Bug 23372 - UIPopoverPresentationController missing "popoverBackgroundViewClass" property
Summary: UIPopoverPresentationController missing "popoverBackgroundViewClass" property
Alias: None
Product: iOS
Classification: Xamarin
Component: Xamarin.iOS.dll ()
Version: XI 8.0.0
Hardware: Macintosh Mac OS
: Normal normal
Target Milestone: Untriaged
Assignee: Bugzilla
Depends on:
Reported: 2014-09-25 11:11 UTC by bilal.durrani
Modified: 2014-11-28 05:59 UTC (History)
4 users (show)

Is this bug a regression?: ---
Last known good build:

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Comment 1 Sebastien Pouliot 2014-09-25 14:51:17 UTC
`popoverBackgroundViewClass` is internal, since we avoid exposing `Class`, but it looks like the Type-based code was not part of the build.

`UIPopoverBackgroundViewMethods` is also internal, maybe because it only had static methods (which is impossible to implement as interfaces in C#). I'll verify that
Comment 2 bilal.durrani 2014-09-29 11:51:38 UTC
Is there an ETA on when these will be added to the API?

Comment 3 Sebastien Pouliot 2014-09-30 10:56:32 UTC
@Bilal ETA is XI 8.4 (as 8.2 is frozen and will be released soon).

Support for popoverBackgroundViewClass added in master / 94f05b7668b902303dca780e7164d2b0317781d1

QA: unit tests added in same revision
Comment 4 Sebastien Pouliot 2014-09-30 11:17:26 UTC
UIPopoverBackgroundViewMethods exposed in master / 2a4a418ce72e74b07b6b7003168ff997265de878
Comment 5 Adam Kemp 2014-10-27 11:19:30 UTC
I don't see this in Xamarin.iOS 8.4. Did it slip?
Comment 6 Sebastien Pouliot 2014-10-27 11:30:42 UTC
The iOS 8.1 release required us to do an out-of-sync release (and re-number releases). IOW:

* XI 8.4 was not from master (where the fix is) but from 8.2 (branch) + iOS8.1 additions.
* XI 8.6 is now the (next) revision planned out of master.

If needed I can share some code that would expose it for you.
Comment 7 Adam Kemp 2014-10-27 11:36:54 UTC
That would help. We're kind of being forced to switch to this API so I'm trying to keep things working as they were before. I'm ok with using a hack until the property is in a stable release.
Comment 8 Adam Kemp 2014-10-28 12:48:37 UTC
Did you figure out how I could access this property in the meantime? I got this far (adapted from the UIPopoverController binding):

        private IntPtr _popoverBackgroundViewClass = IntPtr.Zero;
        public Type BackgroundViewType
                IntPtr popoverBackgroundViewClass = _popoverBackgroundViewClass;
                if (popoverBackgroundViewClass == IntPtr.Zero)
                    return null;
                return MonoTouch.ObjCRuntime.Class.Lookup(_popoverBackgroundViewClass);
                _popoverBackgroundViewClass = ((!(value == null)) ? MonoTouch.ObjCRuntime.Class.GetHandle(value) : IntPtr.Zero);

The problem is the Lookup function, which is internal. Is there any public way to get the C# Type for a given Objective-C Class handle?
Comment 9 Adam Kemp 2014-10-28 13:59:31 UTC
Ok, I came up with something that works. I abandoned my attempts at using the Type, and instead I just use the registered name of the class (for now). Here is my code for anyone who might need it:

        private string _backgroundViewType;
        public string BackgroundViewType
                return _backgroundViewType;
                _backgroundViewType = value;


        private static readonly Selector BackgroundViewClassGetSelector = new Selector("popoverBackgroundViewClass");
        private static readonly Selector BackgroundViewClassSetSelector = new Selector("setPopoverBackgroundViewClass:");
        private IntPtr PopoverBackgroundViewClass
                return Messaging.IntPtr_objc_msgSend(PopoverPresentationController.Handle, BackgroundViewClassGetSelector.Handle);

                Messaging.IntPtr_objc_msgSend_IntPtr(PopoverPresentationController.Handle, BackgroundViewClassSetSelector.Handle, value);

        private void UpdateBackgroundViewType()
            var controller = PopoverPresentationController;
            if (controller != null)
                PopoverBackgroundViewClass = ((_backgroundViewType != null) ? Class.GetHandle(_backgroundViewType) : IntPtr.Zero);

This only works if you use a [Register] attribute for the class you want to use, and you have to supply the string that you use for that attribute.
Comment 10 Sebastien Pouliot 2014-10-28 14:04:20 UTC
Lookup is not exposed since it depends on the registrar being used (old/new + static/dynamic) so it needs a bit more (reflection) code to get it to work.

You can use those helpers to achieve the same (as newer XI will do):

		static Type GetType (UIPopoverPresentationController c)
			var p = Messaging.IntPtr_objc_msgSend (c.Handle, Selector.GetHandle ("popoverBackgroundViewClass"));
			if (p == IntPtr.Zero)
				return null;
			var field = typeof(Runtime).GetField ("Registrar", BindingFlags.NonPublic | BindingFlags.Static);
			var registrar = field.GetValue (null);
			var lookup = registrar.GetType ().GetMethod ("Lookup");
			return (Type) lookup.Invoke (registrar, new object [] { p, false });

		static void SetType (UIPopoverPresentationController c, Type t)
			IntPtr p = t == null ? IntPtr.Zero : Class.GetHandle (t);
			Messaging.void_objc_msgSend_IntPtr (c.Handle, Selector.GetHandle ("setPopoverBackgroundViewClass:"), p);
Comment 11 Akhilesh kumar 2014-11-27 08:38:01 UTC
Hi Sebastien,

I have checked this issue and observed that property  ‘PopoverBackgroundViewType’ has been added in class UIPopoverPresentationController. 
Screencast: http://screencast.com/t/ixU552Bv5Cy

And I have also verified that property 'popoverBackgroundViewClass' has been implemented in class 'UIPopoverPresentationController'.

And when I tried to verify the implementation of 'UIPopoverBackgroundViewMethods' in class 'UIPopoverPresentationController' in assembly browser then I am not getting any method with name 'UIPopoverBackgroundViewMethods' in class 'UIPopoverPresentationController'. 

To verify this I have created an object of class 'UIPopoverPresentationController' and when I type class object and press dot(.) then it is not showing method named 'UIPopoverBackgroundViewMethods' in intellisence window.
Screencast: http://screencast.com/t/zXZhI6sg1

Could you please provide some steps/instructions so that I can verify the implementation of "UIPopoverBackgroundViewMethods".

Comment 12 Sebastien Pouliot 2014-11-27 09:53:45 UTC

> Also missing is the protocol UIPopoverBackgroundViewMethods

^ because it's a protocol and not a method
Comment 13 Akhilesh kumar 2014-11-27 13:09:39 UTC
Thanks Sebastien

Can I verify this issue at our end? 
Actually I am not sure where should I check that protocol "UIPopoverBackgroundViewMethods".
Comment 14 Sebastien Pouliot 2014-11-27 17:22:00 UTC
Since it's a protocol you'll see an interface like this in monotouch.dll:

namespace MonoTouch.UIKit
	[Protocol (Name = "UIPopoverBackgroundViewMethods", WrapperType = typeof(UIPopoverBackgroundViewMethodsWrapper)), Since (8, 0)]
	public interface IUIPopoverBackgroundViewMethods : INativeObject, IDisposable
Comment 15 Akhilesh kumar 2014-11-28 05:59:48 UTC
@Sebastien: Thank you very much for your kind help.

I am getting this protocol interface for both Unified API and Classic API. 

For Classic API: http://screencast.com/t/dAOfrsv1P
For Unified API: http://screencast.com/t/QH5EuGdoqC

Hence, closing this issue.