I am trying to make an animated donut view that when given a value between 0 and 100 it will animate round the view up to that number. I have this working fine but want to fade the color from one to another, then another on the way around. Currently, when I add my gradient it goes from left to right and not around the circumference of the donut view.
class CircleScoreView: UIView {
private let outerCircleLayer = CAShapeLayer()
private let outerCircleGradientLayer = CAGradientLayer()
private let outerCircleLineWidth: CGFloat = 5
override init(frame: CGRect) {
super.init(frame: .zero)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
buildLayers()
}
/// Value must be within 0...100 range
func setScore(_ value: Int, animated: Bool = false) {
if value != 0 {
let clampedValue: CGFloat = CGFloat(value.clamped(to: 0...100)) / 100
if !animated {
outerCircleLayer.strokeEnd = clampedValue
} else {
let outerCircleAnimation = CABasicAnimation(keyPath: "strokeEnd")
outerCircleAnimation.duration = 1.0
outerCircleAnimation.fromValue = 0
outerCircleAnimation.toValue = clampedValue
outerCircleAnimation.timingFunction = CAMediaTimingFunction(name: .easeInEaseOut)
outerCircleLayer.strokeEnd = clampedValue
outerCircleLayer.add(outerCircleAnimation, forKey: "outerCircleAnimation")
}
outerCircleGradientLayer.colors = [Constant.Palette.CircleScoreView.startValue.cgColor,
Constant.Palette.CircleScoreView.middleValue.cgColor,
Constant.Palette.CircleScoreView.endValue.cgColor]
}
}
private func buildLayers() {
// Outer background circle
let arcCenter = CGPoint(x: frame.size.width / 2, y: frame.size.height / 2)
let startAngle = CGFloat(-0.5 * Double.pi)
let endAngle = CGFloat(1.5 * Double.pi)
let circlePath = UIBezierPath(arcCenter: arcCenter,
radius: (frame.size.width - outerCircleLineWidth) / 2,
startAngle: startAngle,
endAngle: endAngle,
clockwise: true)
// Outer circle
setupOuterCircle(outerCirclePath: circlePath)
}
private func setupOuterCircle(outerCirclePath: UIBezierPath) {
outerCircleLayer.path = outerCirclePath.cgPath
outerCircleLayer.fillColor = UIColor.clear.cgColor
outerCircleLayer.strokeColor = UIColor.black.cgColor
outerCircleLayer.lineWidth = outerCircleLineWidth
outerCircleLayer.lineCap = CAShapeLayerLineCap.round
outerCircleGradientLayer.startPoint = CGPoint(x: 0.0, y: 0.5)
outerCircleGradientLayer.endPoint = CGPoint(x: 1.0, y: 0.5)
outerCircleGradientLayer.frame = bounds
outerCircleGradientLayer.mask = outerCircleLayer
layer.addSublayer(outerCircleGradientLayer)
}
}
I am going for something like this but the color isn't one block but gradients around the donut view from one color to the next.
If you imported AngleGradientLayer into your project then all you should need to do is change:
private let outerCircleGradientLayer = CAGradientLayer() to
private let outerCircleGradientLayer = AngleGradientLayer()
Related
I have checked some of the StackOverflow answers regarding custom UIView slider but using them I unable to make the slider like this. This makes a circle or half circle. I have figured out some library that makes circle slider using UIView but its not helpful to me so could anyone please help me out. How can I make slider like in below UIImage? Thanks!
You will probably just roll your own. (You obviously could search for third party implementations, but that would be out of scope for StackOverflow.) There are a lot of ways of tackling this, but the basic elements here are:
The pink arc for the overall path. Personally, I'd use a CAShapeLayer for that.
The white arc from the start to the current progress (measured from 0 to 1). Again, a CAShapeLayer would be logical.
The white dot placed at the spot of the current progress. Below I create a CALayer with white background and then apply a CAGradientLayer as a mask to that. You could also just create a UIImage for this.
In terms of how to set the progress, you would set the paths of the pink and white arcs to the same path, but just update the strokeEnd of the white arc. You would also adjust the position of the white dot layer accordingly.
The only complicated thing here is figuring out the center of the arc. In my example below, I calculate it with some trigonometry based upon the bounds of the view so that arc goes from lower left corner, to the top, and back down the the lower right corner. Or you might instead pass the center of the arc as a parameter.
Anyway, it might look like:
#IBDesignable
class ArcView: UIView {
#IBInspectable
var lineWidth: CGFloat = 7 { didSet { updatePaths() } }
#IBInspectable
var progress: CGFloat = 0 { didSet { updatePaths() } }
override func prepareForInterfaceBuilder() {
super.prepareForInterfaceBuilder()
progress = 0.35
}
lazy var currentPositionDotLayer: CALayer = {
let layer = CALayer()
layer.backgroundColor = UIColor.white.cgColor
let rect = CGRect(x: 0, y: 0, width: lineWidth * 3, height: lineWidth * 3)
layer.frame = rect
let gradientLayer = CAGradientLayer()
gradientLayer.colors = [UIColor.white.cgColor, UIColor.clear.cgColor]
gradientLayer.type = .radial
gradientLayer.frame = rect
gradientLayer.startPoint = CGPoint(x: 0.5, y: 0.5)
gradientLayer.endPoint = CGPoint(x: 1, y: 1)
gradientLayer.locations = [0.5, 1]
layer.mask = gradientLayer
return layer
}()
lazy var progressShapeLayer: CAShapeLayer = {
let shapeLayer = CAShapeLayer()
shapeLayer.lineCap = .round
shapeLayer.lineWidth = lineWidth
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.strokeColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
return shapeLayer
}()
lazy var totalShapeLayer: CAShapeLayer = {
let shapeLayer = CAShapeLayer()
shapeLayer.lineCap = .round
shapeLayer.lineWidth = lineWidth
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.strokeColor = #colorLiteral(red: 0.9439327121, green: 0.5454334617, blue: 0.6426400542, alpha: 1)
return shapeLayer
}()
override init(frame: CGRect) {
super.init(frame: frame)
configure()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
configure()
}
override func layoutSubviews() {
super.layoutSubviews()
updatePaths()
}
}
// MARK: - Private utility methods
private extension ArcView {
func configure() {
layer.addSublayer(totalShapeLayer)
layer.addSublayer(progressShapeLayer)
layer.addSublayer(currentPositionDotLayer)
}
func updatePaths() {
let rect = bounds.insetBy(dx: lineWidth / 2, dy: lineWidth / 2)
let halfWidth = rect.width / 2
let height = rect.height
let theta = atan(halfWidth / height)
let radius = sqrt(halfWidth * halfWidth + height * height) / 2 / cos(theta)
let center = CGPoint(x: rect.midX, y: rect.minY + radius)
let delta = (.pi / 2 - theta) * 2
let startAngle = .pi * 3 / 2 - delta
let endAngle = .pi * 3 / 2 + delta
let path = UIBezierPath(arcCenter: center,
radius: radius,
startAngle: startAngle,
endAngle: endAngle,
clockwise: true)
progressShapeLayer.path = path.cgPath // white arc
totalShapeLayer.path = path.cgPath // pink arc
progressShapeLayer.strokeEnd = progress
let currentAngle = (endAngle - startAngle) * progress + startAngle
let dotCenter = CGPoint(x: center.x + radius * cos(currentAngle),
y: center.y + radius * sin(currentAngle))
currentPositionDotLayer.position = dotCenter
}
}
Above, I set the background color of the ArcView so you could see its bounds, but you would obviously set the background color to be transparent.
Now there are tons of additional features you might add (e.g. add user interaction so you could “scrub” it, etc.). See https://github.com/robertmryan/ArcView for example. But the key when designing this sort of stuff is to just break it down into its constituent elements, layering one on top of the other.
You can programmatically set the progress of the arcView to get it to change the current value between values of 0 and 1:
func startUpdating() {
arcView.progress = 0
var current = 0
Timer.scheduledTimer(withTimeInterval: 0.2, repeats: true) { [weak self] timer in
current += 1
guard let self = self, current <= 10 else {
timer.invalidate()
return
}
self.arcView.progress = CGFloat(current) / 10
}
}
Resulting in:
I would like to animate little red dot rotating around circle that is expanding in a pulse manner (go from small to big, then start back from small). It seems that little dot keeps rotating around original shape and does not take into account that circle it's expanding... I have this in code:
// MARK: - Properties
private lazy var containerView = UIView()
let littleCircleRadius: CGFloat = 10
private lazy var littleRedDot: CALayer = {
let layer = CALayer()
layer.backgroundColor = UIColor.red.cgColor
let littleDotSize = CGSize(width: 10, height: 10)
layer.frame = CGRect(x: containerView.bounds.center.x - littleDotSize.width / 2,
y: containerView.bounds.center.y - littleCircleRadius - littleDotSize.width/2 ,
width: littleDotSize.width,
height: littleDotSize.height)
return layer
}()
private lazy var littleCircleLayer: CAShapeLayer = {
let layer = CAShapeLayer()
layer.lineWidth = 1.5
layer.lineCap = .round
layer.strokeColor = UIColor.black.cgColor
layer.fillColor = UIColor.clear.cgColor
return layer
}()
// MARK: - Setup
func setup() {
view.addSubview(containerView)
containerView.frame = CGRect(x: 40, y: 200, width: 300, height: 300)
containerView.backgroundColor = UIColor.gray.withAlphaComponent(0.2)
littleCircleLayer.path = makeArcPath(arcCenter: containerView.bounds.center, radius: 10)
containerView.layer.addSublayer(littleCircleLayer)
containerView.layer.addSublayer(littleRedDot)
}
// MARK: - Animations
func animate() {
CATransaction.begin()
CATransaction.setAnimationDuration(1.5)
animateLittleRedDotRotation()
animateCircleExpanding()
CATransaction.commit()
}
func animateLittleRedDotRotation() {
let anim = CAKeyframeAnimation(keyPath: "position")
anim.duration = 1.5
anim.rotationMode = .rotateAuto
anim.repeatCount = Float.infinity
anim.path = littleCircleLayer.path
littleRedDot.add(anim, forKey: "rotate")
}
func animateCircleExpanding() {
let maxCircle = makeArcPath(arcCenter: containerView.bounds.center, radius: 100)
let circleExpandingAnim = CABasicAnimation(keyPath: "path")
circleExpandingAnim.fromValue = littleCircleLayer.path
circleExpandingAnim.toValue = maxCircle
circleExpandingAnim.repeatCount = Float.infinity
circleExpandingAnim.duration = 1.5
littleCircleLayer.add(circleExpandingAnim, forKey: "pulseCircuitAnimation")
}
This creates following effect:
However I would like to achieve for little dot to be rotating along the expanding circle path (as it animates from small circle to bigger circle), not the original small circle path. Any ideas ?
Using CoreAnimation to animate the position of the red dot based upon the path assumes that the path isn't changing. You could, theoretically, define a spiral path that mirrors the expanding circle. Personally, I'd just use CADisplayLink, a special timer designed optimally for screen refreshes, and retire the CoreAnimation calls entirely. E.g.
func startDisplayLink() {
let displayLink = CADisplayLink(target: self, selector: #selector(handleDisplayLink(_:)))
displayLink.add(to: .main, forMode: .common)
}
#objc func handleDisplayLink(_ displayLink: CADisplayLink) {
let percent = CGFloat(displayLink.timestamp).truncatingRemainder(dividingBy: duration) / duration
let radius = ...
let center = containerView.bounds.center
circleLayer.path = makeArcPath(arcCenter: center, radius: radius)
let angle = percent * .pi * 2
let dotCenter = CGPoint(x: center.x + cos(angle) * radius, y: center.y + sin(angle) * radius)
redDot.path = makeArcPath(arcCenter: dotCenter, radius: 5)
}
That yields:
The full example:
class ViewController: UIViewController {
private let radiusRange: ClosedRange<CGFloat> = 10...100
private let duration: CGFloat = 1.5
private lazy var containerView: UIView = {
let containerView = UIView()
containerView.translatesAutoresizingMaskIntoConstraints = false
return containerView
}()
private lazy var redDot: CAShapeLayer = {
let layer = CAShapeLayer()
layer.fillColor = UIColor.red.cgColor
return layer
}()
private lazy var circleLayer: CAShapeLayer = {
let layer = CAShapeLayer()
layer.lineWidth = 1.5
layer.strokeColor = UIColor.black.cgColor
layer.fillColor = UIColor.clear.cgColor
return layer
}()
private weak var displayLink: CADisplayLink?
override func viewDidLoad() {
super.viewDidLoad()
setup()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
startDisplayLink()
}
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(animated)
stopDisplayLink()
}
}
// MARK: Private utility methods
private extension ViewController {
func setup() {
addContainer()
containerView.layer.addSublayer(circleLayer)
containerView.layer.addSublayer(redDot)
}
func addContainer() {
view.addSubview(containerView)
NSLayoutConstraint.activate([
containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
containerView.topAnchor.constraint(equalTo: view.topAnchor),
containerView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
])
}
func makeArcPath(arcCenter: CGPoint, radius: CGFloat) -> CGPath {
UIBezierPath(arcCenter: arcCenter, radius: radius, startAngle: 0, endAngle: .pi * 2, clockwise: true).cgPath
}
}
// MARK: - DisplayLink related methods
private extension ViewController {
func startDisplayLink() {
stopDisplayLink() // stop existing display link, if any
let displayLink = CADisplayLink(target: self, selector: #selector(handleDisplayLink(_:)))
displayLink.add(to: .main, forMode: .common)
self.displayLink = displayLink
}
func stopDisplayLink() {
displayLink?.invalidate()
}
#objc func handleDisplayLink(_ displayLink: CADisplayLink) {
let percent = CGFloat(displayLink.timestamp).truncatingRemainder(dividingBy: duration) / duration
let radius = radiusRange.percent(percent)
let center = containerView.bounds.center
circleLayer.path = makeArcPath(arcCenter: center, radius: radius)
let angle = percent * .pi * 2
let dotCenter = CGPoint(x: center.x + cos(angle) * radius, y: center.y + sin(angle) * radius)
redDot.path = makeArcPath(arcCenter: dotCenter, radius: 5)
}
}
// MARK: - CGRect extension
extension CGRect {
var center: CGPoint { return CGPoint(x: midX, y: midY) }
}
// MARK: - ClosedRange extension
extension ClosedRange where Bound: FloatingPoint {
func percent(_ percent: Bound) -> Bound {
(upperBound - lowerBound) * percent + lowerBound
}
}
I'm having quite a bit of difficulty simply ensuring a circular progress bar is always in the centre of the UIView it is associated to.
This is what is happening:
Ignore the grey region, this is simply the UIView on a placeholder card. The red is the UIView I have added as an outlet to the UIViewController.
Below is the code for the class that I have made:
class CircleProgress: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
setupView()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setupView()
}
var progressLyr = CAShapeLayer()
var trackLyr = CAShapeLayer()
var progressClr = UIColor.red {
didSet {
progressLyr.strokeColor = progressClr.cgColor
}
}
var trackClr = UIColor.black {
didSet {
trackLyr.strokeColor = trackClr.cgColor
}
}
private func setupView() {
self.backgroundColor = UIColor.red
let centre = CGPoint(x: frame.size.width/2, y: frame.size.height/2)
let circlePath = UIBezierPath(arcCenter: centre,
radius: 10,
startAngle: 0,
endAngle: 2 * CGFloat.pi,
clockwise: true)
trackLyr.path = circlePath.cgPath
trackLyr.fillColor = UIColor.clear.cgColor
trackLyr.strokeColor = trackClr.cgColor
trackLyr.lineWidth = 5.0
trackLyr.strokeEnd = 1.0
layer.addSublayer(trackLyr)
}
}
The aim is simply to have all 4 edges of the black circle touching the edges of the red square.
Any help is hugely appreciated. I'm thinking it must be too obvious but this has cost me too many hours tonight. :)
The problem is that there is no frame being passed when creating the object. No need for changing anything to your code. For sure you have to change the width and the height to whatever you want.
Here is an example...
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = .white
// Add circleProgress
addCircleProgress()
}
private func addCircleProgress() {
let circleProgress = CircleProgress(frame: CGRect(x: self.view.center.x - 50, y: self.view.center.x - 50, width: 100, height: 100))
self.view.addSubview(circleProgress)
}
}
class CircleProgress: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
setupView()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
var progressLyr = CAShapeLayer()
var trackLyr = CAShapeLayer()
var progressClr = UIColor.red {
didSet {
progressLyr.strokeColor = progressClr.cgColor
}
}
var trackClr = UIColor.black {
didSet {
trackLyr.strokeColor = trackClr.cgColor
}
}
private func setupView() {
self.backgroundColor = UIColor.red
let centre = CGPoint(x: frame.size.width/2, y: frame.size.height/2)
let circlePath = UIBezierPath(arcCenter: centre,
radius: 50,
startAngle: 0,
endAngle: 2 * CGFloat.pi,
clockwise: true)
trackLyr.path = circlePath.cgPath
trackLyr.fillColor = UIColor.clear.cgColor
trackLyr.strokeColor = trackClr.cgColor
trackLyr.lineWidth = 5.0
trackLyr.strokeEnd = 1.0
layer.addSublayer(trackLyr)
}
}
A few suggestions:
I’d suggest making this CircularProgress take up the whole view. If you want this to be inset within the view, then, fine, add a property for that. In my example below, I created a property called inset to capture this value.
Make sure to update your path in layoutSubviews. Especially if you use constraints, you want this to respond to size changes. So add these layers from init, but update the path in layoutSubviews.
Don’t reference frame (which is the location within the superview coordinate system). Use bounds. And inset it by half the line width, so the circle doesn’t exceed the bounds of the view.
You created a progress color and progress layer, but didn’t use either one. I’ve guessed you wanted that to show the progress within the track.
You are stroking your path from 0 to 2π. People tend to expect these circular progress views to start from -π/2 (12 o’clock) and progress to 3π/2. So I’ve updated the path to use those values. But use whatever you want.
If you want, you can make it #IBDesignable if you want to see this rendered in IB.
Thus, pulling that together, you get:
#IBDesignable
public class CircleProgress: UIView {
#IBInspectable
public var lineWidth: CGFloat = 5 { didSet { updatePath() } }
#IBInspectable
public var strokeEnd: CGFloat = 1 { didSet { progressLayer.strokeEnd = strokeEnd } }
#IBInspectable
public var trackColor: UIColor = .black { didSet { trackLayer.strokeColor = trackColor.cgColor } }
#IBInspectable
public var progressColor: UIColor = .red { didSet { progressLayer.strokeColor = progressColor.cgColor } }
#IBInspectable
public var inset: CGFloat = 0 { didSet { updatePath() } }
private lazy var trackLayer: CAShapeLayer = {
let layer = CAShapeLayer()
layer.fillColor = UIColor.clear.cgColor
layer.strokeColor = trackColor.cgColor
layer.lineWidth = lineWidth
return layer
}()
private lazy var progressLayer: CAShapeLayer = {
let layer = CAShapeLayer()
layer.fillColor = UIColor.clear.cgColor
layer.strokeColor = progressColor.cgColor
layer.lineWidth = lineWidth
return layer
}()
override init(frame: CGRect = .zero) {
super.init(frame: frame)
setupView()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setupView()
}
public override func layoutSubviews() {
super.layoutSubviews()
updatePath()
}
}
private extension CircleProgress {
func setupView() {
layer.addSublayer(trackLayer)
layer.addSublayer(progressLayer)
}
func updatePath() {
let rect = bounds.insetBy(dx: lineWidth / 2 + inset, dy: lineWidth / 2 + inset)
let centre = CGPoint(x: rect.midX, y: rect.midY)
let radius = min(rect.width, rect.height) / 2
let path = UIBezierPath(arcCenter: centre,
radius: radius,
startAngle: -.pi / 2,
endAngle: 3 * .pi / 2,
clockwise: true)
trackLayer.path = path.cgPath
trackLayer.lineWidth = lineWidth
progressLayer.path = path.cgPath
progressLayer.lineWidth = lineWidth
}
}
That yields:
Update this function
private func setupView() {
self.backgroundColor = UIColor.red
let centre = CGPoint(x: bounds.midX, y: bounds.midY)
let circlePath = UIBezierPath(arcCenter: centre,
radius: bounds.maxX/2,
startAngle: 0,
endAngle: 2 * CGFloat.pi,
clockwise: true)
trackLyr.path = circlePath.cgPath
trackLyr.fillColor = UIColor.clear.cgColor
trackLyr.strokeColor = trackClr.cgColor
trackLyr.lineWidth = 5.0
trackLyr.strokeEnd = 1.0
layer.addSublayer(trackLyr)
}
I am trying to have an animation in a view controller in which the circle rotates with animation. The circle should rotate until a process completed like a gif below. I have implemented the circle animation but couldn't reach to the point what I want to achieve.
import UIKit
class ViewController: UIViewController {
var circle : Circle?;
override func viewDidLoad() {
super.viewDidLoad();
view.backgroundColor = UIColor.white;
setupViews();
}
func setupViews(){
circle = Circle(frame: self.view.frame);
view.addSubview(circle!);
circle?.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true;
circle?.topAnchor.constraint(equalTo: view.topAnchor).isActive = true;
circle?.heightAnchor.constraint(equalTo: view.heightAnchor).isActive = true;
circle?.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true;
}
}
class Circle : UIView{
override init(frame: CGRect) {
super.init(frame: frame);
self.backgroundColor = .blue;
self.translatesAutoresizingMaskIntoConstraints = false;
setupCircle();
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
let gradientLayer = CAGradientLayer();
func setupCircle(){
layer.addSublayer(shapeLayer);
let circlePath = UIBezierPath(arcCenter: CGPoint(x: self.frame.width / 2 - 50, y: self.frame.height / 2 - 50), radius: 50, startAngle: CGFloat(Double.pi * (0 / 4)), endAngle: CGFloat(Double.pi * 2), clockwise: true);
shapeLayer.path = circlePath.cgPath;
let group = CAAnimationGroup()
group.animations = [animateStrokeEnd, animateOpacity]
group.duration = 0.8
group.repeatCount = HUGE // repeat forver
shapeLayer.add(group, forKey: nil)
}
let shapeLayer: CAShapeLayer = {
let layer = CAShapeLayer();
layer.strokeColor = UIColor.white.cgColor;
layer.lineWidth = 5;
layer.fillColor = UIColor.clear.cgColor;
layer.strokeStart = 0
layer.strokeEnd = 1;
return layer;
}();
let animateOpacity : CABasicAnimation = {
let animation = CABasicAnimation(keyPath: "opacity");
animation.fromValue = 0;
animation.toValue = 0.8;
animation.byValue = 0.01;
animation.repeatCount = Float.infinity;
return animation
}();
let animateStrokeEnd: CABasicAnimation = {
let animation = CABasicAnimation(keyPath: "strokeEnd");
animation.fromValue = 0;
animation.repeatCount = Float.infinity;
animation.toValue = 1;
return animation;
}();
}
I am using strokeEnd animation to implement the animation. And opacity to animate the color. But when the circle reaches 360 degree, its makes a lag before starting a new circle.
Does anybody know how to remove this effect and get smooth animation?
The above code produces this animation
But i want to achieve this animation
Also the stroke colour is different from the original animation. Can we achieve this animation using the CABasicAnimation?
Rather than trying to animate the actual drawing, just draw the view once and then animate it.
Here is a custom PadlockView and a custom CircleView which mimic the animation you showed. To use it, add the code below to your project. Add a UIView to your Storyboard, change its class to PadlockView, and make an #IBOutlet to it (called padlock perhaps). When you want the view to animate, set padlock.circle.isAnimating = true. To stop animating, set padlock.circle.isAnimating = false.
CircleView.swift
// This UIView extension was borrowed from #keval's answer:
// https://stackoverflow.com/a/41160100/1630618
extension UIView {
func rotate360Degrees(duration: CFTimeInterval = 3) {
let rotateAnimation = CABasicAnimation(keyPath: "transform.rotation")
rotateAnimation.fromValue = 0.0
rotateAnimation.toValue = CGFloat.pi * 2
rotateAnimation.isRemovedOnCompletion = false
rotateAnimation.duration = duration
rotateAnimation.repeatCount = Float.infinity
self.layer.add(rotateAnimation, forKey: nil)
}
}
class CircleView: UIView {
var foregroundColor = UIColor.white
var lineWidth: CGFloat = 3.0
var isAnimating = false {
didSet {
if isAnimating {
self.isHidden = false
self.rotate360Degrees(duration: 1.0)
} else {
self.isHidden = true
self.layer.removeAllAnimations()
}
}
}
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
func setup() {
self.isHidden = true
self.backgroundColor = .clear
}
override func draw(_ rect: CGRect) {
let width = bounds.width
let height = bounds.height
let radius = (min(width, height) - lineWidth) / 2.0
var currentPoint = CGPoint(x: width / 2.0 + radius, y: height / 2.0)
var priorAngle = CGFloat(360)
for angle in stride(from: CGFloat(360), through: 0, by: -2) {
let path = UIBezierPath()
path.lineWidth = lineWidth
path.move(to: currentPoint)
currentPoint = CGPoint(x: width / 2.0 + cos(angle * .pi / 180.0) * radius, y: height / 2.0 + sin(angle * .pi / 180.0) * radius)
path.addArc(withCenter: CGPoint(x: width / 2.0, y: height / 2.0), radius: radius, startAngle: priorAngle * .pi / 180.0 , endAngle: angle * .pi / 180.0, clockwise: false)
priorAngle = angle
foregroundColor.withAlphaComponent(angle/360.0).setStroke()
path.stroke()
}
}
}
PadlockView.swift
class PadlockView: UIView {
var circle: CircleView!
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
func setup() {
self.backgroundColor = .clear
circle = CircleView()
circle.translatesAutoresizingMaskIntoConstraints = false
self.addSubview(circle)
circle.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true
circle.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
circle.widthAnchor.constraint(equalTo: self.widthAnchor).isActive = true
circle.heightAnchor.constraint(equalTo: self.heightAnchor).isActive = true
}
override func draw(_ rect: CGRect) {
let width = bounds.width
let height = bounds.height
let lockwidth = width / 3
let lockheight = height / 4
let boltwidth = lockwidth * 2 / 3
UIColor.white.setStroke()
let path = UIBezierPath()
path.move(to: CGPoint(x: (width - lockwidth) / 2, y: height / 2))
path.addLine(to: CGPoint(x: (width + lockwidth) / 2, y: height / 2))
path.addLine(to: CGPoint(x: (width + lockwidth) / 2, y: height / 2 + lockheight))
path.addLine(to: CGPoint(x: (width - lockwidth) / 2, y: height / 2 + lockheight))
path.close()
path.move(to: CGPoint(x: (width - boltwidth) / 2, y: height / 2))
path.addLine(to: CGPoint(x: (width - boltwidth) / 2, y: height / 2 - boltwidth / 4))
path.addArc(withCenter: CGPoint(x: width/2, y: height / 2 - boltwidth / 4), radius: boltwidth / 2, startAngle: .pi, endAngle: 0, clockwise: true)
path.lineWidth = 2.0
path.stroke()
}
}
Note: Continuous animation code courtesy of this answer.
Here is a demo that I setup with the following code in my ViewController:
#IBOutlet weak var padlock: PadlockView!
#IBAction func startStop(_ sender: UIButton) {
if sender.currentTitle == "Start" {
sender.setTitle("Stop", for: .normal)
padlock.circle.isAnimating = true
} else {
sender.setTitle("Start", for: .normal)
padlock.circle.isAnimating = false
}
}
I designed a custom header view that masks an image and draws a border on the bottom edge, which is an arc. It looks like this:
Here's the code for the class:
class HeaderView: UIView
{
private let imageView = UIImageView()
private let dimmerView = UIView()
private let arcShape = CAShapeLayer()
private let maskShape = CAShapeLayer() // Masks the image and the dimmer
private let titleLabel = UILabel()
#IBInspectable var image: UIImage? { didSet { self.imageView.image = self.image } }
#IBInspectable var title: String? { didSet {self.titleLabel.text = self.title} }
#IBInspectable var arcHeight: CGFloat? { didSet {self.setupLayers()} }
// MARK: Initialization
override init(frame: CGRect)
{
super.init(frame:frame)
initMyStuff()
}
required init?(coder aDecoder: NSCoder)
{
super.init(coder:aDecoder)
initMyStuff()
}
override func prepareForInterfaceBuilder()
{
backgroundColor = UIColor.clear()
}
internal func initMyStuff()
{
backgroundColor = UIColor.clear()
titleLabel.font = Font.AvenirNext_Bold(24)
titleLabel.text = "TITLE"
titleLabel.textColor = UIColor.white()
titleLabel.layer.shadowColor = UIColor.black().cgColor
titleLabel.layer.shadowOffset = CGSize(width: 0.0, height: 2.0)
titleLabel.layer.shadowRadius = 0.0;
titleLabel.layer.shadowOpacity = 1.0;
titleLabel.layer.masksToBounds = false
titleLabel.layer.shouldRasterize = true
imageView.contentMode = UIViewContentMode.scaleAspectFill
addSubview(imageView)
dimmerView.frame = self.bounds
dimmerView.backgroundColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.6)
addSubview(dimmerView)
addSubview(titleLabel)
// Add the shapes
self.layer.addSublayer(arcShape)
self.layer.addSublayer(maskShape)
self.layer.masksToBounds = true // This seems to be unneeded...test more
// Set constraints
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView .autoPinEdgesToSuperviewEdges()
titleLabel.autoCenterInSuperview()
}
func setupLayers()
{
let aHeight = arcHeight ?? 10
// Create the arc shape
arcShape.path = AppocalypseUI.createHorizontalArcPath(CGPoint(x: 0, y: bounds.size.height), width: bounds.size.width, arcHeight: aHeight)
arcShape.strokeColor = UIColor.white().cgColor
arcShape.lineWidth = 1.0
arcShape.fillColor = UIColor.clear().cgColor
// Create the mask shape
let maskPath = AppocalypseUI.createHorizontalArcPath(CGPoint(x: 0, y: bounds.size.height), width: bounds.size.width, arcHeight: aHeight, closed: true)
maskPath.moveTo(nil, x: bounds.size.width, y: bounds.size.height)
maskPath.addLineTo(nil, x: bounds.size.width, y: 0)
maskPath.addLineTo(nil, x: 0, y: 0)
maskPath.addLineTo(nil, x: 0, y: bounds.size.height)
//let current = CGPathGetCurrentPoint(maskPath);
//print(current)
let mask_Dimmer = CAShapeLayer()
mask_Dimmer.path = maskPath.copy()
maskShape.fillColor = UIColor(red: 0, green: 0, blue: 0, alpha: 1.0).cgColor
maskShape.path = maskPath
// Apply the masks
imageView.layer.mask = maskShape
dimmerView.layer.mask = mask_Dimmer
}
override func layoutSubviews()
{
super.layoutSubviews()
// Let's go old school here...
imageView.frame = self.bounds
dimmerView.frame = self.bounds
setupLayers()
}
}
Something like this will cause it to just snap to the new size without gradually changing its frame:
UIView.animate(withDuration: 1.0)
{
self.headerView.arcHeight = self.new_headerView_arcHeight
self.headerView.frame = self.new_headerView_frame
}
I figure it must have something to do with the fact that I'm using CALayers, but I don't really know enough about what's going on behind the scenes.
EDIT:
Here's the function I use to create the arc path:
class func createHorizontalArcPath(_ startPoint:CGPoint, width:CGFloat, arcHeight:CGFloat, closed:Bool = false) -> CGMutablePath
{
// http://www.raywenderlich.com/33193/core-graphics-tutorial-arcs-and-paths
let arcRect = CGRect(x: startPoint.x, y: startPoint.y-arcHeight, width: width, height: arcHeight)
let arcRadius = (arcRect.size.height/2) + (pow(arcRect.size.width, 2) / (8*arcRect.size.height));
let arcCenter = CGPoint(x: arcRect.origin.x + arcRect.size.width/2, y: arcRect.origin.y + arcRadius);
let angle = acos(arcRect.size.width / (2*arcRadius));
let startAngle = CGFloat(M_PI)+angle // (180 degrees + angle)
let endAngle = CGFloat(M_PI*2)-angle // (360 degrees - angle)
// let startAngle = radians(180) + angle;
// let endAngle = radians(360) - angle;
let path = CGMutablePath();
path.addArc(nil, x: arcCenter.x, y: arcCenter.y, radius: arcRadius, startAngle: startAngle, endAngle: endAngle, clockwise: false);
if(closed == true)
{path.addLineTo(nil, x: startPoint.x, y: startPoint.y);}
return path;
}
BONUS:
Setting the arcHeight property to 0 results in no white line being drawn. Why?
The Path property can't be animated. You have to approach the problem differently. You can draw an arc 'instantly', any arc, so that tells us that we need to handle the animation manually. If you expect the entire draw process to take say 3 seconds, then you might want to split the process to 1000 parts, and call the arc drawing function 1000 times every 0.3 miliseconds to draw the arc again from the beginning to the current point.
self.headerView.arcHeight is not a animatable property. It is only UIView own properties are animatable
you can do something like this
let displayLink = CADisplayLink(target: self, selector: #selector(update))
displayLink.addToRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode
let expectedFramesPerSecond = 60
var diff : CGFloat = 0
func update() {
let diffUpdated = self.headerView.arcHeight - self.new_headerView_arcHeight
let done = (fabs(diffUpdated) < 0.1)
if(!done){
self.headerView.arcHeight -= diffUpdated/(expectedFramesPerSecond*0.5)
self.setNeedsDisplay()
}
}