CATextLayer字体大小动画速度

Question

I have a little annoying problem. I have a CATextLayer, which I use to display the placeholder of UITextView. The fact is that when animating this layer, its velocity is too small and I see "jumps" during the animation. I use UIView.animate with a velocity parameter, but it ignores it.

GIF FILE:

DispatchQueue.main.async {
    UIView.animate(
        withDuration: 0.2,
        delay: 0.0,
        usingSpringWithDamping: 1.0,
        initialSpringVelocity: 1.0, // Ignore any options
        options: .curveEaseOut,
        animations: {
            self.floatingLabel?.fontSize = 10
            self.floatingLabel?.frame = self.toggledFloaterFrame
        })
}

What could be the problem?

Answer 1

Animation of the fontSize property is not possible. Try using the transform to scale it down.

You can use CGAffineTransform(scaleX: scale, y: scale) with scale being 10/self.floatingLabel.fontSize and CGAffineTransform.identity to go back to full size.