[iOS] Shell TabBar overlaps ContentPage when calling Shell.SetTabBarIsVisible(this, true)

[ewerspej]

Description

On iOS the Shell TabBar cuts off the bottom of a ContentPage when manually setting Shell.SetTabBarIsVisible(BindableObject obj, bool visible) or when binding Shell.TabBarIsVisible to a property.

It seems like there is a layout update missing when calling Shell.SetTabBarIsVisible(this, true);, because bottom items disappear behind the TabBar and centered elements appear lower afterwards. This indicates that the ContentPage extends behind the TabBar instead of being correctly recalculated.

Steps to Reproduce

1. Create a new MAUI app
2. Add a TabBar in the Shell with two Tabs incl. ShellContent
3. Add a Grid to the MainPage with a Label centered vertically and a Button (or any other View element) at the bottom (or fairly close to the bottom)
4. Override OnSizeAllocated(double width, double height) of MainPage and call Shell.SetTabBarIsVisible(this, height > width);
5. Run on a real iOS device
6. Rotate from Portrait into Landscape
7. Rotate from Landscape back into Portrait

Expected result: The TabBar is correctly shown and hidden and the ContentPage is always rendered correctly
Actual result: The TabBar hides the bottom of the ContentPage after calling Shell.SetTabBarIsVisible(this, height > width);

Link to public reproduction project repository

https://github.com/ewerspej/dotnet-maui-bug-tabbar-ios-cutoff/

Version with bug

7.0.0-rc.1.22426.10

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

iOS 15.5

Did you find any workaround?

No

Relevant log output

No response

[ghost]

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.

[jinxinjuan]

Verified this issue with Visual Studio Enterprise 17.7.0 Preview 2.0. Can repro on iOS platform with sample project. dotnet-maui-bug-tabbar-ios-cutoff/