Allow developers to check if a menu of a menu_button is currently opened

[lukas-kirschner]

Is your feature request related to a problem? Please describe.

I am programming a game using bevy and bevy_egui. My map editor uses egui to show selector buttons for different tiles that can be placed on the game board.

Since some of the tiles have different variants, I show those tiles in a drop-down menu:

When a user clicks on a button in the dropdown menu, the click is also registered as a click on the GameBoard, placing a tile on the board. This bug has already been reported here: https://github.com/bevyengine/bevy/issues/3570 - To work around that bug, I am trying to set a flag in my mouse handlers that change their values when a menu is opened.

To set this flag, I currently do not see any possibility of getting the menu open state from my Ui object (menu_state is private in Ui, unfortunately).

Describe the solution you'd like

I could see a solution by either making menu_state public, or by adding a menu_is_open() function in Ui

Describe alternatives you've considered

Additional context

The bug I am trying to fix is reported here: https://github.com/lukas-kirschner/Exodus/issues/44

[abey79]

I've found myself needing to work around this one as well. It would be useful to know:

• if a context menu is opened at all
• if so, if it was open just this frame (for example to run code that should happen only once upon context menu opening).