kwin/xwl/xwayland_interface.h
Roman Gilg 548978bfe1 [xwl] Drag and drop between Xwayland and Wayland native clients
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
2019-02-19 13:09:18 +01:00

63 lines
1.6 KiB
C++

/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright 2019 Roman Gilg <subdiff@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#ifndef KWIN_XWL_XWAYLAND_INTERFACE
#define KWIN_XWL_XWAYLAND_INTERFACE
#include <kwinglobals.h>
#include <QObject>
#include <QPoint>
namespace KWin
{
class Toplevel;
namespace Xwl
{
enum class DragEventReply {
// event should be ignored by the filter
Ignore,
// event is filtered out
Take,
// event should be handled as a Wayland native one
Wayland,
};
}
class KWIN_EXPORT XwaylandInterface : public QObject
{
Q_OBJECT
public:
static XwaylandInterface *self();
virtual Xwl::DragEventReply dragMoveFilter(Toplevel *target, QPoint pos) = 0;
protected:
explicit XwaylandInterface(QObject *parent = nullptr);
virtual ~XwaylandInterface();
};
inline XwaylandInterface *xwayland() {
return XwaylandInterface::self();
}
}
#endif