Simple button


Two approaches when making a button in swift, that isnโ€™t an UIButton.

The Overriding approach

Using subclassing and overriding the already built in gesture recognizers. Instead of adding them again. Example of the latter can be seen on the bottom. Its important to note that using UILongPressGestureRecognizer with threshold set to 0.0sec can still have a delay, if the view its added to has subViews. As such subclassing and overriding can be the only option, if the interaction needs to have zero lag.

/**
 * let customButton:CustomButton = CustomButton.init(frame:CGRect.init(x:0,y:0,width:120,height:40))
 * addSubview(customButton)
 * customButton.tapUpInsideCallBack = {
 *    Swift.print("๐ŸŽ‰")
 * }
 * TODO: Add onTapDownInside method
 */
class CustomButton:UIView{
   var tapUpInsideCallBack:TapUpInsideCallBack = defaultTapUpInside
   override init(frame: CGRect) {
      super.init(frame: frame)
      backgroundColor = .purple//Debug
      isUserInteractionEnabled = true/*โš ๏ธ๏ธ might be needed ? */
   }
   /**
     * On tap down inside
     */
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first, touch.view == self {
            /*touch began*/
        }
        super.touchesBegan(touches, with:event)
    }
    /**
     * On tap up inside
     */
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first, touch.view == self{
            /*Touch ended*/
            tapUpInsideCallBack()
        }
    }
    /**
     * Boilerplate
     */
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}
extension CustomButton{
   typealias TapUpInsideCallBack = () -> Void
   static let defaultTapUpInside:TapUpInsideCallBack = {Swift.print("default \(CustomButton.self).onTapUpInside")}
}

The Gesture approach

Here is an example where we are adding GestureRecognizer to the view. Useful for more advance setups.

/**
 * View that can be pressed like a button
 * EXAMPLE:
 * let btn = ButtonView()
 * btn.onNormal = { btn.backgroundColor = .clearColor() }
 * btn.onPressed = { btn.backgroundColor = .blueColor() }
 * btn.onReleased = yourAction // Function to be called
 * REF: Code found on stackoverflow
 */
class ButtonView : UIView {
    var onNormal = {}/* Called when the view goes to normal state (set desired appearance) */
    var onPressed = {}/* Called when the view goes to pressed state (set desired appearance) */
    var onReleased = {}/* Called when the view is released (perform desired action) */

    override init(frame: CGRect)  {
        super.init(frame: frame)

     let recognizer = UILongPressGestureRecognizer(target: self, action: #selector(touched))
     // recognizer.delegate = self
     recognizer.minimumPressDuration = 0.0
     addGestureRecognizer(recognizer)
     userInteractionEnabled = true

        onNormal()
    }
    /**
     * Gesture handler
     */   
    @objc func touched(sender: UILongPressGestureRecognizer) {
        if sender.state == .began {
            onPressed(self)
        } else if sender.state == .ended {//๐Ÿ‘‰ [.ended,.cancelled,.failed].contains(sender.state)
            onNormal(self)
            onReleased()
        }
    }
    /**
     * Boilerplate
     */
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}