title: How to end editing in NSTextFieldCell inside NSOutlineView after ESC key is pressed
body: <p>I'm trying to get a custom <code>NSTextFieldCell</code> (inside a <code>NSOutlineView</code>) to end editing when the ESC key is pressed but cannot find any way to accomplish this. I tried to add an observer for the <code>NSControlTextDidChangeNotification</code>-notification but it is not fired for the ESC-key nor is <code>keyDown</code> fired in the <code>NSOutlineView</code>.</p>