title: NSTextField and FirstResponder
body: <p>I am developing a cocoa application that has a main window and several panel windows.</p>
  
  <p>I need to autosave some text on a <code>NSTextField</code> (which is on a panel window) when user leaves the textfield by clicking the main window etc.  so far I have tried out by implementing resignFirstResponder on a <code>NSTextField</code> subclass,however if I click on another textfield on the same window "resignFirstResponder" gets triggered but if I just click on somewhere empty on my main window it does not get triggered. (<code>NSTextField</code> loses the blue focus though)</p>
  
  <p>I need to capture this event the <code>NSTextField</code> loses  the focus ring to save the uncommitted changes . Any pointers would be highly appreciated.</p>
  
  <p>This text field is on <code>NSTableCellView</code></p>