A seemingly unrelated change to cursors broke xwayland's clipboard
syncing, presumably because of a change in how startup is ordered with
regards to syncing between our internal wayland connection causing a
crash.
It was fixed with a flush, but ultimately guarding things coming up in
the natural order works better.
Long term plans are to finish removing the internal connection.
See xwayland_selections_test in autotests.
Since WaylandCursorImage no longer flushes the internal connection
connection and dispatches events, the DataBridge must do it to ensure
that the selections are initialized prior to receiving a ProperyNotify
event.
Summary:
Building upon the generic X Selection support this patch establishes another
selection class representing the XDND selection and provides interfaces
to communicate drags originating from Xwayland windows to the Wayland
server KWin and drags originating from Wayland native drags to Xwayland.
For Wayland native drags KWin will claim the XDND selection as owner and
will simply translate all relevant events to the XDND protocol and receive
alike messages by X clients.
When an X client claims the XDND selection KWin is notified via the X protocol
and it decides if it allows the X drag to transcend into the Wayland protocol.
If this is the case the mouse position is tracked and on entering a Wayland
native window a proxy X Window is mapped to the top of the window stack. This
proxy window acts as a drag destination for the drag origin window and again
X messages will be translated into respective Wayland protocol calls. If the
cursor leaves the Wayland window geometry before a drop is registered, the
proxy window is unmapped, what triggers a subsequent drag leave event.
In both directions the necessary core integration is minimal. There is a single
call to be done in the drag and drop event filter through the Xwayland
interface class.
From my tests this patch facilitates drags between any Qt/KDE apps. What needs
extra care are the browsers, which use target formats, that are not directly
compatible with the Wayland protocol's MIME representation. For Chromium an
additional integration step must be done in order to provide it with a net
window stack containing the proxy window.
Test Plan: Manually. Auto tests planned.
Reviewers: #kwin
Subscribers: zzag, kwin, alexde
Tags: #kwin
Maniphest Tasks: T4611
Differential Revision: https://phabricator.kde.org/D15627
Summary:
In this patch an infrastructure is created to represent generic X selections
in a Wayland session and use them for data transfers between Xwayland windows
and Wayland native clients.
The central manager is the DataBridge class, in which Selection objects can be
created. This is hard-coded and such a Selection object persists until the end
of the session, so no arbitrary selections can be created on the fly. For now
the X Clipboard selection is supported, whose corresponding mechanism in the
Wayland protocol is just called Selection.
A Selection object listens for selection owner changes on the X side and for
similar events into the Wayland server interfaces. If a data provider is
available a selection source object is created by the Selection object. In case
data is requested on the other side, a data transfer is initialized by creating
a Transfer object. A Selection keeps track of all transfers and makes sure that
they are destroyed when they are finished or in case they idle because of
misbehaving clients.
The Clipboard class translates the X Clipboard via a proxy window. Selection
changes on the Wayland side are listened to through a new signal on the active
KWayland seat interface.
The previously used X clipboard syncer helper is disabled. The clipboard sync
autotest is changed to the new mechanism.
BUG: 394765
BUG: 395313
Test Plan: Manually and clipboard sync autotest.
Reviewers: #kwin
Subscribers: zzag, graesslin, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D15061
