Swift : Set anchor Point on CABasicAnimation - ios

Question

The code you see below creates a CALayer (rectangle shape) and animates it from the left to the right when the user holds down on the screen ('longPressGestureRecognizer'). When they lift their finger, the CALayer stops animating, it gets pushed into an array, and when they hold on the screen again another CALayer is created. You can copy and paste code directly in new project:
//Global Variables
var layer: CALayer?
var holdGesture = UILongPressGestureRecognizer()
let animation = CABasicAnimation(keyPath: "bounds.size.width")
var layerHolder = [CALayer]()
var widthIndex = CGPoint(x: 0, y: 0)
var nextXOffset = CGFloat(0.0)
var checkIfFull = CGFloat()
var colorIndex : Int = 0
let barColors = [
//Red
UIColor(red: 0.969, green: 0.49, blue: 0.443, alpha: 1),
//Orange
UIColor(red: 0.984, green: 0.647, blue: 0.431, alpha: 1),
//Pink
UIColor(red: 0.894, green: 0.592, blue: 0.698, alpha: 1),
//Purple
UIColor(red: 0.851, green: 0.6, blue: 0.957, alpha: 1),
//Yellow
UIColor(red: 0.98, green: 0.875, blue: 0.455, alpha: 1),
//Green
UIColor(red: 0.49, green: 0.792, blue: 0.616, alpha: 1),
//Blue
UIColor(red: 0.553, green: 0.71, blue: 0.906, alpha: 1)]
func setUpView(){
self.view.addGestureRecognizer(holdGesture)
holdGesture.addTarget(self, action:"handleLongPress:")
}
func handleLongPress(sender : UILongPressGestureRecognizer){
if(sender.state == .Began) {
let newLayer = CALayer()
newLayer.frame = CGRect(x: nextXOffset, y: 0, width: 0, height: 10)
newLayer.backgroundColor = barColors[colorIndex % 7].CGColor
print("before \(nextXOffset)")
newLayer.anchorPoint = widthIndex
animation.fromValue = 0
animation.toValue = self.view.bounds.width * 2 - nextXOffset
animation.duration = 5
self.view.layer.addSublayer(newLayer)
print("Long Press Began")
newLayer.addAnimation(animation, forKey: "bounds.size.width")
layer = newLayer
}
else {
print("Long press ended")
if let layer = layer {
print("after \(nextXOffset)")
pauseLayer(layer)
layer.frame = layer.presentationLayer()!.frame
nextXOffset = CGRectGetMaxX(layer.frame)
layerHolder.append(layer)
colorIndex++
}
}
}
My issue is that when the new CALayer is created and animating, it grows from both sides not just growing to the right. I need them to be side by side to each other, one moving to the right where the other one left off. I didn't notice it until i had them interchange colors. After some research, i believe setting an anchor point from where the last CALayer left off is the correct approach. Ive been trying to achieve this but haven't been able to do it. Help me? Please?
UPDATE : I believe if I was to use the nextXOffset as the anchor point, I may be able to do this, but it is of type CGfloat not CGPoint. Help please!

Answer 1

This works, Im so dumb. Keeping the 'widthIndex' at (0,0) allows it to start where the last bar left off. The code works.