UIPanGestureRecognizer stays at state begin

Question

I have a SpringButton which I want to drag. This is my code:

var gesture = UIPanGestureRecognizer(target: self, action: #selector(userDragged))
card.addGestureRecognizer(gesture)

var cardIsCurrentlyMoving = false

func userDragged(gesture: UIPanGestureRecognizer){
    if !cardIsCurrentlyMoving{
        if let button = gesture.view as? SpringButton {
            if gesture.state == .began {
                print("begon")
                cardIsCurrentlyMoving = true
                startPosition = button.center
            } else if gesture.state == .changed {
                print("changed")
            } else if gesture.state == .ended{
                print("ended")
                cardIsCurrentlyMoving = false
            }
        }
    }
}

The function gets called, and the state gets changed to .began. However, when trying to move the button nothing happens. This is because cardIsCurrentlyMoving is set to true in .began, but never back to false, because gesture.state .changed and .ended never gets called.

When I release my finger and touch the button again, nothing happens as well. Why does UIPanGestureRecognizer not executes .changed and .ended?

Thanks.

Answer 1

I think you need to check your if statement

if !cardIsCurrentlyMoving{ 

}

Pan Gesture continuously calls method with changed state. So userDragged func called continuously but just because of your above if statement, control doesn't go inside if statement.

So i'll suggest to use this, instead of yours.

func userDragged(gesture: UIPanGestureRecognizer){

        if let button = gesture.view as? SpringButton {
            if gesture.state == .began {
                print("begon")
                cardIsCurrentlyMoving = true
                startPosition = button.center
            } else if gesture.state == .changed {
                print("changed")
            } else if gesture.state == .ended{
                print("ended")
                cardIsCurrentlyMoving = false
            }
        }

}