BalloonView with initializer

BalloonView.swift

//
//  BalloonView.swift
//  balloonTest
//
//  Created by Daiki Ito on 2017/05/27.
//  Copyright © 2017年 EAssistant. All rights reserved.
//  Swift3.1 Xcode 8.3.2

import UIKit

class BalloonView: UIView {
    
    var color: CGColor = UIColor.black.cgColor
    var squareRect: CGRect = CGRect()
    var triApexPoint = CGPoint()
    var curveSize: CGFloat = 20
    private var arrSquarePoint = [CGPoint]()
    private var centerPoint = CGPoint()
    var textLabel = UILabel()
    var halfBaseLength: CGFloat = 10
    var imageView = UIImageView()
    private var controlPoint_1 = CGPoint()
    private var controlPoint_2 = CGPoint()
    private var controlPoint_3 = CGPoint()
    private var controlPoint_4 = CGPoint()
    static private var size = CGSize()
    
    init(imageView: UIImageView, squareRect: CGRect, triApexPoint: CGPoint){
        super.init(frame: UIScreen.main.bounds)
        self.imageView = imageView
        self.squareRect = squareRect
        self.triApexPoint = triApexPoint
        controlPoint_1 = CGPoint(x: squareRect.origin.x, y: squareRect.origin.y)
        controlPoint_2 = CGPoint(x: squareRect.origin.x, y:squareRect.origin.y + squareRect.height)
        controlPoint_3 = CGPoint(x: squareRect.origin.x + squareRect.width, y: squareRect.origin.y + squareRect.height)
        controlPoint_4 = CGPoint(x: squareRect.origin.x + squareRect.width, y: squareRect.origin.y)
        arrSquarePoint = [controlPoint_1, controlPoint_2, controlPoint_3, controlPoint_4]
    }
    
    init(){
        super.init(frame: UIScreen.main.bounds)
        self.squareRect = CGRect(x: 0, y: 0, width: 100, height: 100)
        self.triApexPoint = CGPoint(x: 50, y: 150)
        controlPoint_1 = CGPoint(x: squareRect.origin.x, y: squareRect.origin.y)
        controlPoint_2 = CGPoint(x: squareRect.origin.x, y:squareRect.origin.y + squareRect.height)
        controlPoint_3 = CGPoint(x: squareRect.origin.x + squareRect.width, y: squareRect.origin.y + squareRect.height)
        controlPoint_4 = CGPoint(x: squareRect.origin.x + squareRect.width, y: squareRect.origin.y)
        arrSquarePoint = [controlPoint_1, controlPoint_2, controlPoint_3, controlPoint_4]
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
    
    func updateControlPoint(){
        controlPoint_1 = CGPoint(x: squareRect.origin.x, y: squareRect.origin.y)
        controlPoint_2 = CGPoint(x: squareRect.origin.x, y:squareRect.origin.y + squareRect.height)
        controlPoint_3 = CGPoint(x: squareRect.origin.x + squareRect.width, y: squareRect.origin.y + squareRect.height)
        controlPoint_4 = CGPoint(x: squareRect.origin.x + squareRect.width, y: squareRect.origin.y)
        arrSquarePoint = [controlPoint_1, controlPoint_2, controlPoint_3, controlPoint_4]
    }
    
    // Only override draw() if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    override func draw(_ rect: CGRect) {
        BalloonView.size = rect.size
        let image = addBalloonImageView(squareRect: squareRect, color: color, curve: curveSize)
        imageView.image = image
        imageView.frame = self.frame
        self.addSubview(imageView)
        setTextLabel();
    }
    
    func removeImageView(){
        imageView.removeFromSuperview()
    }
    
    override func layerWillDraw(_ layer: CALayer) {
        self.backgroundColor = UIColor.clear
    }
    
    private func setTextLabel(){
        textLabel.sizeToFit()
        textLabel.center = centerPoint
        self.addSubview(textLabel)
    }
    
    private func addBalloonImageView(squareRect: CGRect, color: CGColor, curve: CGFloat)-> UIImage?{
        UIGraphicsBeginImageContextWithOptions(BalloonView.size, false, 0.0)
        guard let context = UIGraphicsGetCurrentContext() else {return nil}
        
        context.setLineWidth(1)
        context.setFillColor(color)

        //Write Square
        context.beginPath()
        
        let squareMoveToPoint_A1 = CGPoint(x: squareRect.origin.x, y: squareRect.origin.y + curve)
        let squareAddLineToPoint_A2 = CGPoint(x: squareRect.origin.x, y: squareRect.origin.y + squareRect.height - curve)
        let squareAddLineToPoint_B3 = CGPoint(x: squareRect.origin.x + curve, y: squareRect.origin.y + squareRect.height)
        let squareAddLineToPoint_B4 = CGPoint(x: squareRect.origin.x + squareRect.width - curve, y: squareRect.origin.y + squareRect.height)
        let squareAddLineToPoint_C5 = CGPoint(x: squareRect.origin.x + squareRect.width, y: squareRect.origin.y + squareRect.height - curve)
        let squareAddLineToPoint_C6 = CGPoint(x: squareRect.origin.x + squareRect.width, y: squareRect.origin.y + curve)
        let squareAddLineToPoint_D7 = CGPoint(x: squareRect.origin.x + squareRect.width - curve, y: squareRect.origin.y)
        let squareAddLineToPoint_D8 = CGPoint(x: squareRect.origin.x + curve, y: squareRect.origin.y)
        
        context.move(to: squareMoveToPoint_A1)
        context.addLine(to: squareAddLineToPoint_A2)
        context.addQuadCurve(to: squareAddLineToPoint_B3, control: controlPoint_2)
        context.addLine(to: squareAddLineToPoint_B4)
        context.addQuadCurve(to: squareAddLineToPoint_C5, control: controlPoint_3)
        context.addLine(to: squareAddLineToPoint_C6)
        context.addQuadCurve(to: squareAddLineToPoint_D7, control: controlPoint_4)
        context.addLine(to: squareAddLineToPoint_D8)
        context.addQuadCurve(to: squareMoveToPoint_A1, control: controlPoint_1)
        
        context.closePath()
        context.fillPath()
        
        // Write triangle
        context.beginPath()
        let resultPoints = triangle(arrSquarePoint: arrSquarePoint, apex: triApexPoint)
        context.move(to: triApexPoint)
        context.addLine(to: resultPoints[0])
        context.addLine(to: resultPoints[1])
        context.addLine(to: triApexPoint)
        
        context.closePath()
        context.fillPath()
        
        context.strokePath()
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image!
    }
        
    private func triangle(arrSquarePoint: [CGPoint], apex: CGPoint)-> [CGPoint]{

        centerPoint = center(arrSquarePoint: arrSquarePoint)
        let alpha = atan((apex.y - centerPoint.y) / (apex.x - centerPoint.x)) - CGFloat.pi/2
        
        let basePointX_1 = halfBaseLength * cos(alpha) + centerPoint.x
        let basePointY_1 = halfBaseLength * sin(alpha) + centerPoint.y
        let basePoint_1 = CGPoint(x: basePointX_1, y: basePointY_1)
        
        let basePointX_2 = halfBaseLength * cos(CGFloat.pi + alpha) + centerPoint.x
        let basePointY_2 = halfBaseLength * sin(CGFloat.pi + alpha) + centerPoint.y
        let basePoint_2 = CGPoint(x: basePointX_2, y: basePointY_2)
        
        let resultPoints = [basePoint_1, basePoint_2]
        
        return resultPoints
    }
    
    private func center(arrSquarePoint: [CGPoint])-> CGPoint{
        
        let A = (arrSquarePoint[0].y - arrSquarePoint[2].y) / (arrSquarePoint[0].x - arrSquarePoint[2].x)
        let B = (arrSquarePoint[1].y - arrSquarePoint[3].y) / (arrSquarePoint[1].x - arrSquarePoint[3].x)
        let centerX = (B*arrSquarePoint[1].x - A*arrSquarePoint[0].x + arrSquarePoint[0].y - arrSquarePoint[1].y)/(B - A)
        let centerY = A*(centerX - arrSquarePoint[0].x) + arrSquarePoint[0].y
        
        let resultPoint = CGPoint(x: centerX, y: centerY)
        
        return resultPoint
    }
    
    func squareCenterPoint() -> CGPoint{
        let point = center(arrSquarePoint: arrSquarePoint)
        return point
    }
    
    func slant(point1: CGPoint, point2: CGPoint)-> Float{
        let absX = fabs(point1.x - point2.x)
        let absY = fabs(point1.y - point1.y)
        let powX = powf(Float(absX), 2)
        let powY = powf(Float(absY), 2)
        let length = sqrtf(powX + powY)
        return length
    }
    
}

ViewController.swift

import UIKit

class ViewController: UIViewController {
    
    
    let squareRect = CGRect(x: 150, y: 300, width: 100, height: 100)
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading tvarview, typically from a nib.
        let imageView = UIImageView()
        let squareRect = CGRect(x: 200, y: 200, width: 100, height: 100)
        let triApexPoint = CGPoint(x: 200, y: 500)
        let balloonView = BalloonView(imageView: imageView, squareRect: squareRect, triApexPoint: triApexPoint)
        balloonView.color = UIColor.gray.cgColor
        balloonView.textLabel.textColor = UIColor.white
        balloonView.textLabel.text = "Hello World"
        
        print(balloonView.squareCenterPoint())
        
        balloonView.frame = self.view.frame
        self.view.addSubview(balloonView)
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
}