After rotating a CALayer using CABasicAnimation the layer jumps back to it's unrotated position

iphone calayer cabasicanimation
Mikle picture Mikle · Sep 4, 2009 · Viewed 26.1k times · Source

I am trying to create a falling coin. The coin image is a CALayer with 2 CABasicAnimations on it - a falling down and a rotation one. When the falling down animation gets to its end, it stays there. The rotation animation though, which is supposed to be random and end up in a different angle every time, just pops back to the original CALAyer image.

I want it to stay in the angle it finished the animation on. Is it possible? How do I do it?

Code:

//Moving down animation:
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform.translation.y"];
anim.duration = 1;
anim.autoreverses = NO;
anim.removedOnCompletion = YES;

anim.fromValue = [NSNumber numberWithInt: -80 - row_height * (8 - _col)];
anim.toValue = [NSNumber numberWithInt: 0];

//Rotation Animation:
CABasicAnimation *rota = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
rota.duration = 4;
rota.autoreverses = NO;
rota.removedOnCompletion = NO;
rota.fromValue = [NSNumber numberWithFloat: 0];
rota.toValue = [NSNumber numberWithFloat: 2.5 * 3.15 ];
[cl addAnimation: rota forKey: @"rotation"];
[cl addAnimation: anim forKey: @"animateFalling"];

Answer

Allan Bazinet picture Allan Bazinet · Sep 4, 2009

Have you set the removedOnCompletion property of the rotation animation to NO, e.g.,

rota.removedOnCompletion = NO;

That should leave the presentation layer where it was when the animation finished. The default is YES, which will snap back to the model value, i.e., the behavior you describe.

The fillMode should also be set, i.e., 

rota.fillMode = kCAFillModeForwards;

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