iPhone - Get Position of UIView within entire UIWindow

Question

The position of a UIView can obviously be determined by view.center or view.frame etc. but this only returns the position of the UIView in relation to it's immediate superview.

I need to determine the position of the UIView in the entire 320x480 co-ordinate system. For example, if the UIView is in a UITableViewCell it's position within the window could change dramatically irregardless of the superview.

Any ideas if and how this is possible?

Cheers :)

Solution 1

That's an easy one:

[aView convertPoint:localPosition toView:nil];

... converts a point in local coordinate space to window coordinates. You can use this method to calculate a view's origin in window space like this:

[aView.superview convertPoint:aView.frame.origin toView:nil];

2014 Edit: Looking at the popularity of Matt__C's comment it seems reasonable to point out that the coordinates...

1. don't change when rotating the device.
2. always have their origin in the top left corner of the unrotated screen.
3. are window coordinates: The coordinate system ist defined by the bounds of the window. The screen's and device coordinate systems are different and should not be mixed up with window coordinates.

Solution 2

Swift 5+:

let globalPoint = aView.superview?.convert(aView.frame.origin, to: nil)

Solution 3

Swift 3, with extension:

extension UIView{
    var globalPoint :CGPoint? {
        return self.superview?.convert(self.frame.origin, to: nil)
    }

    var globalFrame :CGRect? {
        return self.superview?.convert(self.frame, to: nil)
    }
}

Solution 4

In Swift:

let globalPoint = aView.superview?.convertPoint(aView.frame.origin, toView: nil)

Solution 5

Here is a combination of the answer by @Mohsenasm and a comment from @Ghigo adopted to Swift

extension UIView {
    var globalFrame: CGRect? {
        let rootView = UIApplication.shared.keyWindow?.rootViewController?.view
        return self.superview?.convert(self.frame, to: rootView)
    }
}

View more solutions

Comments

[Lior Frenkel]

awesome :) I thought it should be simple, but I had the feeling apple wouldn't give it so easy... well they did. thanks

[Lior Frenkel]

I added a different question - it worked for me in simulator but not on the real device :(

[Matt__C]

Be aware that specifying nil in the toView parameter gives you device co-ordinates, which won't be what you want if you are not in portrait orientation. See convertpointtoview-in-landscape-mode-giving-wrong-values

[Nikolai Ruhe]

@Matt__C: Specifying nil calculates window coordinates, not device coordinates. If you want device coordinates you have to further convert using UIWindow's conversion methods.

[Dan Abramov]

This method kept returning aView.frame.origin for me. It took me a whlie to realize my view's superview did not have a superview itself.

[user4951]

If your superView did not have a superView your view should not be seen at all

[Nikolai Ruhe]

@JimThio To be super-precise: If the view's superview was a window it would be visible. On iOS UIWindow derives fron UIView.

[devios1]

This isn't working at all for me. Converting (0,0) on a view is giving me negative coordinates! How is that even possible?

[Nikolai Ruhe]

@chaiguy If the view's origin is to the left or above the screen's top left corner its window coordinates will, of course, be negative.

[devios1]

I think the problem was that the tableView must have been in a scrollView or something. I wasn't expecting that. Got it figured out.

[Ghigo]

Adapting @Matt__C linked solution to your case, it would become: [view.superview convertPoint:view.frame.origin toView:[UIApplication sharedApplication].keyWindow.rootViewController.view]

[trdavidson]

@Ghigo this perfectly works to get the position - how would I use this information however to set a view relative to the screen without using autolayout?

[Reid]

I've been trying to do this with a UIToolbar. I need to determine the horizontal margins the system uses for bar button items so that I can adjust my layout (these margins have changed between iOS versions and are different between iPhone and iPad). For the life of me I can't figure it out...no matter what combination of views I supply as arguments and receiver to the method, origin is always (0, 7). Any tips?

[nastassia]

simple and nice!

[famfamfam]

some time superview is not enough sir

[Harsh Thakur]

As good as it can be. Thanks