Qt's activation issue under Wayland

[tsujan]

There's an old Qt issue that hasn't been fixed yet — in Qt6 either — perhaps because no Qt dev can see it with usual Qt styles.

Kvantum makes use of the difference between activeness and inactiveness in Qt to draw inactive windows differently — like GTK does. As far as I've seen, no other Qt style does it.

The bug is this: Under Wayland, if you right click inside an inactive window to show a context menu, only a part of that window will become active. This can be easily seen in an app like PCManFM-Qt with some Kvantum themes that distinguish between active and inactive windows.

Of course, there's no issue under X11.

I can't report it to Qt because they would want a code sample, but nothing could be seen with any code and Fusion. I couldn't tell them, "Please use Kvantum with this or that theme and also a Wayland compositor that activates windows on right clicking inside them." Only if Fusion or Breeze was a little less elementary…

[tsujan]

The only acceptable workaround I've found for this problem is showing context menus by releasing mouse button, instead of pressing it (as in MS Windows). Qt allows that in the DE's Qt plugin (through ContextMenuOnMouseRelease) but, as is explained in lxqt/lxqt-qtplugin#79, Qt's behavior isn't always self-consistent in this regard.