RepeatButton.swift

import UIKit

class RepeatButton: UIButton {
    
    fileprivate let lineTop:CAShapeLayer = {
        let layer = CAShapeLayer()
        let linePath = UIBezierPath()
        //25x25
        linePath.move(to:    CGPoint(x: 10.5, y: 2.5))
        linePath.addLine(to: CGPoint(x: 22.5, y: 2.5))
        linePath.addLine(to: CGPoint(x: 22.5, y: 22.5))
        linePath.addLine(to: CGPoint(x: 19,   y: 22.5))
        layer.path = linePath.cgPath
        layer.fillColor = nil
        layer.lineWidth = 2
        layer.opacity = 1.0
        layer.cornerRadius = 4
        return layer
    }()
    
    fileprivate let lineBottom:CAShapeLayer = {
        let layer = CAShapeLayer()
        let linePath = UIBezierPath()
        //25x25
        linePath.move(to:    CGPoint(x: 7,    y: 2.5))
        linePath.addLine(to: CGPoint(x: 2.5,  y: 2.5))
        linePath.addLine(to: CGPoint(x: 2.5,  y: 22.5))
        linePath.addLine(to: CGPoint(x: 13.5, y: 22.5))
        linePath.lineJoinStyle = .bevel
        linePath.lineCapStyle = .round
        layer.path = linePath.cgPath
        layer.fillColor = nil
        layer.lineWidth = 2
        layer.opacity = 1.0
        return layer
    }()
    
    fileprivate let triangleTop: CAShapeLayer = {
        let layer = CAShapeLayer()
        let linePath = UIBezierPath()
        //25x25
        linePath.move(to:    CGPoint(x: 13, y: 0))
        linePath.addLine(to: CGPoint(x: 13, y: 5))
        linePath.addLine(to: CGPoint(x: 8,  y: 2.5))
        layer.path = linePath.cgPath
        layer.lineWidth = 0
        layer.opacity = 1.0
        return layer
    }()
    
    fileprivate let triangleBottom: CAShapeLayer = {
        let layer = CAShapeLayer()
        let linePath = UIBezierPath()
        //25x25
        linePath.move(to:    CGPoint(x: 13, y: 20))
        linePath.addLine(to: CGPoint(x: 18, y: 22.5))
        linePath.addLine(to: CGPoint(x: 13, y: 25))
        layer.path = linePath.cgPath
        layer.lineWidth = 0
        layer.opacity = 1.0
        return layer
    }()
    
    fileprivate var lines: [CAShapeLayer] {
        return [lineTop, lineBottom]
    }
    
    fileprivate var triangles: [CAShapeLayer] {
        return [triangleTop, triangleBottom]
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }
    
    func commonInit() {
        (lines + triangles).forEach {
            self.layer.addSublayer($0)
        }
    }
    
    override func draw(_ rect: CGRect) {
        super.draw(rect)
        let lineColor = tintColor.cgColor
        (lines + triangles).forEach {
            $0.transform = CATransform3DMakeScale(rect.width/25, rect.height/25, 1)
        }
        lines.forEach { $0.strokeColor = lineColor }
        triangles.forEach { $0.fillColor = lineColor }
    }

}