UIGraphicsGetCurrentContext didn't appear inside UIView - ios

Question

I have to draw a shape and detect if user touches are inside the shape or not, so I defined a custom class inherit from UIView as follow :
class ShapeView: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func draw(_ rect: CGRect) {
drawShape()
}
func drawShape() {
guard let ctx = UIGraphicsGetCurrentContext() else { return }
let zero = CGPoint(x: frame.midX, y: frame.midY)
let size: CGFloat = 50
ctx.beginPath()
ctx.move(to: .zero)
ctx.addLine(to: CGPoint(x: -size, y: -size))
ctx.addLine(to: CGPoint(x: zero.x , y: (-size * 2)))
ctx.addLine(to: CGPoint(x: size, y: -size))
ctx.closePath()
ctx.setFillColor(UIColor.red.cgColor)
ctx.fillPath()
}
this code should draw shape like this
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
let path = UIBezierPath(ovalIn: self.frame)
return path.contains(point)
}
}
and in the viewController I wrote this code to add this custom view to UIViewController :
var shape: ShapeView?
override func viewDidLoad() {
super.viewDidLoad()
let x = view.frame.midX
let y = view.frame.midY
self.shape = ShapeView(frame: CGRect(x: x, y: y, width: 100, height: 100))
shape?.backgroundColor = .green
view.addSubview(shape!)
}
I knew that the shape is inside the view after wrote this method :
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let location = touches.first!.location(in: self.view)
if (shape?.point(inside: location, with: event))! {
print("inside view")
} else {
print("outside view")
}
but overall result was this image it just has one color of the view as green and there's a subview but no color appeared
So what's wrong with this code ?

Answer 1

You should use the size of the rect of the override func draw(_ rect: CGRect) to do your calculations on.
I also think your calculations are incorrect, haven't tested it but I think it should be something like this:
ctx.move(to: CGPoint(x: rect.width / 2, y: 0))
ctx.addLine(to: CGPoint(x: rect.width, y: rect.height / 2))
ctx.addLine(to: CGPoint(x: rect.width / 2 , y: rect.height))
ctx.addLine(to: CGPoint(x: 0, y: rect.height / 2))