First guess would be not to explicitly set -anchorPosition. It defaults to (0.5, 0.5), which refers to the middle of the bounds, and transforms (like scaling) are applied relative to that position.
> On Sep 14, 2019, at 6:25 AM, Gabriel Zachmann via Cocoa-dev > <cocoa-dev@lists.apple.com> wrote: > > Maybe, I haven't understood how the animation of the bounds property works, > or the bounds property of a CALayer itself , > or I am making a stupid mistake. > > Here is my code: > > CALayer * imgLayer = [CALayer layer]; > imgLayer.contents = (__bridge id) imageRef; > imgLayer.delegate = nil; > imgLayer.opacity = 1.0; > imgLayer.anchorPoint = CGPointMake( 0.0, 0.0 ); > imgLayer.zPosition = -1.0; > > CABasicAnimation * anim = [CABasicAnimation animationWithKeyPath: > @"bounds"]; > anim.timingFunction = [CAMediaTimingFunction functionWithName: > kCAMediaTimingFunctionLinear]; > anim.duration = 5; // sec > anim.autoreverses = YES; > anim.repeatCount = 1000000; // = > forever > > NSRect from_rect = NSMakeRect( 100.0, 100.0, 200.0, 200.0 ); > anim.fromValue = [NSValue valueWithRect: from_rect ]; > NSRect to_rect = NSMakeRect( 200.0, 200.0, 300.0, 300.0 ); > anim.toValue = [NSValue valueWithRect: to_rect ]; > > [imgLayer addAnimation: anim forKey: @"myBoundsAnim"]; > > > What I am seeing is that the image gets scaled (from 200 to 300 > width/height) which is fine, > but it always sits in the lower left corner of the screen (I am working under > macOS). > > I want the lower left corner of the image to be animated , too. > (Eventually, the animation will be a bit more complex, but for now I am just > trying to understand this.) > > What am I missing? or going wrong? > > I guess I could achieve the effect by animating the position property of the > layer, > but I'd rather prefer to understand what is going on. > I have also re-read the "Core Animation Basics" , but it doesn't explain the > meaning of bounds.origin. > In the drawings, it's always (0,0). > > Thanks a lot in advance for any insights. > > Best regards, Gabriel _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
