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When in -mouseEntered: don't use NSPointInRect for checking which tracking area is hit

Do not assume that the mouse location of any mouse tracking NSEvent is necessarily inside or outside of the tracking rectangle as specified by the NSTrackingArea. Use the -trackingArea method of NSEvent instead of NSPointInRect to check, which trackingArea has triggered the event.

Bad code

- (void) syncInsideWithEvent:(NSEvent *) event
{
   NSPoint       point;
   unsigned int  i;
   
   point = [self convertPoint:[event locationInWindow] 
                     fromView:nil];
   for( i = 0; i < N_AREAS; i++)
      inside_[ i] = NSPointInRect( point, area_[ i]);

   [self setNeedsDisplay:YES];
}


- (void) mouseEntered:(NSEvent *) event 
{ 
   [self syncInsideWithEvent:event];
}


- (void) mouseExited:(NSEvent *) event 
{ 
   [self syncInsideWithEvent:event];
}

Better code

- (void) syncInsideWithEvent:(NSEvent *) event
                      invert:(BOOL) invert
{
   NSTrackingArea   *hit;
   NSTrackingArea   *area;
   NSArray          *areas;
   unsigned int     i;
   
   hit   = [event trackingArea];
   areas = [self trackingAreas];

   for( i = 0; i < N_AREAS; i++)
   {
      area        = [areas objectAtIndex:i];
      inside_[ i] = invert ? NO : (area == hit);
   }
   [self setNeedsDisplay:YES];
}


- (void) mouseEntered:(NSEvent *) event
{
   [self syncInsideWithEvent:event
                      invert:NO];
}


- (void) mouseExited:(NSEvent *) event
{
   [self syncInsideWithEvent:event
                      invert:YES];
}