kwin/plugins/platforms/x11/standalone/effects_x11.cpp
Vlad Zagorodniy 38e22ce6d1 [platforms/x11] Properly unload effects on X11
Summary:
When Compositor finishes compositing, it destroys EffectsHandlerImpl,
which in its turn tries to unload all effects. But there is a problem...

EffectsHandlerImpl has platform-specific hooks to ungrab keyboard and
also stop mouse interception. Given that any call made to a virtual function
in the destructor of a base class(EffectsHandlerImpl) won't go to a derived
class(EffectsHandlerImplX11), keyboard won't be ungrabbed even if effect
that grabbed it is already gone.

BUG: 399572

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D19178
2019-03-11 09:23:24 +02:00

124 lines
4.4 KiB
C++

/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 2006 Lubos Lunak <l.lunak@kde.org>
Copyright (C) 2010, 2011, 2017 Martin Gräßlin <mgraesslin@kde.org>
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/>.
*********************************************************************/
#include "effects_x11.h"
#include "effects_mouse_interception_x11_filter.h"
#include "cursor.h"
#include "screenedge.h"
#include "screens.h"
#include "utils.h"
#include "workspace.h"
#include <QDesktopWidget>
namespace KWin
{
EffectsHandlerImplX11::EffectsHandlerImplX11(Compositor *compositor, Scene *scene)
: EffectsHandlerImpl(compositor, scene)
{
connect(this, &EffectsHandlerImpl::screenGeometryChanged, this,
[this] (const QSize &size) {
if (m_mouseInterceptionWindow.isValid()) {
m_mouseInterceptionWindow.setGeometry(QRect(0, 0, size.width(), size.height()));
}
}
);
}
EffectsHandlerImplX11::~EffectsHandlerImplX11()
{
// EffectsHandlerImpl tries to unload all effects when it's destroyed.
// The routine that unloads effects makes some calls (indirectly) to
// doUngrabKeyboard and doStopMouseInterception, which are virtual.
// Given that any call to a virtual function in the destructor of a base
// class will never go to a derived class, we have to unload effects
// here. Yeah, this is quite a bit ugly but it's fine; someday, X11
// will be dead (or not?).
unloadAllEffects();
}
bool EffectsHandlerImplX11::doGrabKeyboard()
{
bool ret = grabXKeyboard();
if (!ret)
return false;
// Workaround for Qt 5.9 regression introduced with 2b34aefcf02f09253473b096eb4faffd3e62b5f4
// we no longer get any events for the root window, one needs to call winId() on the desktop window
// TODO: change effects event handling to create the appropriate QKeyEvent without relying on Qt
// as it's done already in the Wayland case.
qApp->desktop()->winId();
return ret;
}
void EffectsHandlerImplX11::doUngrabKeyboard()
{
ungrabXKeyboard();
}
void EffectsHandlerImplX11::doStartMouseInterception(Qt::CursorShape shape)
{
// NOTE: it is intended to not perform an XPointerGrab on X11. See documentation in kwineffects.h
// The mouse grab is implemented by using a full screen input only window
if (!m_mouseInterceptionWindow.isValid()) {
const QSize &s = screens()->size();
const QRect geo(0, 0, s.width(), s.height());
const uint32_t mask = XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK;
const uint32_t values[] = {
true,
XCB_EVENT_MASK_BUTTON_PRESS | XCB_EVENT_MASK_BUTTON_RELEASE | XCB_EVENT_MASK_POINTER_MOTION
};
m_mouseInterceptionWindow.reset(Xcb::createInputWindow(geo, mask, values));
defineCursor(shape);
} else {
defineCursor(shape);
}
m_mouseInterceptionWindow.map();
m_mouseInterceptionWindow.raise();
m_x11MouseInterception = std::make_unique<EffectsMouseInterceptionX11Filter>(m_mouseInterceptionWindow, this);
// Raise electric border windows above the input windows
// so they can still be triggered.
ScreenEdges::self()->ensureOnTop();
}
void EffectsHandlerImplX11::doStopMouseInterception()
{
m_mouseInterceptionWindow.unmap();
m_x11MouseInterception.reset();
Workspace::self()->stackScreenEdgesUnderOverrideRedirect();
}
void EffectsHandlerImplX11::defineCursor(Qt::CursorShape shape)
{
const xcb_cursor_t c = Cursor::x11Cursor(shape);
if (c != XCB_CURSOR_NONE) {
m_mouseInterceptionWindow.defineCursor(c);
}
}
void EffectsHandlerImplX11::doCheckInputWindowStacking()
{
m_mouseInterceptionWindow.raise();
// Raise electric border windows above the input windows
// so they can still be triggered. TODO: Do both at once.
ScreenEdges::self()->ensureOnTop();
}
}