iOS-箭头视图绘制

//
//  ViewController.swift
//  Draw
//
//

import UIKit
import CoreGraphics

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
        let v = MyArrowView(frame: CGRect(x: 20, y: 100, width: 200, height: 100))
        v.backgroundColor = .clear
        v.layer.shadowColor   = UIColor.black.cgColor
        v.layer.shadowOpacity = 0.12
        v.layer.shadowOffset  = CGSize(width: 0, height:0)
        v.layer.shadowRadius  = 2
        v.layer.cornerRadius  = 10
        self.view.addSubview(v)
    }
    
    
}


class  MyArrowView : UIView {
    
    override init(frame: CGRect) {
        super.init(frame: frame)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func draw(_ rect: CGRect) {
        let context = UIGraphicsGetCurrentContext()!
        context.saveGState ()
        
        let contourPath = CGMutablePath()
        
        
        let x = 40
        let y = 100
        let arrowWidth = 20
        let arrowHeight = 20
        let cornerRadius:CGFloat = 10
        let bubbleFrame = CGRect(x: 0, y: 0, width: 200, height: 80)
        contourPath.move(to: CGPoint(x: x, y: y))
        
        
        contourPath.addLine(to: CGPoint(x: x - arrowWidth / 2, y: y + (-1) * arrowHeight))
        
        drawBubbleBottomShape(bubbleFrame, cornerRadius: cornerRadius, path: contourPath)
        
        contourPath.addLine(to: CGPoint(x: x + arrowWidth / 2, y: y +  (-1) * arrowHeight))
        
        contourPath.closeSubpath()
        context.addPath(contourPath)
        context.clip()
        paintBubble(context)
        
       
        
        drawBorder(contourPath, context: context)
        context.restoreGState()
    }
    
    fileprivate func paintBubble(_ context: CGContext) {
        context.setFillColor(UIColor.yellow.cgColor)
        context.fill(bounds)
    }
    
    fileprivate func drawBorder(_ borderPath: CGPath, context: CGContext) {
        context.addPath(borderPath)
        context.setStrokeColor(UIColor.orange.cgColor)
        context.setLineWidth(2)
        context.strokePath()
    }
    
    fileprivate func drawBubbleBottomShape(_ frame: CGRect, cornerRadius: CGFloat, path: CGMutablePath) {
        
        path.addArc(tangent1End: CGPoint(x: frame.x, y: frame.y + frame.height), tangent2End: CGPoint(x: frame.x, y: frame.y), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x, y: frame.y), tangent2End: CGPoint(x: frame.x + frame.width, y: frame.y), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x + frame.width, y: frame.y), tangent2End: CGPoint(x: frame.x + frame.width, y: frame.y + frame.height), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x + frame.width, y: frame.y + frame.height), tangent2End: CGPoint(x: frame.x, y: frame.y + frame.height), radius: cornerRadius)
    }
    
    fileprivate func drawBubbleTopShape(_ frame: CGRect, cornerRadius: CGFloat, path: CGMutablePath) {
        
        path.addArc(tangent1End: CGPoint(x: frame.x, y: frame.y), tangent2End: CGPoint(x: frame.x, y: frame.y + frame.height), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x, y:  frame.y + frame.height), tangent2End: CGPoint(x: frame.x + frame.width, y: frame.y + frame.height), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x + frame.width, y: frame.y + frame.height), tangent2End: CGPoint(x: frame.x + frame.width, y: frame.y), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x + frame.width, y: frame.y), tangent2End: CGPoint(x: frame.x, y: frame.y), radius: cornerRadius)
    }
    
    fileprivate func drawBubbleRightShape(_ frame: CGRect, cornerRadius: CGFloat, path: CGMutablePath) {
        
        path.addArc(tangent1End: CGPoint(x: frame.x + frame.width, y: frame.y), tangent2End: CGPoint(x: frame.x, y: frame.y), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x, y: frame.y), tangent2End: CGPoint(x: frame.x, y: frame.y + frame.height), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x, y: frame.y + frame.height), tangent2End: CGPoint(x: frame.x + frame.width, y: frame.y + frame.height), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x + frame.width, y: frame.y + frame.height), tangent2End: CGPoint(x: frame.x + frame.width, y: frame.height), radius: cornerRadius)
        
    }
    
    fileprivate func drawBubbleLeftShape(_ frame: CGRect, cornerRadius: CGFloat, path: CGMutablePath) {
        
        path.addArc(tangent1End: CGPoint(x: frame.x, y: frame.y), tangent2End: CGPoint(x: frame.x + frame.width, y: frame.y), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x + frame.width, y: frame.y), tangent2End: CGPoint(x: frame.x + frame.width, y: frame.y + frame.height), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x + frame.width, y: frame.y + frame.height), tangent2End: CGPoint(x: frame.x, y: frame.y + frame.height), radius: cornerRadius)
        path.addArc(tangent1End: CGPoint(x: frame.x, y: frame.y + frame.height), tangent2End: CGPoint(x: frame.x, y: frame.y), radius: cornerRadius)
    }
}









extension CGRect {
    var x: CGFloat {
        get {
            return self.origin.x
        }
        set {
            self.origin.x = newValue
        }
    }
    
    var y: CGFloat {
        get {
            return self.origin.y
        }
        
        set {
            self.origin.y = newValue
        }
    }
    //
    //    var width: CGFloat {
    //        get {
    //         return self.size.width
    //        }
    //
    //        set {
    //            self.size.width = newValue
    //        }
    //    }
    //
    //    var height: CGFloat {
    //        get {
    //            return self.size.height
    //        }
    //
    //        set{
    //            self.size.height = newValue
    //        }
    //    }
    
    //    var maxX: CGFloat {
    //        return self.maxX
    //    }
    //
    //    var maxY: CGFloat {
    //        return self.maxY
    //    }
    
    var center: CGPoint {
        return CGPoint(x: self.x + self.width / 2, y: self.y + self.height / 2)
    }
}