by jchw | 2025-08-08 14:41:25+00:00
Unfortunately the KiCAD messaging has been a bit messy. They list a spectrum of issues, some of which are very vague and also clearly issues with KiCAD (like "Application freezes and crashes: Instability issues specific to the Wayland environment" - unless the compositor is crashing I fail to see why you would assume KiCAD crashing is an issue with Wayland or your compositor.) On the other hand I don't really blame application developers for being frustrated in general, because a lot of us have been waiting a really long time to see Wayland issues get resolved, and the pace was so slow until recently that it basically felt like it would take an eternity for anything to get resolved. These days though, the pace is very fast, to the point where almost anything written about Wayland will be out of date in a couple of months, mostly for good reasons.

> KiCAD needs the ability to move cursor to provide good user experience.

Most applications are implementing pointer warping using pointer-constraints-unstable-v1. This lets you confine the pointer to a region, at which point you can use relative events to get movement, render the cursor yourself and do whatever you want. There is the locked_pointer_v1::set_cursor_position_hint function to allow one to set the location where the cursor should be released at when the constraint is lifted, which should make everything seamless.

And sure, it might actually be that pointer-constraints-unstable-v1 isn't enough for KiCAD's particular UX somehow, maybe they need pointer-warp-v1 or something even more advanced. However, applications generally don't need to set the mouse position to arbitrary locations on-screen at any time... That is a useful capability for something doing automation, but it should really not be needed for general application development.

> KiCAD needs the ability to move and place windows wherever it likes.

KiCAD isn't a window manager, it's a damn EDA tool. I do agree that Wayland needs to provide multi-window applications with better tools to hint to the compositor what to do with window placement and especially to save and restore window positions, but this doesn't translate to "applications need to be able to decide where exactly windows go." There is basically no behavior which literally requires this, and certainly no sane behavior that requires this.

Having every application perform its own sort of logic to decide where windows go is a mess everywhere it exists. It would be cleaner and better for users if we could just figure out what sorts of higher level tools applications need for good UX and try to build around that. In most cases merely being able to position windows relative to each-other is enough. (You can obviously do this in Wayland already to some extent, though I'm sure there are missing tools that are needed.)

On Wayland today, applications can't absolutely control window placement, or even know where they are on screen. There really isn't even a global window coordinate space to even leak to applications. It's a pretty radical departure from almost everything else, so yeah, application developers are obviously not thrilled about having to deal with it. But on the other hand, it's probably the right way to go. Just because ability to control absolute positions is convenient does not mean it is necessarily the right way to go, especially if you can provide higher level tools that encode intent better and let the user decide how your application's intent should be interpreted.

> KiCAD needs to control focus.

Honestly I have no clue what they're complaining about with focus. It's too vague.

If your application is in the foreground, you can grab an activation token and use it, so even with "extreme" focus protection, there should not be any issues with KiCAD being able to focus its own windows.

As for other software being able to focus itself from KiCAD, well, this article describes how you do it. It's pretty straight-forward and it's not obvious how you would misuse it. Pretty sure the same protocol exists in X11 as well.

They're also talking about modals, which might be related to their complaints. The xdg-dialog-v1 protocol (supported in KDE 6.4, GNOME 48, and used by Qt 6.8+) gives applications the ability to mark dialogs as modals. It is a bit crazy that it took as long as it did for this to become supported by everything, but it did cross the finish line. On Ubuntu 25.04, for example, you should get GNOME 48 and Qt 6.8.

> KiCAD needs to prevent OpenGL throttling on inactive windows

OpenGL isn't throttled, it is stalled if the window is entirely occluded. You can now resolve this issue with the fifo-v1 protocol and Mesa 25.0 or newer. For example, Ubuntu 25.04 ships Mesa 25.x and GNOME 48 which has fifo-v1. fifo-v1 is also available in KDE as of 6.4.

This should give applications the frame pacing behavior that they want. It is possible to work around the issue to some degree, it's just annoying.

If KiCAD developers don't want to support Wayland because it's effort they'd rather spend on other shit then fine, XWayland should mostly continue to work as-expected anyways. Best option for now is to force KiCAD to use X11, like Krita does. I'm sure that's not a 100% panacea but it should be good enough especially if KiCAD is so buggy on Wayland that it actively crashes.