On Mon, 16 Nov 2009 10:25:07 -0800, Kyle Sluder <kyle.slu...@gmail.com> said: >On Mon, Nov 16, 2009 at 9:23 AM, Matt Neuburg <m...@tidbits.com> wrote: >> On Sun, 15 Nov 2009 22:38:04 -0600, Gordon Apple <g...@ed4u.com> said: >>> What I don't understand, is that, according to the core animation guide, >>>kCATransition seems to be what I want for a key instead of "sublayers". The >>>guide says this is triggered by "replaceSublayer: with:". However, stepping >>>it through, I never see this key come through the delegate. >> >> You seem to be imagining that you can call addAnimation:forKey: and then the >> animation will just lurk there, waiting for something called the "key" to >> come along, and then the animation will trigger. That is not what >> addAnimation:forKey: does, and it isn't what the "key" means. > >No, I believe now he is talking about the delegate method >-actionForLayer:forKey:, and wondering why he never gets a key of >kCATransition, instead getting one for @"sublayers". This runs >contrary to the documentation.
Nothing here "runs contrary to the documentation." We're now talking apples and oranges. The "key" used in addAnimation:forKey: (such as kCATransition) has nothing whatever to do with the "key" that arrives in actionForLayer:forKey:. They both happen to be called "key" but that's all. The former, as I explained in my previous message, is just an arbitrary name, which is used just in case you need to call removeAnimationForKey: later, and for no other purpose. The latter is the name of a CALayer animatable property; that property is changing, and you are now being asked whether to animate that property. It is a pity that Apple has used the word "key" (and, by implication, keyPath) in such a fast-and-loose way all over the place. If addAnimation:forKey: were called addAnimation:withArbitraryName:, and actionForLayer:forKey: were called actionForLayer:forAnimatableProperty:, we wouldn't be having this problem now. :) If you want to complain about the documentation, the thing to complain about is that it's so hard to discover what the keys are for actionForLayer:forKey:. Well, yes, there is a list of the keys under "Animatable Properties" in the Core Animation Programming Guide; but nothing tells you that replaceSublayer:with: corresponds to the "sublayers" animatable property key. m. -- matt neuburg, phd = m...@tidbits.com, <http://www.tidbits.com/matt/> A fool + a tool + an autorelease pool = cool! AppleScript: the Definitive Guide - Second Edition! http://www.tidbits.com/matt/default.html#applescriptthings _______________________________________________ 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
