A custom ImageView that is used to cover the surface of other view like a scratch card, user can swipe the mulch to see the view below

MCScratchImageView


GIF Showcase


Requirments

iOS 8.0+
Xcode 7.2+
Swift 4.0

Installation

CocoaPods

pod "MCScratchImageView"

Manually

Just drag MCScratchImageView.swift to the project tree

Usage

Import

If you use CocoaPods, first import MCScratchImageView

import MCScratchImageView

Define the class variables

var scratchImageView: MCScratchImageView!

Initialize it

// init()
scratchImageView = MCScratchImageView()
// init(frame:)
scratchImageView = MCScratchImageView(frame: yourRect)

Or use StoryBoard.

Set the mask image & radius

// use default touch point radius
scratchImageView.setMaskImage(yourUIImage)
// use custom touch point radius
scratchImageView.setMaskImage(yourUIImage, spotRadius: 100)

Implement the delegate methods:

// set the delegate
scratchImageView.delegate = ***

/* ... */

// implement the MCScratchImageViewDelegate method
extension YourController: MCScratchImageViewDelegate {
    
    func mcScratchImageView(_ mcScratchImageView: MCScratchImageView, didChangeProgress progress: CGFloat) {
        print("Progress did changed: " + String(format: "%.2f", progress))
        if (progress >= 0.8) {
            mcScratchImageView.scratchAll()
        }
    }
    
}

API declaration

// current scratched progress
public var progress: CGFloat
// Determin the radius of the touch point
private(set) var spotRadius: CGFloat = 45.0

// set the mask image & radius
public func setMaskImage(_ image: UIImage)
public func setMaskImage(_ image: UIImage, spotRadius: CGFloat)

// scratch all mask fields
public func scratchAll()

Example Project

In "Example" folder.

Tips

  • Don't set the scratchImageView.image directlly, you need to use setMaskImage(paras) to set the mask image.
  • Don't set the touch point radius (var spotRadius: CGFloat) directlly.
  • The contentMode should use default resize mode.

Author

Minecode, minecoder@163.com

License

MCScratchImageView is available under the MIT license. See the LICENSE file for more info.

GitHub

https://github.com/Minecodecraft/MCScratchImageView