Remove Popup and ContentPage from LogicalChildren when Popup is closed on iOS

[cat0363]

This PR resolves the issue where Popup and Content Page are not removed from LogicalChildren after closing Popup on iOS.

Description of Change

To accomplish this, first add MapOnClosed to the ControlPopUpCommandMapper.

[src\CommunityToolkit.Maui\HandlerImplementation\Popup\Popup.shared.cs]

	public static CommandMapper<IPopup, PopupHandler> ControlPopUpCommandMapper = new(PopupHandler.PopUpCommandMapper)
	{
#if IOS || MACCATALYST
		[nameof(IPopup.OnOpened)] = MapOnOpened,
		[nameof(IPopup.OnClosed)] = MapOnClosed
#endif
	};

Next, within the MapOnClosed method, remove Popup and ContentPage from LogicalChildren.

[src\CommunityToolkit.Maui\HandlerImplementation\Popup\Popup.macios.cs]

	public static void MapOnClosed(PopupHandler handler, IPopup view, object? result)
	{
		var parent = view.Parent as Element;
		if (parent is not null)
		{
			var contentPage = parent.LogicalChildrenInternal
				.Where(
					x => x is ContentPage
				)
				.LastOrDefault();

			var popup = parent.LogicalChildrenInternal
				.Where(
					x => x is Popup
				)
				.LastOrDefault();

			if (contentPage is not null)
			{
				parent.RemoveLogicalChild(contentPage);
			}
			if (popup is not null)
			{
				parent.RemoveLogicalChild(popup);
			}
		}
	}

Since Popup and ContentPage are stacked in LogicalChildren, remove the Popup and ContentPage added to LogicalChildren when the Popup was displayed last.

This will remove Popups and ContentPages from LogicalChildren in the order that Popups are closed.

Linked Issues

• Fixes [BUG] iOS: Popup Remains in Page's LogicalChildren after Closing #2149

PR Checklist

• Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• Has tests (if omitted, state reason in description)
• Has samples (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Changes adhere to coding standard
• Documentation created or updated: https://github.com/MicrosoftDocs/CommunityToolkit/pulls

Additional information

Below are the verification results.
For verification, I used the reproduction code of Issue #2149.

iPhone.15.iOS.17.0.2024-09-03.20-36-10.mp4

You can see that Popup and ContentPage are removed from LogicalChildren.

Next, I verified a pattern that displays popups hierarchically.

iPhone.15.iOS.17.0.2024-09-03.20-49-09.mp4

Similarly, you can see that Popup and ContentPage have been removed from LogicalChildren.

[bijington]

Thanks @cat0363 this is great work as always

[cat0363]

@bijington , I found that the following code causes a problem in which Popup does not close when calling the CloseAsync or Close method of the Popup class.

[src\CommunityToolkit.Maui\HandlerImplementation\Popup\Popup.shared.cs]

	public static CommandMapper<IPopup, PopupHandler> ControlPopUpCommandMapper = new(PopupHandler.PopUpCommandMapper)
	{
#if IOS || MACCATALYST
		[nameof(IPopup.OnOpened)] = MapOnOpened,
		[nameof(IPopup.OnClosed)] = MapOnClosed        // <= here
#endif
	};

The above code prevents the following methods from being called.

[src\CommunityToolkit.Maui.Core\Handlers\Popup\PopupHandler.macios.cs]

	public static async void MapOnClosed(PopupHandler handler, IPopup view, object? result)
	{
		var presentationController = handler.PlatformView.PresentationController;
		if (presentationController?.PresentedViewController is UIViewController presentationViewController)
		{
			await presentationViewController.DismissViewControllerAsync(true);
		}

		view.HandlerCompleteTCS.TrySetResult();

		handler.DisconnectHandler(handler.PlatformView);
	}

I'm currently looking into how to fix it.

[cat0363]

@bijington , I have created a new PR #2202.
I apologize that this PR affected the closing of Pop Up by calling the Close or CloseAsync methods.