Detecting the collision b/w two objects in Swift 3.0?

Question

I've added 2 UIViews on my screen and I want to detect if they collide. If so, then I need to show an alert on the screen.

Answer 1

what about

if (CGRectIntersectsRect(secondView.frame, sender.frame)) {
        // Do something
    }

Answer 2

You can check wether 2 views are intersecting by checking if their frames are intersecting. Here is an example:

let view1 = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
let view2 = UIView(frame: CGRect(x: 90, y: 90, width: 50, height: 50))

extension UIView {
    func intersects(_ otherView: UIView) -> Bool {
        if self === otherView { return false }
        return self.frame.intersects(otherView.frame)
    }
}

print(view1.intersects(view2)) // Prints true because the 2 views are intersecting

You can call intersects(_:) every time you update any of your views frames (ie. change their size and/or position). If the method returns true , show an alert using UIAlertController .

Answer 3

// The Pan Gesture
func createPanGestureRecognizer(targetView: UIImageView) 
{

    var panGesture = UIPanGestureRecognizer(target: self, action:("handlePanGesture:"))
    targetView.addGestureRecognizer(panGesture)
}

// THE HANDLE

   func handlePanGesture(panGesture: UIPanGestureRecognizer) {


    //        get translation

    var translation = panGesture.translationInView(view)
    panGesture.setTranslation(CGPointZero, inView: view)
    println(translation)


    //create a new Label and give it the parameters of the old one
    var label = panGesture.view as UIImageView
    label.center = CGPoint(x: label.center.x+translation.x, y: label.center.y+translation.y)
    label.multipleTouchEnabled = true
    label.userInteractionEnabled = true

    if panGesture.state == UIGestureRecognizerState.Began {

        //add something you want to happen when the Label Panning has started
    }

    if panGesture.state == UIGestureRecognizerState.Ended {

       //add something you want to happen when the Label Panning has ended

    }


    if panGesture.state == UIGestureRecognizerState.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
    }

    }