iphone - How to have a handler to repeat UIView animateWithDuration?

Question

I'm using UIView class method animateWithDuration for repeating my view animation. How can I have a handler that could be used to stop this animation later? For example, repeated animation starts in one method and I need to stop it later from another method.

Answer 1

The purpose of the animation is to repeatedly animate the bounce of an image. When there is no worry about manually stopping it then you just need to set three properties (UIViewAnimationOptionCurveEaseIn | UIViewAnimationOptionAutoreverse | UIViewAnimationOptionRepeat) and animation block code for moving the image - self.image.center = CGPointMake(self.image.center.x, self.image.center.y+25); Here is the full code of the animation:

[UIView animateWithDuration:0.5 delay:0 options:( UIViewAnimationOptionCurveEaseIn | 
 UIViewAnimationOptionAutoreverse | UIViewAnimationOptionRepeat | 
 UIViewAnimationOptionAllowUserInteraction) animations:^{self.image.center = 
 CGPointMake(self.image.center.x, self.image.center.y+25);} completion:nil];

That's it. But if you need a manual control then some additional code is required. First, according to jaminguy, you need to have a BOOL property for indication loop/stop (self.playAnimationForImage) the animation and clean separate method with animation code that would be called from elsewhere. Here is the method:

-(void)animateImageBounce{
 [UIView animateWithDuration:0.5 delay:0 options:( 
  UIViewAnimationOptionCurveEaseIn | UIViewAnimationOptionAutoreverse |  
  UIViewAnimationOptionAllowUserInteraction) animations:^{self.image.center = 
  CGPointMake(self.image.center.x, self.image.center.y+25);} completion:^(BOOL finished){if 
  (finished && self.playAnimationForImage){
    self.image.center = CGPointMake(self.image.center.x, self.image.center.y-25); 
    [self animateImageBounce];
  }}]; 

and here is the start of the animation call from some method

-(void)someMethod{
...
self.playAnimationForFingers = YES;
[self animateImageBounce];

}

The thing that I would like to note is that, in manual control, you need to reset the center.y of the image back right before next recursive call is performed.