Double clicking a file changes focus to editor. Double clicking a directory toggles expansion. Single clicking doesn't ever change focus away from tree view.

spec/extensions/tree-view-spec.coffee

@@ -123,25 +123,47 @@ describe "TreeView", ->
       expect(child.directory.subscriptionCount()).toBe 0
       expect(grandchild.directory.subscriptionCount()).toBe 0
 
-  describe "when a file is clicked", ->
-    it "opens it in the active editor, focuses it and selects it", ->
+  describe "when a file is single-clicked", ->
+    it "selects the files and opens it in the active editor, without changing focus", ->
       expect(rootView.activeEditor()).toBeUndefined()
 
-      sampleJs.click()
+      sampleJs.trigger clickEvent(originalEvent: { detail: 1 })
       expect(sampleJs).toHaveClass 'selected'
       expect(rootView.activeEditor().buffer.path).toBe require.resolve('fixtures/sample.js')
+      expect(rootView.activeEditor().isFocused).toBeFalsy()
 
-      sampleTxt.click()
+      sampleTxt.trigger clickEvent(originalEvent: { detail: 1 })
       expect(sampleTxt).toHaveClass 'selected'
       expect(treeView.find('.selected').length).toBe 1
       expect(rootView.activeEditor().buffer.path).toBe require.resolve('fixtures/sample.txt')
+      expect(rootView.activeEditor().isFocused).toBeFalsy()
 
-  describe "when a directory is clicked", ->
+  describe "when a file is double-clicked", ->
+    it "selects the file and opens it in the active editor on the first click, then changes focus to the active editor on the second", ->
+      sampleJs.trigger clickEvent(originalEvent: { detail: 1 })
+      expect(sampleJs).toHaveClass 'selected'
+      expect(rootView.activeEditor().buffer.path).toBe require.resolve('fixtures/sample.js')
+      expect(rootView.activeEditor().isFocused).toBeFalsy()
+
+      sampleJs.trigger clickEvent(originalEvent: { detail: 2 })
+      expect(rootView.activeEditor().isFocused).toBeTruthy()
+
+  describe "when a directory is single-clicked", ->
     it "is selected", ->
       subdir = treeView.root.find('.directory:first').view()
-      subdir.click()
+      subdir.trigger clickEvent(originalEvent: { detail: 1 })
       expect(subdir).toHaveClass 'selected'
 
+  describe "when a directory is double-clicked", ->
+    it "toggles the directory expansion state and does not change the focus to the editor", ->
+      sampleJs.trigger clickEvent(originalEvent: { detail: 1 })
+      subdir = treeView.root.find('.directory:first').view()
+      subdir.trigger clickEvent(originalEvent: { detail: 1 })
+      expect(subdir).toHaveClass 'selected'
+      subdir.trigger clickEvent(originalEvent: { detail: 2 })
+      expect(subdir).toHaveClass 'expanded'
+      expect(rootView.activeEditor().isFocused).toBeFalsy()
+
   describe "when a new file is opened in the active editor", ->
     it "is selected in the tree view if visible", ->
       sampleJs.click()

spec/spec-helper.coffee

@@ -71,9 +71,6 @@ window.keydownEvent = (pattern, properties={}) ->
   event.keystroke = (new Keymap).keystrokeStringForEvent(event)
   event
 
-window.clickEvent = (properties={}) ->
-  $.Event "click", properties
-
 window.mouseEvent = (type, properties) ->
   if properties.point
     {point, editor} = properties
@@ -83,6 +80,9 @@ window.mouseEvent = (type, properties) ->
   properties.originalEvent ?= {detail: 1}
   $.Event type, properties
 
+window.clickEvent = (properties={}) ->
+  window.mouseEvent("click", properties)
+
 window.mousedownEvent = (properties={}) ->
   window.mouseEvent('mousedown', properties)