Highlight active toolbar buttons on hover on macOS

[cbrnr]

On macOS, Qt doesn't highlight toolbar buttons on hover (they call it "autoraise"), see here. This is quite unfortunate, because (1) native macOS application do highlight on hover, and (2) from a usability point of view, it is really difficult to discover if a button is active or not.

Although this is not an MNELAB issue, maybe we could implement a workaround as outlined here if it is not too hacky (e.g., it needs to support both light and dark themes).

[hoechenberger]

One of the challenges I foresee for the workaround implementation is properly dealing with the OS theme (light vs dark)

[cbrnr]

Yes, maybe, although it is possible to determine which system theme is active (and there is also a signal which is emitted if the theme changes).

For reference, here's the toolbar of a native macOS app (Notes) in both light and dark modes:

Screen.Recording.2024-12-12.at.06.43.30.mov

Screen.Recording.2024-12-12.at.06.42.43.mov