title: Focus Ring in field editor for NSTextFieldCell in an NSTableView
body: <p>I have a cell-based NSTableView with a text cell in a particular column. I want to provide a custom field editor so that I can do auto completion without the user pressing F5.</p>
  
  <pre><code>@implementation AutoCompleteFieldEditorTextView
  
  -(id)init
  {
      self = [super init];
      if (self)
      {
          self.focusRingType = NSFocusRingTypeDefault;
          self.fieldEditor = YES;
      }
      return self;
  }
  
  @end
  </code></pre>
  
  <p>This works ok except the focus ring does not exist. Even if I add:</p>
  
  <pre><code>-(void)drawFocusRingMask
  {
      NSRectFill([self bounds]);
  }
  
  -(NSRect)focusRingMaskBounds
  {
      return [self bounds];
  }
  </code></pre>
  
  <p>it still does not work. How can I get the exact focus ring that appears with the default NSTextView used as a field editor in an NSTableView?</p>