Thanks for that, I will take a look at it, and study it, and study it some more...
Peace, Love, and Light, /s/ Jon C. Munson II > -----Original Message----- > From: I. Savant [mailto:idiotsavant2...@gmail.com] > Sent: Wednesday, February 25, 2009 10:36 AM > To: jmun...@his.com > Cc: cocoa-dev > Subject: Re: [Q] What causes an NSArrayController to know that an entity > was inserted via a different window? > > 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
