sf::Mouse::setPosition not working with Wayland/xwayland

[eXpl0it3r]

Prerequisite Checklist

• I searched for existing issues to prevent duplicates
• I searched for existing discussions on the forum to prevent duplicates
• I am here to report an issue and not to just ask a question or look for help (use the forum or Discord instead)

Describe your issue here

We've received multiple reports that sf::Mouse::setPosition() doesn't seem to work to work when using Wayland:

• ArchLinux: https://en.sfml-dev.org/forums/index.php?topic=29196.0
• Debian GNOME: https://en.sfml-dev.org/forums/index.php?topic=29246.0

It might just be a bug in xwayland, but we should double check

Maybe related to #2709

Your Environment

• OS / distro / window manager: ArchLinux Plasma KDE / Debian GNOME through xwayland
• SFML version: 2.5.1 / apt (probably 2.5.1)
• Compiler / toolchain: ?
• Special compiler / CMake flags: ?

Steps to reproduce

1. Run the following example

#include <SFML/Graphics.hpp>

int main()
{
    sf::RenderWindow window(sf::VideoMode({1280, 720}), "Minimal, complete and verifiable example");
    window.setFramerateLimit(60);

    while (window.isOpen())
    {
        for (sf::Event event; window.pollEvent(event);)
        {
            if (event.type == sf::Event::Closed)
                window.close();
            else if (event.type == sf::Event::KeyPressed)
                sf::Mouse::setPosition({200, 200});
        }

        window.clear();
        window.display();
    }
}

Expected behavior

When pressing any key, the mouse should be moved to position (200, 200)

Actual behavior

The mouse is not moved

[danieljpetersen]

Doesn't seem to work in Sway (wlroots) either.

[Bambo-Borris]

I tested the sample code & experienced this issue within my own project, but have come to the conclusion I think it does work, but not as expected. I adjusted the sample code above to also print the mouse position every frame. When I hit any key press I do not visually see my cursor migrate on the screen, but the position reported is {200, 200}.

[danieljpetersen]

Tangentially related to this, window.setCursorGrabbed doesn't work on Sway either. It doesn't confine the mouse to the window, though nothing else is focusable, so clicks outside of the window do nothing.

[lukaslihotzki]

Wayland does not support getting the mouse position in desktop coordinates (although this seems to work through XWayland), and it does not support setting the mouse position in general (not even in XWayland).

setMouseCursorGrabbed can be implemented with the pointer-constraints-unstable-v1 protocol (when using native Wayland instead of XWayland), the relative-pointer-unstable-v1 protocol may also be helpful.

[Bambo-Borris]

Wayland does not support getting the mouse position in desktop coordinates (although this seems to work through XWayland), and it does not support setting the mouse position in general (not even in XWayland).

setMouseCursorGrabbed can be implemented with the pointer-constraints-unstable-v1 protocol (when using native Wayland instead of XWayland), the relative-pointer-unstable-v1 protocol may also be helpful.

The inability to set the mouse position seems rather cumbersome limit to overcome for some game types, or even supporting existing game codebases that rely on this. Grabbing the cursor isn't enough for some control schemes to work correctly.

[eXpl0it3r]

Came across this list, that has a lot of X11 stuff which are broken in Wayland: https://gist.github.com/probonopd/9feb7c20257af5dd915e3a9f2d1f2277

Additionally, there's this repo with some potential workarounds: https://github.com/probonopd/wayland-x11-compat-protocols/