Only emit editor-open event once (on first attachment)

spec/app/editor-spec.coffee

@@ -52,16 +52,19 @@ describe "Editor", ->
       expect(newEditor.editSessions[0]).not.toBe(editor.editSessions[0])
 
   describe "editor-open event", ->
-    it 'triggers an editor-open event when it is added to the DOM', ->
+    it 'only triggers an editor-open event when it is first added to the DOM', ->
       openHandler = jasmine.createSpy('openHandler')
       editor.on 'editor-open', openHandler
 
       editor.simulateDomAttachment()
-
       expect(openHandler).toHaveBeenCalled()
       [event, eventEditor] = openHandler.argsForCall[0]
       expect(eventEditor).toBe editor
 
+      openHandler.reset()
+      editor.simulateDomAttachment()
+      expect(openHandler).not.toHaveBeenCalled()
+
   describe "text rendering", ->
     it "creates a line element for each line in the buffer with the html-escaped text of the line", ->
       expect(editor.lines.find('.line').length).toEqual(buffer.numLines())

src/app/editor.coffee

@@ -201,7 +201,9 @@ class Editor extends View
       else
         @gutter.addClass('drop-shadow')
 
-    @on 'attach', =>
+    @on 'attach', (e) =>
+      return if @attached
+      @attached = true
       @calculateDimensions()
       @hiddenInput.width(@charWidth)
       @setMaxLineLength() if @softWrap