     @handleEvents()
 
+  hasFocus: ->
+    @is(':focus') or @is(':has(:focus)')
+
   handleEvents: ->
     @subscribe @model.$activeItem, 'value', @onActiveItemChanged
     @subscribe @model, 'item-added', @onItemAdded
@@ -59,9 +60,21 @@ class Pane extends View
     @subscribe @model, 'before-item-destroyed', @onBeforeItemDestroyed
     @subscribe @model, 'item-destroyed', @onItemDestroyed
 
-    @subscribe this, 'focus', => @activeView?.focus(); false
-    @subscribe this, 'focusin', => @makeActive(); @model.focus()
-    @subscribe this, 'focusout', => @model.blur()
+    @subscribe @model.$focused, 'value', (focused) =>
+      if focused
+        @focus() unless @hasFocus()
+      else
+        @blur() if @hasFocus()
+
+    @subscribe this, 'focus', =>
+      @model.suppressBlur => @activeView?.focus()
+      false
+
+    @subscribe this, 'focusin', =>
+      @makeActive()
+      @model.focus()
+
+    @subscribe this, 'focusout', (e) => @model.blur()
 
     @command 'pane:save-items', => @saveItems()
     @command 'pane:show-next-item', => @showNextItem()
@@ -93,9 +106,7 @@ class Pane extends View
 
   # Private:
   afterAttach: (onDom) ->
-    if @focusOnAttach and onDom
-      @focusOnAttach = null
-      @focus()
+    @focus() if @model.focused and onDom
 
     return if @attached
     @attached = true
@@ -141,7 +152,8 @@ class Pane extends View
     @itemViews.children().not(view).hide()
     @itemViews.append(view) unless view.parent().is(@itemViews)
     view.show() if @attached
-    view.focus() if isFocused
+    if isFocused
+      @model.suppressBlur -> view.focus()
     @activeView = view
     @trigger 'pane:active-item-changed', [item]
 
@@ -223,12 +235,10 @@ class Pane extends View
   remove: (selector, keepData) ->
     return super if keepData
 
-    if @is(':has(:focus)')
-      @getContainer().focusNextPane() or atom.workspaceView?.focus()
-    else if @isActive()
+    @unsubscribe()
+    @model.destroy() unless @model.isDestroyed()
+
+    if @isActive()
       @getContainer().makeNextPaneActive()
 
-    @parent().view().removeChild(this) unless keepData
-    item.destroy?() for item in @getItems()
-
     super

From 073ea84d69293ec964ccb2a3dcb9e6cd1639984b Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 16:05:00 -0700
Subject: [PATCH 33/89] Handle consequences of item removal in the model

---
 spec/pane-model-spec.coffee | 20 ++++++++++++++++++++
 src/pane-model.coffee       | 11 +++++------
 src/pane.coffee             | 31 +++++++++++--------------------
 3 files changed, 36 insertions(+), 26 deletions(-)

diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index 794507ba5..2b9cb40bb 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -1,6 +1,7 @@
 PaneModel = require '../src/pane-model'
 PaneAxisModel = require '../src/pane-axis-model'
 PaneContainerModel = require '../src/pane-container-model'
+FocusContext = require '../src/focus-context'
 
 describe "PaneModel", ->
   describe "split methods", ->
@@ -83,6 +84,25 @@ describe "PaneModel", ->
       pane2 = pane1.splitRight()
       expect(pane2.focused).toBe true
 
+  describe "::removeItemAtIndex(index)", ->
+    describe "when the removal of the item causes blur to be called on the pane model", ->
+      it "remains focused if it was before the item was removed", ->
+        pane = new PaneModel(items: ["A", "B", "C"], focusContext: new FocusContext)
+        pane.on 'item-removed', -> pane.blur()
+        pane.focus()
+        pane.removeItemAtIndex(0)
+        expect(pane.focused).toBe true
+
+        pane.blur()
+        pane.removeItemAtIndex(0)
+        expect(pane.focused).toBe false
+
+    describe "when the last item is removed", ->
+      it "destroys the pane", ->
+        pane = new PaneModel(items: ["A", "B"])
+        pane.removeItemAtIndex(0)
+        pane.removeItemAtIndex(0)
+        expect(pane.isDestroyed()).toBe true
   describe "::destroy()", ->
     [pane1, container] = []
 
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 6d310c47c..1930e93db 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -94,16 +94,15 @@ class PaneModel extends Model
     item
 
   # Public:
-  removeItem: (item, detach) ->
+  removeItem: (item) ->
     index = @items.indexOf(item)
-    @removeItemAtIndex(index, detach) if index >= 0
+    @removeItemAtIndex(index) if index >= 0
 
   # Public: Just remove the item at the given index.
-  removeItemAtIndex: (index, detach) ->
+  removeItemAtIndex: (index) ->
     item = @items[index]
     @showNextItem() if item is @activeItem and @items.length > 1
-    @items.splice(index, 1)
-    @emit 'item-removed', item, index, detach
+    @suppressBlur => @items.splice(index, 1)
 
   # Public: Moves the given item to a the new index.
   moveItem: (item, newIndex) ->
@@ -115,7 +114,7 @@ class PaneModel extends Model
   # Public: Moves the given item to another pane.
   moveItemToPane: (item, pane, index) ->
     pane.addItem(item, index)
-    @removeItem(item, true)
+    @removeItem(item)
 
   # Public: Remove the currently active item.
   destroyActiveItem: ->
diff --git a/src/pane.coffee b/src/pane.coffee
index 0121c8d36..c145c5b6b 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -53,6 +53,8 @@ class Pane extends View
     @is(':focus') or @is(':has(:focus)')
 
   handleEvents: ->
+    @subscribe @model, 'destroyed', => @remove()
+
     @subscribe @model.$activeItem, 'value', @onActiveItemChanged
     @subscribe @model, 'item-added', @onItemAdded
     @subscribe @model, 'item-removed', @onItemRemoved
@@ -158,12 +160,10 @@ class Pane extends View
     @trigger 'pane:active-item-changed', [item]
 
   onItemAdded: (item, index) =>
-    if typeof item.on is 'function'
-      @subscribe item, 'destroyed', => @destroyItem(item)
     @trigger 'pane:item-added', [item, index]
 
-  onItemRemoved: (item, index, detach) =>
-    @cleanupItemView(item, detach)
+  onItemRemoved: (item, index) =>
+    @cleanupItemView(item)
     @trigger 'pane:item-removed', [item, index]
 
   onItemMoved: (item, newIndex) =>
@@ -181,27 +181,15 @@ class Pane extends View
     @trigger 'pane:active-item-title-changed'
 
   # Private:
-  cleanupItemView: (item, detach) ->
+  cleanupItemView: (item) ->
     if item instanceof $
       viewToRemove = item
     else if viewToRemove = @viewsByItem.get(item)
       @viewsByItem.delete(item)
 
-    if @items.length > 0
-      if detach and item is viewToRemove
-        viewToRemove?.detach()
-      else if detach and viewToRemove?.setModel
-        viewToRemove.setModel(null) # dont want to destroy the model, so set to null
-        viewToRemove.remove()
-      else
-        viewToRemove?.remove()
-    else
-      if detach and item is viewToRemove
-        viewToRemove?.detach()
-      else if detach and viewToRemove?.setModel
-        viewToRemove.setModel(null) # dont want to destroy the model, so set to null
-
-      @parent().view().removeChild(this)
+    if viewToRemove?
+      viewToRemove.setModel?(null)
+      viewToRemove.detach()
 
   # Private:
   viewForItem: (item) ->
@@ -231,6 +219,9 @@ class Pane extends View
   getContainer: ->
     @closest('.panes').view()
 
+  beforeRemove: ->
+    @trigger 'pane:removed', [this]
+
   # Private:
   remove: (selector, keepData) ->
     return super if keepData

From 4dcba4bb27fbdab67f34d7feb95178e2b592b319 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 16:06:02 -0700
Subject: [PATCH 34/89] Destroy remaining items when a pane is destroyed

---
 spec/pane-model-spec.coffee | 8 +++++++-
 src/pane-model.coffee       | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index 2b9cb40bb..c036232e4 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -107,9 +107,15 @@ describe "PaneModel", ->
     [pane1, container] = []
 
     beforeEach ->
-      pane1 = new PaneModel(items: ["A"])
+      pane1 = new PaneModel(items: [new Model, new Model])
       container = new PaneContainerModel(root: pane1)
 
+    it "destroys the pane's destroyable items", ->
+      [item1, item2] = pane1.items
+      pane1.destroy()
+      expect(item1.isDestroyed()).toBe true
+      expect(item2.isDestroyed()).toBe true
+
     describe "if the pane's parent has more than two children", ->
       it "removes the pane from its parent", ->
         pane2 = pane1.splitRight()
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 1930e93db..881fc2f48 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -142,6 +142,7 @@ class PaneModel extends Model
 
   # Private: Called by model superclass
   destroyed: ->
+    item.destroy?() for item in @items.slice()
     @parent.focusNextPane() if @focused
 
   # Public: Prompt the user to save the given item.

From 5ca7ad3bceb2c80980d2a9235f61ebe095b77bf8 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 16:07:57 -0700
Subject: [PATCH 35/89] Add spec for destroyed pane items getting removed at
 the model layer

---
 spec/pane-model-spec.coffee | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index c036232e4..7add9e949 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -1,3 +1,4 @@
+{Model} = require 'theorist'
 PaneModel = require '../src/pane-model'
 PaneAxisModel = require '../src/pane-axis-model'
 PaneContainerModel = require '../src/pane-container-model'
@@ -103,6 +104,14 @@ describe "PaneModel", ->
         pane.removeItemAtIndex(0)
         pane.removeItemAtIndex(0)
         expect(pane.isDestroyed()).toBe true
+
+  describe "when an item emits a destroyed event", ->
+    it "removes it from the list of items", ->
+      pane = new PaneModel(items: [new Model, new Model, new Model])
+      [item1, item2, item3] = pane.items
+      pane.items[1].destroy()
+      expect(pane.items).toEqual [item1, item3]
+
   describe "::destroy()", ->
     [pane1, container] = []
 

From 964abd3141dd4081427e1d01e3cb9804e11dd9f0 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 16:08:52 -0700
Subject: [PATCH 36/89] Suppress blur when replacing a pane axis with its last
 child

If the pane axis contains a child pane, its temporary removal from the
DOM causes a blur event that we don't want to screw up our focused
state.
---
 src/pane-axis-model.coffee | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index d23e93493..064ad95b8 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -70,4 +70,5 @@ class PaneAxisModel extends Model
     @children.splice(index + 1, 0, newChild)
 
   reparentLastChild: ->
-    @parent.replaceChild(this, @children[0])
+    @focusContext.suppressBlur =>
+      @parent.replaceChild(this, @children[0])

From 4026e6ca5c3dcbaa4f259e41659168227629243a Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 16:09:22 -0700
Subject: [PATCH 37/89] Properly serialize pane focus state

---
 spec/pane-container-model-spec.coffee | 16 ++++++++++++++++
 src/pane-axis-model.coffee            |  5 +++--
 src/pane-container-model.coffee       |  3 ++-
 src/pane-model.coffee                 |  3 ++-
 4 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 spec/pane-container-model-spec.coffee

diff --git a/spec/pane-container-model-spec.coffee b/spec/pane-container-model-spec.coffee
new file mode 100644
index 000000000..9379a2c8d
--- /dev/null
+++ b/spec/pane-container-model-spec.coffee
@@ -0,0 +1,16 @@
+PaneContainerModel = require '../src/pane-container-model'
+PaneModel = require '../src/pane-model'
+
+describe "PaneContainerModel", ->
+  describe "serialization", ->
+    it "preserves the focused pane across serialization", ->
+      pane1A = new PaneModel
+      containerA = new PaneContainerModel(root: pane1A)
+      pane2A = pane1A.splitRight()
+      pane3A = pane2A.splitDown()
+      expect(pane3A.focused).toBe true
+
+      containerB = containerA.testSerialization()
+      [pane1A, pane2A, pane3A] = containerB.getPanes()
+      expect(pane3A.focusContext).toBe containerB.focusContext
+      expect(pane3A.focused).toBe true
diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index 064ad95b8..a4495f417 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -16,7 +16,7 @@ class PaneAxisModel extends Model
 
   @property 'focusContext'
 
-  constructor: ({@orientation, children}) ->
+  constructor: ({@focusContext, @orientation, children}) ->
     @children = Sequence.fromArray(children ? [])
 
     @subscribe @$focusContext, (focusContext) =>
@@ -33,7 +33,8 @@ class PaneAxisModel extends Model
     @when @children.$length.becomesLessThan(1), 'destroy'
 
   deserializeParams: (params) ->
-    params.children = params.children.map (childState) -> atom.deserializers.deserialize(childState)
+    {focusContext} = params
+    params.children = params.children.map (childState) -> atom.deserializers.deserialize(childState, {focusContext})
     params
 
   serializeParams: ->
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index 10ab34292..7d704a41c 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -20,7 +20,8 @@ class PaneContainerModel extends Model
         root.focusContext = @focusContext
 
   deserializeParams: (params) ->
-    params.root = atom.deserializers.deserialize(params.root)
+    params.focusContext ?= new FocusContext
+    params.root = atom.deserializers.deserialize(params.root, focusContext: params.focusContext)
     params
 
   serializeParams: (params) ->
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 881fc2f48..60a768b56 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -13,12 +13,13 @@ class PaneModel extends Model
   Focusable.includeInto(this)
 
   @properties
-    items: -> []
     activeItem: null
 
   constructor: (params) ->
     super
 
+    @focus() if params?.focused
+
     @items = Sequence.fromArray(params?.items ? [])
     @activeItem ?= @items[0]
 

From 5e1b2e269608c3aa57cc400729574e40be95cc46 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 17:40:04 -0700
Subject: [PATCH 38/89] Manage the active pane at the model level

---
 package.json                          |  2 +-
 spec/pane-container-model-spec.coffee | 36 ++++++++++++++++++++++++---
 spec/pane-model-spec.coffee           |  3 ++-
 src/pane-axis-model.coffee            | 15 ++++-------
 src/pane-container-model.coffee       | 23 ++++++++++++++---
 src/pane-model.coffee                 | 29 +++++++++++++++++----
 6 files changed, 84 insertions(+), 24 deletions(-)

diff --git a/package.json b/package.json
index e23497b3e..90da3ba15 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
     "temp": "0.5.0",
     "text-buffer": "0.12.0",
     "underscore-plus": "0.6.1",
-    "theorist": "~0.9.0",
+    "theorist": "~0.10.0",
     "delegato": "~0.4.0",
     "mixto": "~0.4.0"
   },
diff --git a/spec/pane-container-model-spec.coffee b/spec/pane-container-model-spec.coffee
index 9379a2c8d..5052b2830 100644
--- a/spec/pane-container-model-spec.coffee
+++ b/spec/pane-container-model-spec.coffee
@@ -11,6 +11,36 @@ describe "PaneContainerModel", ->
       expect(pane3A.focused).toBe true
 
       containerB = containerA.testSerialization()
-      [pane1A, pane2A, pane3A] = containerB.getPanes()
-      expect(pane3A.focusContext).toBe containerB.focusContext
-      expect(pane3A.focused).toBe true
+      [pane1B, pane2B, pane3B] = containerB.getPanes()
+      expect(pane3B.focusContext).toBe containerB.focusContext
+      expect(pane3B.focused).toBe true
+
+  describe "::activePane", ->
+    [container, pane1, pane2] = []
+
+    beforeEach ->
+      pane1 = new PaneModel
+      container = new PaneContainerModel(root: pane1)
+
+    it "references the first pane if no pane has been focused", ->
+      expect(container.activePane).toBe pane1
+      expect(pane1.active).toBe true
+
+    it "references the most recently focused pane", ->
+      pane2 = pane1.splitRight()
+      expect(container.activePane).toBe pane2
+      expect(pane1.active).toBe false
+      expect(pane2.active).toBe true
+      pane1.focus()
+      expect(container.activePane).toBe pane1
+      expect(pane1.active).toBe true
+      expect(pane2.active).toBe false
+
+    it "is reassigned to the next pane if the current active pane is unfocused and destroyed", ->
+      pane2 = pane1.splitRight()
+      pane2.blur()
+      pane2.destroy()
+      expect(container.activePane).toBe pane1
+      expect(pane1.active).toBe true
+      pane1.destroy()
+      expect(container.activePane).toBe null
diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index 7add9e949..f17b141c9 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -88,7 +88,8 @@ describe "PaneModel", ->
   describe "::removeItemAtIndex(index)", ->
     describe "when the removal of the item causes blur to be called on the pane model", ->
       it "remains focused if it was before the item was removed", ->
-        pane = new PaneModel(items: ["A", "B", "C"], focusContext: new FocusContext)
+        pane = new PaneModel(items: ["A", "B", "C"])
+        container = new PaneContainerModel(root: pane)
         pane.on 'item-removed', -> pane.blur()
         pane.focus()
         pane.removeItemAtIndex(0)
diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index a4495f417..d35e88032 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -12,19 +12,14 @@ class PaneAxisModel extends Model
   Serializable.includeInto(this)
   Delegator.includeInto(this)
 
-  @delegatesMethod 'focusNextPane', toProperty: 'parent'
+  @delegatesProperty 'focusContext', toProperty: 'container'
 
-  @property 'focusContext'
-
-  constructor: ({@focusContext, @orientation, children}) ->
+  constructor: ({@container, @orientation, children}) ->
     @children = Sequence.fromArray(children ? [])
 
-    @subscribe @$focusContext, (focusContext) =>
-      child.focusContext = focusContext for child in @children
-
     @subscribe @children.onEach (child) =>
       child.parent = this
-      child.focusContext = @focusContext
+      child.container = @container
       @subscribe child, 'destroyed', => @removeChild(child)
 
     @subscribe @children.onRemoval (child) => @unsubscribe(child)
@@ -33,8 +28,8 @@ class PaneAxisModel extends Model
     @when @children.$length.becomesLessThan(1), 'destroy'
 
   deserializeParams: (params) ->
-    {focusContext} = params
-    params.children = params.children.map (childState) -> atom.deserializers.deserialize(childState, {focusContext})
+    {container} = params
+    params.children = params.children.map (childState) -> atom.deserializers.deserialize(childState, {container})
     params
 
   serializeParams: ->
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index 7d704a41c..ebbf250db 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -2,6 +2,7 @@
 Serializable = require 'serializable'
 {find} = require 'underscore-plus'
 FocusContext = require './focus-context'
+PaneModel = require './pane-model'
 
 module.exports =
 class PaneContainerModel extends Model
@@ -10,18 +11,23 @@ class PaneContainerModel extends Model
 
   @properties
     root: null
-    focusContext: -> new FocusContext
+    focusContext: null
+    activePane: null
 
   constructor: ->
     super
+
+    @focusContext ?= new FocusContext
+
     @subscribe @$root, (root) =>
       if root?
         root.parent = this
-        root.focusContext = @focusContext
+        root.container = this
+        @activePane ?= root if root instanceof PaneModel
 
   deserializeParams: (params) ->
-    params.focusContext ?= new FocusContext
-    params.root = atom.deserializers.deserialize(params.root, focusContext: params.focusContext)
+    @focusContext ?= params.focusContext ? new FocusContext
+    params.root = atom.deserializers.deserialize(params.root, container: this)
     params
 
   serializeParams: (params) ->
@@ -57,3 +63,12 @@ class PaneContainerModel extends Model
       true
     else
       false
+
+  makeNextPaneActive: ->
+    panes = @getPanes()
+    if panes.length > 1
+      currentIndex = panes.indexOf(@activePane)
+      nextIndex = (currentIndex + 1) % panes.length
+      @activePane = panes[nextIndex]
+    else
+      @activePane = null
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 60a768b56..8fc2e0fa3 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -13,26 +13,38 @@ class PaneModel extends Model
   Focusable.includeInto(this)
 
   @properties
+    container: null
     activeItem: null
 
+  @behavior 'active', ->
+    @$container
+      .flatMapLatest((container) -> container?.$activePane)
+      .map((activePane) => activePane is this)
+      .distinctUntilChanged()
+
   constructor: (params) ->
     super
 
-    @focus() if params?.focused
-
     @items = Sequence.fromArray(params?.items ? [])
     @activeItem ?= @items[0]
 
+    @subscribe @$container, (container) =>
+      @focusContext = container?.focusContext
+
     @subscribe @items.onEach (item) =>
       if typeof item.on is 'function'
         @subscribe item, 'destroyed', => @removeItem(item)
 
     @subscribe @items.onRemoval (item, index) =>
-      @unsubscribe item
+      @unsubscribe item if typeof item.on is 'function'
       @emit 'item-removed', item, index
 
     @when @items.$length.becomesLessThan(1), 'destroy'
 
+    @when @$focused, => @makeActive()
+
+    @focus() if params?.focused
+
   serializeParams: ->
     items: compact(@items.map((item) -> item.serialize?()))
     activeItemUri: @activeItem?.getUri?()
@@ -46,6 +58,10 @@ class PaneModel extends Model
 
   getViewClass: -> Pane ?= require './pane'
 
+  isActive: -> @active
+
+  makeActive: -> @container.activePane = this
+
   getPanes: -> [this]
 
   # Public: Returns all contained views.
@@ -144,7 +160,10 @@ class PaneModel extends Model
   # Private: Called by model superclass
   destroyed: ->
     item.destroy?() for item in @items.slice()
-    @parent.focusNextPane() if @focused
+    if @focused
+      @container.focusNextPane()
+    else if @isActive()
+      @container.makeNextPaneActive()
 
   # Public: Prompt the user to save the given item.
   promptToSaveItem: (item) ->
@@ -223,7 +242,7 @@ class PaneModel extends Model
 
   split: (orientation, side, params) ->
     if @parent.orientation isnt orientation
-      @parent.replaceChild(this, new PaneAxisModel({orientation, children: [this]}))
+      @parent.replaceChild(this, new PaneAxisModel({@container, orientation, children: [this]}))
 
     newPane = new @constructor(params)
     switch side

From 86471379525fa28564bd54cfdaca40c659acb0e3 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 18:00:54 -0700
Subject: [PATCH 39/89] Remove active status management from Pane view; rely on
 model instead

---
 src/pane.coffee | 40 +++++++++++-----------------------------
 1 file changed, 11 insertions(+), 29 deletions(-)

diff --git a/src/pane.coffee b/src/pane.coffee
index c145c5b6b..3d968e742 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -33,7 +33,7 @@ class Pane extends View
     'moveItem', 'moveItemToPane', 'destroyItem', 'destroyItems', 'destroyActiveItem',
     'destroyInactiveItems', 'saveActiveItem', 'saveActiveItemAs', 'saveItem', 'saveItemAs',
     'saveItems', 'itemForUri', 'showItemForUri', 'promptToSaveItem', 'copyActiveItem',
-    toProperty: 'model'
+    'isActive', 'makeActive', toProperty: 'model'
 
   previousActiveItem: null
 
@@ -61,6 +61,7 @@ class Pane extends View
     @subscribe @model, 'item-moved', @onItemMoved
     @subscribe @model, 'before-item-destroyed', @onBeforeItemDestroyed
     @subscribe @model, 'item-destroyed', @onItemDestroyed
+    @subscribe @model.$active, 'value', @onActiveStatusChanged
 
     @subscribe @model.$focused, 'value', (focused) =>
       if focused
@@ -68,16 +69,12 @@ class Pane extends View
       else
         @blur() if @hasFocus()
 
+    @subscribe this, 'focusin', => @model.focus()
+    @subscribe this, 'focusout', => @model.blur()
     @subscribe this, 'focus', =>
       @model.suppressBlur => @activeView?.focus()
       false
 
-    @subscribe this, 'focusin', =>
-      @makeActive()
-      @model.focus()
-
-    @subscribe this, 'focusout', (e) => @model.blur()
-
     @command 'pane:save-items', => @saveItems()
     @command 'pane:show-next-item', => @showNextItem()
     @command 'pane:show-previous-item', => @showPreviousItem()
@@ -114,23 +111,13 @@ class Pane extends View
     @attached = true
     @trigger 'pane:attached', [this]
 
-  # Public: Focus this pane.
-  makeActive: ->
-    wasActive = @isActive()
-    for pane in @getContainer().getPanes() when pane isnt this
-      pane.makeInactive()
-    @addClass('active')
-    @trigger 'pane:became-active' unless wasActive
-
-  # Public: Unfocus this pane.
-  makeInactive: ->
-    wasActive = @isActive()
-    @removeClass('active')
-    @trigger 'pane:became-inactive' if wasActive
-
-  # Public: Returns whether this pane is currently focused.
-  isActive: ->
-    @getContainer()?.getActivePane() == this
+  onActiveStatusChanged: (active) =>
+    if active
+      @addClass('active')
+      @trigger 'pane:became-active'
+    else
+      @removeClass('active')
+      @trigger 'pane:became-inactive'
 
   # Public: Returns the next pane, ordered by creation.
   getNextPane: ->
@@ -225,11 +212,6 @@ class Pane extends View
   # Private:
   remove: (selector, keepData) ->
     return super if keepData
-
     @unsubscribe()
     @model.destroy() unless @model.isDestroyed()
-
-    if @isActive()
-      @getContainer().makeNextPaneActive()
-
     super

From cd699d8b9b0a721d7e0609872b9acf00a8dda08e Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 18:17:02 -0700
Subject: [PATCH 40/89] Transfer focus to the root view when the last focused
 pane is destroyed

---
 spec/pane-container-model-spec.coffee | 20 ++++++++++++++++++++
 src/pane-container-model.coffee       |  1 +
 src/pane-container.coffee             |  4 ++++
 3 files changed, 25 insertions(+)

diff --git a/spec/pane-container-model-spec.coffee b/spec/pane-container-model-spec.coffee
index 5052b2830..7897387b4 100644
--- a/spec/pane-container-model-spec.coffee
+++ b/spec/pane-container-model-spec.coffee
@@ -44,3 +44,23 @@ describe "PaneContainerModel", ->
       expect(pane1.active).toBe true
       pane1.destroy()
       expect(container.activePane).toBe null
+
+  # TODO: Remove this behavior when we have a proper workspace model we can explicitly focus
+  describe "when the last pane is removed", ->
+    [container, pane, surrenderedFocusHandler] = []
+
+    beforeEach ->
+      pane = new PaneModel
+      container = new PaneContainerModel(root: pane)
+      container.on 'surrendered-focus', surrenderedFocusHandler = jasmine.createSpy("surrenderedFocusHandler")
+
+    describe "if the pane is focused", ->
+      it "emits a 'surrendered-focus' event", ->
+        pane.focus()
+        pane.destroy()
+        expect(surrenderedFocusHandler).toHaveBeenCalled()
+
+    describe "if the pane is not focused", ->
+      it "does not emit an event", ->
+        expect(pane.focused).toBe false
+        expect(surrenderedFocusHandler).not.toHaveBeenCalled()
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index ebbf250db..70834cc7e 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -51,6 +51,7 @@ class PaneContainerModel extends Model
       panes[nextIndex].focus()
       true
     else
+      @emit 'surrendered-focus'
       false
 
   focusPreviousPane: ->
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index bc5f0e2f4..8f2d71750 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -21,6 +21,7 @@ class PaneContainer extends View
       @model = new PaneContainerModel({root: params?.root?.model})
 
     @subscribe @model.$root, 'value', @onRootChanged
+    @subscribe @model, 'surrendered-focus', @onSurrenderedFocus
 
     @subscribe this, 'pane:attached', (event, pane) =>
       @triggerActiveItemChange() if @getActivePane() is pane
@@ -89,6 +90,9 @@ class PaneContainer extends View
       @append(view)
       view.makeActive?()
 
+  onSurrenderedFocus: =>
+    atom?.workspaceView?.focus()
+
   removeChild: (child) ->
     throw new Error("Removing non-existant child") unless @getRoot() is child
     @setRoot(null)

From 60daa483e6855e08a6af7a324ab671146894dc52 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 18:34:09 -0700
Subject: [PATCH 41/89] Include orientation when serializing PaneAxisModel

---
 src/pane-axis-model.coffee | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index d35e88032..ce6a2b54b 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -34,6 +34,7 @@ class PaneAxisModel extends Model
 
   serializeParams: ->
     children: @children.map (child) -> child.serialize()
+    orientation: @orientation
 
   getViewClass: ->
     if @orientation is 'vertical'

From e87b8dc46392de2665c6e74cba82e89d9960c3cd Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 18:34:50 -0700
Subject: [PATCH 42/89] Remove focusNext/PreviousPane methods from
 PaneContainer view

---
 spec/pane-container-spec.coffee |  2 ++
 src/pane-container.coffee       | 31 ++++---------------------------
 2 files changed, 6 insertions(+), 27 deletions(-)

diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index cd2f7264e..0b60ccf64 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -42,6 +42,8 @@ describe "PaneContainer", ->
   describe ".focusPreviousPane()", ->
     it "focuses the pane preceding the focused pane or the last pane if no pane has focus", ->
       container.attachToDom()
+      pane3.focusout()
+
       container.focusPreviousPane()
       expect(pane3.activeItem).toMatchSelector ':focus'
       container.focusPreviousPane()
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index 8f2d71750..1c39da151 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -1,4 +1,5 @@
 Serializable = require 'serializable'
+Delegator = require 'delegato'
 {$, View} = require './space-pen-extensions'
 Pane = require './pane'
 PaneContainerModel = require './pane-container-model'
@@ -7,6 +8,7 @@ PaneContainerModel = require './pane-container-model'
 module.exports =
 class PaneContainer extends View
   Serializable.includeInto(this)
+  Delegator.includeInto(this)
 
   @deserialize: (state) ->
     new this(PaneContainerModel.deserialize(state.model))
@@ -14,6 +16,8 @@ class PaneContainer extends View
   @content: ->
     @div class: 'panes'
 
+  @delegatesMethods 'focusNextPane', 'focusPreviousPane', toProperty: 'model'
+
   initialize: (params) ->
     if params instanceof PaneContainerModel
       @model = params
@@ -47,33 +51,6 @@ class PaneContainer extends View
 
   ### Public ###
 
-  focusNextPane: ->
-    panes = @getPanes()
-    if panes.length > 1
-      currentIndex = panes.indexOf(@getFocusedPane())
-      nextIndex = (currentIndex + 1) % panes.length
-      panes[nextIndex].focus()
-      true
-    else
-      false
-
-  focusPreviousPane: ->
-    panes = @getPanes()
-    if panes.length > 1
-      currentIndex = panes.indexOf(@getFocusedPane())
-      previousIndex = currentIndex - 1
-      previousIndex = panes.length - 1 if previousIndex < 0
-      panes[previousIndex].focus()
-      true
-    else
-      false
-
-  makeNextPaneActive: ->
-    panes = @getPanes()
-    currentIndex = panes.indexOf(@getActivePane())
-    nextIndex = (currentIndex + 1) % panes.length
-    panes[nextIndex].makeActive()
-
   itemDestroyed: (item) ->
     @trigger 'item-destroyed', item
 

From 5a3353ec2873096864f21d025dd32baef1477b9e Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 18:35:16 -0700
Subject: [PATCH 43/89] Add PaneContainer view to deserializers

---
 src/pane-container.coffee | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index 1c39da151..102281b8c 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -7,6 +7,7 @@ PaneContainerModel = require './pane-container-model'
 # Private: Manages the list of panes within a {WorkspaceView}
 module.exports =
 class PaneContainer extends View
+  atom.deserializers.add(this)
   Serializable.includeInto(this)
   Delegator.includeInto(this)
 

From 9aefafb8318928e28563f2ba652f631628a89310 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Thu, 9 Jan 2014 18:58:01 -0700
Subject: [PATCH 44/89] Use PaneContainerModel::$activePaneItem for
 'active-item-changed' events

Yay behaviors
---
 package.json                    |  2 +-
 src/pane-container-model.coffee |  3 +++
 src/pane-container.coffee       | 19 ++++---------------
 3 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/package.json b/package.json
index 90da3ba15..f440ad28a 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
     "temp": "0.5.0",
     "text-buffer": "0.12.0",
     "underscore-plus": "0.6.1",
-    "theorist": "~0.10.0",
+    "theorist": "~0.11.0",
     "delegato": "~0.4.0",
     "mixto": "~0.4.0"
   },
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index 70834cc7e..fc6154057 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -14,6 +14,9 @@ class PaneContainerModel extends Model
     focusContext: null
     activePane: null
 
+  @behavior 'activePaneItem', ->
+    @$activePane.flatMapLatest (activePane) -> activePane?.$activeItem
+
   constructor: ->
     super
 
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index 102281b8c..0ce46ed38 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -26,27 +26,13 @@ class PaneContainer extends View
       @model = new PaneContainerModel({root: params?.root?.model})
 
     @subscribe @model.$root, 'value', @onRootChanged
+    @subscribe @model.$activePaneItem.changes, 'value', @onActivePaneItemChanged
     @subscribe @model, 'surrendered-focus', @onSurrenderedFocus
 
-    @subscribe this, 'pane:attached', (event, pane) =>
-      @triggerActiveItemChange() if @getActivePane() is pane
-
-    @subscribe this, 'pane:removed', (event, pane) =>
-      @triggerActiveItemChange() unless @getActivePane()?
-
-    @subscribe this, 'pane:became-active', =>
-      @triggerActiveItemChange()
-
-    @subscribe this, 'pane:active-item-changed', (event, item) =>
-      @triggerActiveItemChange() if @getActivePaneItem() is item
-
   viewForModel: (model) ->
     viewClass = model.getViewClass()
     model._view ?= new viewClass(model)
 
-  triggerActiveItemChange: ->
-    @trigger 'pane-container:active-pane-item-changed', [@getActivePaneItem()]
-
   serializeParams: ->
     model: @model.serialize()
 
@@ -68,6 +54,9 @@ class PaneContainer extends View
       @append(view)
       view.makeActive?()
 
+  onActivePaneItemChanged: (activeItem) =>
+    @trigger 'pane-container:active-pane-item-changed', [activeItem]
+
   onSurrenderedFocus: =>
     atom?.workspaceView?.focus()
 

From a0b733b53d0d87dc7ad0d6c778ff4985784bb553 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:20:12 -0700
Subject: [PATCH 45/89] Skip the flexbox-repaint-hack when seeking editor pane
 with ::parents

---
 src/editor-view.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/editor-view.coffee b/src/editor-view.coffee
index eb8d2cfbc..3c1d76490 100644
--- a/src/editor-view.coffee
+++ b/src/editor-view.coffee
@@ -1070,7 +1070,7 @@ class EditorView extends View
   #
   # Returns a {Pane}.
   getPane: ->
-    @parent('.item-views').parent('.pane').view()
+    @parents('.pane').view()
 
   remove: (selector, keepData) ->
     return super if keepData or @removed

From a9d7564f3e3b540864598629d5544f660f8af53b Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:21:10 -0700
Subject: [PATCH 46/89] Account for the .flexbox-repaint-hack in
 WorkspaceView::getEditorViews

---
 src/workspace-view.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/workspace-view.coffee b/src/workspace-view.coffee
index e13dab341..55e37a0b7 100644
--- a/src/workspace-view.coffee
+++ b/src/workspace-view.coffee
@@ -240,7 +240,7 @@ class WorkspaceView extends View
 
   # Private: Returns an Array of  all of the application's {EditorView}s.
   getEditorViews: ->
-    @panes.find('.pane > .item-views > .editor').map(-> $(this).view()).toArray()
+    @panes.find('.pane > .flexbox-repaint-hack > .item-views > .editor').map(-> $(this).view()).toArray()
 
   # Private: Retrieves all of the modified buffers that are open and unsaved.
   #

From c69febd44d757141c5e2139838ac8dc28f68e3a0 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:21:46 -0700
Subject: [PATCH 47/89] Preserve the active pane across serialization

---
 spec/pane-container-model-spec.coffee | 14 +++++++++++++-
 src/pane-model.coffee                 |  2 ++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/spec/pane-container-model-spec.coffee b/spec/pane-container-model-spec.coffee
index 7897387b4..bf249e3f8 100644
--- a/spec/pane-container-model-spec.coffee
+++ b/spec/pane-container-model-spec.coffee
@@ -3,11 +3,15 @@ PaneModel = require '../src/pane-model'
 
 describe "PaneContainerModel", ->
   describe "serialization", ->
-    it "preserves the focused pane across serialization", ->
+    [containerA, pane1A, pane2A, pane3A] = []
+
+    beforeEach ->
       pane1A = new PaneModel
       containerA = new PaneContainerModel(root: pane1A)
       pane2A = pane1A.splitRight()
       pane3A = pane2A.splitDown()
+
+    it "preserves the focused pane across serialization", ->
       expect(pane3A.focused).toBe true
 
       containerB = containerA.testSerialization()
@@ -15,6 +19,14 @@ describe "PaneContainerModel", ->
       expect(pane3B.focusContext).toBe containerB.focusContext
       expect(pane3B.focused).toBe true
 
+    it "preserves the active pane across serialization, independent of focus", ->
+      pane3A.blur()
+      expect(containerA.activePane).toBe pane3A
+
+      containerB = containerA.testSerialization()
+      [pane1B, pane2B, pane3B] = containerB.getPanes()
+      expect(containerB.activePane).toBe pane3B
+
   describe "::activePane", ->
     [container, pane1, pane2] = []
 
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 8fc2e0fa3..f834ec3d5 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -44,11 +44,13 @@ class PaneModel extends Model
     @when @$focused, => @makeActive()
 
     @focus() if params?.focused
+    @makeActive() if params?.active
 
   serializeParams: ->
     items: compact(@items.map((item) -> item.serialize?()))
     activeItemUri: @activeItem?.getUri?()
     focused: @focused
+    active: @active
 
   deserializeParams: (params) ->
     {items, activeItemUri} = params

From 5e1e092650b5cc8875b02bd0a51f721aa0fe4234 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:22:19 -0700
Subject: [PATCH 48/89] When the last pane is destroyed, null out the root and
 active pane

---
 spec/pane-container-model-spec.coffee |  5 +++++
 src/pane-container-model.coffee       | 22 +++++++++++++++++-----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/spec/pane-container-model-spec.coffee b/spec/pane-container-model-spec.coffee
index bf249e3f8..22c0f8668 100644
--- a/spec/pane-container-model-spec.coffee
+++ b/spec/pane-container-model-spec.coffee
@@ -66,6 +66,11 @@ describe "PaneContainerModel", ->
       container = new PaneContainerModel(root: pane)
       container.on 'surrendered-focus', surrenderedFocusHandler = jasmine.createSpy("surrenderedFocusHandler")
 
+    it "assigns null to the root and the activePane", ->
+      pane.destroy()
+      expect(container.root).toBe null
+      expect(container.activePane).toBe null
+
     describe "if the pane is focused", ->
       it "emits a 'surrendered-focus' event", ->
         pane.focus()
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index fc6154057..2e7ebb3bd 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -14,6 +14,8 @@ class PaneContainerModel extends Model
     focusContext: null
     activePane: null
 
+  previousRoot: null
+
   @behavior 'activePaneItem', ->
     @$activePane.flatMapLatest (activePane) -> activePane?.$activeItem
 
@@ -22,11 +24,7 @@ class PaneContainerModel extends Model
 
     @focusContext ?= new FocusContext
 
-    @subscribe @$root, (root) =>
-      if root?
-        root.parent = this
-        root.container = this
-        @activePane ?= root if root instanceof PaneModel
+    @subscribe @$root, @onRootChanged
 
   deserializeParams: (params) ->
     @focusContext ?= params.focusContext ? new FocusContext
@@ -76,3 +74,17 @@ class PaneContainerModel extends Model
       @activePane = panes[nextIndex]
     else
       @activePane = null
+
+  onRootChanged: (root) =>
+    @unsubscribe(@previousRoot) if @previousRoot?
+    @previousRoot = root
+    return unless root?
+
+    root.parent = this
+    root.container = this
+
+    if root instanceof PaneModel
+      @activePane ?= root
+      @subscribe root, 'destroyed', =>
+        @activePane = null
+        @root = null

From 339e30d973c781133d8fba1001ad0a0313a6e386 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:23:58 -0700
Subject: [PATCH 49/89] Account for pane axis class name changes in
 pane-container-spec

---
 spec/workspace-view-spec.coffee | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/spec/workspace-view-spec.coffee b/spec/workspace-view-spec.coffee
index 216466aee..8db9b479a 100644
--- a/spec/workspace-view-spec.coffee
+++ b/spec/workspace-view-spec.coffee
@@ -58,10 +58,10 @@ describe "WorkspaceView", ->
         simulateReload()
 
         expect(atom.workspaceView.getEditorViews().length).toBe 4
-        editor1 = atom.workspaceView.panes.find('.row > .pane .editor:eq(0)').view()
-        editor3 = atom.workspaceView.panes.find('.row > .pane .editor:eq(1)').view()
-        editor2 = atom.workspaceView.panes.find('.row > .column > .pane .editor:eq(0)').view()
-        editor4 = atom.workspaceView.panes.find('.row > .column > .pane .editor:eq(1)').view()
+        editor1 = atom.workspaceView.panes.find('.pane-row > .pane .editor:eq(0)').view()
+        editor3 = atom.workspaceView.panes.find('.pane-row > .pane .editor:eq(1)').view()
+        editor2 = atom.workspaceView.panes.find('.pane-row > .pane-column > .pane .editor:eq(0)').view()
+        editor4 = atom.workspaceView.panes.find('.pane-row > .pane-column > .pane .editor:eq(1)').view()
 
         expect(editor1.getPath()).toBe atom.project.resolve('a')
         expect(editor2.getPath()).toBe atom.project.resolve('b')
@@ -298,14 +298,14 @@ describe "WorkspaceView", ->
           expect(pane2[0]).not.toBe pane1[0]
           expect(editor.getPath()).toBe require.resolve('./fixtures/dir/b')
 
-          expect(atom.workspaceView.panes.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
+          expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
 
           editor = atom.workspaceView.openSync('file1', split: 'right')
           pane3 = atom.workspaceView.getActivePane()
           expect(pane3[0]).toBe pane2[0]
           expect(editor.getPath()).toBe require.resolve('./fixtures/dir/file1')
 
-          expect(atom.workspaceView.panes.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
+          expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
 
   describe ".openSingletonSync(filePath, options)", ->
     describe "when there is an active pane", ->
@@ -320,7 +320,7 @@ describe "WorkspaceView", ->
         expect(pane2[0]).not.toBe pane1[0]
         expect(pane1.itemForUri('b')).toBeFalsy()
         expect(pane2.itemForUri('b')).not.toBeFalsy()
-        expect(atom.workspaceView.panes.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
+        expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
 
         pane1.focus()
         expect(atom.workspaceView.getActivePane()[0]).toBe pane1[0]
@@ -330,7 +330,7 @@ describe "WorkspaceView", ->
         expect(pane3[0]).toBe pane2[0]
         expect(pane1.itemForUri('b')).toBeFalsy()
         expect(pane2.itemForUri('b')).not.toBeFalsy()
-        expect(atom.workspaceView.panes.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
+        expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
 
       it "handles split: left by opening to the left pane when necessary", ->
         atom.workspaceView.openSingletonSync('b', split: 'right')
@@ -344,7 +344,7 @@ describe "WorkspaceView", ->
 
         expect(pane1.itemForUri('file1')).toBeTruthy()
         expect(pane2.itemForUri('file1')).toBeFalsy()
-        expect(atom.workspaceView.panes.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
+        expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
 
         pane2.focus()
         expect(atom.workspaceView.getActivePane()[0]).toBe pane2[0]
@@ -352,7 +352,7 @@ describe "WorkspaceView", ->
         atom.workspaceView.openSingletonSync('file1', split: 'left')
         activePane = atom.workspaceView.getActivePane()
         expect(activePane[0]).toBe pane1[0]
-        expect(atom.workspaceView.panes.find('.row .pane').toArray()).toEqual [pane1[0], pane2[0]]
+        expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
 
       it "reuses the file when already open", ->
         atom.workspaceView.openSync('b')

From edfc86f1533216b279deaa4b9ec27a1348a106d9 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:34:26 -0700
Subject: [PATCH 50/89] Make PaneContainer::getActivePaneItem retrieve it from
 the model

---
 src/pane-container.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index 7602057b6..c2d67f244 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -99,7 +99,7 @@ class PaneContainer extends View
     @find('.pane.active').view() ? @find('.pane:first').view()
 
   getActivePaneItem: ->
-    @getActivePane()?.activeItem
+    @model.activePaneItem
 
   getActiveView: ->
     @getActivePane()?.activeView

From 732d36af2872a64d47ca1e148e226fb77780cb91 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:37:42 -0700
Subject: [PATCH 51/89] Null guard container in Pane::makeActive

Panes can exist outside of containers, albeit only briefly. If
::makeActive is called when the pane is in this state, consider it a
no-op.
---
 src/pane-model.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index f834ec3d5..4b0e518b2 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -62,7 +62,7 @@ class PaneModel extends Model
 
   isActive: -> @active
 
-  makeActive: -> @container.activePane = this
+  makeActive: -> @container?.activePane = this
 
   getPanes: -> [this]
 

From d2146f9b2ec4b295006c963592b2bb40c4bae4cc Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:45:08 -0700
Subject: [PATCH 52/89] Emit 'pane:removed' event in container when last pane
 is removed

Doing it in the pane view is awkward because the view may have already
been detached.
---
 src/pane-container.coffee | 4 +++-
 src/pane.coffee           | 3 ---
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index c2d67f244..eb9297e04 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -48,7 +48,9 @@ class PaneContainer extends View
     @model.root = root?.model
 
   onRootChanged: (root) =>
-    @children().detach()
+    oldRoot = @getRoot()
+    @trigger 'pane:removed', [oldRoot] if @getRoot() instanceof Pane
+    oldRoot?.detach()
     if root?
       view = @viewForModel(root)
       @append(view)
diff --git a/src/pane.coffee b/src/pane.coffee
index 3d968e742..cc8173554 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -206,9 +206,6 @@ class Pane extends View
   getContainer: ->
     @closest('.panes').view()
 
-  beforeRemove: ->
-    @trigger 'pane:removed', [this]
-
   # Private:
   remove: (selector, keepData) ->
     return super if keepData

From d34327a6670ca3e4288573fce6baa1f3dfe9c525 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 11:56:19 -0700
Subject: [PATCH 53/89] Remove the EditorView when Editor is destroyed

---
 spec/editor-view-spec.coffee | 2 +-
 src/editor-view.coffee       | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/spec/editor-view-spec.coffee b/spec/editor-view-spec.coffee
index 96d10e98c..2f428dddd 100644
--- a/spec/editor-view-spec.coffee
+++ b/spec/editor-view-spec.coffee
@@ -2809,7 +2809,7 @@ describe "EditorView", ->
       atom.workspaceView.attachToDom()
       editorView = atom.workspaceView.getActiveView()
 
-      willBeRemovedHandler = jasmine.createSpy('fileChange')
+      willBeRemovedHandler = jasmine.createSpy('willBeRemovedHandler')
       editorView.on 'editor:will-be-removed', willBeRemovedHandler
       editorView.getPane().destroyActiveItem()
       expect(willBeRemovedHandler).toHaveBeenCalled()
diff --git a/src/editor-view.coffee b/src/editor-view.coffee
index 3c1d76490..770c7895f 100644
--- a/src/editor-view.coffee
+++ b/src/editor-view.coffee
@@ -827,6 +827,9 @@ class EditorView extends View
 
     @editor.setVisible(true)
 
+    @editor.on "destroyed", =>
+      @remove()
+
     @editor.on "contents-conflicted.editor", =>
       @showBufferConflictAlert(@editor)
 

From 720b2ad47da964f80017d6ff12a8354cb4e6cc8b Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 12:11:19 -0700
Subject: [PATCH 54/89] Upgrade to serializable 0.3.0 to handle undefined
 states

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index d3b8ef04e..9d67bd7d2 100644
--- a/package.json
+++ b/package.json
@@ -36,7 +36,7 @@
     "mkdirp": "0.3.5",
     "keytar": "0.13.0",
     "less-cache": "0.10.0",
-    "serializable": "0.1.0",
+    "serializable": "0.3.0",
     "nslog": "0.1.0",
     "oniguruma": "0.24.0",
     "optimist": "0.4.0",

From 4b0d22917b60a4ef0fdb3939ca6acb3ee488092c Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 12:12:44 -0700
Subject: [PATCH 55/89] Trust CSS to perform layout now that we've switched to
 flexbox

The behavior of flexbox is actually slightly different in that it
divides space evenly among the immediate children of a row or column
rather than accounting for all splits. But it's actually not that big
a deal.
---
 spec/pane-spec.coffee | 69 -------------------------------------------
 1 file changed, 69 deletions(-)

diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index 00364ac77..d032ce92c 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -601,75 +601,6 @@ describe "Pane", ->
         expect(pane3.getItems()).toEqual [view3, view4]
         expect(container.find('.pane-column .pane').toArray()).toEqual [pane3[0], pane2[0], pane[0]]
 
-    it "lays out nested panes by equally dividing their containing row / column", ->
-      container.width(520).height(240).attachToDom()
-      pane1.showItem($("1"))
-      pane1
-        .splitLeft($("2"))
-        .splitUp($("3"))
-        .splitLeft($("4"))
-        .splitDown($("5"))
-
-      row1 = container.children(':eq(0)')
-      expect(row1.children().length).toBe 2
-      column1 = row1.children(':eq(0)').view()
-      pane1 = row1.children(':eq(1)').view()
-      expect(column1.outerWidth()).toBe Math.round(2/3 * container.width())
-      expect(column1.outerHeight()).toBe container.height()
-      expect(pane1.outerWidth()).toBe Math.round(1/3 * container.width())
-      expect(pane1.outerHeight()).toBe container.height()
-      expect(Math.round(pane1.position().left)).toBe column1.outerWidth()
-
-      expect(column1.children().length).toBe 2
-      row2 = column1.children(':eq(0)').view()
-      pane2 = column1.children(':eq(1)').view()
-      expect(row2.outerWidth()).toBe column1.outerWidth()
-      expect(row2.height()).toBe 2/3 * container.height()
-      expect(pane2.outerWidth()).toBe column1.outerWidth()
-      expect(pane2.outerHeight()).toBe 1/3 * container.height()
-      expect(Math.round(pane2.position().top)).toBe row2.height()
-
-      expect(row2.children().length).toBe 2
-      column3 = row2.children(':eq(0)').view()
-      pane3 = row2.children(':eq(1)').view()
-      expect(column3.outerWidth()).toBe Math.round(1/3 * container.width())
-      expect(column3.outerHeight()).toBe row2.outerHeight()
-      # the built in rounding seems to be rounding x.5 down, but we need to go up. this sucks.
-      expect(Math.round(pane3.trueWidth())).toBe Math.round(1/3 * container.width())
-      expect(pane3.height()).toBe row2.outerHeight()
-      expect(Math.round(pane3.position().left)).toBe column3.width()
-
-      expect(column3.children().length).toBe 2
-      pane4 = column3.children(':eq(0)').view()
-      pane5 = column3.children(':eq(1)').view()
-      expect(pane4.outerWidth()).toBe column3.width()
-      expect(pane4.outerHeight()).toBe 1/3 * container.height()
-      expect(pane5.outerWidth()).toBe column3.width()
-      expect(Math.round(pane5.position().top)).toBe pane4.outerHeight()
-      expect(pane5.outerHeight()).toBe 1/3 * container.height()
-
-      pane5.remove()
-      expect(column3.parent()).not.toExist()
-      expect(pane2.outerHeight()).toBe Math.floor(1/2 * container.height())
-      expect(pane3.outerHeight()).toBe Math.floor(1/2 * container.height())
-      expect(pane4.outerHeight()).toBe Math.floor(1/2 * container.height())
-
-      pane4.remove()
-      expect(row2.parent()).not.toExist()
-      expect(pane1.outerWidth()).toBe Math.floor(1/2 * container.width())
-      expect(pane2.outerWidth()).toBe Math.floor(1/2 * container.width())
-      expect(pane3.outerWidth()).toBe Math.floor(1/2 * container.width())
-
-      pane3.remove()
-      expect(column1.parent()).not.toExist()
-      expect(pane2.outerHeight()).toBe container.height()
-
-      pane2.remove()
-      expect(row1.parent()).not.toExist()
-      expect(container.children().length).toBe 1
-      expect(container.children('.pane').length).toBe 1
-      expect(pane1.outerWidth()).toBe container.width()
-
   describe "::itemForUri(uri)", ->
     it "returns the item for which a call to .getUri() returns the given uri", ->
       expect(pane.itemForUri(editor1.getUri())).toBe editor1

From 7665cd1a6afbad635270dba73c115e7663be71e9 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 12:35:12 -0700
Subject: [PATCH 56/89] When a pane view is removed in anyway, make sure its
 model is destroyed

---
 src/pane.coffee | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/pane.coffee b/src/pane.coffee
index cc8173554..88fac9c61 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -206,9 +206,11 @@ class Pane extends View
   getContainer: ->
     @closest('.panes').view()
 
+  beforeRemove: ->
+    @model.destroy() unless @model.isDestroyed()
+
   # Private:
   remove: (selector, keepData) ->
     return super if keepData
     @unsubscribe()
-    @model.destroy() unless @model.isDestroyed()
     super

From 104271861c57a6bb562067bb968d2e877cfe28a4 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 13:07:39 -0700
Subject: [PATCH 57/89] Upgrade markdown-preview to 0.24.0 for
 .flexbox-repaint-hack fix

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 9d67bd7d2..821a0ef0b 100644
--- a/package.json
+++ b/package.json
@@ -84,7 +84,7 @@
     "grammar-selector": "0.16.0",
     "image-view": "0.14.0",
     "keybinding-resolver": "0.8.0",
-    "markdown-preview": "0.23.0",
+    "markdown-preview": "0.24.0",
     "metrics": "0.20.0",
     "package-generator": "0.23.0",
     "release-notes": "0.15.0",

From 7801d8562f7a00aa39b6b0d13568458380302ec2 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 13:08:47 -0700
Subject: [PATCH 58/89] Upgrade archive-view to 0.19.0 for
 .flexbox-repaint-hack fix

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 821a0ef0b..e0754a2af 100644
--- a/package.json
+++ b/package.json
@@ -62,7 +62,7 @@
     "base16-tomorrow-dark-theme": "0.8.0",
     "solarized-dark-syntax": "0.6.0",
     "solarized-light-syntax": "0.2.0",
-    "archive-view": "0.18.0",
+    "archive-view": "0.19.0",
     "autocomplete": "0.19.0",
     "autoflow": "0.11.0",
     "autosave": "0.10.0",

From 47870a1214075cc378db50e20a8064dd9372ad96 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 13:35:18 -0700
Subject: [PATCH 59/89] Remove views (rather than detaching) if
 Pane::destroyItem is called

---
 spec/pane-spec.coffee |  5 +++++
 src/pane-model.coffee |  8 ++++++--
 src/pane.coffee       | 11 +++++++----
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index d032ce92c..204730aee 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -196,6 +196,11 @@ describe "Pane", ->
           expect(pane.getItems().indexOf(editor2)).not.toBe -1
           expect(editor2.isDestroyed()).toBe false
 
+    it "removes the item's associated view", ->
+      view1.remove = (selector, keepData) -> @wasRemoved = not keepData
+      pane.destroyItem(view1)
+      expect(view1.wasRemoved).toBe true
+
   describe "::removeItem(item)", ->
     it "removes the item from the items list and shows the next item if it was showing", ->
       pane.removeItem(view1)
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 4b0e518b2..840924baf 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -22,6 +22,8 @@ class PaneModel extends Model
       .map((activePane) => activePane is this)
       .distinctUntilChanged()
 
+  destroyingItem: false
+
   constructor: (params) ->
     super
 
@@ -37,7 +39,7 @@ class PaneModel extends Model
 
     @subscribe @items.onRemoval (item, index) =>
       @unsubscribe item if typeof item.on is 'function'
-      @emit 'item-removed', item, index
+      @emit 'item-removed', item, index, @destroyingItem
 
     @when @items.$length.becomesLessThan(1), 'destroy'
 
@@ -145,7 +147,9 @@ class PaneModel extends Model
     @emit 'before-item-destroyed', item
     if @promptToSaveItem(item)
       @emit 'item-destroyed', item
-      @removeItem(item, options)
+      @destroyingItem = true
+      @removeItem(item)
+      @destroyingItem = false
       item.destroy?()
       true
     else
diff --git a/src/pane.coffee b/src/pane.coffee
index 88fac9c61..dcee94658 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -149,8 +149,8 @@ class Pane extends View
   onItemAdded: (item, index) =>
     @trigger 'pane:item-added', [item, index]
 
-  onItemRemoved: (item, index) =>
-    @cleanupItemView(item)
+  onItemRemoved: (item, index, destroyed) =>
+    @cleanupItemView(item, destroyed)
     @trigger 'pane:item-removed', [item, index]
 
   onItemMoved: (item, newIndex) =>
@@ -168,7 +168,7 @@ class Pane extends View
     @trigger 'pane:active-item-title-changed'
 
   # Private:
-  cleanupItemView: (item) ->
+  cleanupItemView: (item, destroyed) ->
     if item instanceof $
       viewToRemove = item
     else if viewToRemove = @viewsByItem.get(item)
@@ -176,7 +176,10 @@ class Pane extends View
 
     if viewToRemove?
       viewToRemove.setModel?(null)
-      viewToRemove.detach()
+      if destroyed
+        viewToRemove.remove()
+      else
+        viewToRemove.detach()
 
   # Private:
   viewForItem: (item) ->

From 1ee783fdb9fa1ff3d19775b89e1b8e21b6688a1a Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 13:44:02 -0700
Subject: [PATCH 60/89] Base PaneContainer::getActivePane on the model's active
 pane

---
 src/pane-container.coffee | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index eb9297e04..c5371afd0 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -30,8 +30,9 @@ class PaneContainer extends View
     @subscribe @model, 'surrendered-focus', @onSurrenderedFocus
 
   viewForModel: (model) ->
-    viewClass = model.getViewClass()
-    model._view ?= new viewClass(model)
+    if model?
+      viewClass = model.getViewClass()
+      model._view ?= new viewClass(model)
 
   serializeParams: ->
     model: @model.serialize()
@@ -98,7 +99,7 @@ class PaneContainer extends View
     @find('.pane:has(:focus)').view()
 
   getActivePane: ->
-    @find('.pane.active').view() ? @find('.pane:first').view()
+    @viewForModel(@model.activePane)
 
   getActivePaneItem: ->
     @model.activePaneItem

From 284d823ad5cc75983246edab6496548ce893b4d9 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 14:36:07 -0700
Subject: [PATCH 61/89] Tighten up search for parent pane

The introduction of the .flexbox-redraw-hack required the query to be
loosened, but I went too far. We don't want to return a pane for mini
editors that happen to be nested on another view that's inside a pane.
---
 src/editor-view.coffee | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/editor-view.coffee b/src/editor-view.coffee
index 770c7895f..9ae326c54 100644
--- a/src/editor-view.coffee
+++ b/src/editor-view.coffee
@@ -1073,7 +1073,7 @@ class EditorView extends View
   #
   # Returns a {Pane}.
   getPane: ->
-    @parents('.pane').view()
+    @parent('.item-views').parents('.pane').view()
 
   remove: (selector, keepData) ->
     return super if keepData or @removed

From c7fded0d7f367be8b0884ba39c7bae69d4651d5f Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 15:04:51 -0700
Subject: [PATCH 62/89] Only emit 'pane:removed' events if the pane is actually
 destroyed

The pane may only be detached temporarily during splitting/unsplitting
---
 src/pane-axis.coffee      | 4 +++-
 src/pane-container.coffee | 3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/pane-axis.coffee b/src/pane-axis.coffee
index bdee142ad..5d535da4a 100644
--- a/src/pane-axis.coffee
+++ b/src/pane-axis.coffee
@@ -30,7 +30,9 @@ class PaneAxis extends View
     view = @viewForModel(child)
     view.detach()
     Pane ?= require './pane'
-    @getContainer()?.trigger 'pane:removed', [view] if view instanceof Pane
+
+    if view instanceof Pane and view.model.isDestroyed()
+      @getContainer()?.trigger 'pane:removed', [view]
 
   getContainer: ->
     @closest('.panes').view()
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index c5371afd0..bf7c1657d 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -50,7 +50,8 @@ class PaneContainer extends View
 
   onRootChanged: (root) =>
     oldRoot = @getRoot()
-    @trigger 'pane:removed', [oldRoot] if @getRoot() instanceof Pane
+    if oldRoot instanceof Pane and oldRoot.model.isDestroyed()
+      @trigger 'pane:removed', [oldRoot]
     oldRoot?.detach()
     if root?
       view = @viewForModel(root)

From 23e805fe9e2fbf0bb42d8706a3a81100bf961959 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 15:28:17 -0700
Subject: [PATCH 63/89] Remove assertion for impossible situation

We were testing the behavior of returning the active pane by removing
the active class from its view. But "active" is a model-level concept
now, so this assertion makes no sense.
---
 spec/pane-container-spec.coffee | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index 0b60ccf64..efd43f262 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -71,10 +71,6 @@ describe "PaneContainer", ->
       expect(container.getFocusedPane()).toBe pane3
       expect(container.getActivePane()).toBe pane3
 
-      # returns the first pane if none have been set to active
-      container.find('.pane.active').removeClass('active')
-      expect(container.getActivePane()).toBe pane1
-
   describe ".eachPane(callback)", ->
     it "runs the callback with all current and future panes until the subscription is cancelled", ->
       panes = []

From 9694d255f0819711425b8d207962e3a05bbc1430 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 15:48:08 -0700
Subject: [PATCH 64/89] Simplify item removal

- Move emitting of item removal event into ::removeItemAtIndex. Pass a
destroying param instead of setting state.

- Destroy the pane if ::items is empty at the in the item removal
method, rather than with a condition. This gives the item removal event
a chance to fire first.
---
 src/pane-model.coffee | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 840924baf..db25259e1 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -22,8 +22,6 @@ class PaneModel extends Model
       .map((activePane) => activePane is this)
       .distinctUntilChanged()
 
-  destroyingItem: false
-
   constructor: (params) ->
     super
 
@@ -39,9 +37,6 @@ class PaneModel extends Model
 
     @subscribe @items.onRemoval (item, index) =>
       @unsubscribe item if typeof item.on is 'function'
-      @emit 'item-removed', item, index, @destroyingItem
-
-    @when @items.$length.becomesLessThan(1), 'destroy'
 
     @when @$focused, => @makeActive()
 
@@ -115,15 +110,17 @@ class PaneModel extends Model
     item
 
   # Public:
-  removeItem: (item) ->
+  removeItem: (item, destroying) ->
     index = @items.indexOf(item)
-    @removeItemAtIndex(index) if index >= 0
+    @removeItemAtIndex(index, destroying) if index >= 0
 
   # Public: Just remove the item at the given index.
-  removeItemAtIndex: (index) ->
+  removeItemAtIndex: (index, destroying) ->
     item = @items[index]
     @showNextItem() if item is @activeItem and @items.length > 1
-    @suppressBlur => @items.splice(index, 1)
+    @items.splice(index, 1)
+    @suppressBlur => @emit 'item-removed', item, index, destroying
+    @destroy() if @items.length is 0
 
   # Public: Moves the given item to a the new index.
   moveItem: (item, newIndex) ->
@@ -147,9 +144,7 @@ class PaneModel extends Model
     @emit 'before-item-destroyed', item
     if @promptToSaveItem(item)
       @emit 'item-destroyed', item
-      @destroyingItem = true
-      @removeItem(item)
-      @destroyingItem = false
+      @removeItem(item, true)
       item.destroy?()
       true
     else

From c127237cc677ba421fd169c8e401b6a5fc73c450 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 15:49:07 -0700
Subject: [PATCH 65/89] Upgrade tabs to 0.17.0 so they unsubscribe when the
 pane is removed

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index e0754a2af..4de193c38 100644
--- a/package.json
+++ b/package.json
@@ -94,7 +94,7 @@
     "status-bar": "0.30.0",
     "styleguide": "0.19.0",
     "symbols-view": "0.27.0",
-    "tabs": "0.16.0",
+    "tabs": "0.17.0",
     "terminal": "0.23.0",
     "timecop": "0.12.0",
     "to-the-hubs": "0.17.0",

From ddf7c04e66edcc9f780635493aa0b85b083600fc Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 15:51:27 -0700
Subject: [PATCH 66/89] Use -> arrows on methods moved to the model

---
 src/pane-model.coffee | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index db25259e1..e29dd405d 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -72,7 +72,7 @@ class PaneModel extends Model
     @items[index]
 
   # Public: Switches to the next contained item.
-  showNextItem: =>
+  showNextItem: ->
     index = @getActiveItemIndex()
     if index < @items.length - 1
       @showItemAtIndex(index + 1)
@@ -80,7 +80,7 @@ class PaneModel extends Model
       @showItemAtIndex(0)
 
   # Public: Switches to the previous contained item.
-  showPreviousItem: =>
+  showPreviousItem: ->
     index = @getActiveItemIndex()
     if index > 0
       @showItemAtIndex(index - 1)
@@ -182,11 +182,11 @@ class PaneModel extends Model
       when 2 then true
 
   # Public: Saves the currently focused item.
-  saveActiveItem: =>
+  saveActiveItem: ->
     @saveItem(@activeItem)
 
   # Public: Save and prompt for path for the currently focused item.
-  saveActiveItemAs: =>
+  saveActiveItemAs: ->
     @saveItemAs(@activeItem)
 
   # Public: Saves the specified item and call the next action when complete.
@@ -210,7 +210,7 @@ class PaneModel extends Model
       nextAction?()
 
   # Public: Saves all items in this pane.
-  saveItems: =>
+  saveItems: ->
     @saveItem(item) for item in @getItems()
 
   # Public: Finds the first item that matches the given uri.

From 72fe5861018d1ef9ef9162c549f0e9565beec42f Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 17:25:30 -0700
Subject: [PATCH 67/89] Remove the concept of focus from the model

---
 spec/focusable-spec.coffee            | 36 -------------------
 spec/pane-container-model-spec.coffee | 26 ++++----------
 spec/pane-container-spec.coffee       |  2 +-
 spec/pane-model-spec.coffee           | 26 +-------------
 src/focus-context.coffee              | 15 --------
 src/focusable.coffee                  | 28 ---------------
 src/pane-axis-model.coffee            |  5 +--
 src/pane-axis.coffee                  | 12 ++++---
 src/pane-container-model.coffee       | 36 +++----------------
 src/pane-container.coffee             | 32 +++++++++++++----
 src/pane-model.coffee                 | 27 +++++++--------
 src/pane.coffee                       | 50 ++++++++++++---------------
 src/space-pen-extensions.coffee       |  3 ++
 13 files changed, 85 insertions(+), 213 deletions(-)
 delete mode 100644 spec/focusable-spec.coffee
 delete mode 100644 src/focus-context.coffee
 delete mode 100644 src/focusable.coffee

diff --git a/spec/focusable-spec.coffee b/spec/focusable-spec.coffee
deleted file mode 100644
index 0cb26b908..000000000
--- a/spec/focusable-spec.coffee
+++ /dev/null
@@ -1,36 +0,0 @@
-{Model} = require 'theorist'
-Focusable = require '../src/focusable'
-FocusContext = require '../src/focus-context'
-
-describe "Focusable mixin", ->
-  it "ensures that only a single model is focused for a given focus manager", ->
-    class Item extends Model
-      Focusable.includeInto(this)
-
-    focusContext = new FocusContext
-    item1 = new Item({focusContext})
-    item2 = new Item({focusContext})
-    item3 = new Item({focusContext})
-
-    expect(focusContext.focusedObject).toBe null
-    expect(item1.focused).toBe false
-    expect(item2.focused).toBe false
-    expect(item3.focused).toBe false
-
-    item1.focus()
-    expect(focusContext.focusedObject).toBe item1
-    expect(item1.focused).toBe true
-    expect(item2.focused).toBe false
-    expect(item3.focused).toBe false
-
-    item2.focus()
-    expect(focusContext.focusedObject).toBe item2
-    expect(item1.focused).toBe false
-    expect(item2.focused).toBe true
-    expect(item3.focused).toBe false
-
-    item2.blur()
-    expect(focusContext.focusedObject).toBe null
-    expect(item1.focused).toBe false
-    expect(item2.focused).toBe false
-    expect(item3.focused).toBe false
diff --git a/spec/pane-container-model-spec.coffee b/spec/pane-container-model-spec.coffee
index 22c0f8668..dd6e14e60 100644
--- a/spec/pane-container-model-spec.coffee
+++ b/spec/pane-container-model-spec.coffee
@@ -16,11 +16,10 @@ describe "PaneContainerModel", ->
 
       containerB = containerA.testSerialization()
       [pane1B, pane2B, pane3B] = containerB.getPanes()
-      expect(pane3B.focusContext).toBe containerB.focusContext
       expect(pane3B.focused).toBe true
 
     it "preserves the active pane across serialization, independent of focus", ->
-      pane3A.blur()
+      pane3A.makeActive()
       expect(containerA.activePane).toBe pane3A
 
       containerB = containerA.testSerialization()
@@ -34,30 +33,30 @@ describe "PaneContainerModel", ->
       pane1 = new PaneModel
       container = new PaneContainerModel(root: pane1)
 
-    it "references the first pane if no pane has been focused", ->
+    it "references the first pane if no pane has been made active", ->
       expect(container.activePane).toBe pane1
       expect(pane1.active).toBe true
 
-    it "references the most recently focused pane", ->
+    it "references the most pane on which ::makeActive was most recently called", ->
       pane2 = pane1.splitRight()
+      pane2.makeActive()
       expect(container.activePane).toBe pane2
       expect(pane1.active).toBe false
       expect(pane2.active).toBe true
-      pane1.focus()
+      pane1.makeActive()
       expect(container.activePane).toBe pane1
       expect(pane1.active).toBe true
       expect(pane2.active).toBe false
 
-    it "is reassigned to the next pane if the current active pane is unfocused and destroyed", ->
+    it "is reassigned to the next pane if the current active pane is destroyed", ->
       pane2 = pane1.splitRight()
-      pane2.blur()
+      pane2.makeActive()
       pane2.destroy()
       expect(container.activePane).toBe pane1
       expect(pane1.active).toBe true
       pane1.destroy()
       expect(container.activePane).toBe null
 
-  # TODO: Remove this behavior when we have a proper workspace model we can explicitly focus
   describe "when the last pane is removed", ->
     [container, pane, surrenderedFocusHandler] = []
 
@@ -70,14 +69,3 @@ describe "PaneContainerModel", ->
       pane.destroy()
       expect(container.root).toBe null
       expect(container.activePane).toBe null
-
-    describe "if the pane is focused", ->
-      it "emits a 'surrendered-focus' event", ->
-        pane.focus()
-        pane.destroy()
-        expect(surrenderedFocusHandler).toHaveBeenCalled()
-
-    describe "if the pane is not focused", ->
-      it "does not emit an event", ->
-        expect(pane.focused).toBe false
-        expect(surrenderedFocusHandler).not.toHaveBeenCalled()
diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index efd43f262..2dd46707f 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -42,7 +42,7 @@ describe "PaneContainer", ->
   describe ".focusPreviousPane()", ->
     it "focuses the pane preceding the focused pane or the last pane if no pane has focus", ->
       container.attachToDom()
-      pane3.focusout()
+      $(document.body).focus() # clear focus
 
       container.focusPreviousPane()
       expect(pane3.activeItem).toMatchSelector ':focus'
diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index f17b141c9..77f1db022 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -2,7 +2,6 @@
 PaneModel = require '../src/pane-model'
 PaneAxisModel = require '../src/pane-axis-model'
 PaneContainerModel = require '../src/pane-container-model'
-FocusContext = require '../src/focus-context'
 
 describe "PaneModel", ->
   describe "split methods", ->
@@ -80,25 +79,12 @@ describe "PaneModel", ->
           expect(column.orientation).toBe 'vertical'
           expect(column.children).toEqual [pane1, pane3, pane2]
 
-    it "focuses the new pane, even if the current pane isn't focused", ->
+    it "sets up the new pane to be focused", ->
       expect(pane1.focused).toBe false
       pane2 = pane1.splitRight()
       expect(pane2.focused).toBe true
 
   describe "::removeItemAtIndex(index)", ->
-    describe "when the removal of the item causes blur to be called on the pane model", ->
-      it "remains focused if it was before the item was removed", ->
-        pane = new PaneModel(items: ["A", "B", "C"])
-        container = new PaneContainerModel(root: pane)
-        pane.on 'item-removed', -> pane.blur()
-        pane.focus()
-        pane.removeItemAtIndex(0)
-        expect(pane.focused).toBe true
-
-        pane.blur()
-        pane.removeItemAtIndex(0)
-        expect(pane.focused).toBe false
-
     describe "when the last item is removed", ->
       it "destroys the pane", ->
         pane = new PaneModel(items: ["A", "B"])
@@ -146,13 +132,3 @@ describe "PaneModel", ->
         expect(container.root.children).toEqual [pane1, pane2]
         pane2.destroy()
         expect(container.root).toBe pane1
-
-    describe "if the pane is focused", ->
-      it "shifts focus to the next pane", ->
-        pane2 = pane1.splitRight()
-        pane3 = pane2.splitRight()
-        pane2.focus()
-        expect(pane2.focused).toBe true
-        expect(pane3.focused).toBe false
-        pane2.destroy()
-        expect(pane3.focused).toBe true
diff --git a/src/focus-context.coffee b/src/focus-context.coffee
deleted file mode 100644
index c17514471..000000000
--- a/src/focus-context.coffee
+++ /dev/null
@@ -1,15 +0,0 @@
-{Model} = require 'theorist'
-
-module.exports =
-class FocusContext extends Model
-  @property 'focusedObject', null
-
-  blurSuppressionCounter: 0
-
-  isBlurSuppressed: ->
-    @blurSuppressionCounter > 0
-
-  suppressBlur: (fn) ->
-    @blurSuppressionCounter++
-    fn()
-    @blurSuppressionCounter--
diff --git a/src/focusable.coffee b/src/focusable.coffee
deleted file mode 100644
index c046e7cd2..000000000
--- a/src/focusable.coffee
+++ /dev/null
@@ -1,28 +0,0 @@
-Mixin = require 'mixto'
-
-module.exports =
-class Focusable extends Mixin
-  @included: ->
-    @property 'focusContext'
-    @behavior 'focused', ->
-      @$focusContext
-        .flatMapLatest((context) -> context?.$focusedObject)
-        .map((focusedObject) => focusedObject is this)
-        .distinctUntilChanged()
-
-  focus: ->
-    throw new Error("Object must be assigned a focusContext to be focus") unless @focusContext
-    unless @focused
-      @suppressBlur =>
-        @focusContext.focusedObject = this
-
-  blur: ->
-    throw new Error("Object must be assigned a focusContext to be blurred") unless @focusContext
-    if @focused and not @focusContext.isBlurSuppressed()
-      @focusContext.focusedObject = null
-
-  suppressBlur: (fn) ->
-    if @focusContext?
-      @focusContext.suppressBlur(fn)
-    else
-      fn()
diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index ce6a2b54b..f019856e6 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -12,8 +12,6 @@ class PaneAxisModel extends Model
   Serializable.includeInto(this)
   Delegator.includeInto(this)
 
-  @delegatesProperty 'focusContext', toProperty: 'container'
-
   constructor: ({@container, @orientation, children}) ->
     @children = Sequence.fromArray(children ? [])
 
@@ -67,5 +65,4 @@ class PaneAxisModel extends Model
     @children.splice(index + 1, 0, newChild)
 
   reparentLastChild: ->
-    @focusContext.suppressBlur =>
-      @parent.replaceChild(this, @children[0])
+    @parent.replaceChild(this, @children[0])
diff --git a/src/pane-axis.coffee b/src/pane-axis.coffee
index 5d535da4a..79ed2cfb1 100644
--- a/src/pane-axis.coffee
+++ b/src/pane-axis.coffee
@@ -7,10 +7,8 @@ Pane = null
 module.exports =
 class PaneAxis extends View
   initialize: (@model) ->
-    @subscribe @model.children.onRemoval @onChildRemoved
-    @subscribe @model.children.onEach @onChildAdded
-
-    @onChildAdded(child) for child in children ? []
+    @onChildAdded(child) for child in @model.children
+    @subscribe @model.children, 'changed', @onChildrenChanged
 
   viewForModel: (model) ->
     viewClass = model.getViewClass()
@@ -22,6 +20,12 @@ class PaneAxis extends View
   removeChild: (child) ->
     @model.removeChild(child.model)
 
+  onChildrenChanged:  ({index, removedValues, insertedValues}) =>
+    focusedElement = document.activeElement if @hasFocus()
+    @onChildRemoved(child, index) for child in removedValues
+    @onChildAdded(child, index + i) for child, i in insertedValues
+    focusedElement?.focus() if document.activeElement is document.body
+
   onChildAdded: (child, index) =>
     view = @viewForModel(child)
     @insertAt(index, view)
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index 2e7ebb3bd..b32f28135 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -1,7 +1,6 @@
 {Model} = require 'theorist'
 Serializable = require 'serializable'
 {find} = require 'underscore-plus'
-FocusContext = require './focus-context'
 PaneModel = require './pane-model'
 
 module.exports =
@@ -11,7 +10,6 @@ class PaneContainerModel extends Model
 
   @properties
     root: null
-    focusContext: null
     activePane: null
 
   previousRoot: null
@@ -21,13 +19,9 @@ class PaneContainerModel extends Model
 
   constructor: ->
     super
-
-    @focusContext ?= new FocusContext
-
     @subscribe @$root, @onRootChanged
 
   deserializeParams: (params) ->
-    @focusContext ?= params.focusContext ? new FocusContext
     params.root = atom.deserializers.deserialize(params.root, container: this)
     params
 
@@ -41,31 +35,6 @@ class PaneContainerModel extends Model
   getPanes: ->
     @root?.getPanes() ? []
 
-  getFocusedPane: ->
-    find @getPanes(), (pane) -> pane.focused
-
-  focusNextPane: ->
-    panes = @getPanes()
-    if panes.length > 1
-      currentIndex = panes.indexOf(@getFocusedPane())
-      nextIndex = (currentIndex + 1) % panes.length
-      panes[nextIndex].focus()
-      true
-    else
-      @emit 'surrendered-focus'
-      false
-
-  focusPreviousPane: ->
-    panes = @getPanes()
-    if panes.length > 1
-      currentIndex = panes.indexOf(@getFocusedPane())
-      previousIndex = currentIndex - 1
-      previousIndex = panes.length - 1 if previousIndex < 0
-      panes[previousIndex].focus()
-      true
-    else
-      false
-
   makeNextPaneActive: ->
     panes = @getPanes()
     if panes.length > 1
@@ -78,7 +47,10 @@ class PaneContainerModel extends Model
   onRootChanged: (root) =>
     @unsubscribe(@previousRoot) if @previousRoot?
     @previousRoot = root
-    return unless root?
+
+    unless root?
+      @activePane = null
+      return
 
     root.parent = this
     root.container = this
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index bf7c1657d..eeb54f74b 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -17,8 +17,6 @@ class PaneContainer extends View
   @content: ->
     @div class: 'panes'
 
-  @delegatesMethods 'focusNextPane', 'focusPreviousPane', toProperty: 'model'
-
   initialize: (params) ->
     if params instanceof PaneContainerModel
       @model = params
@@ -27,7 +25,6 @@ class PaneContainer extends View
 
     @subscribe @model.$root, 'value', @onRootChanged
     @subscribe @model.$activePaneItem.changes, 'value', @onActivePaneItemChanged
-    @subscribe @model, 'surrendered-focus', @onSurrenderedFocus
 
   viewForModel: (model) ->
     if model?
@@ -49,6 +46,8 @@ class PaneContainer extends View
     @model.root = root?.model
 
   onRootChanged: (root) =>
+    focusedElement = document.activeElement if @hasFocus()
+
     oldRoot = @getRoot()
     if oldRoot instanceof Pane and oldRoot.model.isDestroyed()
       @trigger 'pane:removed', [oldRoot]
@@ -56,14 +55,11 @@ class PaneContainer extends View
     if root?
       view = @viewForModel(root)
       @append(view)
-      view.makeActive?()
+      focusedElement?.focus()
 
   onActivePaneItemChanged: (activeItem) =>
     @trigger 'pane-container:active-pane-item-changed', [activeItem]
 
-  onSurrenderedFocus: =>
-    atom?.workspaceView?.focus()
-
   removeChild: (child) ->
     throw new Error("Removing non-existant child") unless @getRoot() is child
     @setRoot(null)
@@ -117,3 +113,25 @@ class PaneContainer extends View
   removeEmptyPanes: ->
     for pane in @getPanes() when pane.getItems().length == 0
       pane.remove()
+
+  focusNextPane: ->
+    panes = @getPanes()
+    if panes.length > 1
+      currentIndex = panes.indexOf(@getFocusedPane())
+      nextIndex = (currentIndex + 1) % panes.length
+      panes[nextIndex].focus()
+      true
+    else
+      atom.workspaceView?.focus()
+      false
+
+  focusPreviousPane: ->
+    panes = @getPanes()
+    if panes.length > 1
+      currentIndex = panes.indexOf(@getFocusedPane())
+      previousIndex = currentIndex - 1
+      previousIndex = panes.length - 1 if previousIndex < 0
+      panes[previousIndex].focus()
+      true
+    else
+      false
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index e29dd405d..d4f2e6662 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -3,18 +3,17 @@
 {Model, Sequence} = require 'theorist'
 Serializable = require 'serializable'
 PaneAxisModel = require './pane-axis-model'
-Focusable = require './focusable'
 Pane = null
 
 module.exports =
 class PaneModel extends Model
   atom.deserializers.add(this)
   Serializable.includeInto(this)
-  Focusable.includeInto(this)
 
   @properties
     container: null
     activeItem: null
+    focused: false
 
   @behavior 'active', ->
     @$container
@@ -28,9 +27,6 @@ class PaneModel extends Model
     @items = Sequence.fromArray(params?.items ? [])
     @activeItem ?= @items[0]
 
-    @subscribe @$container, (container) =>
-      @focusContext = container?.focusContext
-
     @subscribe @items.onEach (item) =>
       if typeof item.on is 'function'
         @subscribe item, 'destroyed', => @removeItem(item)
@@ -38,9 +34,6 @@ class PaneModel extends Model
     @subscribe @items.onRemoval (item, index) =>
       @unsubscribe item if typeof item.on is 'function'
 
-    @when @$focused, => @makeActive()
-
-    @focus() if params?.focused
     @makeActive() if params?.active
 
   serializeParams: ->
@@ -59,6 +52,13 @@ class PaneModel extends Model
 
   isActive: -> @active
 
+  focus: ->
+    @focused = true
+    @makeActive()
+
+  blur: ->
+    @focused = false
+
   makeActive: -> @container?.activePane = this
 
   getPanes: -> [this]
@@ -119,7 +119,7 @@ class PaneModel extends Model
     item = @items[index]
     @showNextItem() if item is @activeItem and @items.length > 1
     @items.splice(index, 1)
-    @suppressBlur => @emit 'item-removed', item, index, destroying
+    @emit 'item-removed', item, index, destroying
     @destroy() if @items.length is 0
 
   # Public: Moves the given item to a the new index.
@@ -160,11 +160,8 @@ class PaneModel extends Model
 
   # Private: Called by model superclass
   destroyed: ->
+    @container.makeNextPaneActive() if @isActive()
     item.destroy?() for item in @items.slice()
-    if @focused
-      @container.focusNextPane()
-    else if @isActive()
-      @container.makeNextPaneActive()
 
   # Public: Prompt the user to save the given item.
   promptToSaveItem: (item) ->
@@ -245,10 +242,10 @@ class PaneModel extends Model
     if @parent.orientation isnt orientation
       @parent.replaceChild(this, new PaneAxisModel({@container, orientation, children: [this]}))
 
-    newPane = new @constructor(params)
+    newPane = new @constructor(extend({focused: true}, params))
     switch side
       when 'before' then @parent.insertChildBefore(this, newPane)
       when 'after' then @parent.insertChildAfter(this, newPane)
 
-    newPane.focus()
+    newPane.makeActive()
     newPane
diff --git a/src/pane.coffee b/src/pane.coffee
index dcee94658..2c45de329 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -49,9 +49,6 @@ class Pane extends View
     @viewsByItem = new WeakMap()
     @handleEvents()
 
-  hasFocus: ->
-    @is(':focus') or @is(':has(:focus)')
-
   handleEvents: ->
     @subscribe @model, 'destroyed', => @remove()
 
@@ -63,16 +60,10 @@ class Pane extends View
     @subscribe @model, 'item-destroyed', @onItemDestroyed
     @subscribe @model.$active, 'value', @onActiveStatusChanged
 
-    @subscribe @model.$focused, 'value', (focused) =>
-      if focused
-        @focus() unless @hasFocus()
-      else
-        @blur() if @hasFocus()
-
     @subscribe this, 'focusin', => @model.focus()
     @subscribe this, 'focusout', => @model.blur()
     @subscribe this, 'focus', =>
-      @model.suppressBlur => @activeView?.focus()
+      @activeView?.focus()
       false
 
     @command 'pane:save-items', => @saveItems()
@@ -141,8 +132,8 @@ class Pane extends View
     @itemViews.children().not(view).hide()
     @itemViews.append(view) unless view.parent().is(@itemViews)
     view.show() if @attached
-    if isFocused
-      @model.suppressBlur -> view.focus()
+    view.focus() if isFocused
+
     @activeView = view
     @trigger 'pane:active-item-changed', [item]
 
@@ -150,7 +141,25 @@ class Pane extends View
     @trigger 'pane:item-added', [item, index]
 
   onItemRemoved: (item, index, destroyed) =>
-    @cleanupItemView(item, destroyed)
+    if item instanceof $
+      viewToRemove = item
+    else if viewToRemove = @viewsByItem.get(item)
+      @viewsByItem.delete(item)
+
+    removingLastItem = @model.items.length is 0
+    hasFocus = @hasFocus()
+
+    @getContainer().focusNextPane() if hasFocus and removingLastItem
+
+    if viewToRemove?
+      viewToRemove.setModel?(null)
+      if destroyed
+        viewToRemove.remove()
+      else
+        viewToRemove.detach()
+
+    # @focus() if hasFocus and not removingLastItem
+
     @trigger 'pane:item-removed', [item, index]
 
   onItemMoved: (item, newIndex) =>
@@ -167,20 +176,6 @@ class Pane extends View
   activeItemTitleChanged: =>
     @trigger 'pane:active-item-title-changed'
 
-  # Private:
-  cleanupItemView: (item, destroyed) ->
-    if item instanceof $
-      viewToRemove = item
-    else if viewToRemove = @viewsByItem.get(item)
-      @viewsByItem.delete(item)
-
-    if viewToRemove?
-      viewToRemove.setModel?(null)
-      if destroyed
-        viewToRemove.remove()
-      else
-        viewToRemove.detach()
-
   # Private:
   viewForItem: (item) ->
     if item instanceof $
@@ -210,6 +205,7 @@ class Pane extends View
     @closest('.panes').view()
 
   beforeRemove: ->
+    @getContainer()?.focusNextPane() if @hasFocus()
     @model.destroy() unless @model.isDestroyed()
 
   # Private:
diff --git a/src/space-pen-extensions.coffee b/src/space-pen-extensions.coffee
index d7504ebe2..02d08f8ab 100644
--- a/src/space-pen-extensions.coffee
+++ b/src/space-pen-extensions.coffee
@@ -59,6 +59,9 @@ jQuery.fn.destroyTooltip = ->
   @hideTooltip()
   @tooltip('destroy')
 
+jQuery.fn.hasFocus = ->
+  @is(':focus') or @is(':has(:focus)')
+
 jQuery.fn.setTooltip.getKeystroke = getKeystroke
 jQuery.fn.setTooltip.humanizeKeystrokes = humanizeKeystrokes
 

From 578ca8b1978864d592574dd1eadd0ec322b65446 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 17:56:04 -0700
Subject: [PATCH 68/89] Don't update highlighted gutter lines unless the editor
 is alive

---
 src/editor-view.coffee | 2 ++
 src/gutter.coffee      | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/src/editor-view.coffee b/src/editor-view.coffee
index 9ae326c54..43b1c9079 100644
--- a/src/editor-view.coffee
+++ b/src/editor-view.coffee
@@ -217,6 +217,8 @@ class EditorView extends View
       do (name, method) =>
         @command name, (e) => method.call(this, e); false
 
+  isAlive: -> @editor?.isAlive()
+
   # {Delegates to: Editor.getCursor}
   getCursor: -> @editor.getCursor()
 
diff --git a/src/gutter.coffee b/src/gutter.coffee
index 7b7ee15a1..f3471fad0 100644
--- a/src/gutter.coffee
+++ b/src/gutter.coffee
@@ -230,6 +230,8 @@ class Gutter extends View
       @highlightedLineNumbers.push(highlightedLineNumber)
 
   highlightLines: ->
+    return unless @getEditorView().isAlive()
+
     if @getEditorView().getSelection().isEmpty()
       row = @getEditorView().getCursorScreenPosition().row
       rowRange = new Range([row, 0], [row, 0])

From 3afbcbe25fa7bac2c25c675ccd3d767122487983 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 18:07:10 -0700
Subject: [PATCH 69/89] Allow focusout events to bubble out of panes

---
 src/pane-model.coffee | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index d4f2e6662..7e767ed21 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -58,6 +58,7 @@ class PaneModel extends Model
 
   blur: ->
     @focused = false
+    true # if this is called from an event handler, don't cancel it
 
   makeActive: -> @container?.activePane = this
 

From 263ab3b4a6b26c4813e771a5a744922f9b671653 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 18:27:11 -0700
Subject: [PATCH 70/89] Kill unused require

---
 src/pane-container-model.coffee | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index b32f28135..0128049d8 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -1,6 +1,5 @@
 {Model} = require 'theorist'
 Serializable = require 'serializable'
-{find} = require 'underscore-plus'
 PaneModel = require './pane-model'
 
 module.exports =

From 8b0b997db60c09bb9295fae1b29e2487d622cb5e Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 18:28:01 -0700
Subject: [PATCH 71/89] Kill EditorView::isAlive and just tunnel to the model
 where it was used

---
 src/editor-view.coffee | 2 --
 src/gutter.coffee      | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/editor-view.coffee b/src/editor-view.coffee
index 43b1c9079..9ae326c54 100644
--- a/src/editor-view.coffee
+++ b/src/editor-view.coffee
@@ -217,8 +217,6 @@ class EditorView extends View
       do (name, method) =>
         @command name, (e) => method.call(this, e); false
 
-  isAlive: -> @editor?.isAlive()
-
   # {Delegates to: Editor.getCursor}
   getCursor: -> @editor.getCursor()
 
diff --git a/src/gutter.coffee b/src/gutter.coffee
index f3471fad0..be02dc6d4 100644
--- a/src/gutter.coffee
+++ b/src/gutter.coffee
@@ -230,7 +230,7 @@ class Gutter extends View
       @highlightedLineNumbers.push(highlightedLineNumber)
 
   highlightLines: ->
-    return unless @getEditorView().isAlive()
+    return unless @getEditorView().editor?.isAlive()
 
     if @getEditorView().getSelection().isEmpty()
       row = @getEditorView().getCursorScreenPosition().row

From 738bfd7253af4c825a880a87c2b1e328160543f4 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Fri, 10 Jan 2014 19:02:19 -0700
Subject: [PATCH 72/89] Fix layout of tabs with flexbox repaint hack

The .item-views div needs to be the first child of pane and contain
the absolutely positioned repaint hack div inside it, otherwise the tabs
don't get honored as flexbox items.
---
 src/editor-view.coffee    |  2 +-
 src/pane.coffee           |  4 ++--
 src/workspace-view.coffee |  2 +-
 static/panes.less         | 29 ++++++++++++++---------------
 4 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/src/editor-view.coffee b/src/editor-view.coffee
index 9ae326c54..220dd699a 100644
--- a/src/editor-view.coffee
+++ b/src/editor-view.coffee
@@ -1073,7 +1073,7 @@ class EditorView extends View
   #
   # Returns a {Pane}.
   getPane: ->
-    @parent('.item-views').parents('.pane').view()
+    @parent('.flexbox-repaint-hack').parents('.pane').view()
 
   remove: (selector, keepData) ->
     return super if keepData or @removed
diff --git a/src/pane.coffee b/src/pane.coffee
index 2c45de329..1c644d6de 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -24,8 +24,8 @@ class Pane extends View
 
   @content: (wrappedView) ->
     @div class: 'pane', tabindex: -1, =>
-      @div class: 'flexbox-repaint-hack', =>
-        @div class: 'item-views', outlet: 'itemViews'
+      @div class: 'item-views', =>
+        @div class: 'flexbox-repaint-hack', outlet: 'itemViews'
 
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
   @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
diff --git a/src/workspace-view.coffee b/src/workspace-view.coffee
index 55e37a0b7..d4281c7e9 100644
--- a/src/workspace-view.coffee
+++ b/src/workspace-view.coffee
@@ -240,7 +240,7 @@ class WorkspaceView extends View
 
   # Private: Returns an Array of  all of the application's {EditorView}s.
   getEditorViews: ->
-    @panes.find('.pane > .flexbox-repaint-hack > .item-views > .editor').map(-> $(this).view()).toArray()
+    @panes.find('.pane > .item-views > .flexbox-repaint-hack > .editor').map(-> $(this).view()).toArray()
 
   # Private: Retrieves all of the modified buffers that are open and unsaved.
   #
diff --git a/static/panes.less b/static/panes.less
index 238cdb4a0..d5e016427 100644
--- a/static/panes.less
+++ b/static/panes.less
@@ -21,18 +21,9 @@
 
   .pane {
     position: relative;
+    display: -webkit-flex;
     -webkit-flex: 1;
-
-    .flexbox-repaint-hack {
-      display: -webkit-flex;
-      -webkit-flex-flow: column;
-
-      position: absolute;
-      top: 0;
-      right: 0;
-      bottom: 0;
-      left: 0;
-    }
+    -webkit-flex-direction: column;
 
     .pane-item {
       color: @text-color;
@@ -43,11 +34,19 @@
       -webkit-flex: 1;
       display: -webkit-flex;
       min-height: 0;
-    }
+      position: relative;
 
-    .item-views > * {
-      -webkit-flex: 1;
-      min-width: 0;
+      .flexbox-repaint-hack {
+        display: -webkit-flex;
+        -webkit-flex-flow: column;
+
+        position: absolute;
+        top: 0;
+        right: 0;
+        bottom: 0;
+        left: 0;
+        min-width: 0;
+      }
     }
   }
 }

From 1fdc78a157ee9fbdc0833c66e34fe79d26458c5a Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 10:24:18 -0700
Subject: [PATCH 73/89] Upgrade find-and-replace to 0.74.0 for fix to parent
 pane dom query

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 4de193c38..5a4d95784 100644
--- a/package.json
+++ b/package.json
@@ -75,7 +75,7 @@
     "editor-stats": "0.12.0",
     "exception-reporting": "0.10.0",
     "feedback": "0.22.0",
-    "find-and-replace": "0.70.0",
+    "find-and-replace": "0.74.0",
     "fuzzy-finder": "0.30.0",
     "gists": "0.13.0",
     "git-diff": "0.21.0",

From 545bf4bd9809be84829fef8733c26f7585e7675d Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 10:38:47 -0700
Subject: [PATCH 74/89] Upgrade to theorist 0.12.0 to remove dependence on
 harmony proxies

They're turning out to cause instability in the current version of v8
or atom-shell. Perhaps we can revisit this after the upgrade to chromium
31. Once we have Object.observe, we could at least throw an exception
when someone assigns a sequence index directly via ::[] or assigns to
::length.
---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 5a4d95784..b4a59b860 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
     "temp": "0.5.0",
     "text-buffer": "0.12.0",
     "underscore-plus": "0.6.1",
-    "theorist": "~0.11.0",
+    "theorist": "~0.12.0",
     "delegato": "~0.4.0",
     "mixto": "~0.4.0"
   },

From e2170ea907a966f2320e0a33f4f6f379d24583f2 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 10:45:33 -0700
Subject: [PATCH 75/89] Remove unused requires and mixins

---
 src/pane-axis-model.coffee | 2 --
 src/pane-axis.coffee       | 4 +---
 src/pane-container.coffee  | 2 --
 src/pane-model.coffee      | 2 +-
 src/pane.coffee            | 2 --
 5 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/src/pane-axis-model.coffee b/src/pane-axis-model.coffee
index f019856e6..bbea4f969 100644
--- a/src/pane-axis-model.coffee
+++ b/src/pane-axis-model.coffee
@@ -1,6 +1,5 @@
 {Model, Sequence} = require 'theorist'
 {flatten} = require 'underscore-plus'
-Delegator = require 'delegato'
 Serializable = require 'serializable'
 
 PaneRow = null
@@ -10,7 +9,6 @@ module.exports =
 class PaneAxisModel extends Model
   atom.deserializers.add(this)
   Serializable.includeInto(this)
-  Delegator.includeInto(this)
 
   constructor: ({@container, @orientation, children}) ->
     @children = Sequence.fromArray(children ? [])
diff --git a/src/pane-axis.coffee b/src/pane-axis.coffee
index 79ed2cfb1..27757dfbf 100644
--- a/src/pane-axis.coffee
+++ b/src/pane-axis.coffee
@@ -1,6 +1,4 @@
-Serializable = require 'serializable'
-{$, View} = require './space-pen-extensions'
-PaneAxisModel = require './pane-axis-model'
+{View} = require './space-pen-extensions'
 Pane = null
 
 ### Internal ###
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index eeb54f74b..ee875254e 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -1,5 +1,4 @@
 Serializable = require 'serializable'
-Delegator = require 'delegato'
 {$, View} = require './space-pen-extensions'
 Pane = require './pane'
 PaneContainerModel = require './pane-container-model'
@@ -9,7 +8,6 @@ module.exports =
 class PaneContainer extends View
   atom.deserializers.add(this)
   Serializable.includeInto(this)
-  Delegator.includeInto(this)
 
   @deserialize: (state) ->
     new this(PaneContainerModel.deserialize(state.model))
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 7e767ed21..3c255b34a 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -1,4 +1,4 @@
-{find, compact, clone, extend} = require 'underscore-plus'
+{find, compact, extend} = require 'underscore-plus'
 {dirname} = require 'path'
 {Model, Sequence} = require 'theorist'
 Serializable = require 'serializable'
diff --git a/src/pane.coffee b/src/pane.coffee
index 1c644d6de..c374bcb79 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -3,8 +3,6 @@ Serializable = require 'serializable'
 Delegator = require 'delegato'
 
 PaneModel = require './pane-model'
-PaneRow = require './pane-row'
-PaneColumn = require './pane-column'
 
 # Public: A container which can contains multiple items to be switched between.
 #

From 6fe1bae40d930839deaf317098ee9c13ccf92dad Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 10:46:57 -0700
Subject: [PATCH 76/89] Upgrade to image-view 0.15.0 for fix to parent pane
 query

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index b4a59b860..2bba21140 100644
--- a/package.json
+++ b/package.json
@@ -82,7 +82,7 @@
     "github-sign-in": "0.15.0",
     "go-to-line": "0.14.0",
     "grammar-selector": "0.16.0",
-    "image-view": "0.14.0",
+    "image-view": "0.15.0",
     "keybinding-resolver": "0.8.0",
     "markdown-preview": "0.24.0",
     "metrics": "0.20.0",

From 452d86ac0cf3557b0c55e5bf161a421040e241fd Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 11:04:37 -0700
Subject: [PATCH 77/89] Upgrade ui themes for rename of `.row` to `.pane-row`

---
 package.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/package.json b/package.json
index 2bba21140..1a1442f5e 100644
--- a/package.json
+++ b/package.json
@@ -56,9 +56,9 @@
   },
   "packageDependencies": {
     "atom-dark-syntax": "0.10.0",
-    "atom-dark-ui": "0.18.0",
+    "atom-dark-ui": "0.19.0",
     "atom-light-syntax": "0.10.0",
-    "atom-light-ui": "0.17.0",
+    "atom-light-ui": "0.18.0",
     "base16-tomorrow-dark-theme": "0.8.0",
     "solarized-dark-syntax": "0.6.0",
     "solarized-light-syntax": "0.2.0",

From b04f9f9488528dc53303f8b9977c666c49822ef9 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 11:11:04 -0700
Subject: [PATCH 78/89] Remove unused methods from PaneAxis

---
 src/pane-axis.coffee | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/src/pane-axis.coffee b/src/pane-axis.coffee
index 27757dfbf..0a37f1bbb 100644
--- a/src/pane-axis.coffee
+++ b/src/pane-axis.coffee
@@ -12,12 +12,6 @@ class PaneAxis extends View
     viewClass = model.getViewClass()
     model._view ?= new viewClass(model)
 
-  addChild: (child, index) ->
-    @model.addChild(child.model, index)
-
-  removeChild: (child) ->
-    @model.removeChild(child.model)
-
   onChildrenChanged:  ({index, removedValues, insertedValues}) =>
     focusedElement = document.activeElement if @hasFocus()
     @onChildRemoved(child, index) for child in removedValues
@@ -38,15 +32,3 @@ class PaneAxis extends View
 
   getContainer: ->
     @closest('.panes').view()
-
-  getActivePaneItem: ->
-    @getActivePane()?.activeItem
-
-  getActivePane: ->
-    @find('.pane.active').view() ? @find('.pane:first').view()
-
-  insertChildBefore: (currentChild, newChild) ->
-    @model.insertChildBefore(currentChild, newChild)
-
-  insertChildAfter: (currentChild, newChild) ->
-    @model.insertChildAfter(currentChild, newChild)

From ef8b7531b045a86147ce9d283cbe8ddf2f71c093 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 11:19:19 -0700
Subject: [PATCH 79/89] Upgrade to theorist 0.13.0 to rename
 Signal::flatMapLatest -> ::switch

Shorter, simpler, less intimidating.
---
 package.json                    | 2 +-
 src/pane-container-model.coffee | 2 +-
 src/pane-model.coffee           | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index 1a1442f5e..7b2756acb 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
     "temp": "0.5.0",
     "text-buffer": "0.12.0",
     "underscore-plus": "0.6.1",
-    "theorist": "~0.12.0",
+    "theorist": "~0.13.0",
     "delegato": "~0.4.0",
     "mixto": "~0.4.0"
   },
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index 0128049d8..92fcd4558 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -14,7 +14,7 @@ class PaneContainerModel extends Model
   previousRoot: null
 
   @behavior 'activePaneItem', ->
-    @$activePane.flatMapLatest (activePane) -> activePane?.$activeItem
+    @$activePane.switch (activePane) -> activePane?.$activeItem
 
   constructor: ->
     super
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 3c255b34a..711dd731f 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -17,7 +17,7 @@ class PaneModel extends Model
 
   @behavior 'active', ->
     @$container
-      .flatMapLatest((container) -> container?.$activePane)
+      .switch((container) -> container?.$activePane)
       .map((activePane) => activePane is this)
       .distinctUntilChanged()
 

From 3ab7836ab277b0018a036ce1fae591f0d8ae18f1 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 11:22:31 -0700
Subject: [PATCH 80/89] Upgrade to emissary 0.31.0 for implicit 'value'
 subscriptions on signals

Previously, when you always had to specify the event name of 'value'
when calling `::subscribe` with a signal. Now, if you don't specify an
event name, 'value' is assumed.
---
 package.json                | 2 +-
 src/display-buffer.coffee   | 2 +-
 src/editor.coffee           | 4 ++--
 src/pane-container.coffee   | 4 ++--
 src/pane.coffee             | 4 ++--
 src/tokenized-buffer.coffee | 2 +-
 6 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/package.json b/package.json
index 7b2756acb..e2a29142b 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
     "clear-cut": "0.2.0",
     "coffee-script": "1.6.3",
     "coffeestack": "0.6.0",
-    "emissary": "0.19.0",
+    "emissary": "0.31.0",
     "first-mate": "0.14.0",
     "fs-plus": "0.14.0",
     "fstream": "0.1.24",
diff --git a/src/display-buffer.coffee b/src/display-buffer.coffee
index a7904fcad..6974ad9ba 100644
--- a/src/display-buffer.coffee
+++ b/src/display-buffer.coffee
@@ -35,7 +35,7 @@ class DisplayBuffer extends Model
     @subscribe @buffer, 'markers-updated', @handleBufferMarkersUpdated
     @subscribe @buffer, 'marker-created', @handleBufferMarkerCreated
 
-    @subscribe @$softWrap, 'value', (softWrap) =>
+    @subscribe @$softWrap, (softWrap) =>
       @emit 'soft-wrap-changed', softWrap
       @updateWrappedScreenLines()
 
diff --git a/src/editor.coffee b/src/editor.coffee
index 291024c7b..085a68ef0 100644
--- a/src/editor.coffee
+++ b/src/editor.coffee
@@ -73,8 +73,8 @@ class Editor extends Model
 
     @languageMode = new LanguageMode(this, @buffer.getExtension())
 
-    @subscribe @$scrollTop, 'value', (scrollTop) => @emit 'scroll-top-changed', scrollTop
-    @subscribe @$scrollLeft, 'value', (scrollLeft) => @emit 'scroll-left-changed', scrollLeft
+    @subscribe @$scrollTop, (scrollTop) => @emit 'scroll-top-changed', scrollTop
+    @subscribe @$scrollLeft, (scrollLeft) => @emit 'scroll-left-changed', scrollLeft
 
     atom.project.addEditor(this) if registerEditor
 
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index ee875254e..60393d634 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -21,8 +21,8 @@ class PaneContainer extends View
     else
       @model = new PaneContainerModel({root: params?.root?.model})
 
-    @subscribe @model.$root, 'value', @onRootChanged
-    @subscribe @model.$activePaneItem.changes, 'value', @onActivePaneItemChanged
+    @subscribe @model.$root, @onRootChanged
+    @subscribe @model.$activePaneItem.changes, @onActivePaneItemChanged
 
   viewForModel: (model) ->
     if model?
diff --git a/src/pane.coffee b/src/pane.coffee
index c374bcb79..11b564dbe 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -50,13 +50,13 @@ class Pane extends View
   handleEvents: ->
     @subscribe @model, 'destroyed', => @remove()
 
-    @subscribe @model.$activeItem, 'value', @onActiveItemChanged
+    @subscribe @model.$activeItem, @onActiveItemChanged
     @subscribe @model, 'item-added', @onItemAdded
     @subscribe @model, 'item-removed', @onItemRemoved
     @subscribe @model, 'item-moved', @onItemMoved
     @subscribe @model, 'before-item-destroyed', @onBeforeItemDestroyed
     @subscribe @model, 'item-destroyed', @onItemDestroyed
-    @subscribe @model.$active, 'value', @onActiveStatusChanged
+    @subscribe @model.$active, @onActiveStatusChanged
 
     @subscribe this, 'focusin', => @model.focus()
     @subscribe this, 'focusout', => @model.blur()
diff --git a/src/tokenized-buffer.coffee b/src/tokenized-buffer.coffee
index bb28a708e..f6a4c3681 100644
--- a/src/tokenized-buffer.coffee
+++ b/src/tokenized-buffer.coffee
@@ -35,7 +35,7 @@ class TokenizedBuffer extends Model
     @subscribe @buffer, "changed", (e) => @handleBufferChange(e)
     @subscribe @buffer, "path-changed", => @bufferPath = @buffer.getPath()
 
-    @subscribe @$tabLength.changes.onValue (tabLength) =>
+    @subscribe @$tabLength.changes, (tabLength) =>
       lastRow = @buffer.getLastRow()
       @tokenizedLines = @buildPlaceholderTokenizedLinesForRows(0, lastRow)
       @invalidateRow(0)

From b21eb6f9348179878ed98448a1f98d05ff0da7c5 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 19:13:00 -0700
Subject: [PATCH 81/89] Drop .flexbox-repaint-hack div and use pseudo selector
 instead

We don't actually need structural markup to ensure that all pane views
are absolutely positioned. We can just use the `> *` selector inside of
.pane-items.

/cc @probablycorey is there anything I'm missing here?
---
 src/editor-view.coffee    |  2 +-
 src/pane.coffee           |  3 +--
 src/workspace-view.coffee |  2 +-
 static/panes.less         | 15 ++++++---------
 4 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/src/editor-view.coffee b/src/editor-view.coffee
index 220dd699a..9ae326c54 100644
--- a/src/editor-view.coffee
+++ b/src/editor-view.coffee
@@ -1073,7 +1073,7 @@ class EditorView extends View
   #
   # Returns a {Pane}.
   getPane: ->
-    @parent('.flexbox-repaint-hack').parents('.pane').view()
+    @parent('.item-views').parents('.pane').view()
 
   remove: (selector, keepData) ->
     return super if keepData or @removed
diff --git a/src/pane.coffee b/src/pane.coffee
index 11b564dbe..fd1b3bb44 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -22,8 +22,7 @@ class Pane extends View
 
   @content: (wrappedView) ->
     @div class: 'pane', tabindex: -1, =>
-      @div class: 'item-views', =>
-        @div class: 'flexbox-repaint-hack', outlet: 'itemViews'
+      @div class: 'item-views', outlet: 'itemViews'
 
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
   @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
diff --git a/src/workspace-view.coffee b/src/workspace-view.coffee
index d4281c7e9..e13dab341 100644
--- a/src/workspace-view.coffee
+++ b/src/workspace-view.coffee
@@ -240,7 +240,7 @@ class WorkspaceView extends View
 
   # Private: Returns an Array of  all of the application's {EditorView}s.
   getEditorViews: ->
-    @panes.find('.pane > .item-views > .flexbox-repaint-hack > .editor').map(-> $(this).view()).toArray()
+    @panes.find('.pane > .item-views > .editor').map(-> $(this).view()).toArray()
 
   # Private: Retrieves all of the modified buffers that are open and unsaved.
   #
diff --git a/static/panes.less b/static/panes.less
index d5e016427..f2fcb14ab 100644
--- a/static/panes.less
+++ b/static/panes.less
@@ -25,27 +25,24 @@
     -webkit-flex: 1;
     -webkit-flex-direction: column;
 
-    .pane-item {
-      color: @text-color;
-      background-color: @pane-item-background-color;
-    }
-
     .item-views {
       -webkit-flex: 1;
       display: -webkit-flex;
       min-height: 0;
+      min-width: 0;
       position: relative;
 
-      .flexbox-repaint-hack {
-        display: -webkit-flex;
-        -webkit-flex-flow: column;
+      .pane-item {
+        color: @text-color;
+        background-color: @pane-item-background-color;
+      }
 
+      > * {
         position: absolute;
         top: 0;
         right: 0;
         bottom: 0;
         left: 0;
-        min-width: 0;
       }
     }
   }

From 2188dd201ddab34099769139768569d13da26c3a Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 19:28:33 -0700
Subject: [PATCH 82/89] Update wrap-guide to 0.11.0 for specs fix with flexbox
 panes

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index e2a29142b..2d4a75b4a 100644
--- a/package.json
+++ b/package.json
@@ -102,7 +102,7 @@
     "visual-bell": "0.6.0",
     "welcome": "0.4.0",
     "whitespace": "0.10.0",
-    "wrap-guide": "0.10.0",
+    "wrap-guide": "0.11.0",
     "language-c": "0.2.0",
     "language-clojure": "0.1.0",
     "language-coffee-script": "0.4.0",

From f5bc71e559a7159267b5d5d2308eb3bc0000916d Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 19:49:25 -0700
Subject: [PATCH 83/89] Move $.fn.hasFocus to space-pen

---
 package.json                    | 2 +-
 src/space-pen-extensions.coffee | 3 ---
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/package.json b/package.json
index 2d4a75b4a..5e4927e83 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,7 @@
     "scandal": "0.11.0",
     "season": "0.14.0",
     "semver": "1.1.4",
-    "space-pen": "3.0.3",
+    "space-pen": "3.1.0",
     "temp": "0.5.0",
     "text-buffer": "0.12.0",
     "underscore-plus": "0.6.1",
diff --git a/src/space-pen-extensions.coffee b/src/space-pen-extensions.coffee
index 02d08f8ab..d7504ebe2 100644
--- a/src/space-pen-extensions.coffee
+++ b/src/space-pen-extensions.coffee
@@ -59,9 +59,6 @@ jQuery.fn.destroyTooltip = ->
   @hideTooltip()
   @tooltip('destroy')
 
-jQuery.fn.hasFocus = ->
-  @is(':focus') or @is(':has(:focus)')
-
 jQuery.fn.setTooltip.getKeystroke = getKeystroke
 jQuery.fn.setTooltip.humanizeKeystrokes = humanizeKeystrokes
 

From 28b085be1c92be3a4949ac5d6109f2631362da18 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 20:48:01 -0700
Subject: [PATCH 84/89] Rename ::makeActive to ::activate and focus panes when
 they're activated

---
 spec/pane-container-model-spec.coffee | 10 +++++-----
 spec/pane-container-spec.coffee       |  2 +-
 spec/pane-spec.coffee                 | 18 ++++--------------
 spec/workspace-view-spec.coffee       |  5 ++---
 src/pane-container-model.coffee       |  4 ++--
 src/pane-container.coffee             |  3 ++-
 src/pane-model.coffee                 | 12 +++++++-----
 src/pane.coffee                       | 18 +++++++-----------
 src/workspace-view.coffee             |  6 +++---
 9 files changed, 33 insertions(+), 45 deletions(-)

diff --git a/spec/pane-container-model-spec.coffee b/spec/pane-container-model-spec.coffee
index dd6e14e60..a37772d7d 100644
--- a/spec/pane-container-model-spec.coffee
+++ b/spec/pane-container-model-spec.coffee
@@ -19,7 +19,7 @@ describe "PaneContainerModel", ->
       expect(pane3B.focused).toBe true
 
     it "preserves the active pane across serialization, independent of focus", ->
-      pane3A.makeActive()
+      pane3A.activate()
       expect(containerA.activePane).toBe pane3A
 
       containerB = containerA.testSerialization()
@@ -37,20 +37,20 @@ describe "PaneContainerModel", ->
       expect(container.activePane).toBe pane1
       expect(pane1.active).toBe true
 
-    it "references the most pane on which ::makeActive was most recently called", ->
+    it "references the most pane on which ::activate was most recently called", ->
       pane2 = pane1.splitRight()
-      pane2.makeActive()
+      pane2.activate()
       expect(container.activePane).toBe pane2
       expect(pane1.active).toBe false
       expect(pane2.active).toBe true
-      pane1.makeActive()
+      pane1.activate()
       expect(container.activePane).toBe pane1
       expect(pane1.active).toBe true
       expect(pane2.active).toBe false
 
     it "is reassigned to the next pane if the current active pane is destroyed", ->
       pane2 = pane1.splitRight()
-      pane2.makeActive()
+      pane2.activate()
       pane2.destroy()
       expect(container.activePane).toBe pane1
       expect(pane1.active).toBe true
diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index 2dd46707f..30a89328d 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -249,7 +249,7 @@ describe "PaneContainer", ->
         expect(activeItemChangedHandler).not.toHaveBeenCalled()
 
       it "is triggered when the active pane is changed", ->
-        pane1.makeActive()
+        pane1.activate()
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item1a
 
diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index 204730aee..cf85d9828 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -41,7 +41,7 @@ describe "Pane", ->
       expect(pane.activeItem).toBe view2
 
     it "triggers 'pane:active-item-changed' if the item isn't already the activeItem", ->
-      pane.makeActive()
+      pane.activate()
       itemChangedHandler = jasmine.createSpy("itemChangedHandler")
       container.on 'pane:active-item-changed', itemChangedHandler
 
@@ -447,24 +447,14 @@ describe "Pane", ->
         paneToRight = pane.splitRight(pane.copyActiveItem())
         container.attachToDom()
 
-      describe "when the removed pane is focused", ->
-        it "activates and focuses the next pane", ->
-          pane.focus()
+      describe "when the removed pane is active", ->
+        it "makes the next the next pane active and focuses it", ->
+          pane.activate()
           pane.remove()
           expect(paneToLeft.isActive()).toBeFalsy()
           expect(paneToRight.isActive()).toBeTruthy()
           expect(paneToRight).toMatchSelector ':has(:focus)'
 
-      describe "when the removed pane is active but not focused", ->
-        it "activates the next pane, but does not focus it", ->
-          $(document.activeElement).blur()
-          expect(pane).not.toMatchSelector ':has(:focus)'
-          pane.makeActive()
-          pane.remove()
-          expect(paneToLeft.isActive()).toBeFalsy()
-          expect(paneToRight.isActive()).toBeTruthy()
-          expect(paneToRight).not.toMatchSelector ':has(:focus)'
-
       describe "when the removed pane is not active", ->
         it "does not affect the active pane or the focus", ->
           paneToLeft.focus()
diff --git a/spec/workspace-view-spec.coffee b/spec/workspace-view-spec.coffee
index 8db9b479a..51625a590 100644
--- a/spec/workspace-view-spec.coffee
+++ b/spec/workspace-view-spec.coffee
@@ -311,7 +311,6 @@ describe "WorkspaceView", ->
     describe "when there is an active pane", ->
       [pane1] = []
       beforeEach ->
-        spyOn(Pane.prototype, 'focus').andCallFake -> @makeActive()
         pane1 = atom.workspaceView.getActivePane()
 
       it "creates a new pane and reuses the file when already open", ->
@@ -322,7 +321,7 @@ describe "WorkspaceView", ->
         expect(pane2.itemForUri('b')).not.toBeFalsy()
         expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
 
-        pane1.focus()
+        pane1.activate()
         expect(atom.workspaceView.getActivePane()[0]).toBe pane1[0]
 
         atom.workspaceView.openSingletonSync('b', split: 'right')
@@ -346,7 +345,7 @@ describe "WorkspaceView", ->
         expect(pane2.itemForUri('file1')).toBeFalsy()
         expect(atom.workspaceView.panes.find('.pane-row .pane').toArray()).toEqual [pane1[0], pane2[0]]
 
-        pane2.focus()
+        pane2.activate()
         expect(atom.workspaceView.getActivePane()[0]).toBe pane2[0]
 
         atom.workspaceView.openSingletonSync('file1', split: 'left')
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index 92fcd4558..81f93df64 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -34,12 +34,12 @@ class PaneContainerModel extends Model
   getPanes: ->
     @root?.getPanes() ? []
 
-  makeNextPaneActive: ->
+  activateNextPane: ->
     panes = @getPanes()
     if panes.length > 1
       currentIndex = panes.indexOf(@activePane)
       nextIndex = (currentIndex + 1) % panes.length
-      @activePane = panes[nextIndex]
+      panes[nextIndex].activate()
     else
       @activePane = null
 
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index 60393d634..6c03ddbe2 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -54,6 +54,8 @@ class PaneContainer extends View
       view = @viewForModel(root)
       @append(view)
       focusedElement?.focus()
+    else
+      atom.workspaceView?.focus() if focusedElement?
 
   onActivePaneItemChanged: (activeItem) =>
     @trigger 'pane-container:active-pane-item-changed', [activeItem]
@@ -120,7 +122,6 @@ class PaneContainer extends View
       panes[nextIndex].focus()
       true
     else
-      atom.workspaceView?.focus()
       false
 
   focusPreviousPane: ->
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 711dd731f..48547e8aa 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -34,7 +34,7 @@ class PaneModel extends Model
     @subscribe @items.onRemoval (item, index) =>
       @unsubscribe item if typeof item.on is 'function'
 
-    @makeActive() if params?.active
+    @activate() if params?.active
 
   serializeParams: ->
     items: compact(@items.map((item) -> item.serialize?()))
@@ -54,13 +54,15 @@ class PaneModel extends Model
 
   focus: ->
     @focused = true
-    @makeActive()
+    @activate() unless @isActive()
 
   blur: ->
     @focused = false
     true # if this is called from an event handler, don't cancel it
 
-  makeActive: -> @container?.activePane = this
+  activate: ->
+    @container?.activePane = this
+    @emit 'activated'
 
   getPanes: -> [this]
 
@@ -161,7 +163,7 @@ class PaneModel extends Model
 
   # Private: Called by model superclass
   destroyed: ->
-    @container.makeNextPaneActive() if @isActive()
+    @container.activateNextPane() if @isActive()
     item.destroy?() for item in @items.slice()
 
   # Public: Prompt the user to save the given item.
@@ -248,5 +250,5 @@ class PaneModel extends Model
       when 'before' then @parent.insertChildBefore(this, newPane)
       when 'after' then @parent.insertChildAfter(this, newPane)
 
-    newPane.makeActive()
+    newPane.activate()
     newPane
diff --git a/src/pane.coffee b/src/pane.coffee
index fd1b3bb44..37c15add7 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -30,7 +30,7 @@ class Pane extends View
     'moveItem', 'moveItemToPane', 'destroyItem', 'destroyItems', 'destroyActiveItem',
     'destroyInactiveItems', 'saveActiveItem', 'saveActiveItemAs', 'saveItem', 'saveItemAs',
     'saveItems', 'itemForUri', 'showItemForUri', 'promptToSaveItem', 'copyActiveItem',
-    'isActive', 'makeActive', toProperty: 'model'
+    'isActive', 'activate', toProperty: 'model'
 
   previousActiveItem: null
 
@@ -55,6 +55,7 @@ class Pane extends View
     @subscribe @model, 'item-moved', @onItemMoved
     @subscribe @model, 'before-item-destroyed', @onBeforeItemDestroyed
     @subscribe @model, 'item-destroyed', @onItemDestroyed
+    @subscribe @model, 'activated', @onActivated
     @subscribe @model.$active, @onActiveStatusChanged
 
     @subscribe this, 'focusin', => @model.focus()
@@ -99,6 +100,9 @@ class Pane extends View
     @attached = true
     @trigger 'pane:attached', [this]
 
+  onActivated: =>
+    @focus() unless @hasFocus()
+
   onActiveStatusChanged: (active) =>
     if active
       @addClass('active')
@@ -123,13 +127,13 @@ class Pane extends View
 
     return unless item?
 
-    isFocused = @is(':has(:focus)')
+    hasFocus = @hasFocus()
     item.on? 'title-changed', @activeItemTitleChanged
     view = @viewForItem(item)
     @itemViews.children().not(view).hide()
     @itemViews.append(view) unless view.parent().is(@itemViews)
     view.show() if @attached
-    view.focus() if isFocused
+    view.focus() if hasFocus
 
     @activeView = view
     @trigger 'pane:active-item-changed', [item]
@@ -143,11 +147,6 @@ class Pane extends View
     else if viewToRemove = @viewsByItem.get(item)
       @viewsByItem.delete(item)
 
-    removingLastItem = @model.items.length is 0
-    hasFocus = @hasFocus()
-
-    @getContainer().focusNextPane() if hasFocus and removingLastItem
-
     if viewToRemove?
       viewToRemove.setModel?(null)
       if destroyed
@@ -155,8 +154,6 @@ class Pane extends View
       else
         viewToRemove.detach()
 
-    # @focus() if hasFocus and not removingLastItem
-
     @trigger 'pane:item-removed', [item, index]
 
   onItemMoved: (item, newIndex) =>
@@ -202,7 +199,6 @@ class Pane extends View
     @closest('.panes').view()
 
   beforeRemove: ->
-    @getContainer()?.focusNextPane() if @hasFocus()
     @model.destroy() unless @model.isDestroyed()
 
   # Private:
diff --git a/src/workspace-view.coffee b/src/workspace-view.coffee
index e13dab341..daac10423 100644
--- a/src/workspace-view.coffee
+++ b/src/workspace-view.coffee
@@ -173,7 +173,7 @@ class WorkspaceView extends View
 
         @itemOpened(editor)
         activePane.showItem(editor)
-        activePane.focus() if changeFocus
+        activePane.activate() if changeFocus
         @trigger "uri-opened"
         editor
       .catch (error) ->
@@ -208,7 +208,7 @@ class WorkspaceView extends View
 
     @itemOpened(paneItem)
 
-    pane.focus() if changeFocus
+    pane.activate() if changeFocus
     paneItem
 
   openSingletonSync: (uri, {changeFocus, initialLine, split}={}) ->
@@ -219,7 +219,7 @@ class WorkspaceView extends View
     if pane
       paneItem = pane.itemForUri(uri)
       pane.showItem(paneItem)
-      pane.focus() if changeFocus
+      pane.activate() if changeFocus
       paneItem
     else
       @openSync(uri, {changeFocus, initialLine, split})

From 2a8a5268c68f5f410361ccf523c94b453c970e72 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sat, 11 Jan 2014 22:06:37 -0700
Subject: [PATCH 85/89] Clean up PaneModel api docs

---
 src/pane-model.coffee | 107 ++++++++++++++++++++++++++++++++----------
 1 file changed, 81 insertions(+), 26 deletions(-)

diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 48547e8aa..8ccef977e 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -5,6 +5,9 @@ Serializable = require 'serializable'
 PaneAxisModel = require './pane-axis-model'
 Pane = null
 
+# Public: A container for multiple items, one of which is *active* at a given
+# time. With the default packages, a tab is displayed for each item and the
+# active item's view is displayed.
 module.exports =
 class PaneModel extends Model
   atom.deserializers.add(this)
@@ -15,12 +18,16 @@ class PaneModel extends Model
     activeItem: null
     focused: false
 
+  # Public: Only one pane is considered *active* at a time. A pane is activated
+  # when it is focused, and when focus returns to the pane container after
+  # moving to another element such as a panel, it returns to the active pane.
   @behavior 'active', ->
     @$container
       .switch((container) -> container?.$activePane)
       .map((activePane) => activePane is this)
       .distinctUntilChanged()
 
+  # Private:
   constructor: (params) ->
     super
 
@@ -36,37 +43,45 @@ class PaneModel extends Model
 
     @activate() if params?.active
 
+  # Private: Called by the Serializable mixin during serialization.
   serializeParams: ->
     items: compact(@items.map((item) -> item.serialize?()))
     activeItemUri: @activeItem?.getUri?()
     focused: @focused
     active: @active
 
+  # Private: Called by the Serializable mixin during deserialization.
   deserializeParams: (params) ->
     {items, activeItemUri} = params
     params.items = items.map (itemState) -> atom.deserializers.deserialize(itemState)
     params.activeItem = find params.items, (item) -> item.getUri?() is activeItemUri
     params
 
+  # Private: Called by the view layer to construct a view for this model.
   getViewClass: -> Pane ?= require './pane'
 
   isActive: -> @active
 
+  # Private: Called by the view layer to indicate that the pane has gained focus.
   focus: ->
     @focused = true
     @activate() unless @isActive()
 
+  # Private: Called by the view layer to indicate that the pane has lost focus.
   blur: ->
     @focused = false
     true # if this is called from an event handler, don't cancel it
 
+  # Public: Makes this pane the *active* pane, causing it to gain focus
+  # immediately.
   activate: ->
     @container?.activePane = this
     @emit 'activated'
 
+  # Private:
   getPanes: -> [this]
 
-  # Public: Returns all contained views.
+  # Public:
   getItems: ->
     @items.slice()
 
@@ -74,7 +89,7 @@ class PaneModel extends Model
   itemAtIndex: (index) ->
     @items[index]
 
-  # Public: Switches to the next contained item.
+  # Public: Makes the next item active.
   showNextItem: ->
     index = @getActiveItemIndex()
     if index < @items.length - 1
@@ -82,7 +97,7 @@ class PaneModel extends Model
     else
       @showItemAtIndex(0)
 
-  # Public: Switches to the previous contained item.
+  # Public: Makes the previous item active.
   showPreviousItem: ->
     index = @getActiveItemIndex()
     if index > 0
@@ -90,21 +105,29 @@ class PaneModel extends Model
     else
       @showItemAtIndex(@items.length - 1)
 
-  # Public: Returns the index of the currently active item.
+  # Public: Returns the index of the current active item.
   getActiveItemIndex: ->
     @items.indexOf(@activeItem)
 
-  # Public: Switch to the item associated with the given index.
+  # Public: Makes the item at the given index active.
   showItemAtIndex: (index) ->
     @showItem(@itemAtIndex(index))
 
-  # Public: Focuses the given item.
+  # Public: Makes the given item active, adding the item if necessary.
   showItem: (item) ->
     if item?
       @addItem(item)
       @activeItem = item
 
-  # Public: Add an additional item at the specified index.
+  # Public: Adds the item to the pane.
+  #
+  # * item:
+  #     The item to add. It can be a model with an associated view or a view.
+  # * index:
+  #     An optional index at which to add the item. If omitted, the item is
+  #     added to the end.
+  #
+  # Returns the added item
   addItem: (item, index=@getActiveItemIndex() + 1) ->
     return if item in @items
 
@@ -112,12 +135,10 @@ class PaneModel extends Model
     @emit 'item-added', item, index
     item
 
-  # Public:
   removeItem: (item, destroying) ->
     index = @items.indexOf(item)
     @removeItemAtIndex(index, destroying) if index >= 0
 
-  # Public: Just remove the item at the given index.
   removeItemAtIndex: (index, destroying) ->
     item = @items[index]
     @showNextItem() if item is @activeItem and @items.length > 1
@@ -125,25 +146,26 @@ class PaneModel extends Model
     @emit 'item-removed', item, index, destroying
     @destroy() if @items.length is 0
 
-  # Public: Moves the given item to a the new index.
+  # Public: Moves the given item to the specified index.
   moveItem: (item, newIndex) ->
     oldIndex = @items.indexOf(item)
     @items.splice(oldIndex, 1)
     @items.splice(newIndex, 0, item)
     @emit 'item-moved', item, newIndex
 
-  # Public: Moves the given item to another pane.
+  # Public: Moves the given item to the given index at another pane.
   moveItemToPane: (item, pane, index) ->
     pane.addItem(item, index)
     @removeItem(item)
 
-  # Public: Remove the currently active item.
+  # Public: Destroys the currently active item and make the next item active.
   destroyActiveItem: ->
     @destroyItem(@activeItem)
     false
 
-  # Public: Remove the specified item.
-  destroyItem: (item, options) ->
+  # Public: Destroys the given item. If it is the active item, activate the next
+  # one. If this is the last item, also destroys the pane.
+  destroyItem: (item) ->
     @emit 'before-item-destroyed', item
     if @promptToSaveItem(item)
       @emit 'item-destroyed', item
@@ -153,20 +175,21 @@ class PaneModel extends Model
     else
       false
 
-  # Public: Remove and delete all items.
+  # Public: Destroys all items and destroys the pane.
   destroyItems: ->
     @destroyItem(item) for item in @getItems()
 
-  # Public: Remove and delete all but the currently focused item.
+  # Public: Destroys all items but the active one.
   destroyInactiveItems: ->
     @destroyItem(item) for item in @getItems() when item isnt @activeItem
 
-  # Private: Called by model superclass
+  # Private: Called by model superclass.
   destroyed: ->
     @container.activateNextPane() if @isActive()
     item.destroy?() for item in @items.slice()
 
-  # Public: Prompt the user to save the given item.
+  # Public: Prompts the user to save the given item if it can be saved and is
+  # currently unsaved.
   promptToSaveItem: (item) ->
     return true unless item.shouldPromptToSave?()
 
@@ -181,15 +204,18 @@ class PaneModel extends Model
       when 1 then false
       when 2 then true
 
-  # Public: Saves the currently focused item.
+  # Public: Saves the active item.
   saveActiveItem: ->
     @saveItem(@activeItem)
 
-  # Public: Save and prompt for path for the currently focused item.
+  # Public: Saves the active item at a prompted-for location.
   saveActiveItemAs: ->
     @saveItemAs(@activeItem)
 
-  # Public: Saves the specified item and call the next action when complete.
+  # Public: Saves the specified item.
+  #
+  # * item: The item to save.
+  # * nextAction: An optional function which will be called after the item is saved.
   saveItem: (item, nextAction) ->
     if item.getUri?()
       item.save?()
@@ -197,8 +223,10 @@ class PaneModel extends Model
     else
       @saveItemAs(item, nextAction)
 
-  # Public: Prompts for path and then saves the specified item. Upon completion
-  # it also calls the next action.
+  # Public: Saves the given item at a prompted-for location.
+  #
+  # * item: The item to save.
+  # * nextAction: An optional function which will be called after the item is saved.
   saveItemAs: (item, nextAction) ->
     return unless item.saveAs?
 
@@ -209,15 +237,17 @@ class PaneModel extends Model
       item.saveAs(path)
       nextAction?()
 
-  # Public: Saves all items in this pane.
+  # Public: Saves all items.
   saveItems: ->
     @saveItem(item) for item in @getItems()
 
-  # Public: Finds the first item that matches the given uri.
+  # Public: Returns the first item that matches the given URI or undefined if
+  # none exists.
   itemForUri: (uri) ->
     find @items, (item) -> item.getUri?() is uri
 
-  # Public: Focuses the first item that matches the given uri.
+  # Public: Activates the first item that matches the given URI. Returns a
+  # boolean indicating whether a matching item was found.
   showItemForUri: (uri) ->
     if item = @itemForUri(uri)
       @showItem(item)
@@ -229,18 +259,43 @@ class PaneModel extends Model
   copyActiveItem: ->
     @activeItem.copy?() ? atom.deserializers.deserialize(@activeItem.serialize())
 
+  # Public: Creates a new pane to the left of the receiver.
+  #
+  # * params:
+  #   + items: An optional array of items with which to construct the new pane.
+  #
+  # Returns the new {PaneModel}.
   splitLeft: (params) ->
     @split('horizontal', 'before', params)
 
+  # Public: Creates a new pane to the right of the receiver.
+  #
+  # * params:
+  #   + items: An optional array of items with which to construct the new pane.
+  #
+  # Returns the new {PaneModel}.
   splitRight: (params) ->
     @split('horizontal', 'after', params)
 
+  # Public: Creates a new pane above the receiver.
+  #
+  # * params:
+  #   + items: An optional array of items with which to construct the new pane.
+  #
+  # Returns the new {PaneModel}.
   splitUp: (params) ->
     @split('vertical', 'before', params)
 
+  # Public: Creates a new pane below the receiver.
+  #
+  # * params:
+  #   + items: An optional array of items with which to construct the new pane.
+  #
+  # Returns the new {PaneModel}.
   splitDown: (params) ->
     @split('vertical', 'after', params)
 
+  # Private:
   split: (orientation, side, params) ->
     if @parent.orientation isnt orientation
       @parent.replaceChild(this, new PaneAxisModel({@container, orientation, children: [this]}))

From 561e31c0c53ff0478778532bf9403242ffbf6c8d Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sun, 12 Jan 2014 17:25:51 -0700
Subject: [PATCH 86/89] Remove ::removeItemAtIndex and make ::removeItem
 private

Call ::destroyItem or just destroy the item directly (it should emit the
'destroyed' event)
---
 spec/pane-container-spec.coffee | 28 ++++++++++++++--------------
 spec/pane-model-spec.coffee     |  8 ++++----
 spec/pane-spec.coffee           | 27 +++++++++++++--------------
 src/pane-model.coffee           |  6 ++----
 src/pane.coffee                 | 10 +++++-----
 5 files changed, 38 insertions(+), 41 deletions(-)

diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index 30a89328d..b9cb64d7d 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -183,27 +183,27 @@ describe "PaneContainer", ->
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item1a
 
-      it "is triggered when the active pane item is removed", ->
+      it "is triggered when the active pane item is destroyed", ->
         pane1.showItem(item1b)
         activeItemChangedHandler.reset()
 
-        pane1.removeItem(item1b)
+        pane1.destroyItem(item1b)
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item1a
 
-      it "is not triggered when an inactive pane item is removed", ->
+      it "is not triggered when an inactive pane item is destroyed", ->
         pane1.showItem(item1b)
         activeItemChangedHandler.reset()
 
-        pane1.removeItem(item1a)
+        pane1.destroyItem(item1a)
         expect(activeItemChangedHandler).not.toHaveBeenCalled()
 
-      it "is triggered when all pane items are removed", ->
-        pane1.removeItem(item1a)
+      it "is triggered when all pane items are destroyed", ->
+        pane1.destroyItem(item1a)
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toBe undefined
 
-      it "is triggered when the pane is removed", ->
+      it "is triggered when the pane is destroyed", ->
         pane1.remove()
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toBe undefined
@@ -224,27 +224,27 @@ describe "PaneContainer", ->
         pane1.showItem(item1b)
         expect(activeItemChangedHandler).not.toHaveBeenCalled()
 
-      it "is triggered when the active pane item removed from the active pane", ->
+      it "is triggered when the active pane's active item is destroyed", ->
         pane2.showItem(item2b)
         activeItemChangedHandler.reset()
 
-        pane2.removeItem(item2b)
+        pane2.destroyItem(item2b)
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item2a
 
-      it "is not triggered when the active pane item removed from an inactive pane", ->
+      it "is not triggered when an inactive pane's active item is destroyed", ->
         pane1.showItem(item1b)
         activeItemChangedHandler.reset()
 
-        pane1.removeItem(item1b)
+        pane1.destroyItem(item1b)
         expect(activeItemChangedHandler).not.toHaveBeenCalled()
 
-      it "is triggered when the active pane is removed", ->
+      it "is triggered when the active pane is destroyed", ->
         pane2.remove()
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item1a
 
-      it "is not triggered when an inactive pane is removed", ->
+      it "is not triggered when an inactive pane is destroyed", ->
         pane1.remove()
         expect(activeItemChangedHandler).not.toHaveBeenCalled()
 
@@ -263,7 +263,7 @@ describe "PaneContainer", ->
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item3a
 
-      it "is not triggered when the non active pane is removed", ->
+      it "is not triggered when an inactive pane is destroyed", ->
         pane3 = pane2.splitDown(item3a)
         activeItemChangedHandler.reset()
 
diff --git a/spec/pane-model-spec.coffee b/spec/pane-model-spec.coffee
index 77f1db022..6eb897b06 100644
--- a/spec/pane-model-spec.coffee
+++ b/spec/pane-model-spec.coffee
@@ -84,12 +84,12 @@ describe "PaneModel", ->
       pane2 = pane1.splitRight()
       expect(pane2.focused).toBe true
 
-  describe "::removeItemAtIndex(index)", ->
-    describe "when the last item is removed", ->
+  describe "::destroyItem(item)", ->
+    describe "when the last item is destroyed", ->
       it "destroys the pane", ->
         pane = new PaneModel(items: ["A", "B"])
-        pane.removeItemAtIndex(0)
-        pane.removeItemAtIndex(0)
+        pane.destroyItem("A")
+        pane.destroyItem("B")
         expect(pane.isDestroyed()).toBe true
 
   describe "when an item emits a destroyed event", ->
diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index cf85d9828..c24d10447 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -125,10 +125,10 @@ describe "Pane", ->
           pane.showPreviousItem()
           expect(pane.itemViews.find('.test-view').length).toBe initialViewCount + 2
 
-          pane.removeItem(model2)
+          pane.destroyItem(model2)
           expect(pane.itemViews.find('.test-view').length).toBe initialViewCount + 1
 
-          pane.removeItem(model1)
+          pane.destroyItem(model1)
           expect(pane.itemViews.find('.test-view').length).toBe initialViewCount
 
     describe "when showing a view item", ->
@@ -201,27 +201,26 @@ describe "Pane", ->
       pane.destroyItem(view1)
       expect(view1.wasRemoved).toBe true
 
-  describe "::removeItem(item)", ->
     it "removes the item from the items list and shows the next item if it was showing", ->
-      pane.removeItem(view1)
+      pane.destroyItem(view1)
       expect(pane.getItems()).toEqual [editor1, view2, editor2]
       expect(pane.activeItem).toBe editor1
 
       pane.showItem(editor2)
-      pane.removeItem(editor2)
+      pane.destroyItem(editor2)
       expect(pane.getItems()).toEqual [editor1, view2]
       expect(pane.activeItem).toBe editor1
 
     it "triggers 'pane:item-removed' with the item and its former index", ->
       itemRemovedHandler = jasmine.createSpy("itemRemovedHandler")
       pane.on 'pane:item-removed', itemRemovedHandler
-      pane.removeItem(editor1)
+      pane.destroyItem(editor1)
       expect(itemRemovedHandler).toHaveBeenCalled()
       expect(itemRemovedHandler.argsForCall[0][1..2]).toEqual [editor1, 1]
 
     describe "when removing the last item", ->
       it "removes the pane", ->
-        pane.removeItem(item) for item in pane.getItems()
+        pane.destroyItem(item) for item in pane.getItems()
         expect(pane.hasParent()).toBeFalsy()
 
       describe "when the pane is focused", ->
@@ -231,22 +230,22 @@ describe "Pane", ->
           pane2 = pane.splitRight(new TestView(id: 'view-3', text: 'View 3'))
           pane.focus()
           expect(pane).toMatchSelector(':has(:focus)')
-          pane.removeItem(item) for item in pane.getItems()
+          pane.destroyItem(item) for item in pane.getItems()
           expect(pane2).toMatchSelector ':has(:focus)'
 
     describe "when the item is a view", ->
       it "removes the item from the 'item-views' div", ->
         expect(view1.parent()).toMatchSelector pane.itemViews
-        pane.removeItem(view1)
+        pane.destroyItem(view1)
         expect(view1.parent()).not.toMatchSelector pane.itemViews
 
     describe "when the item is a model", ->
       it "removes the associated view only when all items that require it have been removed", ->
         pane.showItem(editor1)
         pane.showItem(editor2)
-        pane.removeItem(editor2)
+        pane.destroyItem(editor2)
         expect(pane.itemViews.find('.editor')).toExist()
-        pane.removeItem(editor1)
+        pane.destroyItem(editor1)
         expect(pane.itemViews.find('.editor')).not.toExist()
 
   describe "::moveItem(item, index)", ->
@@ -286,9 +285,9 @@ describe "Pane", ->
 
     describe "when it is the last item on the source pane", ->
       it "removes the source pane, but does not destroy the item", ->
-        pane.removeItem(view1)
-        pane.removeItem(view2)
-        pane.removeItem(editor2)
+        pane.destroyItem(view1)
+        pane.destroyItem(view2)
+        pane.destroyItem(editor2)
 
         expect(pane.getItems()).toEqual [editor1]
         pane.moveItemToPane(editor1, pane2, 1)
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 8ccef977e..15db07345 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -135,12 +135,10 @@ class PaneModel extends Model
     @emit 'item-added', item, index
     item
 
+  # Private:
   removeItem: (item, destroying) ->
     index = @items.indexOf(item)
-    @removeItemAtIndex(index, destroying) if index >= 0
-
-  removeItemAtIndex: (index, destroying) ->
-    item = @items[index]
+    return if index is -1
     @showNextItem() if item is @activeItem and @items.length > 1
     @items.splice(index, 1)
     @emit 'item-removed', item, index, destroying
diff --git a/src/pane.coffee b/src/pane.coffee
index 37c15add7..b52329127 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -26,11 +26,11 @@ class Pane extends View
 
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
   @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
-    'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex',  'removeItem', 'removeItemAtIndex',
-    'moveItem', 'moveItemToPane', 'destroyItem', 'destroyItems', 'destroyActiveItem',
-    'destroyInactiveItems', 'saveActiveItem', 'saveActiveItemAs', 'saveItem', 'saveItemAs',
-    'saveItems', 'itemForUri', 'showItemForUri', 'promptToSaveItem', 'copyActiveItem',
-    'isActive', 'activate', toProperty: 'model'
+    'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex', 'moveItem', 'moveItemToPane',
+    'destroyItem', 'destroyItems', 'destroyActiveItem', 'destroyInactiveItems',
+    'saveActiveItem', 'saveActiveItemAs', 'saveItem', 'saveItemAs', 'saveItems',
+    'itemForUri', 'showItemForUri', 'promptToSaveItem', 'copyActiveItem', 'isActive',
+    'activate', toProperty: 'model'
 
   previousActiveItem: null
 

From b438b311f341375e4052bcc918849449cfd57902 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sun, 12 Jan 2014 17:40:57 -0700
Subject: [PATCH 87/89] Rename showItem methods to activateItem

These methods set the *active* item, so the verb activate provides a
clearer correspondence. We could change the noun to "shown" item, but
that's awkward and having both active panes and active items is a nice
correspondence in terminology.
---
 spec/editor-view-spec.coffee    |  4 +-
 spec/pane-container-spec.coffee | 22 +++++------
 spec/pane-spec.coffee           | 66 ++++++++++++++++-----------------
 spec/workspace-view-spec.coffee | 10 ++---
 src/pane-model.coffee           | 24 ++++++------
 src/pane.coffee                 | 43 ++++++++++++++-------
 src/workspace-view.coffee       |  6 +--
 7 files changed, 95 insertions(+), 80 deletions(-)

diff --git a/spec/editor-view-spec.coffee b/spec/editor-view-spec.coffee
index 2f428dddd..6ab18ccdf 100644
--- a/spec/editor-view-spec.coffee
+++ b/spec/editor-view-spec.coffee
@@ -2756,7 +2756,7 @@ describe "EditorView", ->
         editorView = atom.workspaceView.getActiveView()
 
         view = $$ -> @div id: 'view', tabindex: -1, 'View'
-        editorView.getPane().showItem(view)
+        editorView.getPane().activateItem(view)
         expect(editorView.isVisible()).toBeFalsy()
 
         editorView.setText('hidden changes')
@@ -2764,7 +2764,7 @@ describe "EditorView", ->
 
         displayUpdatedHandler = jasmine.createSpy("displayUpdatedHandler")
         editorView.on 'editor:display-updated', displayUpdatedHandler
-        editorView.getPane().showItem(editorView.getModel())
+        editorView.getPane().activateItem(editorView.getModel())
         expect(editorView.isVisible()).toBeTruthy()
 
         waitsFor ->
diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index b9cb64d7d..5fb759860 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -88,7 +88,7 @@ describe "PaneContainer", ->
 
   describe ".saveAll()", ->
     it "saves all open pane items", ->
-      pane1.showItem(new TestView('4'))
+      pane1.activateItem(new TestView('4'))
 
       container.saveAll()
 
@@ -167,24 +167,24 @@ describe "PaneContainer", ->
 
     describe "when there is one pane", ->
       it "is triggered when a new pane item is added", ->
-        pane1.showItem(item1b)
+        pane1.activateItem(item1b)
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item1b
 
       it "is not triggered when the active pane item is shown again", ->
-        pane1.showItem(item1a)
+        pane1.activateItem(item1a)
         expect(activeItemChangedHandler).not.toHaveBeenCalled()
 
       it "is triggered when switching to an existing pane item", ->
-        pane1.showItem(item1b)
+        pane1.activateItem(item1b)
         activeItemChangedHandler.reset()
 
-        pane1.showItem(item1a)
+        pane1.activateItem(item1a)
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item1a
 
       it "is triggered when the active pane item is destroyed", ->
-        pane1.showItem(item1b)
+        pane1.activateItem(item1b)
         activeItemChangedHandler.reset()
 
         pane1.destroyItem(item1b)
@@ -192,7 +192,7 @@ describe "PaneContainer", ->
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item1a
 
       it "is not triggered when an inactive pane item is destroyed", ->
-        pane1.showItem(item1b)
+        pane1.activateItem(item1b)
         activeItemChangedHandler.reset()
 
         pane1.destroyItem(item1a)
@@ -216,16 +216,16 @@ describe "PaneContainer", ->
         activeItemChangedHandler.reset()
 
       it "is triggered when a new pane item is added to the active pane", ->
-        pane2.showItem(item2b)
+        pane2.activateItem(item2b)
         expect(activeItemChangedHandler.callCount).toBe 1
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item2b
 
       it "is not triggered when a new pane item is added to an inactive pane", ->
-        pane1.showItem(item1b)
+        pane1.activateItem(item1b)
         expect(activeItemChangedHandler).not.toHaveBeenCalled()
 
       it "is triggered when the active pane's active item is destroyed", ->
-        pane2.showItem(item2b)
+        pane2.activateItem(item2b)
         activeItemChangedHandler.reset()
 
         pane2.destroyItem(item2b)
@@ -233,7 +233,7 @@ describe "PaneContainer", ->
         expect(activeItemChangedHandler.argsForCall[0][1]).toEqual item2a
 
       it "is not triggered when an inactive pane's active item is destroyed", ->
-        pane1.showItem(item1b)
+        pane1.activateItem(item1b)
         activeItemChangedHandler.reset()
 
         pane1.destroyItem(item1b)
diff --git a/spec/pane-spec.coffee b/spec/pane-spec.coffee
index c24d10447..d1d031240 100644
--- a/spec/pane-spec.coffee
+++ b/spec/pane-spec.coffee
@@ -32,10 +32,10 @@ describe "Pane", ->
     it "displays the first item in the pane", ->
       expect(pane.itemViews.find('#view-1')).toExist()
 
-  describe "::showItem(item)", ->
+  describe "::activateItem(item)", ->
     it "hides all item views except the one being shown and sets the activeItem", ->
       expect(pane.activeItem).toBe view1
-      pane.showItem(view2)
+      pane.activateItem(view2)
       expect(view1.css('display')).toBe 'none'
       expect(view2.css('display')).not.toBe 'none'
       expect(pane.activeItem).toBe view2
@@ -46,35 +46,35 @@ describe "Pane", ->
       container.on 'pane:active-item-changed', itemChangedHandler
 
       expect(pane.activeItem).toBe view1
-      pane.showItem(view2)
-      pane.showItem(view2)
+      pane.activateItem(view2)
+      pane.activateItem(view2)
       expect(itemChangedHandler.callCount).toBe 1
       expect(itemChangedHandler.argsForCall[0][1]).toBe view2
       itemChangedHandler.reset()
 
-      pane.showItem(editor1)
+      pane.activateItem(editor1)
       expect(itemChangedHandler).toHaveBeenCalled()
       expect(itemChangedHandler.argsForCall[0][1]).toBe editor1
       itemChangedHandler.reset()
 
-    describe "if the pane's active view is focused before calling showItem", ->
+    describe "if the pane's active view is focused before calling activateItem", ->
       it "focuses the new active view", ->
         container.attachToDom()
         pane.focus()
         expect(pane.activeView).not.toBe view2
         expect(pane.activeView).toMatchSelector ':focus'
-        pane.showItem(view2)
+        pane.activateItem(view2)
         expect(view2).toMatchSelector ':focus'
 
     describe "when the given item isn't yet in the items list on the pane", ->
       view3 = null
       beforeEach ->
         view3 = new TestView(id: 'view-3', text: "View 3")
-        pane.showItem(editor1)
+        pane.activateItem(editor1)
         expect(pane.getActiveItemIndex()).toBe 1
 
       it "adds it to the items list after the active item", ->
-        pane.showItem(view3)
+        pane.activateItem(view3)
         expect(pane.getItems()).toEqual [view1, editor1, view3, view2, editor2]
         expect(pane.activeItem).toBe view3
         expect(pane.getActiveItemIndex()).toBe 2
@@ -83,21 +83,21 @@ describe "Pane", ->
         events = []
         container.on 'pane:item-added', (e, item, index) -> events.push(['pane:item-added', item, index])
         container.on 'pane:active-item-changed', (e, item) -> events.push(['pane:active-item-changed', item])
-        pane.showItem(view3)
+        pane.activateItem(view3)
         expect(events).toEqual [['pane:item-added', view3, 2], ['pane:active-item-changed', view3]]
 
     describe "when showing a model item", ->
       describe "when no view has yet been appended for that item", ->
         it "appends and shows a view to display the item based on its `.getViewClass` method", ->
-          pane.showItem(editor1)
+          pane.activateItem(editor1)
           editorView = pane.activeView
           expect(editorView.css('display')).not.toBe 'none'
           expect(editorView.editor).toBe editor1
 
       describe "when a valid view has already been appended for another item", ->
         it "multiple views are created for multiple items", ->
-          pane.showItem(editor1)
-          pane.showItem(editor2)
+          pane.activateItem(editor1)
+          pane.activateItem(editor2)
           expect(pane.itemViews.find('.editor').length).toBe 2
           editorView = pane.activeView
           expect(editorView.css('display')).not.toBe 'none'
@@ -118,11 +118,11 @@ describe "Pane", ->
             serialize: -> {@id, @text}
             getViewClass: -> TestView
 
-          pane.showItem(model1)
-          pane.showItem(model2)
+          pane.activateItem(model1)
+          pane.activateItem(model2)
           expect(pane.itemViews.find('.test-view').length).toBe initialViewCount + 2
 
-          pane.showPreviousItem()
+          pane.activatePreviousItem()
           expect(pane.itemViews.find('.test-view').length).toBe initialViewCount + 2
 
           pane.destroyItem(model2)
@@ -134,7 +134,7 @@ describe "Pane", ->
     describe "when showing a view item", ->
       it "appends it to the itemViews div if it hasn't already been appended and shows it", ->
         expect(pane.itemViews.find('#view-2')).not.toExist()
-        pane.showItem(view2)
+        pane.activateItem(view2)
         expect(pane.itemViews.find('#view-2')).toExist()
         expect(pane.activeView).toBe view2
 
@@ -206,7 +206,7 @@ describe "Pane", ->
       expect(pane.getItems()).toEqual [editor1, view2, editor2]
       expect(pane.activeItem).toBe editor1
 
-      pane.showItem(editor2)
+      pane.activateItem(editor2)
       pane.destroyItem(editor2)
       expect(pane.getItems()).toEqual [editor1, view2]
       expect(pane.activeItem).toBe editor1
@@ -241,8 +241,8 @@ describe "Pane", ->
 
     describe "when the item is a model", ->
       it "removes the associated view only when all items that require it have been removed", ->
-        pane.showItem(editor1)
-        pane.showItem(editor2)
+        pane.activateItem(editor1)
+        pane.activateItem(editor2)
         pane.destroyItem(editor2)
         expect(pane.itemViews.find('.editor')).toExist()
         pane.destroyItem(editor1)
@@ -300,12 +300,12 @@ describe "Pane", ->
       it "preserves data by detaching instead of removing", ->
         view1.data('preservative', 1234)
         pane.moveItemToPane(view1, pane2, 1)
-        pane2.showItemAtIndex(1)
+        pane2.activateItemAtIndex(1)
         expect(pane2.activeView.data('preservative')).toBe 1234
 
   describe "pane:close", ->
     it "destroys all items and removes the pane", ->
-      pane.showItem(editor1)
+      pane.activateItem(editor1)
       pane.trigger 'pane:close'
       expect(pane.hasParent()).toBeFalsy()
       expect(editor2.isDestroyed()).toBe true
@@ -313,7 +313,7 @@ describe "Pane", ->
 
   describe "pane:close-other-items", ->
     it "destroys all items except the current", ->
-      pane.showItem(editor1)
+      pane.activateItem(editor1)
       pane.trigger 'pane:close-other-items'
       expect(editor2.isDestroyed()).toBe true
       expect(pane.getItems()).toEqual [editor1]
@@ -323,7 +323,7 @@ describe "Pane", ->
       describe "when the current item has a save method", ->
         it "saves the current item", ->
           spyOn(editor2, 'save')
-          pane.showItem(editor2)
+          pane.activateItem(editor2)
           pane.saveActiveItem()
           expect(editor2.save).toHaveBeenCalled()
 
@@ -341,7 +341,7 @@ describe "Pane", ->
         it "opens a save dialog and saves the current item as the selected path", ->
           newEditor = atom.project.openSync()
           spyOn(newEditor, 'saveAs')
-          pane.showItem(newEditor)
+          pane.activateItem(newEditor)
 
           pane.saveActiveItem()
 
@@ -361,7 +361,7 @@ describe "Pane", ->
     describe "when the current item has a saveAs method", ->
       it "opens the save dialog and calls saveAs on the item with the selected path", ->
         spyOn(editor2, 'saveAs')
-        pane.showItem(editor2)
+        pane.activateItem(editor2)
 
         pane.saveActiveItemAs()
 
@@ -409,7 +409,7 @@ describe "Pane", ->
       expect(activeItemTitleChangedHandler).toHaveBeenCalled()
       activeItemTitleChangedHandler.reset()
 
-      pane.showItem(view2)
+      pane.activateItem(view2)
       view2.trigger 'title-changed'
       expect(activeItemTitleChangedHandler).toHaveBeenCalled()
 
@@ -417,7 +417,7 @@ describe "Pane", ->
     it "removes the pane item", ->
       filePath = temp.openSync('atom').path
       editor = atom.project.openSync(filePath)
-      pane.showItem(editor)
+      pane.activateItem(editor)
       expect(pane.items).toHaveLength(5)
 
       fs.removeSync(filePath)
@@ -441,7 +441,7 @@ describe "Pane", ->
       [paneToLeft, paneToRight] = []
 
       beforeEach ->
-        pane.showItem(editor1)
+        pane.activateItem(editor1)
         paneToLeft = pane.splitLeft(pane.copyActiveItem())
         paneToRight = pane.splitRight(pane.copyActiveItem())
         container.attachToDom()
@@ -485,7 +485,7 @@ describe "Pane", ->
 
   describe "::getNextPane()", ->
     it "returns the next pane if one exists, wrapping around from the last pane to the first", ->
-      pane.showItem(editor1)
+      pane.activateItem(editor1)
       expect(pane.getNextPane()).toBeUndefined
       pane2 = pane.splitRight(pane.copyActiveItem())
       expect(pane.getNextPane()).toBe pane2
@@ -531,7 +531,7 @@ describe "Pane", ->
     [pane1, view3, view4] = []
     beforeEach ->
       pane1 = pane
-      pane.showItem(editor1)
+      pane.activateItem(editor1)
       view3 = new TestView(id: 'view-3', text: 'View 3')
       view4 = new TestView(id: 'view-4', text: 'View 4')
 
@@ -606,7 +606,7 @@ describe "Pane", ->
       expect(newPane.getItems()).toEqual [view1, editor1, view2, editor2]
 
     it "restores the active item on deserialization", ->
-      pane.showItem(editor2)
+      pane.activateItem(editor2)
       newPane = pane.testSerialization()
       expect(newPane.activeItem).toEqual editor2
 
@@ -616,7 +616,7 @@ describe "Pane", ->
       class Unserializable
         getViewClass: -> TestView
 
-      pane.showItem(new Unserializable)
+      pane.activateItem(new Unserializable)
 
       newPane = pane.testSerialization()
       expect(newPane.activeItem).toEqual pane.items[0]
diff --git a/spec/workspace-view-spec.coffee b/spec/workspace-view-spec.coffee
index 51625a590..a47854dae 100644
--- a/spec/workspace-view-spec.coffee
+++ b/spec/workspace-view-spec.coffee
@@ -48,10 +48,10 @@ describe "WorkspaceView", ->
         pane2 = pane1.splitRight()
         pane3 = pane2.splitRight()
         pane4 = pane2.splitDown()
-        pane2.showItem(atom.project.openSync('b'))
-        pane3.showItem(atom.project.openSync('../sample.js'))
+        pane2.activateItem(atom.project.openSync('b'))
+        pane3.activateItem(atom.project.openSync('../sample.js'))
         pane3.activeItem.setCursorScreenPosition([2, 4])
-        pane4.showItem(atom.project.openSync('../sample.txt'))
+        pane4.activateItem(atom.project.openSync('../sample.txt'))
         pane4.activeItem.setCursorScreenPosition([0, 2])
         pane2.focus()
 
@@ -570,7 +570,7 @@ describe "WorkspaceView", ->
     it "saves active editor until there are none", ->
       editor = atom.project.openSync('../sample.txt')
       spyOn(editor, 'save')
-      atom.workspaceView.getActivePane().showItem(editor)
+      atom.workspaceView.getActivePane().activateItem(editor)
       atom.workspaceView.trigger('core:save')
       expect(editor.save).toHaveBeenCalled()
 
@@ -581,6 +581,6 @@ describe "WorkspaceView", ->
     it "saves active editor until there are none", ->
       editor = atom.project.openSync('../sample.txt')
       spyOn(editor, 'saveAs')
-      atom.workspaceView.getActivePane().showItem(editor)
+      atom.workspaceView.getActivePane().activateItem(editor)
       atom.workspaceView.trigger('core:save-as')
       expect(editor.saveAs).toHaveBeenCalled()
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 15db07345..66b231f85 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -90,31 +90,31 @@ class PaneModel extends Model
     @items[index]
 
   # Public: Makes the next item active.
-  showNextItem: ->
+  activateNextItem: ->
     index = @getActiveItemIndex()
     if index < @items.length - 1
-      @showItemAtIndex(index + 1)
+      @activateItemAtIndex(index + 1)
     else
-      @showItemAtIndex(0)
+      @activateItemAtIndex(0)
 
   # Public: Makes the previous item active.
-  showPreviousItem: ->
+  activatePreviousItem: ->
     index = @getActiveItemIndex()
     if index > 0
-      @showItemAtIndex(index - 1)
+      @activateItemAtIndex(index - 1)
     else
-      @showItemAtIndex(@items.length - 1)
+      @activateItemAtIndex(@items.length - 1)
 
   # Public: Returns the index of the current active item.
   getActiveItemIndex: ->
     @items.indexOf(@activeItem)
 
   # Public: Makes the item at the given index active.
-  showItemAtIndex: (index) ->
-    @showItem(@itemAtIndex(index))
+  activateItemAtIndex: (index) ->
+    @activateItem(@itemAtIndex(index))
 
   # Public: Makes the given item active, adding the item if necessary.
-  showItem: (item) ->
+  activateItem: (item) ->
     if item?
       @addItem(item)
       @activeItem = item
@@ -139,7 +139,7 @@ class PaneModel extends Model
   removeItem: (item, destroying) ->
     index = @items.indexOf(item)
     return if index is -1
-    @showNextItem() if item is @activeItem and @items.length > 1
+    @activateNextItem() if item is @activeItem and @items.length > 1
     @items.splice(index, 1)
     @emit 'item-removed', item, index, destroying
     @destroy() if @items.length is 0
@@ -246,9 +246,9 @@ class PaneModel extends Model
 
   # Public: Activates the first item that matches the given URI. Returns a
   # boolean indicating whether a matching item was found.
-  showItemForUri: (uri) ->
+  activateItemForUri: (uri) ->
     if item = @itemForUri(uri)
-      @showItem(item)
+      @activateItem(item)
       true
     else
       false
diff --git a/src/pane.coffee b/src/pane.coffee
index b52329127..0385bcf23 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -25,11 +25,11 @@ class Pane extends View
       @div class: 'item-views', outlet: 'itemViews'
 
   @delegatesProperties 'items', 'activeItem', toProperty: 'model'
-  @delegatesMethods 'getItems', 'showNextItem', 'showPreviousItem', 'getActiveItemIndex',
-    'showItemAtIndex', 'showItem', 'addItem', 'itemAtIndex', 'moveItem', 'moveItemToPane',
+  @delegatesMethods 'getItems', 'activateNextItem', 'activatePreviousItem', 'getActiveItemIndex',
+    'activateItemAtIndex', 'activateItem', 'addItem', 'itemAtIndex', 'moveItem', 'moveItemToPane',
     'destroyItem', 'destroyItems', 'destroyActiveItem', 'destroyInactiveItems',
     'saveActiveItem', 'saveActiveItemAs', 'saveItem', 'saveItemAs', 'saveItems',
-    'itemForUri', 'showItemForUri', 'promptToSaveItem', 'copyActiveItem', 'isActive',
+    'itemForUri', 'activateItemForUri', 'promptToSaveItem', 'copyActiveItem', 'isActive',
     'activate', toProperty: 'model'
 
   previousActiveItem: null
@@ -65,18 +65,18 @@ class Pane extends View
       false
 
     @command 'pane:save-items', => @saveItems()
-    @command 'pane:show-next-item', => @showNextItem()
-    @command 'pane:show-previous-item', => @showPreviousItem()
+    @command 'pane:show-next-item', => @activateNextItem()
+    @command 'pane:show-previous-item', => @activatePreviousItem()
 
-    @command 'pane:show-item-1', => @showItemAtIndex(0)
-    @command 'pane:show-item-2', => @showItemAtIndex(1)
-    @command 'pane:show-item-3', => @showItemAtIndex(2)
-    @command 'pane:show-item-4', => @showItemAtIndex(3)
-    @command 'pane:show-item-5', => @showItemAtIndex(4)
-    @command 'pane:show-item-6', => @showItemAtIndex(5)
-    @command 'pane:show-item-7', => @showItemAtIndex(6)
-    @command 'pane:show-item-8', => @showItemAtIndex(7)
-    @command 'pane:show-item-9', => @showItemAtIndex(8)
+    @command 'pane:show-item-1', => @activateItemAtIndex(0)
+    @command 'pane:show-item-2', => @activateItemAtIndex(1)
+    @command 'pane:show-item-3', => @activateItemAtIndex(2)
+    @command 'pane:show-item-4', => @activateItemAtIndex(3)
+    @command 'pane:show-item-5', => @activateItemAtIndex(4)
+    @command 'pane:show-item-6', => @activateItemAtIndex(5)
+    @command 'pane:show-item-7', => @activateItemAtIndex(6)
+    @command 'pane:show-item-8', => @activateItemAtIndex(7)
+    @command 'pane:show-item-9', => @activateItemAtIndex(8)
 
     @command 'pane:split-left', => @splitLeft(@copyActiveItem())
     @command 'pane:split-right', => @splitRight(@copyActiveItem())
@@ -92,6 +92,21 @@ class Pane extends View
   serializeParams: ->
     model: @model.serialize()
 
+  # Deprecated: Use ::activateItem
+  showItem: (item) -> @activateItem(item)
+
+  # Deprecated: Use ::activateItemForUri
+  showItemForUri: (item) -> @activateItemForUri(item)
+
+  # Deprecated: Use ::activateItemAtIndex
+  showItemAtIndex: (index) -> @activateItemAtIndex(index)
+
+  # Deprecated: Use ::activateNextItem
+  showNextItem: -> @activateNextItem()
+
+  # Deprecated: Use ::activatePreviousItem
+  showPreviousItem: -> @activatePreviousItem()
+
   # Private:
   afterAttach: (onDom) ->
     @focus() if @model.focused and onDom
diff --git a/src/workspace-view.coffee b/src/workspace-view.coffee
index daac10423..cd5075784 100644
--- a/src/workspace-view.coffee
+++ b/src/workspace-view.coffee
@@ -172,7 +172,7 @@ class WorkspaceView extends View
           @panes.setRoot(activePane)
 
         @itemOpened(editor)
-        activePane.showItem(editor)
+        activePane.activateItem(editor)
         activePane.activate() if changeFocus
         @trigger "uri-opened"
         editor
@@ -200,7 +200,7 @@ class WorkspaceView extends View
       else if split == 'left'
         pane = @getPanes()[0]
 
-      pane.showItem(paneItem)
+      pane.activateItem(paneItem)
     else
       paneItem = atom.project.openSync(uri, {initialLine})
       pane = new Pane(paneItem)
@@ -218,7 +218,7 @@ class WorkspaceView extends View
 
     if pane
       paneItem = pane.itemForUri(uri)
-      pane.showItem(paneItem)
+      pane.activateItem(paneItem)
       pane.activate() if changeFocus
       paneItem
     else

From 3fc3d48deff4f3a86c01cd6f29141b95105b9a82 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sun, 12 Jan 2014 17:49:08 -0700
Subject: [PATCH 88/89] Destroy empty panes after deserializing

Fixes #1399
---
 spec/pane-container-model-spec.coffee | 12 +++++++++---
 spec/pane-container-spec.coffee       |  2 +-
 src/pane-container-model.coffee       |  7 ++++++-
 src/pane-container.coffee             |  4 ----
 src/pane-model.coffee                 |  2 +-
 5 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/spec/pane-container-model-spec.coffee b/spec/pane-container-model-spec.coffee
index a37772d7d..027272218 100644
--- a/spec/pane-container-model-spec.coffee
+++ b/spec/pane-container-model-spec.coffee
@@ -6,10 +6,16 @@ describe "PaneContainerModel", ->
     [containerA, pane1A, pane2A, pane3A] = []
 
     beforeEach ->
-      pane1A = new PaneModel
+      # This is a dummy item to prevent panes from being empty on deserialization
+      class Item
+        atom.deserializers.add(this)
+        @deserialize: -> new this
+        serialize: -> deserializer: 'Item'
+
+      pane1A = new PaneModel(items: [new Item])
       containerA = new PaneContainerModel(root: pane1A)
-      pane2A = pane1A.splitRight()
-      pane3A = pane2A.splitDown()
+      pane2A = pane1A.splitRight(items: [new Item])
+      pane3A = pane2A.splitDown(items: [new Item])
 
     it "preserves the focused pane across serialization", ->
       expect(pane3A.focused).toBe true
diff --git a/spec/pane-container-spec.coffee b/spec/pane-container-spec.coffee
index 5fb759860..374b84a00 100644
--- a/spec/pane-container-spec.coffee
+++ b/spec/pane-container-spec.coffee
@@ -130,7 +130,7 @@ describe "PaneContainer", ->
       expect(newContainer.find('.pane-row > :contains(1)').width()).toBe 150
       expect(newContainer.find('.pane-row > .pane-column > :contains(2)').height()).toBe 100
 
-    xit "removes empty panes on deserialization", ->
+    it "removes empty panes on deserialization", ->
       # only deserialize pane 1's view successfully
       TestView.deserialize = ({name}) -> new TestView(name) if name is '1'
       newContainer = atom.deserializers.deserialize(container.serialize())
diff --git a/src/pane-container-model.coffee b/src/pane-container-model.coffee
index 81f93df64..f7fa4c0c6 100644
--- a/src/pane-container-model.coffee
+++ b/src/pane-container-model.coffee
@@ -16,12 +16,14 @@ class PaneContainerModel extends Model
   @behavior 'activePaneItem', ->
     @$activePane.switch (activePane) -> activePane?.$activeItem
 
-  constructor: ->
+  constructor: (params) ->
     super
     @subscribe @$root, @onRootChanged
+    @destroyEmptyPanes() if params?.destroyEmptyPanes
 
   deserializeParams: (params) ->
     params.root = atom.deserializers.deserialize(params.root, container: this)
+    params.destroyEmptyPanes = true
     params
 
   serializeParams: (params) ->
@@ -59,3 +61,6 @@ class PaneContainerModel extends Model
       @subscribe root, 'destroyed', =>
         @activePane = null
         @root = null
+
+  destroyEmptyPanes: ->
+    pane.destroy() for pane in @getPanes() when pane.items.length is 0
diff --git a/src/pane-container.coffee b/src/pane-container.coffee
index 6c03ddbe2..4b258ff7d 100644
--- a/src/pane-container.coffee
+++ b/src/pane-container.coffee
@@ -110,10 +110,6 @@ class PaneContainer extends View
       return pane if view?
     null
 
-  removeEmptyPanes: ->
-    for pane in @getPanes() when pane.getItems().length == 0
-      pane.remove()
-
   focusNextPane: ->
     panes = @getPanes()
     if panes.length > 1
diff --git a/src/pane-model.coffee b/src/pane-model.coffee
index 66b231f85..4866e068b 100644
--- a/src/pane-model.coffee
+++ b/src/pane-model.coffee
@@ -53,7 +53,7 @@ class PaneModel extends Model
   # Private: Called by the Serializable mixin during deserialization.
   deserializeParams: (params) ->
     {items, activeItemUri} = params
-    params.items = items.map (itemState) -> atom.deserializers.deserialize(itemState)
+    params.items = compact(items.map (itemState) -> atom.deserializers.deserialize(itemState))
     params.activeItem = find params.items, (item) -> item.getUri?() is activeItemUri
     params
 

From 4179d9d2682c329c968fb43a4206d0b8f24c26d3 Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@github.com>
Date: Sun, 12 Jan 2014 17:55:29 -0700
Subject: [PATCH 89/89] Add deprecated Pane::removeItem

---
 src/pane.coffee | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/pane.coffee b/src/pane.coffee
index 0385bcf23..879e530cc 100644
--- a/src/pane.coffee
+++ b/src/pane.coffee
@@ -92,6 +92,9 @@ class Pane extends View
   serializeParams: ->
     model: @model.serialize()
 
+  # Deprecated: Use ::destroyItem
+  removeItem: (item) -> @destroyItem(item)
+
   # Deprecated: Use ::activateItem
   showItem: (item) -> @activateItem(item)