Swift-Animate Cashapelayer Stroke Color

Swift-animate CAshapeLayer stroke color

Updated to Swift 5.

Found out the solution. Enjoy. After you create the CAShapeLayer of course :

    let animcolor = CABasicAnimation(keyPath: "strokeColor")
    animcolor.fromValue         = UIColor.green.cgColor
    animcolor.toValue           = UIColor.orange.cgColor
    animcolor.duration          = 1.0
    animcolor.repeatCount       = 0
    animcolor.autoreverses      = true
    myLayer.add(animcolor, forKey: "strokeColor")

Swift- animate CAshapeLayer stroke color

Found out the solution. Enjoy. After you create the CAShapeLayer of course :

        let animcolor = CABasicAnimation(keyPath: "strokeColor")
        animcolor.fromValue         = UIColor.greenColor().CGColor
        animcolor.toValue           = UIColor.orangeColor().CGColor
        animcolor.duration          = 1.0;
        animcolor.repeatCount       = 0;
        animcolor.autoreverses      = true
        circleLayer.addAnimation(animcolor, forKey: "strokeColor")

CAShapeLayer stroke issue

edit/update:

It would be easier to multiply the line width by 2 and add a mask to your shape:

class Triangle: NSView {
    let shapeLayer = CAShapeLayer()
    var lineWidth: CGFloat
    var strokeColor: NSColor = .clear
    var fillColor: NSColor = .clear
    init(size: CGSize, lineWidth: CGFloat = 10, strokeColor: NSColor = .white,  fillColor: NSColor = .black) {
        self.lineWidth = lineWidth*2
        self.strokeColor = strokeColor
        self.fillColor = fillColor
        super.init(frame: .init(origin: .zero, size: size))
        wantsLayer = true
        let path = NSBezierPath()
        path.move(to: .zero)
        path.line(to: .init(x: size.width/2 , y: size.height))
        path.line(to: .init(x: size.width, y: .zero))
        path.close()
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        shapeLayer.mask = mask
        shapeLayer.path = path.cgPath
        shapeLayer.lineWidth = self.lineWidth
        shapeLayer.strokeColor = strokeColor.cgColor
        shapeLayer.fillColor = fillColor.cgColor
//      layer?.borderWidth = 1
//      layer?.borderColor = NSColor.red.cgColor
        layer?.addSublayer(shapeLayer)
    }
    convenience init(width: CGFloat, height: CGFloat, lineWidth: CGFloat = 10, strokeColor: NSColor = .white, fillColor: NSColor = .black) {
        self.init(size: .init(width: width, height: height), lineWidth: lineWidth, strokeColor: strokeColor, fillColor: fillColor)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

---

extension NSBezierPath {
    var cgPath: CGPath {
        let path = CGMutablePath()
        var points: [CGPoint] = .init(repeating: .zero, count: 3)
        for i in 0..<elementCount {
            switch element(at: i, associatedPoints: &points) {
            case .moveTo: path.move(to: points[0])
            case .lineTo: path.addLine(to: points[0])
            case .curveTo: path.addCurve(to: points[2], control1: points[0], control2: points[1])
            case .closePath: path.closeSubpath()
            @unknown default: fatalError()
            }
        }
        return path
    }

}

---

class ViewController: NSViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let triangle = Triangle(width: 200, height: 200, lineWidth: 1)
        view.addSubview(triangle)
    }
}

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How to set CAShapeLayer 's strokeColor in swift

Here is the code snippet:

        let path = UIBezierPath()
        path.move(to: CGPoint.zero)
        path.addLine(to: CGPoint(x: 50, y: 50))

        let view = UIView(frame: CGRect(x: 100, y: 100, width: 50, height: 50))
        view.backgroundColor = UIColor.green

        let diagonal = CAShapeLayer()
        diagonal.frame = view.bounds
        diagonal.path = path.cgPath
        diagonal.strokeColor = UIColor.orange.cgColor
        diagonal.lineWidth = 15
        diagonal.backgroundColor = UIColor.blue.cgColor
        // view.layer.mask = mask

        view.layer.addSublayer(diagonal)

        self.view.addSubview(view)

This results in:

Animating CAShapeLayer's strokeColor with CABasicAnimation

The code below works great for me. What is the lineWidth of your shapeLayer stroke path? Could that be the issue?

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIBezierPath * circle = [UIBezierPath bezierPathWithOvalInRect:self.view.bounds];

    CAShapeLayer * shapeLayer = [CAShapeLayer layer];
    shapeLayer.path = circle.CGPath;
    shapeLayer.strokeColor =[UIColor blueColor].CGColor;
    [shapeLayer setLineWidth:15.0];

    [self.view.layer addSublayer:shapeLayer];

    CABasicAnimation *strokeAnim = [CABasicAnimation animationWithKeyPath:@"strokeColor"];
    strokeAnim.fromValue         = (id) [UIColor redColor].CGColor;
    strokeAnim.toValue           = (id) [UIColor greenColor].CGColor;
    strokeAnim.duration          = 3.0;
    strokeAnim.repeatCount       = 0;
    strokeAnim.autoreverses      = YES;
    [shapeLayer addAnimation:strokeAnim forKey:@"animateStrokeColor"];

}

Let me know if it works for you...

How to animate CAShapeLayer path and fillColor

To animate path

  //setup the CAShapeLayer
myShapeLayer.strokeColor = [[UIColor blueColor] CGColor];
myShapeLayer.lineWidth = 5;
myShapeLayer.fillColor = [[UIColor yellowColor] CGColor];

//Display it!
[self.view.layer addSublayer:myShapeLayer];

//Animate path
CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
pathAnimation.duration = 1.5f;
pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];
pathAnimation.repeatCount = 10;
pathAnimation.autoreverses = YES;
[myShapeLayer addAnimation:pathAnimation forKey:@"strokeEnd"];

//Animate colorFill
CABasicAnimation *fillColorAnimation = [CABasicAnimation animationWithKeyPath:@"fillColor"];
fillColorAnimation.duration = 1.5f;
fillColorAnimation.fromValue = (id)[[UIColor clearColor] CGColor];
fillColorAnimation.toValue = (id)[[UIColor yellowColor] CGColor];
fillColorAnimation.repeatCount = 10;
fillColorAnimation.autoreverses = YES;
[myShapeLayer addAnimation:fillColorAnimation forKey:@"fillColor"];

I hope this helps :)

2021 Update

Swift

    myShapeLayer.strokeColor = UIColor.blue.cgColor
myShapeLayer.lineWidth = 5
myShapeLayer.fillColor = UIColor.yellow.cgColor

//Display it!
view.layer.addSublayer(myShapeLayer)

//Animate path
let pathAnimation = CABasicAnimation(keyPath: "strokeEnd")
pathAnimation.duration = 1.5
pathAnimation.fromValue = NSNumber(value: 0.0)
pathAnimation.toValue = NSNumber(value: 1.0)
pathAnimation.repeatCount = 10
pathAnimation.autoreverses = true
myShapeLayer.add(pathAnimation, forKey: "strokeEnd")

//Animate colorFill
let fillColorAnimation = CABasicAnimation(keyPath: "fillColor")
fillColorAnimation.duration = 1.5
fillColorAnimation.fromValue = UIColor.clear.cgColor
fillColorAnimation.toValue = UIColor.yellow.cgColor
fillColorAnimation.repeatCount = 10
fillColorAnimation.autoreverses = true
myShapeLayer.add(fillColorAnimation, forKey: "fillColor")

the strokeColor of CAShapeLayer not work

You are adding your shape layer as a mask layer. That allows the brightness of the mask layer's pixels to determine the opacity of the layer it's masking. It sounds like that's not what you want.

Instead, add your shape layer as a sublayer of your view's layer. Change

self.layer.mask = shapeLayer;

to

[self.layer addSublayer: shapeLayer];

That will cause your shape layer to drawn on top of your view's layer.

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