Menu handling is rather bugged, with multiple symptoms I think share the same root cause:
Clicking a new menu item fails to close the menu:
Tested on multiple Linux DEs, both X and Wayland:
Open a menu.
Click and hold anywhere on the window (either on or off the menu) to close it. (The bug occurs regardless if you hold it for a short or long time.)
Shortly before or after releasing the mouse, hover a different menu item. (Optionally move your mouse off the menu bar.)
The new menu will open. This will not happen if you put more of a gap between moving the mouse and hovering a menu item.
This behavior is absent from GTK4 apps (not many have menu bars, try gtk4-widget-factory, Page 2) and Qt apps (most KDE apps have menu bars).
gtk3-widget-factory kinda has this behavior. It's even more lenient if you click on a menu item, move your mouse to a different one, and release it. But if you click off a menu item, I was unable to keep the menu open.
Menu handling is rather bugged, with multiple symptoms I think share the same root cause:
Clicking a new menu item fails to close the menu:
Tested on multiple Linux DEs, both X and Wayland:
The new menu will open. This will not happen if you put more of a gap between moving the mouse and hovering a menu item.
This behavior is absent from GTK4 apps (not many have menu bars, try gtk4-widget-factory, Page 2) and Qt apps (most KDE apps have menu bars).
gtk3-widget-factory kinda has this behavior. It's even more lenient if you click on a menu item, move your mouse to a different one, and release it. But if you click off a menu item, I was unable to keep the menu open.
https://user-images.githubusercontent.com/913957/123017614-cb4d1300-d381-11eb-8d9d-2a2fd5c1a56d.mp4
Clicking the window fails to close the menu:
This is a lot trickier to reproduce than the above, but is more clearly a bug (rather than a defensible choice of behavior).
If you get it right, the new menu appears, and doesn't close even though you clicked the window background to close the new menu.
https://user-images.githubusercontent.com/913957/123017816-3991d580-d382-11eb-93e7-4c15bf340be7.mp4
These videos were recorded at 60fps. I recommend watching them in mpv, using , and . for frame rewind and advance (or [ and ] for slow motion).