RootView constructor can be called with serialized view state data

Move the saving of serialized root view data to window.coffee. The window.startup method looks for window state on the atom object and instantiates the root view with that if it is present.

src/app/atom.coffee

@@ -10,12 +10,13 @@ class Atom
   keymap: null
   windows: null
   userConfigurationPath: null
+  rootViewStates: null
 
   constructor: (@loadPath, nativeMethods)->
     @windows = []
     @setUpKeymap()
     @userConfigurationPath = fs.absolute "~/.atom/atom.coffee"
-    @windowStatesByWindowNumber = {}
+    @rootViewStates = {}
 
   setUpKeymap: ->
     @keymap = new Keymap()

src/app/root-view.coffee

@@ -18,10 +18,7 @@ class RootView extends View
     @div id: 'root-view', tabindex: -1, =>
       @div id: 'panes', outlet: 'panes'
 
-  initialize: (params) ->
-    {path} = params
-    @createProject(path)
-
+  initialize: ({ pathToOpen, projectPath, panesViewState }) ->
     @on 'toggle-file-finder', => @toggleFileFinder()
     @on 'show-console', => window.showConsole()
     @on 'find-in-file', => @commandPanel.show("/")
@@ -34,18 +31,53 @@ class RootView extends View
 
     @commandPanel = new CommandPanel({rootView: this})
 
-    $(window).on 'beforeunload', =>
-      atom.windowStatesByWindowNumber[$windowNumber] = @getWindowState()
+    if projectPath?
+      @project = new Project(projectPath)
+    else if pathToOpen?
+      @project = new Project(fs.directory(pathToOpen))
+      @open(pathToOpen) if fs.isFile(pathToOpen)
+    else if not panesViewState
+      @activeEditor().setBuffer(new Buffer)
 
-    if windowState = atom.windowStatesByWindowNumber[$windowNumber]
-      @setWindowState(windowState)
+    @deserializePanes(panesViewState) if panesViewState
 
-  createProject: (path) ->
-    if path
-      @project = new Project(fs.directory(path))
-      @open(path) if fs.isFile(path)
-    else
-      @activeEditor().setBuffer(new Buffer())
+  serialize: ->
+    projectPath: @project?.path
+    panesViewState: @serializePanes()
+
+  serializePanes: (element = @panes.children(':eq(0)')) ->
+    if element.hasClass('pane')
+      ['editor', element.view().content.getEditorState()]
+    else if element.hasClass('row')
+      ['row'].concat element.children().toArray().map (elt) =>
+        @serializePanes($(elt))
+    else if element.hasClass('column')
+      ['column'].concat element.children().toArray().map (elt) =>
+        @serializePanes($(elt))
+
+  deserializePanes: (panesViewState, parent) ->
+    adjustSplitPanes = false
+    unless parent
+      @panes.empty()
+      adjustSplitPanes = true
+      parent = @panes
+
+    switch panesViewState.shift()
+      when 'editor'
+        editor = new Editor(panesViewState...)
+        parent.append(new Pane(editor))
+      when 'row'
+        row = $$ -> @div class: 'row'
+        parent.append row
+        for child in panesViewState
+          @deserializePanes(child, row)
+      when 'column'
+        column = $$ -> @div class: 'column'
+        parent.append column
+        for child in panesViewState
+          @deserializePanes(child, column)
+
+    @adjustSplitPanes() if adjustSplitPanes
 
   open: (path) ->
     @activeEditor().setBuffer(@project.open(path))
@@ -80,45 +112,16 @@ class RootView extends View
     if editor.length
       editor.view()
     else
-      editor = new Editor
-      pane = new Pane(editor)
-      @panes.append(pane)
-      editor.focus()
-      editor
+      editor = @panes.find('.editor:first')
+      if editor.length
+        editor.view()
+      else
+        editor = new Editor
+        pane = new Pane(editor)
+        @panes.append(pane)
+        editor.focus()
+        editor
 
-  getWindowState: (element = @panes.children(':eq(0)')) ->
-    if element.hasClass('pane')
-      ['editor', element.view().content.getEditorState()]
-    else if element.hasClass('row')
-      ['row'].concat element.children().toArray().map (elt) =>
-        @getWindowState($(elt))
-    else if element.hasClass('column')
-      ['column'].concat element.children().toArray().map (elt) =>
-        @getWindowState($(elt))
-
-  setWindowState: (windowState, parent) ->
-    adjustSplitPanes = false
-    unless parent
-      @panes.empty()
-      adjustSplitPanes = true
-      parent = @panes
-
-    switch windowState.shift()
-      when 'editor'
-        editor = new Editor(windowState...)
-        parent.append(new Pane(editor))
-      when 'row'
-        row = $$ -> @div class: 'row'
-        parent.append row
-        for child in windowState
-          @setWindowState(child, row)
-      when 'column'
-        column = $$ -> @div class: 'column'
-        parent.append column
-        for child in windowState
-          @setWindowState(child, column)
-
-    @adjustSplitPanes() if adjustSplitPanes
 
   addPane: (view, sibling, axis, side) ->
     unless sibling.parent().hasClass(axis)

src/app/window.coffee

@@ -24,6 +24,7 @@ windowAdditions =
     @attachRootView(path)
     @loadUserConfiguration()
     $(window).on 'close', => @close()
+    $(window).on 'beforeunload', => @saveRootViewState()
     $(window).focus()
     atom.windowOpened this
 
@@ -31,12 +32,17 @@ windowAdditions =
     @rootView.remove()
     $(window).unbind('focus')
     $(window).unbind('blur')
+    $(window).off('before')
     atom.windowClosed this
 
-  attachRootView: (path) ->
-    @rootView = new RootView {path}
+  attachRootView: (pathToOpen) ->
+    rootViewState = atom.rootViewStates[$windowNumber] or { pathToOpen }
+    @rootView = new RootView(rootViewState)
     $(@rootViewParentSelector).append @rootView
 
+  saveRootViewState: ->
+    atom.rootViewStates[$windowNumber] = @rootView.serialize()
+
   loadUserConfiguration: ->
     try
       require atom.userConfigurationPath if fs.exists(atom.userConfigurationPath)