Trigger 'pane:active-item-changed' on Pane

This event is triggered when the item changes on the active pane, or
when a different pane becomes active.

Also: Pane now sets itself as the active pane, rather than letting
PaneContainer handle the focusin event.

src/app/pane-container.coffee

@@ -13,11 +13,6 @@ class PaneContainer extends View
   @content: ->
     @div id: 'panes'
 
-  initialize: ->
-    @on 'focusin', (e) =>
-      focusedPane = $(e.target).closest('.pane').view()
-      @setActivePane(focusedPane)
-
   serialize: ->
     deserializer: 'PaneContainer'
     root: @getRoot()?.serialize()
@@ -40,9 +35,6 @@ class PaneContainer extends View
   getActivePane: ->
     @find('.pane.active').view() ? @find('.pane:first').view()
 
-  setActivePane: (pane) ->
-    @find('.pane').removeClass('active')
-    pane.addClass('active')
 
   adjustPaneDimensions: ->
     if root = @getRoot()

src/app/pane.coffee

@@ -27,9 +27,21 @@ class Pane extends View
     @command 'pane:split-right', => @splitRight()
     @command 'pane:split-up', => @splitUp()
     @command 'pane:split-down', => @splitDown()
-    @on 'focus', =>
-      @viewForCurrentItem().focus()
-      false
+    @on 'focus', => @currentView.focus(); false
+    @on 'focusin', => @makeActive()
+
+  makeActive: ->
+    for pane in @getContainer().getPanes() when pane isnt this
+      pane.makeInactive()
+    wasActive = @isActive()
+    @addClass('active')
+    @trigger 'pane:active-item-changed', [@currentItem] unless wasActive
+
+  makeInactive: ->
+    @removeClass('active')
+
+  isActive: ->
+    @hasClass('active')
 
   getItems: ->
     new Array(@items...)
@@ -55,6 +67,7 @@ class Pane extends View
     @showItem(@items[index])
 
   showItem: (item) ->
+    return if item is @currentItem
     @addItem(item)
     @itemViews.children().hide()
     view = @viewForItem(item)
@@ -62,6 +75,7 @@ class Pane extends View
     @currentItem = item
     @currentView = view
     @currentView.show()
+    @trigger 'pane:active-item-changed', [item] if @isActive()
 
   addItem: (item) ->
     return if _.include(@items, item)