Erase/Unerase

Erase and Unerase Using grayscale view class

import Foundation
import UIKit
import AVFoundation


class ClassImageEditingView:UIView{
    
    var context: CGContext?
    var contextBounds = CGRect.zero
    
    var backgroundImage: UIImage?
    var foregroundImage: UIImage?
    var touchWidth: CGFloat = 0.0
    var touchRevealsImage = false
    var firstTouch:Bool = true
    var foregroundImagePicked:UIImage?
    
    
    
    var scratchable:CGImage?
    var scratched:CGImage?
    var location = CGPoint(x: 0, y: 0)
    var PreviosLocation:CGPoint!
    

  
//    static let sharedInstance : ClassImageEditingView = {
//        let instance = ClassImageEditingView()
//        return instance
//    }()
//
    
    struct sharedInstance{
        static var foregroundImagePicked:UIImage?
    }
    
    //MARK: Create createBitmapContext
    
    func createBitmap(){
        
        //setForegroundImage(foregroundImagePicked)
        scratchable = foregroundImage?.cgImage
        
//        let selfRatio: CGFloat = frame.size.width / frame.size.height //change the size later
//        let imgRatio: CGFloat = (foregroundImage?.size.width ?? 0.0) / (foregroundImage?.size.height ?? 0.0)
//
//        var rect : CGRect
//        rect = CGRect(x: 0, y: 0, width: 0, height: 0)
//
//        if selfRatio > imgRatio {
//            // view is wider than img
//            rect.size.height = frame.size.height
//            rect.size.width = imgRatio * (rect.size.height ?? 0.0)
//        } else {
//            // img is wider than view
//            rect.size.width = frame.size.width
//            rect.size.height = (rect.size.width ?? 0.0) / imgRatio
//        }
//
//        rect.origin.x = 0.5 * (frame.size.width - (rect.size.width ?? 0.0))
//        rect.origin.y = 0.5 * (frame.size.height - (rect.size.height ?? 0.0))
        
        
        let width = (Int)(self.bounds.width)//(rect.width)//(self.frame.width)//scratchable?.width
        let hight =  (Int)(self.bounds.height)//(rect.width)//(self.frame.height) //scratchable?.height
        self.isOpaque = false
        
        let size:Int = width * hight
        
        
        let bytePerPixel = 4
        let bitsPerComponent = 8 //scratchable!.bitsPerComponent
        let bytesPerRow =  bytePerPixel*width //scratchable!.bytesPerRow
        let totalBytes = hight * bytesPerRow
        
        
        contextBounds = bounds
        // Grayscale color space
        let colorSpace = CGColorSpaceCreateDeviceGray();
        
        let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue)
        
        // Create bitmap content with current image size and grayscale colorspace
        let pixel: CFMutableData = CFDataCreateMutable(nil, width * hight)//width!*hight!
        
        context = CGContext(data:CFDataGetMutableBytePtr(pixel), width: width, height: hight, bitsPerComponent: 8, bytesPerRow: width /*Int(contextBounds.size.width)*/, space: colorSpace, bitmapInfo: CGImageAlphaInfo.none.rawValue)// bitmapInfo.rawValue
        
        CFDataSetLength(pixel, size)
        let provider = CGDataProvider(data: pixel)
        //CGDataProvider(data: pixel!)
        
        //make it white (touchRevealsImage==NO)
        let black = UIColor.black //[1.0, 1,0]
        context?.setFillColor(black.cgColor)
        context?.fill(bounds) //contextBounds
        
        //set the color of path
        context?.setStrokeColor(UIColor.black.cgColor)
        context?.setLineWidth(touchWidth)
        
        
        //setup drawing for that context
        context?.setLineCap(.round)
        context?.setLineJoin(.round)
        
        
        let mask = CGImage(maskWidth: width, height: hight, bitsPerComponent: 8, bitsPerPixel: 8, bytesPerRow: width, provider: provider!, decode: nil, shouldInterpolate: false)
        scratched = scratchable?.masking(mask!)
        
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        print("begin toich")
        let touch = event?.touches(for: self)?.first as! UITouch
        firstTouch = true
        location = touch.location(in: self)
    }
    
    //  Converted to Swift 5 by Swiftify v5.0.29819 - https://objectivec2swift.com/
    
    
    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        print("move touch")
        let touch = event?.touches(for: self)?.first
        
        // the new line that will be drawn
        if firstTouch == true {
            firstTouch = false
            PreviosLocation = touch?.previousLocation(in: self)
            
        }else {
            location = (touch?.location(in: self))!
            print(location)
            PreviosLocation = touch?.previousLocation(in: self)
            
        }
        
        
        //change the color of stock of erase or not swift
        let color = (touchRevealsImage ? UIColor.white.cgColor : UIColor.black.cgColor)
        context!.setStrokeColor(color)
        context?.setLineWidth(touchWidth)

        
        points(from:PreviosLocation, to:location)
    }
    
    
    
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        print("End of touch")
        let touch = event?.touches(for: self)?.first
        if firstTouch == true {
            firstTouch = false
            PreviosLocation = touch?.location(in: self)
            
        }
        points(from:PreviosLocation, to:location)
    }
    
    func points(from:CGPoint, to:CGPoint){
        context?.move(to: CGPoint(x: PreviosLocation.x, y: PreviosLocation.y))
        context?.addLine(to: CGPoint(x: location.x, y: location.y))
        context?.strokePath()
        setNeedsDisplay()
        
    }
    
    override func draw(_ rect: CGRect) {
        print("we are drawing")
        //this code get you the image in scale fit size
        let selfRatio: CGFloat = bounds.size.width / bounds.size.height //change the size later
        let imgRatio: CGFloat = (foregroundImage?.size.width ?? 0.0) / (foregroundImage?.size.height ?? 0.0)
        
        var rect : CGRect
        rect = CGRect(x: 0, y: 0, width: 0, height: 0)
        
        if selfRatio > imgRatio {
            // view is wider than img
            rect.size.height = bounds.size.height
            rect.size.width = imgRatio * (rect.size.height ?? 0.0)
        } else {
            // img is wider than view
            rect.size.width = bounds.size.width
            rect.size.height = (rect.size.width ?? 0.0) / imgRatio
        }
        
        rect.origin.x = 0.5 * (bounds.size.width - (rect.size.width ?? 0.0))
        rect.origin.y = 0.5 * (bounds.size.height - (rect.size.height ?? 0.0))
        
        //you have to draw in the right place so it follow your finger moves.
        UIGraphicsGetCurrentContext()?.saveGState()
        //UIGraphicsGetCurrentContext()?.translateBy(x: 0, y: rect.height)//self.frame.size.height//
        //UIGraphicsGetCurrentContext()?.scaleBy(x: 1.0, y: -1.0)
        UIGraphicsGetCurrentContext()?.draw(scratched!, in: rect)
        //foregroundImage?.draw(in: rect)
        UIGraphicsGetCurrentContext()?.restoreGState()
        
        
    }
    
    
//    func drawImageScaled(_ image: UIImage?) {
//        print("we are scalling the drawing")
//        // just draws the image scaled down and centered
//
//        let selfRatio: CGFloat = frame.size.width / frame.size.height //change the size later
//        let imgRatio: CGFloat = (image?.size.width ?? 0.0) / (image?.size.height ?? 0.0)
//
//        var rect : CGRect
//        rect = CGRect(x: 0, y: 0, width: 0, height: 0)
//
//        if selfRatio > imgRatio {
//            // view is wider than img
//            rect.size.height = frame.size.height
//            rect.size.width = imgRatio * (rect.size.height ?? 0.0)
//        } else {
//            // img is wider than view
//            rect.size.width = frame.size.width
//            rect.size.height = (rect.size.width ?? 0.0) / imgRatio
//        }
//
//        rect.origin.x = 0.5 * (frame.size.width - (rect.size.width ?? 0.0))
//        rect.origin.y = 0.5 * (frame.size.height - (rect.size.height ?? 0.0))
//
//        image?.draw(in: rect ?? CGRect.zero)
//    }
    
    
    
    
    //    func resetDrawing() {
    //        // draw black or white
    //        //let color = [(touchRevealsImage ? 0.0 : 1.0), 1.0]
    //        let color = (touchRevealsImage ? UIColor.black.cgColor:UIColor.white.cgColor)
    //        //context?.setStrokeColorSpace(color as! CGColorSpace)
    //
    //
    //        context!.setFillColor(color)
    //        context!.fill(contextBounds)
    //
    //        setNeedsDisplay()
    //    }
    
//    override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
//        return subviews.contains(where: {
//            !$0.isHidden && $0.point(inside: self.convert(point, to: $0), with: event)
//        })
//    }
    
    
    
    
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        //fatalError("init(coder:) has not been implemented")
        createBitmap()
        touchWidth = 10.0
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
       // createBitmap()
        touchWidth = 10.0
    }
    
    
    
    func setBackgroundImage(value:UIImage) {
        if value != backgroundImage {
            backgroundImage = value
            setNeedsDisplay()
        }
    }
    
    func setForegroundImage(_ value: UIImage?) {
        if value != foregroundImage {
            foregroundImage = value
            let TopImageRect = AVMakeRect(aspectRatio: foregroundImage!.size, insideRect: bounds).size
            print("The size in the class \(TopImageRect)")

            foregroundImage?.af_imageAspectScaled(toFit:TopImageRect )
            
            setNeedsDisplay()
        }
    }
    
    func setTouchRevealsImage(_ value: Bool) {
        if value != touchRevealsImage {
            touchRevealsImage = value
            setNeedsDisplay()
        }
    }
    
}