kwin/plugins/platforms/x11/standalone/xinputintegration.cpp
Martin Gräßlin 66d1a0cc7a Add event filter for key press/release events while KWin grabbed keyboard on root window
Summary:
The modifier-only-shortcuts break as soon as KWin grabs the keyboard
(e.g. alt+tab, present windows, etc.). The investigation shows that in
that case KWin does not get any raw key events any more and thus gets
confused about the state of the hold modifiers. E.g. alt+tab has the
alt key pressed, but we miss the release as the keyboard is grabbed.

This change addresses the problem by installing an additional event
filter for key press and release event which only filters for key events
on the root window. That way we can be sure that it only operates when
KWin grabbed the keyboard on the root window.

Note: the problem only exists when grabbing on the root window. If the
grab is on another window (e.g. moving a window) we still do get all
events.

The problem also seems to not happen if another application grabbed
keys on the root window. E.g. for key combinations grabbed by
kglobalaccel the correct sequence of key press/release as raw events
are reported. Also while the screen is locked the evemts are reported
and kscreenlocker grabs the keyboard on the root window.

Test Plan:
Used Alt+Tab and Present Windows and tried to activate launcher
afterwards.

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D2980
2016-10-10 16:59:06 +02:00

245 lines
8.3 KiB
C++

/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 2016 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 "xinputintegration.h"
#include "main.h"
#include "logging.h"
#include "platform.h"
#include "x11cursor.h"
#include "keyboard_input.h"
#include "x11eventfilter.h"
#include <kwinglobals.h>
#include <X11/extensions/XInput2.h>
#include <X11/extensions/XI2proto.h>
#include <linux/input.h>
namespace KWin
{
class XInputEventFilter : public X11EventFilter
{
public:
XInputEventFilter(int xi_opcode)
: X11EventFilter(XCB_GE_GENERIC, xi_opcode, QVector<int>{XI_RawMotion, XI_RawButtonPress, XI_RawButtonRelease, XI_RawKeyPress, XI_RawKeyRelease})
{}
virtual ~XInputEventFilter() = default;
bool event(xcb_generic_event_t *event) override {
xcb_ge_generic_event_t *ge = reinterpret_cast<xcb_ge_generic_event_t *>(event);
switch (ge->event_type) {
case XI_RawKeyPress:
if (m_xkb) {
m_xkb->updateKey(reinterpret_cast<xXIRawEvent*>(event)->detail - 8, InputRedirection::KeyboardKeyPressed);
}
break;
case XI_RawKeyRelease:
if (m_xkb) {
m_xkb->updateKey(reinterpret_cast<xXIRawEvent*>(event)->detail - 8, InputRedirection::KeyboardKeyReleased);
}
break;
case XI_RawButtonPress:
if (m_xkb) {
auto e = reinterpret_cast<xXIRawEvent*>(event);
switch (e->detail) {
// TODO: this currently ignores left handed settings, for current usage not needed
// if we want to use also for global mouse shortcuts, this needs to reflect state correctly
case XCB_BUTTON_INDEX_1:
kwinApp()->platform()->pointerButtonPressed(BTN_LEFT, e->time);
break;
case XCB_BUTTON_INDEX_2:
kwinApp()->platform()->pointerButtonPressed(BTN_MIDDLE, e->time);
break;
case XCB_BUTTON_INDEX_3:
kwinApp()->platform()->pointerButtonPressed(BTN_RIGHT, e->time);
break;
case XCB_BUTTON_INDEX_4:
case XCB_BUTTON_INDEX_5:
// vertical axis, ignore on press
break;
// TODO: further buttons, horizontal scrolling?
}
}
if (m_x11Cursor) {
m_x11Cursor->schedulePoll();
}
break;
case XI_RawButtonRelease:
if (m_xkb) {
auto e = reinterpret_cast<xXIRawEvent*>(event);
switch (e->detail) {
// TODO: this currently ignores left handed settings, for current usage not needed
// if we want to use also for global mouse shortcuts, this needs to reflect state correctly
case XCB_BUTTON_INDEX_1:
kwinApp()->platform()->pointerButtonReleased(BTN_LEFT, e->time);
break;
case XCB_BUTTON_INDEX_2:
kwinApp()->platform()->pointerButtonReleased(BTN_MIDDLE, e->time);
break;
case XCB_BUTTON_INDEX_3:
kwinApp()->platform()->pointerButtonReleased(BTN_RIGHT, e->time);
break;
case XCB_BUTTON_INDEX_4:
kwinApp()->platform()->pointerAxisVertical(120, e->time);
break;
case XCB_BUTTON_INDEX_5:
kwinApp()->platform()->pointerAxisVertical(-120, e->time);
break;
// TODO: further buttons, horizontal scrolling?
}
}
if (m_x11Cursor) {
m_x11Cursor->schedulePoll();
}
break;
default:
if (m_x11Cursor) {
m_x11Cursor->schedulePoll();
}
break;
}
return false;
}
void setCursor(const QPointer<X11Cursor> &cursor) {
m_x11Cursor = cursor;
}
void setXkb(Xkb *xkb) {
m_xkb = xkb;
}
private:
QPointer<X11Cursor> m_x11Cursor;
// TODO: QPointer
Xkb *m_xkb = nullptr;
};
class XKeyPressReleaseEventFilter : public X11EventFilter
{
public:
XKeyPressReleaseEventFilter(uint32_t type)
: X11EventFilter(type)
{}
~XKeyPressReleaseEventFilter() = default;
bool event(xcb_generic_event_t *event) override {
xcb_key_press_event_t *ke = reinterpret_cast<xcb_key_press_event_t *>(event);
if (m_xkb && ke->event == ke->root) {
const uint8_t eventType = event->response_type & ~0x80;
if (eventType == XCB_KEY_PRESS) {
m_xkb->updateKey(ke->detail - 8, InputRedirection::KeyboardKeyPressed);
} else {
m_xkb->updateKey(ke->detail - 8, InputRedirection::KeyboardKeyReleased);
}
}
return false;
}
void setXkb(Xkb *xkb) {
m_xkb = xkb;
}
private:
// TODO: QPointer
Xkb *m_xkb = nullptr;
};
XInputIntegration::XInputIntegration(QObject *parent)
: QObject(parent)
{
}
XInputIntegration::~XInputIntegration() = default;
void XInputIntegration::init()
{
Display *dpy = display();
int xi_opcode, event, error;
// init XInput extension
if (!XQueryExtension(dpy, "XInputExtension", &xi_opcode, &event, &error)) {
qCDebug(KWIN_X11STANDALONE) << "XInputExtension not present";
return;
}
// verify that the XInput extension is at at least version 2.0
int major = 2, minor = 0;
int result = XIQueryVersion(dpy, &major, &minor);
if (result == BadImplementation) {
// Xinput 2.2 returns BadImplementation if checked against 2.0
major = 2;
minor = 2;
if (XIQueryVersion(dpy, &major, &minor) != Success) {
qCDebug(KWIN_X11STANDALONE) << "Failed to init XInput";
return;
}
} else if (result != Success) {
qCDebug(KWIN_X11STANDALONE) << "Failed to init XInput";
return;
}
m_hasXInput = true;
m_xiOpcode = xi_opcode;
m_majorVersion = major;
m_minorVersion = minor;
qCDebug(KWIN_X11STANDALONE) << "Has XInput support" << m_majorVersion << "." << m_minorVersion;
}
void XInputIntegration::setCursor(X11Cursor *cursor)
{
m_x11Cursor = QPointer<X11Cursor>(cursor);
}
void XInputIntegration::setXkb(Xkb *xkb)
{
m_xkb = xkb;
}
void XInputIntegration::startListening()
{
// this assumes KWin is the only one setting events on the root window
// given Qt's source code this seems to be true. If it breaks, we need to change
XIEventMask evmasks[1];
unsigned char mask1[XIMaskLen(XI_LASTEVENT)];
memset(mask1, 0, sizeof(mask1));
XISetMask(mask1, XI_RawMotion);
XISetMask(mask1, XI_RawButtonPress);
XISetMask(mask1, XI_RawButtonRelease);
if (m_majorVersion >= 2 && m_minorVersion >= 1) {
// we need to listen to all events, which is only available with XInput 2.1
XISetMask(mask1, XI_RawKeyPress);
XISetMask(mask1, XI_RawKeyRelease);
}
evmasks[0].deviceid = XIAllMasterDevices;
evmasks[0].mask_len = sizeof(mask1);
evmasks[0].mask = mask1;
XISelectEvents(display(), rootWindow(), evmasks, 1);
m_xiEventFilter.reset(new XInputEventFilter(m_xiOpcode));
m_xiEventFilter->setCursor(m_x11Cursor);
m_xiEventFilter->setXkb(m_xkb);
m_keyPressFilter.reset(new XKeyPressReleaseEventFilter(XCB_KEY_PRESS));
m_keyPressFilter->setXkb(m_xkb);
m_keyReleaseFilter.reset(new XKeyPressReleaseEventFilter(XCB_KEY_RELEASE));
m_keyReleaseFilter->setXkb(m_xkb);
}
}