CABasicAnimation responsiveness - ios

Question

I have a custom UIActivityIndicatorView. It is a view, with a CAAnimation on its layer. The problem is the following:
I do some heavy work and create a lot of views. It takes approximately 0.5 seconds. In order for it to be smooth I decided to use activity indicator, while it "happens". It was all fine with default activity indicator, however with the one that I wrote I get unexpected results.
So, when the view loads I launch my activity indicator, which starts animating. When heavy duty work starts my view freezes for 0.5 seconds and when it's done I stop animating it and it disappears. This "freeze" looks very unpleasant to an eye. Because the idea was to keep animating while other views get initialized and added as subviews(although hidden).
I suspect that the problem is that my "activity indicator" is not asynchronous or simply was not coded right.
Here is the code for it:
class CustomActivityIndicatorView: UIView {
// MARK - Variables
var colors = [UIColor.greenColor(),UIColor.grayColor(),UIColor.blueColor(),UIColor.redColor()]
var colorIndex = 0
var animation: CABasicAnimation!
lazy var customView : UIView! = {
let frame : CGRect = CGRectMake(0.0, 0.0, 100, 100)
let view = UIView(frame: frame)
image.frame = frame
image.center = view.center
view.backgroundColor = UIColor.greenColor()
view.clipsToBounds = true
view.layer.cornerRadius = frame.width/2
return view
}()
var isAnimating : Bool = false
var hidesWhenStopped : Bool = true
var from: NSNumber = 1.0
var to: NSNumber = 0.0
var growing = false
override func animationDidStart(anim: CAAnimation!) {
}
override func animationDidStop(anim: CAAnimation!, finished flag: Bool) {
growing = !growing
if growing {
colorIndex++
if colorIndex == colors.count {
colorIndex = 0
}
println(colorIndex)
customView.backgroundColor = colors[colorIndex]
from = 0.0
to = 1.0
} else {
from = 1.0
to = 0.0
}
if isAnimating {
addPulsing()
resume()
}
}
// MARK - Init
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.addSubview(customView)
addPulsing()
pause()
self.hidden = true
}
// MARK - Func
func addPulsing() {
let pulsing : CABasicAnimation = CABasicAnimation(keyPath: "transform.scale")
pulsing.duration = 0.4
pulsing.removedOnCompletion = false
pulsing.fillMode = kCAFillModeForwards
pulsing.fromValue = from
pulsing.toValue = to
pulsing.delegate = self
let layer = customView.layer
layer.addAnimation(pulsing, forKey: "pulsing")
}
func pause() {
let layer = customView.layer
let pausedTime = layer.convertTime(CACurrentMediaTime(), fromLayer: nil)
layer.speed = 0.0
layer.timeOffset = pausedTime
isAnimating = false
}
func resume() {
let layer = customView.layer
let pausedTime : CFTimeInterval = layer.timeOffset
layer.speed = 1.0
layer.timeOffset = 0.0
layer.beginTime = 0.0
let timeSincePause = layer.convertTime(CACurrentMediaTime(), fromLayer: nil) - pausedTime
layer.beginTime = timeSincePause
isAnimating = true
}
func startAnimating () {
if isAnimating {
return
}
if hidesWhenStopped {
self.hidden = false
}
resume()
}
func stopAnimating () {
let layer = customView.layer
if hidesWhenStopped {
self.hidden = true
}
pause()
layer.removeAllAnimations()
}
deinit {
println("Spinner Deinitied")
}
}
Regarding animationDidStop method:
The idea is the following. The view pulsates, and after it has shrunk, it starts growing again and the background color is changed.
Any idea on what I'm doing wrong?

Answer 1

Solved it using CAKeyFrameAnimation to achieve the same effect. For everybody with the same problem, remember that animationDidStart and animationDidStop start running on the main thread, so that whatever you do with your animation there will be halted if the main thread is busy.