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

In case anyone needs the same code in Swift

class Animation {

    static func wiggle(_ btn: UIButton) {
        btn.startWiggling()
    }
} 

extension UIView {

func startWiggling() {

    let count = 5
    let kAnimationRotateDeg = 1.0

    let leftDegrees = (kAnimationRotateDeg * ((count%2 > 0) ? +5 : -5)).convertToDegrees()
    let leftWobble = CGAffineTransform(rotationAngle: leftDegrees)

    let rightDegrees = (kAnimationRotateDeg * ((count%2 > 0) ? -10 : +10)).convertToDegrees()
    let rightWobble = CGAffineTransform(rotationAngle: rightDegrees)

    let moveTransform = rightWobble.translatedBy(x: -2.0, y: 2.0)
    let concatTransform = rightWobble.concatenating(moveTransform)

    self.transform = leftWobble

    UIView.animate(withDuration: 0.1,
                   delay: 0.1,
                   options: [.allowUserInteraction, .repeat, .autoreverse],
                   animations: {
                    UIView.setAnimationRepeatCount(3)
                    self.transform = concatTransform
    }, completion: { success in
        self.layer.removeAllAnimations()
        self.transform = .identity
    })
}
}

Just Call

    Animation.wiggle(viewToBeAnimated)

It is always best to write a wrapper over the functions you are calling so that even if you have to change the function arguments or may be the name of the function, it does not take you to rewrite it everywhere in the code.