On Wed, Feb 25, 2009 at 9:43 AM, Jon C. Munson II <jmun...@his.com> wrote:
> While it would be nice to actually see if a certain attribute got updated This is where a thorough understanding of KVC/KVO (with emphasis on the KVO part) comes in. I'll point you to mmalc's examples: http://homepage.mac.com/mmalc/CocoaExamples/controllers.html Check out the Graphics Bindings example. There may be other examples that highlight what I'm about to mention, but I'm not really familiar - the Graphics Bindings example was what really helped to seal my understanding (after many, many hours of studying / experimenting with ALL the relevant documentation). The thing to pay attention to is that, in this example, you have a custom array controller subclass which does special things on certain events (a key to your understanding), as well as a couple of custom views. The real meat is in the view classes. Specifically to your case, the GraphicsView class. Note how -bind:... is overridden and calls -startObservingGraphics: (and -unbind:... calls -stopObservingGraphics:). This is crucial because it shows how a view that's interested in the *properties* of the objects fed to it via bindings manages to observe specific *properties* of each bound object. That is, it specifically registers interest in the properties of each of the objects in its purview, and unregisters interest when the object is no longer in its purview. The -bind: method is called from the MyDocument class, so you can see that the @"shadowAngle" and @"shadowOffset" key paths are observed for each graphic object. -- I.S. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
