Question

I’d like to make an endless animation (e.g. making a view to move between two positions endlessly)

I wonder if this is a recursion and whether it would cause stack to overflow?
pesudo code:

-(void)doAnimation {
    [UIView animateWithDuration:1.0
            delay:0.0
            options:(UIViewAnimationOptionCurveEaseIn | UIViewAnimationOptionAllowUserInteraction)
            animations:^{
                if(view is at Position A){ 
                    set frame to Postion B;
                }else{
                    set frame to Positon A;
                }
            }
            completion:^(BOOL finished){
                [self doAnimation];
            }
     ];
}

Thanks in advance

Leo

Answer 1

This is the wrong way to perform a repeating animation. Look at the animation options UIViewAnimationOptionRepeat and UIViewAnimationOptionAutoreverse instead (documentation, see Constants at the end) Your animation could be rewritten as follows:

-(void)doAnimation {
    [UIView animateWithDuration:1.0
            delay:0.0
            options:(UIViewAnimationOptionCurveEaseIn | UIViewAnimationOptionAllowUserInteraction |UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse)
            animations:^{
                set frame to Position B;
                }
            }
            completion:nil
            }
     ];
}

Assuming your view starts at position A.