[Android] ApplicationView.GetForCurrentView().Bounds ignores the translucent navigationbar

[takla21]

Current behavior

With windowTranslucentNavigation set to true

ApplicationView.GetForCurrentView().VisibleBounds.Bottom is the same as MainWindow!.Bounds.Bottom

#if __ANDROID__ || __IOS__
        var full = App.Instance.MainWindow!.Bounds;
        var bounds = ApplicationView.GetForCurrentView().VisibleBounds;

        var bottomPadding = full.Bottom - bounds.Bottom;
#else
        var bottomPadding = 0;
#endif

Expected behavior

For the same code on iOS, those two values are different which helps us avoiding phone edges

How to reproduce it (as minimally and precisely as possible)

• Download this sample BottomBoundsIssue.zip
• Deploy on Android

Workaround

Waiting for ApplicationView.GetForCurrentView().VisibleBoundsChanged event to be raised to ensure that it gets the appropriate values

public Page()
{
#if __ANDROID__
	ApplicationView.GetForCurrentView().VisibleBoundsChanged += OnVisibleBoundsChanged;
#else
	InitializeSafeArea();
#endif
}

private void OnVisibleBoundsChanged(ApplicationView sender, object args)
{
	ApplicationView.GetForCurrentView().VisibleBoundsChanged -= OnVisibleBoundsChanged;
	InitializeSafeArea();
}

private void InitializeSafeArea()
{
#if __ANDROID__ || __IOS__
	var full = App.Instance.CurrentWindow.Bounds;
	var bounds = ApplicationView.GetForCurrentView().VisibleBounds;

	var bottomPadding = full.Bottom - bounds.Bottom;
#else
	var bottomPadding = 0;
#endif

	if (bottomPadding > 0)
	{
		SafeAreaRow.Height = new GridLength(bottomPadding);
	}
}

Works on UWP/WinUI

None

Environment

Uno.WinUI / Uno.WinUI.WebAssembly / Uno.WinUI.Skia

NuGet package version(s)

5.1.56

Affected platforms

Android

IDE

Visual Studio 2022

IDE version

17.7.7; 17.10.0 Preview 1.0

Relevant plugins

No response

Anything else we need to know?

On our project, it started to happen when we've updated uno from 4.8.39 to 4.10.34

Related issue #12007

[jeromelaban]

This also feels similar to https://github.com/unoplatform/nventive-private/issues/510, what do you think @kazo0?

[kazo0]

Looks to be a timing issue with when the VisibleBounds is grabbed. If I place a button in the page and cause it to call InitializeSafeArea on click, I see the right values:

But for some reason the VisibleBounds looks to still be reporting as if we are on the splashscreen and displaying fullscreen when the ctor for MainPage is called

[jeromelaban]

It may be that the code relying on VisibleBounds should react on the Window.SizeChanged.

[takla21]

@jeromelaban I've tried on the sample to subscribe to SizeChanged, but it doesn't seem to be raised at all on Android.

However, from what @kazo0 mentioned in his previous comment, I can workaround it by subscribing to the Loaded event. Although it can cause flickers depending on some cases on our actual project, at least it gives us a temporary solution to move the content out of the navigationbar

[kazo0]

@takla21 what about hooking to ApplicationView.GetForCurrentView().VisibleBoundsChanged?

[kazo0]

Ah, it seemingly also depends on when you call MainWindow.Activate() in the App.cs, so placing that call before the navigation to MainPage is performed will avoid this issue but we are still stuck with the Windows Bounds being equal to the VisibleBounds at that point

@MartinZikmund this looks to be related to multi-window changes

[takla21]

@kazo0 so subscribing to ApplicationView.GetForCurrentView().VisibleBoundsChanged works too. However, is it expected to be the permanent solution? Like, I tried to do the same on iOS and that event isn't being called at all.