[PanGestureBasicUsage] basic usage of pan gesture recongizer

readme.txt

This snippet shows the basic usage of pan gesture recongizer.

panGestureBasicUsage.swift

// The Pan Gesture
func createPanGestureRecognizer(targetView: UIImageView) {
    var panGesture = UIPanGestureRecognizer(target: self, action:#selector(handlePanGesture(_:)))
    targetView.addGestureRecognizer(panGesture)
}

@objc func handlePanGesture(panGesture: UIPanGestureRecognizer) {
    // get translation
    let translation = panGesture.translation(in: view)
    // This line is reset translation point to zero, let the next translation base on
    panGesture.setTranslation(CGPoint.zero, in: view)
    print(translation)
    
    // create a new Label and give it the parameters of the old one
    let label = panGesture.view as! UIImageView
    label.center = CGPoint(x: label.center.x+translation.x, y: label.center.y+translation.y)
    label.isMultipleTouchEnabled = true
    label.isUserInteractionEnabled = true
    
    // the next line can use switch instead of if
    if panGesture.state == .began {
        // add something you want to happen when the Label Panning has started
    }
    
    if panGesture.state == .ended {
        // add something you want to happen when the Label Panning has ended
    }
    
    if panGesture.state == .changed {
        // add something you want to happen when the Label Panning has been change ( during the moving/panning )
    } else {
        // or something when its not moving
    }
}