How would I make a UiPanGestureRecognizer check if the finger is in the buttons frame?

Question

I am trying to make an app where the user could drag a finger on top of multiple buttons and get some actions for each button.

There was a similar question from a while back but when I tried to use CGRectContainsPoint(button.frame, point) it said it was replaced with button.frame.contains(point) but this didn’t seem to work for me. Here is a link to the Photo

What I have done so far:

var buttonArray:NSMutableArray!

override func viewDidLoad()
{
    super.viewDidLoad()
    let panGesture = UIPanGestureRecognizer(target: self, action: #selector(panGestureMethod(_:)))
    a1.addGestureRecognizer(panGesture)
    a2.addGestureRecognizer(panGesture)
}
@objc func panGestureMethod(_ gesture: UIPanGestureRecognizer) {
    
    
    if gesture.state == UIGestureRecognizer.State.began {
        buttonArray = NSMutableArray()
    }
    
    let pointInView = gesture.location(in: gesture.view)
    
    if !buttonArray.contains(a1!) && a1.frame.contains(pointInView) {
        buttonArray.add(a1!)
        a1Tapped(a1)
    }
    else if !buttonArray.contains(a2!) && a2.frame.contains(pointInView) {
        buttonArray.add(a2!)
        a2Tapped(a2)
    }

The code did run fine but when I tried to activate the drag nothing happened. Any tips?

Please add code samples of what you have until now (as short as possible) & state what you have tried an why it failed (e.g. errors). — Throvn, Jun 19 '22 at 12:15

calimarkus · Accepted Answer · 2022-06-21T01:54:43.677

0

You want behavior similar to the system keyboard I assume? CGRectContainsPoint is not deprecated: See the docs. In Swift it's written like frame.contains().

When dealing with rects and points you have to make sure both are translated to the same coordinate system first. To do so you can use the convert to/from methods on UIView: See (the docs).

In your case smth. like the following should work (first translate button frames, then check if the point is inside):

func touchedButtonForGestureRecognizer(_ gesture: UIPanGestureRecognizer) -> UIView? {
    let pointInView = gesture.location(in: gesture.view)
    for (button in buttonArray) {
        let rect = gesture.view.convert(button.frame from:button.superview)
        if (rect.contains(pointInView)) {
          return button
        }
    }
    return nil
}

edited Jun 21 '22 at 01:54

answered Jun 19 '22 at 12:34

calimarkus

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Yes I want something like the keyboard but I said wrong in the question. It is not deprecated, it wanted me to replace it with `button.frame.contains(point)`. Do you know a Swift version of this code? – Kristoffer Melen Jun 19 '22 at 12:55
I updated my answer to focus on the rect math & translated it to swift. Hope that helps. You probably want to learn reading objc too though, it is easy to translate it to swift. – calimarkus Jun 21 '22 at 01:55
Thanks! I am away from my Mac atm but i will check when i get back!! Thanks for all the help and your time!! – Kristoffer Melen Jun 22 '22 at 07:33
I think i forgot to do `let rect = gesture.view.convert(button.frame from:button.superview)` – Kristoffer Melen Jun 22 '22 at 08:43
1

I have now tried it and it works perfectly!! I would have never gotten this working without you!! Thank you!!!!! – Kristoffer Melen Jun 29 '22 at 22:23

How would I make a UiPanGestureRecognizer check if the finger is in the buttons frame?

1 Answers1