Handle mousedown events only for left button in editors

src/editor-component.coffee

@@ -469,6 +469,8 @@ EditorComponent = React.createClass
       editor.insertText(char)
 
   onMouseDown: (event) ->
+    return unless event.button is 0 # only handle the left mouse button
+
     {editor} = @props
     {detail, shiftKey, metaKey} = event
     screenPosition = @screenPositionForMouseEvent(event)

src/editor-view.coffee

@@ -368,6 +368,8 @@ class EditorView extends View
       false if @isFocused
 
     @overlayer.on 'mousedown', (e) =>
+      return unless e.which is 1 # only handle the left mouse button
+
       @overlayer.hide()
       clickedElement = document.elementFromPoint(e.pageX, e.pageY)
       @overlayer.show()