Swift: Cant change CALayer background color in array - swift

Question

I am simply trying to change the background color of the last element of a CALayer array. Here is my entire View Class, however its only 2-3 lines that I actually try to access the last element of the CALayer.
Here is my progressViewClass and I put comments to where exactly my problem is:
class ProgressBarView: UIView {
//Variables for progress bar
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 newLayer : CALayer?
var progressBarAnimationDuration : CFTimeInterval = (MainController.sharedInstance.totalMiliSeconsToRecord / 10)
// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {
}
func startProgressBar(){
if(RecordingViewController().currentCameraMode == .recordingMode || RecordingViewController().currentCameraMode == .record1stClipMode) {
newLayer = CALayer()
newLayer?.frame = CGRect(x: nextXOffset, y: 0, width: 0, height: self.bounds.height)
newLayer?.backgroundColor = UIColor(red:0.82, green:0.01, blue:0.11, alpha:1.0).cgColor
//print("before \(nextXOffset)")
newLayer?.anchorPoint = widthIndex
animation.fromValue = 0
animation.toValue = self.bounds.width - nextXOffset
animation.duration = progressBarAnimationDuration - ((MainController.sharedInstance.miliSecondsPassed) / 10)
self.layer.addSublayer(newLayer!)
//print("Long Press Began")
newLayer?.add(animation, forKey: "bounds.size.width")
}
else{
stopProgressBar()
}
}
func stopProgressBar(){
if(RecordingViewController().currentCameraMode != .recordingMode){
pauseLayer(layer: newLayer!)
newLayer?.frame = (newLayer?.presentation()!.frame)!
nextXOffset = (newLayer?.frame.maxX)!
layerHolder.append(newLayer!)
print("Layerholder has elements : \(layerHolder.count)")
}
}
// HERE IS MY PROBLEM
func highlightLastLayer(){
print("in highlight last layer Layerholder has elements : \(layerHolder.count)")
// I CAN HIDE THE CALAYER SO I BELIEVE IM ACCESSING THE CORRECT LAYER
// layerHolder.last?.isHidden = true
// This is suppose to change the last element background color to blue but doesnt
layerHolder.last?.backgroundColor = UIColor.blue.cgColor
}
// ALSO MY PROBLEM
func unhighlightLastLayer(){
print("inside unhighlight last layer")
// I CAN HIDE THE CALAYER SO I BELIEVE IM ACCESSING THE CORRECT LAYER
//layerHolder.last?.isHidden = false
// Changes CALayer back to red
layerHolder.last?.backgroundColor = UIColor(red:0.82, green:0.01, blue:0.11, alpha:1.0).cgColor
}
//Function to pause the Progress Bar
func pauseLayer(layer : CALayer){
let pausedTime : CFTimeInterval = layer.convertTime(CACurrentMediaTime(), from: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
}
}
Simply put, I create a progressView object in my viewController and then call those functions based on certain button input. This view is essentially a progress bar that you'd see in many video recording applications to show how much you have recorded. In the highlightLastLayer, I am trying to grab the last element of the "layerHolder" array and change its color to blue. Simple right? Doesn't work. Any ideas?

Answer 1

Where are you calling highlight and unhighlight. I am pretty sure you are doing this when you are "stopped" or "paused" because thats the only time you add anything to the layerHolder Array. You can only do this when you are not animating because when you are animating the presentation layer is shown instead of the "real" layer. Instead of setting the speed to zero, setup your layer to look like the current animation state and call layer. removeAllAnimations to kill the presentation layer and show the actual layer for your view instead. Now you can make all the changes that you want and they will actually show up.