CODEWITHSUNDEEP
iosswiftcalayercabasicanimation
Sajib Ghosh
Sajib Ghosh

Reputation: 418

How to change the width of a CALayer with animation from left to right?

I added a CALayer in a UIView. And it has a fillColor. It has also some width. I want that layer to expand it's width from zero to actual width with CABasicAnimation from left to right direction.

How to do that?

Upvotes: 3

Views: 8982

Answers (2)

Stacy Smith
Stacy Smith

Reputation: 540

Answer for Swift 3. To make the layer change its width from left (not from center!) to right I used the following approach:

I have layer named "layer" and I want to change it width from 0 to myWidth

 layer.position = CGPoint(x: 0, y: 0)
 layer.anchorPoint = CGPoint(x: 0, y: 0.5)
 let layerAnimation = CABasicAnimation(keyPath: "bounds.size.width")
 layerAnimation.duration = 2
 layerAnimation.fromValue = 0
 layerAnimation.toValue = myWidth
 layer.add(layerAnimation, forKey: "anim")

Upvotes: 1

stefos
stefos

Reputation: 1235

Try animating your layer's bounds :

let a = CALayer()
a.bounds = CGRect(x: 0, y: 0, width: 100, height: 40)
a.position = CGPoint(x: 20, y: 20)
a.anchorPoint = CGPoint(x: 0, y: 0)
view.layer.addSublayer(a)

let anim = CABasicAnimation(keyPath: "bounds")
anim.duration = 2
anim.fromValue = NSValue(CGRect: CGRect(x: 0, y: 0, width: 0, height: 30))
anim.toValue = NSValue(CGRect: CGRect(x: 0, y: 0, width: 100, height: 30))
a.addAnimation(anim, forKey: "anim")

It's working for me. Just don't forget to set the achor point.

Upvotes: 6

Related Questions