animation options not respected/error in second animation block

Question

Using a simple CGAffineTransformMakeScale to make a pulsing label, I get an error when trying apply ease out options, delay etc on the second block? Without this I get jerky animation as im getting ease out on the increase and none on the return to the original size

  [UIView animateWithDuration:1.0f delay:0 options: UIViewAnimationCurveEaseInOut|UIViewAnimationOptionAllowUserInteraction animations: ^{

[UIView setAnimationRepeatCount:10];

    self.transform = CGAffineTransformMakeScale(1.1,1.1);

} completion:^(BOOL finished) {


    [UIView animateWithDuration:1.0 animations:^{  // <<< "No known method for selector" error here if I add options

        self.transform = CGAffineTransformMakeScale(1.0,1.0);

    }];
}];

BTW, you omitted the `Option` in `UIViewAnimationOptionCurveEaseInOut`. It turns out that it doesn't matter for ease-in-out (because they're both zero), but if you were using one of the other values, like ease-in only, they are quite different values. — Rob, Jun 20 '13 at 00:27

Rob · Accepted Answer · 2013-06-20T00:18:38.943

If you want it to animate ten times and then stop, you could use the UIViewAnimationOptionRepeat and UIViewAnimationOptionAutoreverse options. This way, it will gracefully reverse itself back to the original before repeating. It also saves you from needing to animate it back at the end:

[UIView animateWithDuration:1.0
                      delay:0.0
                    options:UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse | UIViewAnimationOptionCurveEaseInOut | UIViewAnimationOptionAllowUserInteraction
                 animations:^{
                     [UIView setAnimationRepeatCount:10];
                     self.viewToResize.transform = CGAffineTransformMakeScale(1.1, 1.1);
                 }
                 completion:^(BOOL finished) {
                     self.viewToResize.transform = CGAffineTransformIdentity;
                 }];

score 0 · Answer 2 · answered Jun 19 '13 at 22:45

0

Don't chain animations like that. Use the lower-level CoreAnimation API to specify an animation with keyframes. Here's an example that mimics the way a UIAlertView appears on screen:

CAKeyframeAnimation* bounceAnim = [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
bounceAnim.duration = 0.4f;
bounceAnim.values = @[ @0.01f, @1.1f, @0.9f, @1.f ];
bounceAnim.keyTimes = @[ @0.f, @0.5f, @0.75f, @1.f ];
bounceAnim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
bounceAnim.fillMode = kCAFillModeBoth;
bounceAnim.removedOnCompletion = YES;

[dialog.layer addAnimation:bounceAnim forKey:@"bounce"];

You'll want to modify it so that it loops, also tweak the values and timing to your liking. Check out the CAKeyframeAnimation documentation.

answered Jun 19 '13 at 22:45

Idles

1,131
5
9

Why not chain animations using the complete block? It's not implemented correctly in the question, but it's an acceptable practice. I agree that key frame animations are excellent when you need that additional level of control, but there's nothing wrong with putting another animation in the completion block of another. As the docs say, "For block-based animations, use the completion handler supported by the `animateWithDuration:animations:completion:` and `animateWithDuration:delay:options:animations:completion:` methods to execute any follow-on animations." – Rob Jun 20 '13 at 00:15
1

The question sounded to me that the asker wanted the blocks to call each other repeatedly in order to "pulse". That wouldn't have worked for obvious reasons. – Idles Jun 20 '13 at 00:23
Agreed. Sorry, I thought you were issuing a general admonition, because putting animations inside the completion block is quite common. But you're quite right that his attempt was not going to work given the desired UX. – Rob Jun 20 '13 at 00:25

animation options not respected/error in second animation block

2 Answers2