Always focus active pane item when pane is activated

Signed-off-by: Nathan Sobo <nathan@github.com>

spec/pane-element-spec.coffee

@@ -162,6 +162,10 @@ describe "PaneElement", ->
       paneElement.focus()
       expect(document.activeElement).toBe item
 
+      document.body.focus()
+      pane.activate()
+      expect(document.activeElement).toBe item
+
     it "makes the pane active", ->
       pane.splitRight()
       expect(pane.isActive()).toBe false

src/pane-element.coffee

@@ -27,7 +27,7 @@ class PaneElement extends HTMLElement
 
   subscribeToDOMEvents: ->
     handleFocus = (event) =>
-      @model.focus()
+      @model.focus() unless @isActivating
       if event.target is this and view = @getActiveView()
         view.focus()
         event.stopPropagation()
@@ -66,7 +66,9 @@ class PaneElement extends HTMLElement
   getModel: -> @model
 
   activated: ->
-    @focus() unless @hasFocus()
+    @isActivating = true
+    @focus()
+    @isActivating = false
 
   activeStatusChanged: (active) ->
     if active