We are currently developing an application that contains a series of icons. We want the icons to wiggle like the app deletion animations when pressed. What would be the be
func startWiggling() {
deleteButton.isHidden = false
guard contentView.layer.animation(forKey: "wiggle") == nil else { return }
guard contentView.layer.animation(forKey: "bounce") == nil else { return }
let angle = 0.04
let wiggle = CAKeyframeAnimation(keyPath: "transform.rotation.z")
wiggle.values = [-angle, angle]
wiggle.autoreverses = true
wiggle.duration = randomInterval(0.1, variance: 0.025)
wiggle.repeatCount = Float.infinity
contentView.layer.add(wiggle, forKey: "wiggle")
let bounce = CAKeyframeAnimation(keyPath: "transform.translation.y")
bounce.values = [4.0, 0.0]
bounce.autoreverses = true
bounce.duration = randomInterval(0.12, variance: 0.025)
bounce.repeatCount = Float.infinity
contentView.layer.add(bounce, forKey: "bounce")
}
func stopWiggling() {
deleteButton.isHidden = true
contentView.layer.removeAllAnimations()
}
func randomInterval(_ interval: TimeInterval, variance: Double) -> TimeInterval {
return interval + variance * Double((Double(arc4random_uniform(1000)) - 500.0) / 500.0)
}
Look at this iOS SpingBoard example
Looking at the iOS implementation a bit closer, there are two things that make theirs a bit more realistic than the code mentioned here:
I based myself on the answers here (and with some help from this answer) to add the rotation, the bounce and a bit of randomness to the duration of each animation.
#define kWiggleBounceY 4.0f
#define kWiggleBounceDuration 0.12
#define kWiggleBounceDurationVariance 0.025
#define kWiggleRotateAngle 0.06f
#define kWiggleRotateDuration 0.1
#define kWiggleRotateDurationVariance 0.025
-(void)startWiggling {
[UIView animateWithDuration:0
animations:^{
[self.layer addAnimation:[self rotationAnimation] forKey:@"rotation"];
[self.layer addAnimation:[self bounceAnimation] forKey:@"bounce"];
self.transform = CGAffineTransformIdentity;
}];
}
-(CAAnimation*)rotationAnimation {
CAKeyframeAnimation* animation = [CAKeyframeAnimation animationWithKeyPath:@"transform.rotation.z"];
animation.values = @[@(-kWiggleRotateAngle), @(kWiggleRotateAngle)];
animation.autoreverses = YES;
animation.duration = [self randomizeInterval:kWiggleRotateDuration
withVariance:kWiggleRotateDurationVariance];
animation.repeatCount = HUGE_VALF;
return animation;
}
-(CAAnimation*)bounceAnimation {
CAKeyframeAnimation* animation = [CAKeyframeAnimation animationWithKeyPath:@"transform.translation.y"];
animation.values = @[@(kWiggleBounceY), @(0.0)];
animation.autoreverses = YES;
animation.duration = [self randomizeInterval:kWiggleBounceDuration
withVariance:kWiggleBounceDurationVariance];
animation.repeatCount = HUGE_VALF;
return animation;
}
-(NSTimeInterval)randomizeInterval:(NSTimeInterval)interval withVariance:(double)variance {
double random = (arc4random_uniform(1000) - 500.0) / 500.0;
return interval + variance * random;
}
I implemented this code on a UICollectionView which had 30 items bouncing and the performance was flawless on an iPad 2.
Edited paiego's code to fit my needs: visual error animation feedback upon user's action (tap). It happens once - it's not a constant wiggling like SpringBoard app edit wiggle animation.
- (CAAnimation *)shakeAnimation {
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
CGFloat wobbleAngle = 0.06f;
NSValue *valLeft;
NSValue *valRight;
NSMutableArray *values = [NSMutableArray new];
for (int i = 0; i < 5; i++) {
valLeft = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(wobbleAngle, 0.0f, 0.0f, 1.0f)];
valRight = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(-wobbleAngle, 0.0f, 0.0f, 1.0f)];
[values addObjectsFromArray:@[valLeft, valRight]];
wobbleAngle*=0.66;
}
animation.values = [values copy];
animation.duration = 0.7;
return animation;
}
Usage:
[your_view.layer addAnimation:[self shakeAnimation] forKey:@""]; //do the shake animation
your_view.transform = CGAffineTransformIdentity; //return the view back to original
Hope this helps someone else.
Answered in another thread a Swift 4 version of what is apparently Apple's own algorithm reverse engineered: https://stackoverflow.com/a/47730519/5018607
The answer by Vinzius is very cool. However the wobble only rotates from 0 Radians to 0.08. Thus the wobble can look a little unbalanced. If you get this same issue then you may want to add both a negative and a positive rotation by using a CAKeyframeAnimation rather than a CABasicRotation:
- (CAAnimation*)getShakeAnimation
{
CAKeyframeAnimation* animation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
CGFloat wobbleAngle = 0.06f;
NSValue* valLeft = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(wobbleAngle, 0.0f, 0.0f, 1.0f)];
NSValue* valRight = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(-wobbleAngle, 0.0f, 0.0f, 1.0f)];
animation.values = [NSArray arrayWithObjects:valLeft, valRight, nil];
animation.autoreverses = YES;
animation.duration = 0.125;
animation.repeatCount = HUGE_VALF;
return animation;
}
You can use this animation method for your view or button like this.
[self.yourbutton.layer addAnimation:[self getShakeAnimation] forKey:@""];
SWIFT :-
let transformAnim = CAKeyframeAnimation(keyPath:"transform")
transformAnim.values = [NSValue(CATransform3D: CATransform3DMakeRotation(0.04, 0.0, 0.0, 1.0)),NSValue(CATransform3D: CATransform3DMakeRotation(-0.04 , 0, 0, 1))]
transformAnim.autoreverses = true
transformAnim.duration = (Double(indexPath.row)%2) == 0 ? 0.115 : 0.105
transformAnim.repeatCount = Float.infinity
self.layer.addAnimation(transformAnim, forKey: "transform")
Objective C :-
-(CAKeyframeAnimation *)wiggleView
{
CAKeyframeAnimation* animation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
CGFloat wobbleAngle = 0.04f;
NSValue* valLeft = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(wobbleAngle, 0.0f, 0.0f, 1.0f)];
NSValue* valRight = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(-wobbleAngle, 0.0f, 0.0f, 1.0f)];
animation.values = [NSArray arrayWithObjects:valLeft, valRight, nil];
animation.autoreverses = YES;
animation.duration = 0.125;
animation.repeatCount = HUGE_VALF;
return animation;
}