ControlCatalog: Side-menu toggling breaks after a page is opened

Describe the bug

In the ControlCatalog, if you open the previously collapsed side-menu and select an menu item, you cannot re-open the collapsed side-menu again.

To Reproduce

Steps to reproduce the behavior:

1. Open ControlCatalog (Windows, Android,…)
2. Reduce the width of the Window until the left side-menu collapses/hides (important!)
3. Click the Hamburger button multiple times - the side-menu shows and hides as expected
4. Now, open a menu item like “Calendar”
5. Try to open the side-menu again
6. The side-menu does not open anymore - you have to restart the app to select another page

Expected behavior

The side-menu should always open/close.

Desktop (please complete the following information):

• OS: Windows 11 22H2 (22621.1344)
• Version:
  • Works on 11 Preview 5,
  • Broken on current Master branch (92562b0d9979becc8d8c2316e1c2f0678bdae19d)

Investigation

The SplitView’s IsPaneOpen is bound by the Hamburger button.

SplitView.CoerceIsPaneOpen should always get triggered when the Hamburger button (ToggleButton) gets clicked. When it works, it is called for true and false. As soon as its broken, it’s only called when the value is true.

Wild guess: As the side-menu already closes as soon as the menu-item is pressed (not released!), it seems as the mouse is captured in a weird way by the menu item or something.

Guilty Commit

80394d0097c4acc9b3b74024a863b97774c35d3e (but I think it’s an unhider as this changes IsPaneOpen from DirectProperty to StyledProperty)

Maybe some issue with StyledProperty?

[amwx]

In case it was the same as #10655, I had a look, and the issue here is: https://github.com/AvaloniaUI/Avalonia/blob/cbe0bb861a767b7bf7b268bbaa1d89dcf8523aea/samples/SampleControls/HamburgerMenu/HamburgerMenu.cs#L56-L62

Selecting an item with the SplitView display mode in Overlay results in setting IsPaneOpen to false with Animation priority - which is never reset so the pane can never be reopened as the HamburgerMenuButton ToggleButton in the template is two-way bound to the SplitView

[robloo]

@amwx Thanks for tracking that down!

The fix seems easy: use the brand-new SetCurrentValue() method that won’t destroy bindings and also won’t change binding priority or require setting as animation. Quick test seems to work OK, will open a PR to close.