title: Problem with adding many tool tips to a view
body: <p>My Cocoa application has a view with about fifty colored rectangles to be displayed, which represents a heat map of some data. I cannot figure out how to add tool tips to each of the rectangles showing information about the data which that rectangle represents. I looked at the developer documentation for <code>NSView</code> and have added the following code:</p>
  
  <pre><code>- (NSString *)view:(NSView *)view stringForToolTip:(NSToolTipTag)tag point:(NSPoint)point userData:(void *)data
  {
  
      // use the tags to determine which rectangle is under the mouse
      if (tag == blueTag) {
          return NSLocalizedString(@"The Blue rectangle", @"");
      }
      if (tag == redTag) {
          return NSLocalizedString(@"The Blue rectangle", @"");    
      }
      // we should never get to here!
      return NSLocalizedString(@"Unknown tooltip area", @"");
  }
  </code></pre>
  
  <hr>
  
  <pre><code>// add tooltips for the rectangles (in my  drawRect method 
  // after the rects have been initialized etc.)
  [self removeAllToolTips];
  redTag = [self addToolTipRect:startingRect owner:self userData:NULL];
  blueTag = [self addToolTipRect:blueRect owner:self userData:NULL];
  </code></pre>
  
  <p>I run into two issues:<br>
  1) when I print out the tag for the tooltips, they both show <code>1</code> as the tag even though they are for two different rectangles.<br>
  2) the <code>stringForToolTip</code> method is never called</p>
  
  <p>Any help/suggestions would be great. Thanks!</p>