UI: Set WA_PaintOnScreen for projectors only on X11 to avoid crash on Wayland

[OchiLive]

Description

Only set the "Qt::WA_PaintOnScreen" attribute on windowed projectors when running on X11, but not when running on Wayland.

Motivation and Context

As discussed in issue #11022 OBS crashes on certain Wayland compositors when explicit sync is in use. In the issue, the aforementioned attribute was mentioned as a possible culprit. In my testing on KDE Plasma 6.2.3, it turns out that:

• In X11, setting the attribute seems to be necessary - otherwise OBS hangs while resizing the projector.
• In Wayland, setting the attribute causes a crash. However, not setting the attribute works fine for me.

I therefore set the attribute conditionally only when running on X11.

How Has This Been Tested?

Tested on KDE Plasma 6.2.3 with NVIDIA driver 565.57.01 on Arch Linux in X11 and Wayland mode. Please feel free to test on other Wayland compositors if you can.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[kkartaltepe]

This is still incredibly broken on wayland and why I have not sent this myself. If you only open a projector yes it may appear to be fine.

[OchiLive]

@kkartaltepe Could very well be an instance of "works (only) for me", but I couldn't find the downsides of the change yet. Do you have a specific repro where it shows that it is broken?