I have literally looked over the web for like 2to3 hours, unfortunately couldn't find anything, (2nd problem: being new to swift ->this can be ignored)
Basically I need Circular dashed Loading bar : Every dot should animate Individually like a circular load..
I was able to make a circular dashed circle but couldn't animate it...
Any help would be appreciated even if thats an library from github or anything..
Here's my code for creating a circular dashed circle..
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(true)
let circlePath = UIBezierPath(arcCenter: CGPoint(x: 100,y: 100), radius: 100.0, startAngle: 0.0, endAngle:CGFloat(M_PI * 2), clockwise: true)
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.cgPath
shapeLayer.position = CGPoint(x: 100, y: 100)
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.strokeColor = UIColor.blue.cgColor
shapeLayer.lineWidth = 6.0
let one : NSNumber = 1
let two : NSNumber = 13
shapeLayer.lineDashPattern = [one,two]
shapeLayer.lineCap = kCALineCapRound
view.layer.addSublayer(shapeLayer)
}
override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning()}
}
This is what I want (Below One):
I have been playing around with custom activity indicators, so here's one way to do it
import UIKit
#IBDesignable class ActivityIndicatorCircle: UIView {
var timerInterval: Double = 0.1
var timer : Timer?
var endAngle: CGFloat = 0.0
var angleStep = CGFloat.pi / 20.0
var angleOffset = -CGFloat.pi / 2.0
var shapeLayer = CAShapeLayer()
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override init(frame: CGRect) {
super.init(frame: frame)
}
func startAnimating() {
superview?.bringSubview(toFront: self)
layer.cornerRadius = frame.width / 2
self.clipsToBounds = true
isHidden = false
timer?.invalidate()
timer = nil
timer = Timer.scheduledTimer(timeInterval: timerInterval,
target: self,
selector: #selector(self.updateCircle),
userInfo: nil,
repeats: true)
}
func stopAnimating() {
isHidden = true
timer?.invalidate()
timer = nil
}
func updateCircle() {
endAngle += angleStep
if endAngle > CGFloat.pi * 2.0 {
endAngle -= CGFloat.pi * 2.0
}
DispatchQueue.main.async {
self.shapeLayer.removeFromSuperlayer() // remove the previous version
let lineWidth: CGFloat = 6.0
let radius = self.frame.size.width / 2.0 // if the view is square, this gives us center as well
let circlePath = UIBezierPath(arcCenter: CGPoint(x: radius,y: radius), radius: radius - lineWidth, startAngle: self.angleOffset, endAngle: self.endAngle + self.angleOffset, clockwise: true)
self.shapeLayer.path = circlePath.cgPath
self.shapeLayer.position = CGPoint(x: 0, y: 0)
self.shapeLayer.fillColor = UIColor.clear.cgColor
self.shapeLayer.strokeColor = UIColor.blue.cgColor
self.shapeLayer.lineWidth = lineWidth
let one : NSNumber = 1
let two : NSNumber = 13
self.shapeLayer.lineDashPattern = [one,two]
self.shapeLayer.lineCap = kCALineCapRound
self.layer.addSublayer(self.shapeLayer)
}
}
}
to use this, add a UIView to your storyboard, and set the class to ActivityIndicatorCircle
To start it, call activityIndicatorCircle.startAnimating()
for circular loader you can use this library it will help you. https://github.com/naoyashiga/RPLoadingAnimation
Related
Bit stumped here.
First of all, here is what's going on:
As you can see, my ball is not following the curved quarter-circle path exactly, but vaguely.
Here is the code creating the quarter-circle (p.s. - my container view is 294 units tall and wide):
let startAngle = CGFloat(Double.pi * 2) // top of circle
let endAngle = startAngle + 2 * Double.pi * 0.25
view.layoutIfNeeded()
smallCircleView.parentVC = self
smallCircleView.layer.cornerRadius = 45/2
let circlePath = UIBezierPath(arcCenter: CGPoint(x: 0, y: 0), radius: containerView.frame.self.width, startAngle: startAngle, endAngle: endAngle, clockwise: true)
And here is the code shifting the ball around:
func shiftSmallCircleView(newX : CGFloat){
smallCircleViewLeadingConstraint.constant = newX
let angle = (newX/containerView.frame.self.width)*90 + 180
let y = containerView.frame.size.width * cos((Double.pi * 2 * angle) / 360)
smallCircleViewBottomConstraint.constant = y + containerView.frame.origin.y
}
Since I'm using the cos function, should the ball's path be identical to the original quarter-circle path? How can they be similar but not identical?
Edit:
New outcome with updated code:
let angle = (distanceDelta/containerView.frame.self.width) * -90.0
containerView.transform = CGAffineTransform.init(rotationAngle: angle * Double.pi/180)
Most recent edit:
let angle = (distanceDelta/pathContainerView.frame.self.width) * .pi / -180.0
containerView.transform = CGAffineTransform.init(rotationAngle: angle)
All code:
class SmallCircleView : UIView {
var parentVC : ViewController!
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first as? UITouch {
let point = touch.location(in: self)
}
super.touchesBegan(touches, with: event)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first as? UITouch {
let point = touch.location(in: self.superview)=
parentVC.shiftSmallCircleView(distanceDelta: point.x)=
}
}
}
class ViewController: UIViewController {
#IBOutlet var containerView : UIView!
#IBOutlet var pathContainerView : UIView!
#IBOutlet var smallCircleView : SmallCircleView!
#IBOutlet var smallCircleViewLeadingConstraint : NSLayoutConstraint!
#IBOutlet var smallCircleViewBottomConstraint : NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let startAngle = CGFloat(Double.pi * 2) // top of circle
let endAngle = startAngle + 2 * Double.pi * 0.25
view.layoutIfNeeded()
smallCircleView.parentVC = self
smallCircleView.layer.cornerRadius = 45/2
let circlePath = UIBezierPath(arcCenter: CGPoint(x: 0, y: 0), radius: pathContainerView.frame.self.width, startAngle: startAngle, endAngle: endAngle, clockwise: true)
let shapeLayer = CAShapeLayer()
// The Bezier path that we made needs to be converted to
// a CGPath before it can be used on a layer.
shapeLayer.path = circlePath.cgPath
// apply other properties related to the path
shapeLayer.strokeColor = UIColor.blue.cgColor
shapeLayer.fillColor = UIColor.white.cgColor
shapeLayer.lineWidth = 1.0
shapeLayer.position = CGPoint(x: 0, y: 0)
// add the new layer to our custom view
pathContainerView.layer.addSublayer(shapeLayer)
containerView.bringSubviewToFront(smallCircleView)
}
func shiftSmallCircleView(distanceDelta : CGFloat){
let degrees = min(1, (distanceDelta/pathContainerView.frame.size.width)) * -90
containerView.transform = CGAffineTransform.init(rotationAngle: degrees * M_PI/180)
}
}
I’m on my phone right now and so I can’t provide the code but there is a much much easier way to do this. Don’t bother trying to work out what coordinates the ball needs to be at. Just place the ball into a rectangular view with the centre of this view being at the centre of your circle and the ball being on the path. (Make the container view invisible).
Now… rotate the container view.
That’s it.
Because the ball is a child of the view it will be moved as part of the rotation. And the movement will follow a circle centred around the point of rotation. Which is the centre of the container view.
Example
I made a quick example to show what I mean. In essence... cheat. Don't actually do the hard maths to work out where the ball will be. Use methods to make it look the same in an easier way...
Here is my storyboard...
And the code...
class ViewController: UIViewController {
#IBOutlet weak var containerView: UIView!
#IBOutlet weak var circleView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
circleView.layer.cornerRadius = 20
}
#IBAction func sliderChanged(_ sender: UISlider) {
let rotationAngle = sender.value * .pi / 180
containerView.transform = CGAffineTransform(rotationAngle: CGFloat(rotationAngle))
}
}
And an animation...
And if you make the container background clear...
To answer your original question...
I haven't double-checked your math, but this is another method of positioning your "small circle" view.
Using these two "helper" extensions:
extension CGPoint {
static func pointOnCircle(center: CGPoint, radius: CGFloat, angle: CGFloat) -> CGPoint {
let x = center.x + radius * cos(angle)
let y = center.y + radius * sin(angle)
return CGPoint(x: x, y: y)
}
}
extension CGFloat {
var degreesToRadians: Self { self * .pi / 180 }
var radiansToDegrees: Self { self * 180 / .pi }
}
We can find the point on the arc for a given angle like this:
let arcCenter: CGPoint = .zero
let radius: CGFloat = 250
let degree: CGFloat = 45
let p = CGPoint.pointOnCircle(center: arcCenter, radius: radius, angle: degree.degreesToRadians)
We can then move the "ball" to that point:
circleView.center = p
To get the circle view to "roll along the inside" of the arc, we use the same center point, but decrease the radius of the arc by the radius of the circle (half the width of the view).
If you want to use that approach (rather than rotating a view with the circle in the corner), here is some example code.
Start with our extensions, an enum, and a "small circle view":
extension CGPoint {
static func pointOnCircle(center: CGPoint, radius: CGFloat, angle: CGFloat) -> CGPoint {
let x = center.x + radius * cos(angle)
let y = center.y + radius * sin(angle)
return CGPoint(x: x, y: y)
}
}
extension CGFloat {
var degreesToRadians: Self { self * .pi / 180 }
var radiansToDegrees: Self { self * 180 / .pi }
}
enum FollowType: Int {
case inside, center, outside
}
class SmallCircleView : UIView {
override func layoutSubviews() {
super.layoutSubviews()
layer.cornerRadius = bounds.size.height / 2.0
}
}
Next, a UIView subclass that will handle drawing the arc, adding the circle subview, and it will use a UIViewPropertyAnimator with key frames to make it interactive:
class FollowArcView: UIView {
public var circleColor: UIColor = .red {
didSet {
circleView.backgroundColor = circleColor
}
}
public var arcColor: UIColor = .blue { didSet { setNeedsLayout() } }
public var arcLineWidth: CGFloat = 1 { didSet { setNeedsLayout() } }
public var arcInset: CGFloat = 0 { didSet { setNeedsLayout() } }
public var circleRadius: CGFloat = 25 { didSet { setNeedsLayout() } }
public var followType: FollowType = .inside { didSet { setNeedsLayout() } }
public var fractionComplete: CGFloat = 0 {
didSet {
if animator != nil {
animator.fractionComplete = fractionComplete
}
}
}
private let circleView = SmallCircleView()
private let arcLayer = CAShapeLayer()
private var animator: UIViewPropertyAnimator!
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
commonInit()
}
func commonInit() {
arcLayer.fillColor = UIColor.clear.cgColor
layer.addSublayer(arcLayer)
circleView.frame = CGRect(x: 0, y: 0, width: circleRadius * 2.0, height: circleRadius * 2.0)
circleView.backgroundColor = circleColor
addSubview(circleView)
}
override func layoutSubviews() {
super.layoutSubviews()
var curFraction: CGFloat = 0
// we may be changing properties (such as arc color, inset, etc)
// after we've moved the circleView, so
// save the current .fractionComplete
if animator != nil {
curFraction = animator.fractionComplete
animator.stopAnimation(true)
}
// these properties can be changed after initial view setup
arcLayer.lineWidth = arcLineWidth
arcLayer.strokeColor = arcColor.cgColor
circleView.frame.size = CGSize(width: circleRadius * 2.0, height: circleRadius * 2.0)
let arcCenter = CGPoint(x: arcInset, y: arcInset)
let arcRadius = bounds.width - (arcInset * 2.0)
let followRadius = followType == .inside ? arcRadius - circleRadius : followType == .center ? arcRadius : arcRadius + circleRadius
let pth = UIBezierPath(arcCenter: arcCenter, radius: arcRadius, startAngle: .pi * 0.5, endAngle: 0, clockwise: false)
arcLayer.path = pth.cgPath
let p = CGPoint.pointOnCircle(center: arcCenter, radius: followRadius, angle: CGFloat(90).degreesToRadians)
circleView.center = p
// the animator will take the current position of the circleView
// as Frame 0, so we need to let UIKit update the circleView's position
// before setting up the animator
DispatchQueue.main.async {
self.setupAnim()
self.animator.fractionComplete = curFraction
}
}
private func setupAnim() {
if animator != nil {
animator.stopAnimation(true)
}
// starting point
var startDegrees: CGFloat = 90
// ending point
let endDegrees: CGFloat = 0
// we'll be using percentages
let numSteps: CGFloat = 100
let arcCenter = CGPoint(x: arcInset, y: arcInset)
let arcRadius = bounds.width - (arcInset * 2.0)
let followRadius = followType == .inside ? arcRadius - circleRadius : followType == .center ? arcRadius : arcRadius + circleRadius
animator = UIViewPropertyAnimator(duration: 0.3, curve: .linear)
animator.addAnimations {
UIView.animateKeyframes(withDuration: 0.1, delay: 0.0, animations: {
let stepDegrees: Double = (startDegrees - endDegrees) / Double(numSteps)
for i in 1...Int(numSteps) {
// decrement degrees by step value
startDegrees -= stepDegrees
// get point on discPathRadius circle
let p = CGPoint.pointOnCircle(center: arcCenter, radius: followRadius, angle: startDegrees.degreesToRadians)
// duration is 1 divided by number of steps
let duration = 1.0 / Double(numSteps)
// start time for this frame is duration * this step
let startTime = duration * Double(i)
// add the keyframe
UIView.addKeyframe(withRelativeStartTime: startTime, relativeDuration: duration) {
self.circleView.center = p
}
}
})
}
// start and immediately pause the animation
animator.startAnimation()
animator.pauseAnimation()
}
}
and an example controller class:
class FollowArcVC: UIViewController {
let followArcView = FollowArcView()
override func viewDidLoad() {
super.viewDidLoad()
let slider = UISlider()
let typeControl = UISegmentedControl(items: ["Inside", "Center", "Outside"])
[followArcView, typeControl, slider].forEach { v in
v.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(v)
}
let g = view.safeAreaLayoutGuide
NSLayoutConstraint.activate([
followArcView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 40.0),
followArcView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -40.0),
followArcView.centerYAnchor.constraint(equalTo: g.centerYAnchor),
// 1:1 ratio (square)
followArcView.heightAnchor.constraint(equalTo: followArcView.widthAnchor),
typeControl.topAnchor.constraint(equalTo: g.topAnchor, constant: 40.0),
typeControl.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 40.0),
typeControl.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -40.0),
slider.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -20.0),
slider.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
slider.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
])
typeControl.selectedSegmentIndex = 0
typeControl.addTarget(self, action: #selector(typeChanged(_:)), for: .valueChanged)
slider.addTarget(self, action: #selector(sliderChanged(_:)), for: .valueChanged)
// if we want to see the view frame
//followArcView.backgroundColor = .yellow
}
#objc func typeChanged(_ sender: UISegmentedControl) -> Void {
switch sender.selectedSegmentIndex {
case 0:
followArcView.followType = .inside
case 1:
followArcView.followType = .center
case 2:
followArcView.followType = .outside
default:
()
}
}
#objc func sliderChanged(_ sender: Any?) {
guard let sldr = sender as? UISlider else { return }
followArcView.fractionComplete = CGFloat(sldr.value)
}
}
The result:
Edit
After playing around a bit, this is another way to interactively follow the path -- it uses layer path animation, and avoids the need to manually calculate keyframe positions.
Works with the same sample view controller as above - just replace the FollowArcView class:
class FollowArcView: UIView {
public var circleColor: UIColor = .red {
didSet {
circleView.backgroundColor = circleColor
}
}
public var arcColor: UIColor = .blue {
didSet {
arcLayer.strokeColor = arcColor.cgColor
}
}
public var arcLineWidth: CGFloat = 1 {
didSet {
arcLayer.lineWidth = arcLineWidth
}
}
public var arcInset: CGFloat = 0 { didSet { setNeedsLayout() } }
public var circleRadius: CGFloat = 25 { didSet { setNeedsLayout() } }
public var followType: FollowType = .inside { didSet { setNeedsLayout() } }
public var fractionComplete: CGFloat = 0 {
didSet {
circleView.layer.timeOffset = CFTimeInterval(fractionComplete)
}
}
private let circleView = SmallCircleView()
private let arcLayer = CAShapeLayer()
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
commonInit()
}
func commonInit() {
arcLayer.fillColor = UIColor.clear.cgColor
arcLayer.lineWidth = arcLineWidth
arcLayer.strokeColor = arcColor.cgColor
layer.addSublayer(arcLayer)
circleView.frame = CGRect(x: 0, y: 0, width: circleRadius * 2.0, height: circleRadius * 2.0)
circleView.backgroundColor = circleColor
addSubview(circleView)
}
override func layoutSubviews() {
super.layoutSubviews()
circleView.frame.size = CGSize(width: circleRadius * 2.0, height: circleRadius * 2.0)
let arcCenter = CGPoint(x: arcInset, y: arcInset)
let arcRadius = bounds.width - (arcInset * 2.0)
let pth = UIBezierPath(arcCenter: arcCenter, radius: arcRadius, startAngle: .pi * 0.5, endAngle: 0, clockwise: false)
arcLayer.path = pth.cgPath
self.setupAnim()
}
private func setupAnim() {
let arcCenter = CGPoint(x: arcInset, y: arcInset)
let arcRadius = bounds.width - (arcInset * 2.0)
let followRadius = followType == .inside ? arcRadius - circleRadius : followType == .center ? arcRadius : arcRadius + circleRadius
let pth = UIBezierPath(arcCenter: arcCenter, radius: followRadius, startAngle: .pi * 0.5, endAngle: 0, clockwise: false)
let animation = CAKeyframeAnimation(keyPath: #keyPath(CALayer.position))
animation.duration = 1
animation.fillMode = .forwards
animation.isRemovedOnCompletion = false
animation.path = pth.cgPath
circleView.layer.speed = 0
circleView.layer.timeOffset = 0
circleView.layer.add(animation, forKey: "PathAnim")
DispatchQueue.main.async {
self.circleView.layer.timeOffset = self.fractionComplete
}
}
}
I am trying to make a circle with dash lines. I am able to make lines in rectangle but I don't know how to make these in circle. Here is answer I got but it's in Objective-C: UIView Draw Circle with Dotted Line Border
Here is my code which makes a rectangle with dashed lines.
func addDashedBorder() {
let color = UIColor.red.cgColor
let shapeLayer:CAShapeLayer = CAShapeLayer()
let frameSize = self.frame.size
let shapeRect = CGRect(x: 0, y: 0, width: frameSize.width, height: frameSize.height)
shapeLayer.bounds = shapeRect
shapeLayer.position = CGPoint(x: frameSize.width/2, y: frameSize.height/2)
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.strokeColor = color
shapeLayer.lineWidth = 2
shapeLayer.lineJoin = CAShapeLayerLineJoin.round
shapeLayer.lineDashPattern = [6,3]
shapeLayer.path = UIBezierPath(roundedRect: shapeRect, cornerRadius: 5).cgPath
self.layer.addSublayer(shapeLayer)
}
Certainly you can just render your circular UIBezierPath with the selected dash pattern:
class DashedCircleView: UIView {
private var shapeLayer: CAShapeLayer = {
let shapeLayer = CAShapeLayer()
shapeLayer.strokeColor = UIColor.red.cgColor
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.lineWidth = 10
shapeLayer.lineCap = .round
shapeLayer.lineDashPattern = [20, 60]
return shapeLayer
}()
override init(frame: CGRect = .zero) {
super.init(frame: frame)
configure()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
configure()
}
override func layoutSubviews() {
super.layoutSubviews()
updatePath()
}
}
private extension DashedCircleView {
func configure() {
layer.addSublayer(shapeLayer)
}
func updatePath() {
let rect = bounds.insetBy(dx: shapeLayer.lineWidth / 2, dy: shapeLayer.lineWidth / 2)
let radius = min(rect.width, rect.height) / 2
let center = CGPoint(x: rect.midX, y: rect.midY)
let path = UIBezierPath(arcCenter: center, radius: radius, startAngle: 0, endAngle: .pi * 2, clockwise: true)
shapeLayer.path = path.cgPath
}
}
That yields:
The problem with that approach is that it’s hard to get the dashed pattern to line up (notice the awkward dashing at the “3 o’clock” position). You can fix that by making sure that the two values of lineDashPattern add up to some number that evenly divides into the circumference of the circle (e.g. 2π × radius):
let circumference: CGFloat = 2 * .pi * radius
let count = 30
let relativeDashLength: CGFloat = 0.25
let dashLength = circumference / CGFloat(count)
shapeLayer.lineDashPattern = [dashLength * relativeDashLength, dashLength * (1 - relativeDashLength)] as [NSNumber]
Alternatively, rather than using lineDashPattern at all, you can instead keep a solid stroke and make the path, itself, as a series of small arcs. That way I can achieve the desired dashed effect, but ensuring it’s evenly split into count little arcs as we rotate from 0 to 2π:
class DashedCircleView: UIView {
private var shapeLayer: CAShapeLayer = {
let shapeLayer = CAShapeLayer()
shapeLayer.strokeColor = UIColor.red.cgColor
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.lineWidth = 10
shapeLayer.lineCap = .round
return shapeLayer
}()
override init(frame: CGRect = .zero) {
super.init(frame: frame)
configure()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
configure()
}
override func layoutSubviews() {
super.layoutSubviews()
updatePath()
}
}
private extension DashedCircleView {
func configure() {
layer.addSublayer(shapeLayer)
}
func updatePath() {
let rect = bounds.insetBy(dx: shapeLayer.lineWidth / 2, dy: shapeLayer.lineWidth / 2)
let radius = min(rect.width, rect.height) / 2
let center = CGPoint(x: rect.midX, y: rect.midY)
let path = UIBezierPath()
let count = 30
let relativeDashLength: CGFloat = 0.25 // a value between 0 and 1
let increment: CGFloat = .pi * 2 / CGFloat(count)
for i in 0 ..< count {
let startAngle = increment * CGFloat(i)
let endAngle = startAngle + relativeDashLength * increment
path.move(to: CGPoint(x: center.x + radius * cos(startAngle),
y: center.y + radius * sin(startAngle)))
path.addArc(withCenter: center, radius: radius, startAngle: startAngle, endAngle: endAngle, clockwise: true)
}
shapeLayer.path = path.cgPath
}
}
That yields:
You can use UIBezierPath(ovalIn:) to create a circle path in a square view.
extension UIView {
func addDashedCircle() {
let circleLayer = CAShapeLayer()
circleLayer.path = UIBezierPath(ovalIn: bounds).cgPath
circleLayer.lineWidth = 2.0
circleLayer.strokeColor = UIColor.red.cgColor//border of circle
circleLayer.fillColor = UIColor.white.cgColor//inside the circle
circleLayer.lineJoin = .round
circleLayer.lineDashPattern = [6,3]
layer.addSublayer(circleLayer)
}
}
Set view background color .clear and fill color of the layer .white
class View1: UIViewController {
#IBOutlet weak var circleView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
circleView.backgroundColor = .clear//outside the circle
circleView.addDashedCircle()
}
}
Or using UIBezierPath(arcCenter:radius:startAngle:endAngle:clockwise:)
circleLayer.path = UIBezierPath(arcCenter: CGPoint(x: frame.size.width/2, y: frame.size.height/2),
radius: min(frame.size.height,frame.size.width)/2,
startAngle: 0,
endAngle: .pi * 2,
clockwise: true).cgPath
Draw the path using the circle path variant of UIBezierPath
shapeLayer.path = UIBezierPath(arcCenter: CGPoint(x: frame.size.width * 0.5, y: frame.size.height * 0.5), radius: frame.size.width * 0.5, startAngle: 0, endAngle: .pi * 2, clockwise: true)
I am trying to make custom activity indicator, see the indicator class below
import UIKit
class MyIndicator: UIView {
let gap = CGFloat(.pi/4 / 6.0)
var count = 0
override func draw(_ rect: CGRect) {
super.draw(rect)
}
func blink() {
backgroundColor = .clear
let duration: CFTimeInterval = 1.2
//let beginTime = CACurrentMediaTime()
let beginTimes: [CFTimeInterval] = [0.25, 1, 1.75, 2.5]
let timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
// Animation
let animation = CAKeyframeAnimation(keyPath: "opacity")
animation.keyTimes = [0, 0.5, 1]
animation.timingFunctions = [timingFunction, timingFunction]
animation.values = [1, 0.3, 1]
animation.duration = duration
animation.repeatCount = HUGE
animation.isRemovedOnCompletion = false
for i in 0...3 {
let shape = CAShapeLayer()
shape.frame = self.bounds
shape.fillColor = UIColor.clear.cgColor
shape.lineWidth = 6.8
shape.strokeColor = UIColor.blue.cgColor
let startAngle:CGFloat = CGFloat(i) * CGFloat(Double.pi/2) + gap
let endAngle:CGFloat = startAngle + CGFloat(Double.pi/2) - gap * 2
shape.path = UIBezierPath(arcCenter: center, radius: -20, startAngle: startAngle, endAngle: endAngle, clockwise: true).cgPath
animation.beginTime = beginTimes[i]
shape.add(animation, forKey: "animation")
self.layer.addSublayer(shape)
}
}
func startAnimating() {
blink()
}
}
let indicator = MyIndicator(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
self.view.addSubview(indicator)
indicator.startAnimating()
I have attached my current result.
But you can see that the animation is not in circular motion like standard UIActivityIndicatorView. Can anyone help me to fix this.
Try using a CAReplicatorLayer and instance delay to get everything in sync. Here is a Playground. I am not 100% sure on the visual you want but this should be close.
//: A UIKit based Playground for presenting user interface
import UIKit
import PlaygroundSupport
class MyIndicator: UIView {
let gap = CGFloat(.pi/4 / 6.0)
private var replicatorLayer = CAReplicatorLayer()
private var mainShapeLayer = CAShapeLayer()
override init(frame: CGRect) {
super.init(frame: frame)
commonSetup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonSetup()
}
func commonSetup(){
mainShapeLayer = CAShapeLayer()
mainShapeLayer.frame = self.bounds
mainShapeLayer.fillColor = UIColor.clear.cgColor
mainShapeLayer.lineWidth = 6.8
mainShapeLayer.strokeColor = UIColor.blue.cgColor
let startAngle:CGFloat = CGFloat(Double.pi * 2) + gap/2
let endAngle:CGFloat = startAngle + CGFloat(Double.pi/2) - gap/2
mainShapeLayer.path = UIBezierPath(arcCenter: center, radius: self.bounds.midX - 10, startAngle: startAngle, endAngle: endAngle, clockwise: true).cgPath
replicatorLayer = CAReplicatorLayer()
replicatorLayer.frame = self.bounds
replicatorLayer.instanceCount = 4
let angle = (Double.pi * 2)/4
replicatorLayer.instanceTransform = CATransform3DRotate(CATransform3DIdentity, CGFloat(angle), 0, 0, 1)
replicatorLayer.addSublayer(mainShapeLayer)
replicatorLayer.opacity = 0
self.layer.addSublayer(replicatorLayer)
}
func animate(){
let defaultDuration : Double = 0.75
let animate = CAKeyframeAnimation(keyPath: "opacity")
animate.values = [1, 0.3, 1]
animate.keyTimes = [0, 0.5, 1]
animate.repeatCount = .greatestFiniteMagnitude
animate.duration = defaultDuration
animate.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
replicatorLayer.instanceDelay = defaultDuration/4
self.mainShapeLayer.add(animate, forKey: nil)
let opacityIn = CABasicAnimation(keyPath: "opacity")
opacityIn.fromValue = 1
opacityIn.toValue = 0
opacityIn.duration = 0.2
replicatorLayer.add(opacityIn, forKey: nil)
self.replicatorLayer.opacity = 1
}
func stopAnimating(){
CATransaction.begin()
let opacityOut = CABasicAnimation(keyPath: "opacity")
opacityOut.fromValue = 1
opacityOut.toValue = 0
opacityOut.duration = 0.2
CATransaction.setCompletionBlock {
[weak self] in
self?.mainShapeLayer.removeAllAnimations()
}
replicatorLayer.add(opacityOut, forKey: nil)
self.replicatorLayer.opacity = 0
CATransaction.commit()
}
override func layoutSubviews() {
super.layoutSubviews()
mainShapeLayer.frame = self.bounds
replicatorLayer.frame = self.bounds
}
}
class MyViewController : UIViewController {
override func loadView() {
let view = UIView()
view.backgroundColor = .white
let indicator = MyIndicator(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
indicator.animate()
//just to simulate starting and stoping
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 10) {
indicator.stopAnimating()
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 5) {
indicator.animate()
}
}
view.addSubview(indicator)
self.view = view
}
}
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()
I want to expand and contract a circle using CABasicAnimation. I previously designed a clean and effective way to draw the animation using sin and the drawRect method of the UIView class, but unfortunately it seems you can't animate or force drawRect to fire in UIView.animate methods no matter what you do. Therefore, I've had to come up with a workaround using CABasicAnimation. The result kind of works, but the animation is ugly and doesn't look right. Here's an illustration of what I mean:
Warping occurs during the expansion and contraction, and there appears to be a dent or cavity on the right side when the circle is expanding. Here's the class responsible for animating it:
struct PathConfig {
var arcCenter: CGPoint
var radius: CGFloat
let startAngle: CGFloat = 0.0
let endAngle: CGFloat = CGFloat(2 * M_PI)
}
class RGSStandbyIndicatorView: UIView {
// MARK: - Variables & Constants
/// The drawing layer.
var shapeLayer: CAShapeLayer!
// MARK: - Class Methods
/// Animation function.
func animate(period: CFTimeInterval) {
let p: PathConfig = PathConfig(arcCenter: CGPoint(x: frame.width / 2, y: frame.height / 2) , radius: 17.5)
let b: UIBezierPath = UIBezierPath(arcCenter: p.arcCenter, radius: p.radius, startAngle: p.startAngle, endAngle: p.endAngle, clockwise: true)
let a: CABasicAnimation = CABasicAnimation(keyPath: "path")
a.fromValue = shapeLayer.path
a.toValue = b.cgPath
a.autoreverses = true
a.duration = period
a.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
a.repeatCount = HUGE
shapeLayer.add(a, forKey: "animateRadius")
}
/// Initializes and returns a CAShapeLayer with the given draw path and fill color.
private class func shapeLayerForPath(_ path: CGPath, with fillColor: CGColor) -> CAShapeLayer {
let shapeLayer: CAShapeLayer = CAShapeLayer()
shapeLayer.path = path
shapeLayer.fillColor = fillColor
return shapeLayer
}
/// Configures the UIView
private func setup() {
// Init config, path.
let cfg: PathConfig = PathConfig(arcCenter: CGPoint(x: frame.width / 2, y: frame.height / 2) , radius: 0.0)
let path: UIBezierPath = UIBezierPath(arcCenter: cfg.arcCenter, radius: cfg.radius, startAngle: cfg.startAngle, endAngle: cfg.endAngle, clockwise: true)
// Init CAShapeLayer
shapeLayer = RGSStandbyIndicatorView.shapeLayerForPath(path.cgPath, with: UIColor.white.cgColor)
layer.addSublayer(shapeLayer)
}
// MARK: Class Method Overrides
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
}
I've tried adjusting the start and end angles hoping it was some artifact of the path having no overlap, but it didn't change anything. I'm not sure how to fix this problem, and It's based off Chadwick Wood's answer to a similar question.
Use this UIView subclass
class RadioAnimationView: UIView {
var animatableLayer : CAShapeLayer?
override func awakeFromNib() {
super.awakeFromNib()
self.layer.cornerRadius = self.bounds.height/2
self.animatableLayer = CAShapeLayer()
self.animatableLayer?.fillColor = self.backgroundColor?.cgColor
self.animatableLayer?.path = UIBezierPath(roundedRect: self.bounds, cornerRadius: self.layer.cornerRadius).cgPath
self.animatableLayer?.frame = self.bounds
self.animatableLayer?.cornerRadius = self.bounds.height/2
self.animatableLayer?.masksToBounds = true
self.layer.addSublayer(self.animatableLayer!)
self.startAnimation()
}
func startAnimation()
{
let layerAnimation = CABasicAnimation(keyPath: "transform.scale")
layerAnimation.fromValue = 1
layerAnimation.toValue = 3
layerAnimation.isAdditive = false
layerAnimation.duration = CFTimeInterval(2)
layerAnimation.fillMode = kCAFillModeForwards
layerAnimation.isRemovedOnCompletion = true
layerAnimation.repeatCount = .infinity
layerAnimation.autoreverses = true
self.animatableLayer?.add(layerAnimation, forKey: "growingAnimation")
}
}
Hope this helps you
let block = UIView(frame: CGRectMake(cellWidth-25, cellHeight/2-8, 16, 16))
block.backgroundColor = UIColor(netHex: 0xff3b30)
block.layer.cornerRadius = 9
block.clipsToBounds = true
This is what I have right now, but it's obviously not the right way to do it.
What's the simplest way to do it?
Alert. This old answer is absolutely incorrect.
WARNING! This is an incorrect solution. layers are added infinitely in the drawRect method (every time the view is drawn). You should NEVER add layers in the drawRect method. Use layoutSubview instead.
You can draw a circle with this (Swift 3.0+):
let circlePath = UIBezierPath(arcCenter: CGPoint(x: 100, y: 100), radius: CGFloat(20), startAngle: CGFloat(0), endAngle: CGFloat(Double.pi * 2), clockwise: true)
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.cgPath
// Change the fill color
shapeLayer.fillColor = UIColor.clear.cgColor
// You can change the stroke color
shapeLayer.strokeColor = UIColor.red.cgColor
// You can change the line width
shapeLayer.lineWidth = 3.0
view.layer.addSublayer(shapeLayer)
With the code you have posted you are cropping the corners of the UIView, not adding a circle to the view.
Here's a full example of using that method:
/// A special UIView displayed as a ring of color
class Ring: UIView {
override func drawRect(rect: CGRect) {
drawRingFittingInsideView()
}
internal func drawRingFittingInsideView() -> () {
let halfSize:CGFloat = min( bounds.size.width/2, bounds.size.height/2)
let desiredLineWidth:CGFloat = 1 // your desired value
let circlePath = UIBezierPath(
arcCenter: CGPoint(x:halfSize,y:halfSize),
radius: CGFloat( halfSize - (desiredLineWidth/2) ),
startAngle: CGFloat(0),
endAngle:CGFloat(M_PI * 2),
clockwise: true)
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.CGPath
shapeLayer.fillColor = UIColor.clearColor().CGColor
shapeLayer.strokeColor = UIColor.redColor().CGColor
shapeLayer.lineWidth = desiredLineWidth
layer.addSublayer(shapeLayer)
}
}
Note, however there's an incredibly handy call:
let circlePath = UIBezierPath(ovalInRect: rect)
which does all the work of making the path. (Don't forget to inset it for the line thickness, which is also incredibly easy with CGRectInset.)
internal func drawRingFittingInsideView(rect: CGRect) {
let desiredLineWidth:CGFloat = 4 // Your desired value
let hw:CGFloat = desiredLineWidth/2
let circlePath = UIBezierPath(ovalInRect: CGRectInset(rect,hw,hw))
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.CGPath
shapeLayer.fillColor = UIColor.clearColor().CGColor
shapeLayer.strokeColor = UIColor.redColor().CGColor
shapeLayer.lineWidth = desiredLineWidth
layer.addSublayer(shapeLayer)
}
In practice these days in Swift, you would certainly use #IBDesignable and #IBInspectable. Using these you can actually see and change the rendering, in Storyboard!
As you can see, it actually adds new features to the Inspector on the Storyboard, which you can change on the Storyboard:
/// A dot with a border, which you can control completely in Storyboard
#IBDesignable class Dot: UIView {
#IBInspectable var mainColor: UIColor = UIColor.blueColor() {
didSet {
print("mainColor was set here")
}
}
#IBInspectable var ringColor: UIColor = UIColor.orangeColor() {
didSet {
print("bColor was set here")
}
}
#IBInspectable var ringThickness: CGFloat = 4 {
didSet {
print("ringThickness was set here")
}
}
#IBInspectable var isSelected: Bool = true
override func drawRect(rect: CGRect) {
let dotPath = UIBezierPath(ovalInRect:rect)
let shapeLayer = CAShapeLayer()
shapeLayer.path = dotPath.CGPath
shapeLayer.fillColor = mainColor.CGColor
layer.addSublayer(shapeLayer)
if (isSelected) {
drawRingFittingInsideView(rect)
}
}
internal func drawRingFittingInsideView(rect: CGRect) {
let hw:CGFloat = ringThickness/2
let circlePath = UIBezierPath(ovalInRect: CGRectInset(rect,hw,hw) )
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.CGPath
shapeLayer.fillColor = UIColor.clearColor().CGColor
shapeLayer.strokeColor = ringColor.CGColor
shapeLayer.lineWidth = ringThickness
layer.addSublayer(shapeLayer)
}
}
Finally, note that if you have a UIView (which is square, and which you set to say red in Storyboard) and you simply want to turn it in to a red circle, you can just do the following:
// Makes a UIView into a circular dot of color
class Dot: UIView {
override func layoutSubviews() {
layer.cornerRadius = bounds.size.width/2
}
}
Make a class UIView and assign it this code for a simple circle
import UIKit
#IBDesignable
class DRAW: UIView {
override func draw(_ rect: CGRect) {
var path = UIBezierPath()
path = UIBezierPath(ovalIn: CGRect(x: 50, y: 50, width: 100, height: 100))
UIColor.yellow.setStroke()
UIColor.red.setFill()
path.lineWidth = 5
path.stroke()
path.fill()
}
}
If you want to use a UIView to draw it, then you need to make the radius / of the height or width.
so just change:
block.layer.cornerRadius = 9
to:
block.layer.cornerRadius = block.frame.width / 2
You'll need to make the height and width the same however. If you'd like to use coregraphics, then you'll want to do something like this:
CGContextRef ctx= UIGraphicsGetCurrentContext();
CGRect bounds = [self bounds];
CGPoint center;
center.x = bounds.origin.x + bounds.size.width / 2.0;
center.y = bounds.origin.y + bounds.size.height / 2.0;
CGContextSaveGState(ctx);
CGContextSetLineWidth(ctx,5);
CGContextSetRGBStrokeColor(ctx,0.8,0.8,0.8,1.0);
CGContextAddArc(ctx,locationOfTouch.x,locationOfTouch.y,30,0.0,M_PI*2,YES);
CGContextStrokePath(ctx);
Here is my version using Swift 5 and Core Graphics.
I have created a class to draw two circles. The first circle is created using addEllipse(). It puts the ellipse into a square, thus creating a circle. I find it surprising that there is no function addCircle(). The second circle is created using addArc() of 2pi radians
import UIKit
#IBDesignable
class DrawCircles: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
}
required public init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func draw(_ rect: CGRect) {
guard let context = UIGraphicsGetCurrentContext() else {
print("could not get graphics context")
return
}
context.setLineWidth(2)
context.setStrokeColor(UIColor.blue.cgColor)
context.addEllipse(in: CGRect(x: 30, y: 30, width: 50.0, height: 50.0))
context.strokePath()
context.setStrokeColor(UIColor.red.cgColor)
context.beginPath() // this prevents a straight line being drawn from the current point to the arc
context.addArc(center: CGPoint(x:100, y: 100), radius: 20, startAngle: 0, endAngle: 2.0*CGFloat.pi, clockwise: false)
context.strokePath()
}
}
in your ViewController's didViewLoad() add the following:
let myView = DrawCircles(frame: CGRect(x: 50, y: 50, width: 300, height: 300))
self.view.addSubview(myView)
When it runs it should look like this. I hope you like my solution!
Swift 4 version of accepted answer:
#IBDesignable
class CircledDotView: UIView {
#IBInspectable var mainColor: UIColor = .white {
didSet { print("mainColor was set here") }
}
#IBInspectable var ringColor: UIColor = .black {
didSet { print("bColor was set here") }
}
#IBInspectable var ringThickness: CGFloat = 4 {
didSet { print("ringThickness was set here") }
}
#IBInspectable var isSelected: Bool = true
override func draw(_ rect: CGRect) {
let dotPath = UIBezierPath(ovalIn: rect)
let shapeLayer = CAShapeLayer()
shapeLayer.path = dotPath.cgPath
shapeLayer.fillColor = mainColor.cgColor
layer.addSublayer(shapeLayer)
if (isSelected) {
drawRingFittingInsideView(rect: rect)
}
}
internal func drawRingFittingInsideView(rect: CGRect) {
let hw: CGFloat = ringThickness / 2
let circlePath = UIBezierPath(ovalIn: rect.insetBy(dx: hw, dy: hw))
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.cgPath
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.strokeColor = ringColor.cgColor
shapeLayer.lineWidth = ringThickness
layer.addSublayer(shapeLayer)
}
}
Updating #Dario's code approach for Xcode 8.2.2, Swift 3.x. Noting that in storyboard, set the Background color to "clear" to avoid a black background in the square UIView:
import UIKit
#IBDesignable
class Dot:UIView
{
#IBInspectable var mainColor: UIColor = UIColor.clear
{
didSet { print("mainColor was set here") }
}
#IBInspectable var ringColor: UIColor = UIColor.clear
{
didSet { print("bColor was set here") }
}
#IBInspectable var ringThickness: CGFloat = 4
{
didSet { print("ringThickness was set here") }
}
#IBInspectable var isSelected: Bool = true
override func draw(_ rect: CGRect)
{
let dotPath = UIBezierPath(ovalIn: rect)
let shapeLayer = CAShapeLayer()
shapeLayer.path = dotPath.cgPath
shapeLayer.fillColor = mainColor.cgColor
layer.addSublayer(shapeLayer)
if (isSelected) { drawRingFittingInsideView(rect: rect) }
}
internal func drawRingFittingInsideView(rect: CGRect)->()
{
let hw:CGFloat = ringThickness/2
let circlePath = UIBezierPath(ovalIn: rect.insetBy(dx: hw,dy: hw) )
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.cgPath
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.strokeColor = ringColor.cgColor
shapeLayer.lineWidth = ringThickness
layer.addSublayer(shapeLayer)
}
}
And if you want to control the start and end angles:
import UIKit
#IBDesignable
class Dot:UIView
{
#IBInspectable var mainColor: UIColor = UIColor.clear
{
didSet { print("mainColor was set here") }
}
#IBInspectable var ringColor: UIColor = UIColor.clear
{
didSet { print("bColor was set here") }
}
#IBInspectable var ringThickness: CGFloat = 4
{
didSet { print("ringThickness was set here") }
}
#IBInspectable var isSelected: Bool = true
override func draw(_ rect: CGRect)
{
let dotPath = UIBezierPath(ovalIn: rect)
let shapeLayer = CAShapeLayer()
shapeLayer.path = dotPath.cgPath
shapeLayer.fillColor = mainColor.cgColor
layer.addSublayer(shapeLayer)
if (isSelected) { drawRingFittingInsideView(rect: rect) }
}
internal func drawRingFittingInsideView(rect: CGRect)->()
{
let halfSize:CGFloat = min( bounds.size.width/2, bounds.size.height/2)
let desiredLineWidth:CGFloat = ringThickness // your desired value
let circlePath = UIBezierPath(
arcCenter: CGPoint(x: halfSize, y: halfSize),
radius: CGFloat( halfSize - (desiredLineWidth/2) ),
startAngle: CGFloat(0),
endAngle:CGFloat(Double.pi),
clockwise: true)
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.cgPath
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.strokeColor = ringColor.cgColor
shapeLayer.lineWidth = ringThickness
layer.addSublayer(shapeLayer)
}
}
A much easier and resource friendly approach would be.
import UIKit
#IBDesignable
class CircleDrawView: UIView {
#IBInspectable var borderColor: UIColor = UIColor.red;
#IBInspectable var borderSize: CGFloat = 4
override func draw(_ rect: CGRect)
{
layer.borderColor = borderColor.cgColor
layer.borderWidth = borderSize
layer.cornerRadius = self.frame.height/2
}
}
With Border Color and Border Size and the default Background property you can define the appearance of the circle.
Please note, to draw a circle the view's height and width have to be equal in size.
The code is working for Swift >= 4 and Xcode >= 9.
I find Core Graphics to be pretty simple for Swift 3:
if let cgcontext = UIGraphicsGetCurrentContext() {
cgcontext.strokeEllipse(in: CGRect(x: center.x-diameter/2, y: center.y-diameter/2, width: diameter, height: diameter))
}
A simple function drawing a circle on the middle of your window frame, using a multiplicator percentage
/// CGFloat is a multiplicator from self.view.frame.width
func drawCircle(withMultiplicator coefficient: CGFloat) {
let radius = self.view.frame.width / 2 * coefficient
let circlePath = UIBezierPath(arcCenter: self.view.center, radius: radius, startAngle: CGFloat(0), endAngle:CGFloat(Double.pi * 2), clockwise: true)
let shapeLayer = CAShapeLayer()
shapeLayer.path = circlePath.cgPath
//change the fill color
shapeLayer.fillColor = UIColor.clear.cgColor
shapeLayer.strokeColor = UIColor.darkGray.cgColor
shapeLayer.lineWidth = 2.0
view.layer.addSublayer(shapeLayer)
}
Add in view did load
//Circle Points
var CircleLayer = CAShapeLayer()
let center = CGPoint (x: myCircleView.frame.size.width / 2, y: myCircleView.frame.size.height / 2)
let circleRadius = myCircleView.frame.size.width / 2
let circlePath = UIBezierPath(arcCenter: center, radius: circleRadius, startAngle: CGFloat(M_PI), endAngle: CGFloat(M_PI * 4), clockwise: true)
CircleLayer.path = circlePath.cgPath
CircleLayer.strokeColor = UIColor.red.cgColor
CircleLayer.fillColor = UIColor.blue.cgColor
CircleLayer.lineWidth = 8
CircleLayer.strokeStart = 0
CircleLayer.strokeEnd = 1
Self.View.layer.addSublayer(CircleLayer)
2022, General example of how to actually draw using draw in a UIView.
It's not so easy to properly use UIView#draw.
General beginner tips, you can only draw inside a UIView, it is meaningless otherwise. Further, you can only use the draw commands (.fillEllipse etc) inside the draw call of a UIView.
You almost certainly want to set the intrinsic content size properly. It's important to fully understand how to use this on consumers views, in the two possible situations (a) you are using constraints (b) you are positioning the view by hand in layoutSubviews inside another view.
A huge gotchya is that you cannot draw outside the frame, no matter what. In contrast if you just use lazy vars with a layer to draw a shape (whether dot, circle, etc) it's no problem if you go outside the nominal frame (indeed you often just make the frame size zero so that everything centers easily in your consumer code). But once you start using draw you MUST be inside the frame. This is often confusing as in some cases you "don't know how big your drawing is going to be" until you draw it.
A huge gotchya is, when you are drawing either circles or edges, beginner programmers accidentally cut off half the thickness of that line, due to the fact that draw absolutely can't draw outside the frame. You have to inset the circle or rectangle, by, half the width of the line thickness.
Some code with correct 2022 syntax:
import UIKit
class ExampleDot: UIIView {
// setup ..
// clipsToBounds = false BUT SEE NOTES
// backgroundColor = .clear
override var intrinsicContentSize: CGSize {
return CGSize(width: 40, height: 40)
}
override func draw(_ rect: CGRect) {
guard let ctx = UIGraphicsGetCurrentContext() else { return }
// example of a dot
ctx.setFillColor(UIColor.black.cgColor)
ctx.fillEllipse(in: CGRect(x: 0, y: 0, width: 40, height: 40))
// example of a round circle BUT SEE NOTES
ctx.setStrokeColor(UIColor.systemYellow.cgColor)
ctx.setLineWidth(2)
ctx.strokeEllipse(in: CGRect(x: 1, y: 1, width: 40 - 4, height: 40 - 4))
// example of a smaller inner dot
ctx.setFillColor(UIColor.white.cgColor)
ctx.fillEllipse(in: CGRect(x: 10, y: 10, width: 20, height: 20))
}
}