Menu and Tooltip positioning in Wayland before Qt 6.8

[kbloom]

Issue type

UI bug (incorrect info or interface appearance)

Description with steps to reproduce

Following up on #15285, which I have now fixed. This now uncovers a new bug in the Wayland UI, where popup windows don't reposition. This is a usuability issue in two places.

1. When you move from the mouse one menu heading to the next (or from one menu item with a submenu to the next) , the open menu stays where it is, while its contents update. This actually looks quite bad for main menu items in certain circumstances.

2. When you mouse over one palette item to show a tooltip and then mouse over another one to show its tooltip, the tooltip contents update, but the tooltip doesn't follow your cursor to the new position. (This is probably a relatively minor issue.)

As per https://blog.broulik.de/2024/08/a-fresh-perspective-on-things/ this is fixed in Qt 6.8, and I was able to confirm that by buiding master against Qt 6.7.2, which I downloaded using the Qt installer, and then ran against the Qt 6.8 beta, which I also downloaded using the Qt installer, by setting LD_LIBRARY_PATH to point to Qt 6.8. (I can't seem to build directly against Qt 6.8 for reasons that look like compile errors inside the beta, and I can't build against my system's Qt 6.7.2 and then run against Qt 6.8 because of a missing symbol.) Also impeding my testing was #24097, so I wasn't actually able to test the menu bar, but the tooltips give me some belief that Qt 6.8 also fixes the menu bar.

If we want to support Wayland with a version of Qt that's older than 6.8, then perhaps we want to do something like destroying and recreating the popup whenever it needs to move.

Supporting files, videos and screenshots

None

What is the latest version of MuseScore Studio where this issue is present?

Master 009e3516

Regression

No.

Operating system

Manjaro Linux 24.0.7

Additional context

No response

Checklist

• [X] This report follows the guidelines for reporting bugs and issues
• [X] I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• [X] I have attached all requested files and information to this report
• [X] I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible

[bkunda]

Unfortunately this is at present blocked externally by the fact that we are not yet in a position to update the Qt version.