Re: keeping view's bounds fixed

FROM : Quincey Morris
DATE : Tue Jan 29 06:30:03 2008

On Jan 28, 2008, at 20:38, Nathan Vander Wilt wrote:

> Since I *have* explicitly set the bounds rectangle,
> why is it still being automatically updated to match
> the frame's height/width? Where can I reset the
> bounds, so that they always are set to
> NSMakeRect(-180, -90, 360, 180) when my view's
> drawRect is called? The -viewDidEndLiveResize method
> will not work, because that message isn't passed when
> the window's zoom button is activated.


I don't have the "why?", but I did have a similar situation and after 
lots of hair-tearing-out the only reliable way I found was to monitor 
frame-change notifications. In my case, the view was inside a scroll 
view, so I needed to work off the scroll view's clip view, but if you 
don't have that complication, I think it would be fine to watch your 
own frame-change notification:

// version A
  [self setPostsFrameChangedNotifications: YES];
  [[NSNotificationCenter defaultCenter] addObserver: self selector: 
@selector (frameDidChangeNotification:) name: 
NSViewFrameDidChangeNotification object: self];

or possibly the superview's:

// version B
  [[self superview] setPostsFrameChangedNotifications: YES];
  [[NSNotificationCenter defaultCenter] addObserver: self selector: 
@selector (frameDidChangeNotification:) name: 
NSViewFrameDidChangeNotification object: [self superview]];

which is what I actually did, since the clip view was my view's 
superview. Then all you need is:

- (void) frameDidChangeNotification: (NSNotification*) notification {
  [self setBounds: NSMakeRect (-180, -90, 360, 180)];
}

The only thing to be careful of is not to cause an endless loop of 
notifications. (Setting your view's frame inside the notification 
method is fine with version B of the setup, but not so good with 
version A.)