Translate pen tablet events to mouse events

[darkwater]

Related discussion: #9878

Pen tablets currently don't work at all with applications that don't support the tablet protocol. Examples include Discord (or at least Vesktop) and any Rust application that uses winit (though tablet support landed there last week).

In the linked discussion someone mentions a window rule to control this, but I think whether the application supports the tablet protocol is a good default. The window rule may still be useful in cases where the application doesn't support tablets properly.

If someone could give me some pointers (how to check if a client supports the tablet protocol, where are tablet and mouse events sent) I'd love to try implementing this myself.

[DarkCreepy59]

From what I've seen, tablets always send wl_pointer.motion events, it doesn't matter if the client supports the tablet protocol or not.

If you don't want to change this (because that would be opening another can of worms), then I think you can probably just focus on emulating a mouse button on tablet tip.
I would probably do it using g_pSeatManager->sendPointerButton() because we don't want to trigger keybinds.

As for knowing if the client supports the tablet protocol, the only thing I see is CTabletV2Protocol::m_managers (there should be one for each client that uses the protocol), but maybe there's a better solution.

[darkwater]

Thanks for the hints. I gave it a shot but it looks like it's above what I can do with C++, so I gave up on it.