This unearthed an unspeakably large amount of bugs in the wl_output enumerator,
notably the fact that the wl_output user pointer was to temporary memory!
This was "fixed" in e862856, and was then pointed out as a leak in 4183211,
which was undone in d9ba204. The busted fix was correct that the malloc was an
issue, but wrong about _why_; SDL_AddVideoDisplay copies by value and does not
reuse the pointer, so generally you want your VideoDisplay to be on the stack,
but of course the callbacks don't allow that, so a malloc was a workaround. But
we can do better and just host our temporary display inside WaylandOutputData
because that will be persistent while also not leaking.
Wait, wasn't I talking about move events? Right, that: wl_surface_listener does
at least give us the ability to know what monitor we're on, even though we have
no idea where we are on the monitor. All we need to do is check the wl_output
against the display list and then push a move event that both indicates the
correct display while also not being _too_ much of a lie (but enough of a lie
to where our event doesn't get discarded as "undefined" or whatever). The index
check for the video display is what spawned the great nightmare you see before
you; aside from the bugfix this is actually a really basic patch.
There is no guarantee on what order the Wayland interfaces will come in, but the
callbacks were assuming that wl_data_device_manager would could before wl_seat.
This would cause certain desktops to not have any data_device to work with,
meaning certain features like the clipboard would silently no-op.
KWin has supported the shared and formalised zxdg_decoration since
Plasma 5.16 which came out mid 2019.
Whilst it made sense to support them both for a while, it should not be
needed for future SDL releases.
Note that this is purely to make it possible to enter text that requires
composition - for example, before this commit Kanji input didn't work at all.
The big problem this still has is that we need the window position, and this is
still not implemented. Once we have this information we can do the equivalent
of XTranslateCoordinates to put the rectangle where we want it.
This gives us flexibility to add others hints to control keyboard grab behavior
without having to touch all of the backends. It also allows us to possibly
expose keyboard grab separately from mouse grab for applications that want to
manage those independently.
We support both the org.freedesktop.ScreenSaver D-Bus API (same as the X11
backend) and the Wayland idle_inhibit_unstable_v1 protocol.
Some Wayland compositors only support one or the other, so we need both to
for broad compatibility.
Use zwp_keyboard_shortcuts_inhibit_manager_v1 to allow SDL applications
to capture system keyboard shortcuts like Alt+Tab when keyboard grab is
enabled via SDL_HINT_GRAB_KEYBOARD.
The two are only ever called together, and combining them makes it possible
to eliminate redundant symbol loading and redundant attempts to connect
to a display server.
M Stoeckl
To reproduce:
1. Run any SDL-based program with a Wayland compositor, orphaning it so that it doesn't have an immediate parent process. (For example, from a terminal, running `supertux2 & disown`.) The program should use the wayland backend, i.e. by setting environment variable SDL_VIDEODRIVER=wayland.
2. Kill the compositor process.
Results:
- The SDL program will keep running.
Expected results:
- The SDL program should close. (What close should mean here, I'm not sure - is injecting an SDL_Quit the appropriate action when a video driver disconnects?)
Build data:
2019-06-22, hg tip (12901:bf8d9d29cbf1), Linux, can reproduce with sway, weston, and other Wayland oompositors.
This is just in parity with the existing zxdg-shell-unstable-v6 code. Making
the Wayland target robust (and uh, with title bars) is going to take a lot
of work on top of this.
This is meant to be the desktop-enhanced version of wl_shell. Right now we
just match what the existing wl_shell code does, but there are other areas of
functionality available to us now, that we can fill in later.
This uses the "unstable" API, since this is what ships in Ubuntu 17.10 (as
part of Wayland 1.10), but Wayland 1.12 promotes this to stable with extremely
minor changes. We will add support for the stable version when it makes sense
to do so.
