iOS icon jiggle algorithm

Question

I am writing an iPad app that presents user documents similar to the way Pages presents them (as large icons of the actual document). I also want to mimic the jiggling beha

Answer 1

OK, so the openspringboard code didn't quite do it for me but I did allow me to create some code that I think is a bit better, still not prefect but better. If anyone has suggestions to make this better, I would love to hear them... (add this to the subclass of the view(s) you want to jiggle)

#define degreesToRadians(x) (M_PI * (x) / 180.0)
#define kAnimationRotateDeg 1.0
#define kAnimationTranslateX 2.0
#define kAnimationTranslateY 2.0

- (void)startJiggling:(NSInteger)count {

    CGAffineTransform leftWobble = CGAffineTransformMakeRotation(degreesToRadians( kAnimationRotateDeg * (count%2 ? +1 : -1 ) ));
    CGAffineTransform rightWobble = CGAffineTransformMakeRotation(degreesToRadians( kAnimationRotateDeg * (count%2 ? -1 : +1 ) ));
    CGAffineTransform moveTransform = CGAffineTransformTranslate(rightWobble, -kAnimationTranslateX, -kAnimationTranslateY);
    CGAffineTransform conCatTransform = CGAffineTransformConcat(rightWobble, moveTransform);

    self.transform = leftWobble;  // starting point

    [UIView animateWithDuration:0.1
                          delay:(count * 0.08)
                        options:UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse
                     animations:^{ self.transform = conCatTransform; }
                     completion:nil];
}

- (void)stopJiggling {
    [self.layer removeAllAnimations];
    self.transform = CGAffineTransformIdentity;  // Set it straight 
}