GlowingImageView.swift

//
//  GlowingImageView.swift
//  Glowing Circle
//
//  Created by Alfonso Maria Tesauro on 10/06/2019.
//  Copyright © 2019 Alfonso Maria Tesauro. All rights reserved.
//

import Cocoa

@IBDesignable
class GlowingImageView: NSImageView {

     var animating: Bool = true
     var displayIfStopped: Bool = true
    override var isHidden: Bool {
        willSet(newValue) {
            if newValue == false {
                self.alphaValue = 1.0
            }
        }
    }
    
    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        if !animating {
            if displayIfStopped == false {
                self.isHidden = true
            }
        } else {
            self.startAnimation()
        }
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        if !animating {
            if displayIfStopped == false {
                self.isHidden = true
            }
        } else {
            self.startAnimation()
        }
    }
    
//    override func draw(_ dirtyRect: NSRect) {
//        super.draw(dirtyRect)
//
//        // Drawing code here.
//    }
    
    func startAnimation() {
        
        self.animating = true
        self.isHidden = false
        self.alphaValue = 1.0
        self.fadeOut()
    }
    
    func stopAnimation() {
        
        self.animating = false
        if displayIfStopped == false {
            self.isHidden = true
        }
    }
    
    func fadeIn ()  {
        if self.animating == false {
            return
        }
        CATransaction.begin()
        CATransaction.setAnimationDuration(1.2)
        CATransaction.setAnimationTimingFunction(CAMediaTimingFunction(name: .easeInEaseOut))
        CATransaction.setCompletionBlock {
            self.fadeOut()
        }
        self.animator().alphaValue = 1.0
        CATransaction.commit()
    }
    func fadeOut() {
        if self.animating == false {
            return
        }
        CATransaction.begin()
        CATransaction.setAnimationDuration(1.2)
        CATransaction.setAnimationTimingFunction(CAMediaTimingFunction(name: .easeInEaseOut))
        CATransaction.setCompletionBlock {
            self.fadeIn()
        }
        self.animator().alphaValue = 0.3
        CATransaction.commit()
    }
    
}