Joe Joe - 8 days ago 13
Swift Question

How to detect UITouch location visible in Swift 3

I am trying to detect a

UITouch
event visible.When touch event begins.Currently, I am using below code to detect the touch location.From below code,I can able to print the touch location.Any,help would be greatly appreciated.

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?)
{
if let touch = touches.first {
let position :CGPoint = touch.location(in: view)
print(position.x)
print(position.y)
}
}


Note: I am not trying to draw a line or anything like a drawing app.I,Just want to see the touch event visibly.When happens.

Thanks in advance.

Answer

If you want a circle or something to appear when the user taps the screen, try this:

var touchIndicators: [UIView] = []
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    for touch in touches {
        let location = touch.location(in: view)
        let touchIndicator = UIView(frame: CGRect(x: location.x - 10, y: location.y - 10, width: 20, height: 20))
        touchIndicator.alpha = 0.5
        touchIndicator.backgroundColor = UIColor.red
        touchIndicator.layer.cornerRadius = 10
        self.view.addSubview(touchIndicator)
        touchIndicators.append(touchIndicator)
    }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    for indicator in touchIndicators {
        indicator.removeFromSuperview()
    }
    touchIndicators = []
}

Pretty straightforward. Add circular views when the user touches the screen and remove them when the user lifts his/her fingers. You can also do this using UITapGestureRecognizer.

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