Animate text change in UILabel

Question

I\'m setting a new text value to a UILabel. Currently, the new text appears just fine. However, I\'d like to add some animation when the new text appears. I\

Answer 1

There is one more solution to achieve this. It was described here. The idea is subclassing UILabel and overriding action(for:forKey:) function in the following way:

class LabelWithAnimatedText: UILabel {
    override var text: String? {
        didSet {
            self.layer.setValue(self.text, forKey: "text")
        }
    }

    override func action(for layer: CALayer, forKey event: String) -> CAAction? {
        if event == "text" {
            if let action = self.action(for: layer, forKey: "backgroundColor") as? CAAnimation {
                let transition = CATransition()
                transition.type = kCATransitionFade

                //CAMediatiming attributes
                transition.beginTime = action.beginTime
                transition.duration = action.duration
                transition.speed = action.speed
                transition.timeOffset = action.timeOffset
                transition.repeatCount = action.repeatCount
                transition.repeatDuration = action.repeatDuration
                transition.autoreverses = action.autoreverses
                transition.fillMode = action.fillMode

                //CAAnimation attributes
                transition.timingFunction = action.timingFunction
                transition.delegate = action.delegate

                return transition
            }
        }
        return super.action(for: layer, forKey: event)
    }
}

Usage examples:

// do not forget to set the "Custom Class" IB-property to "LabelWithAnimatedText"
// @IBOutlet weak var myLabel: LabelWithAnimatedText!
// ...

UIView.animate(withDuration: 0.5) {
    myLabel.text = "I am animated!"
}

myLabel.text = "I am not animated!"