When a drag and drop occurs from an X11 client to a Wayland native
client, mutter uses an internal X11 window as a peer for the DnD drop
site.
That internal X11 window is moved and resized to match the Wayland
native windows as the drag destination moves.
When moving from one Wayland native window to another Wayland native
window, the same X11 window is used, and as a result no DND enter/leave
events is emitted.
In that case, the drop may occur on the wrong Wayland native window,
because no new XdndEnter/XdndLeave event were emitted.
To avoid that issue, use a pair of X11 windows instead of just one and
alternate between the two when repicking a new drop surface, so that
moving from a Wayland surface to another will always generate the
expected enter/leave events that we rely on.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2136
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2305>
It might not be there when shutting down, so get it from a more managed
place. Note that this isn't strictly needed right now, but eventually,
the MetaWaylandCompositor pointer will be cleared using a g_clear*()
helper, which clears the pointer before freeing the instance, which
wouldn't work here.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1863>
This object is just being detached, with no code unref'ing it. Do
this whenever the XDnD selection goes unowned, usually a good
indication that the drag source no longer is one.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1720>
The split wasn't 100% clean, and some extra private API had to be
added for it (but well, looking at the API, it's already evident
there's a cleanup/streamlining task due). This is meant to be a
refactor with no functional changes, so just go with it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1193
In XDND, we just get a hint on XdndPosition about what's the action
chosen by the user. Make the data source actions the full set on
XdndEnter (as we can't know better), and pass the hint in XdndPosition
as the user chosen action as it should be.
Makes Wayland drop sites aware of the user action as per XDND with X11
drag sources, and still makes modifiers during DnD work.
https://gitlab.gnome.org/GNOME/mutter/issues/974https://gitlab.gnome.org/GNOME/mutter/merge_requests/1005
