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// Copyright (C) 2025 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include "qvxmousehandler_p.h"
#include <QSocketNotifier>
#include <QStringList>
#include <QPoint>
#include <QGuiApplication>
#include <QScreen>
#include <QLoggingCategory>
#include <qpa/qwindowsysteminterface.h>
#include <qplatformdefs.h>
#include <private/qcore_unix_p.h> // overrides QT_OPEN
#include <errno.h>
#include <evdevLib.h>
QT_BEGIN_NAMESPACE
using namespace Qt::StringLiterals;
Q_LOGGING_CATEGORY(qLcVxMouse, "qt.qpa.input")
std::unique_ptr<QVxMouseHandler> QVxMouseHandler::create(const QString &device, const QString &specification)
{
qCDebug(qLcVxMouse) << "create mouse handler for" << device << specification;
bool compression = true;
int jitterLimit = 0;
int grab = 0;
bool abs = false;
const auto args = QStringView{specification}.split(u':');
for (const auto &arg : args) {
if (arg == "nocompress"_L1)
compression = false;
else if (arg.startsWith("dejitter="_L1))
jitterLimit = arg.mid(9).toInt();
else if (arg.startsWith("grab="_L1))
grab = arg.mid(5).toInt();
}
int fd = qt_safe_open(device.toLocal8Bit().constData(), O_RDONLY | O_NONBLOCK, 0);
if (fd >= 0) {
return std::unique_ptr<QVxMouseHandler>(new QVxMouseHandler(device, fd, compression, jitterLimit));
} else {
qCWarning(qLcVxMouse) << "Cannot open mouse input device" << qPrintable(device) << ":" << strerror(errno);
return nullptr;
}
}
QVxMouseHandler::QVxMouseHandler(const QString &device, int fd, bool compression, int jitterLimit)
: m_device(device), m_fd(fd), m_compression(compression)
{
setObjectName("Evdev Mouse Handler"_L1);
m_jitterLimitSquared = jitterLimit * jitterLimit;
// socket notifier for events on the mouse device
m_notify = new QSocketNotifier(m_fd, QSocketNotifier::Read, this);
connect(m_notify, &QSocketNotifier::activated,
this, &QVxMouseHandler::readMouseData);
}
QVxMouseHandler::~QVxMouseHandler()
{
if (m_fd >= 0)
qt_safe_close(m_fd);
}
void QVxMouseHandler::sendMouseEvent()
{
int x;
int y;
x = m_x - m_prevx;
y = m_y - m_prevy;
if (m_prevInvalid) {
x = y = 0;
m_prevInvalid = false;
}
if (m_eventType == QEvent::MouseMove)
emit handleMouseEvent(x, y, m_buttons, Qt::NoButton, m_eventType);
else
emit handleMouseEvent(x, y, m_buttons, m_button, m_eventType);
m_prevx = m_x;
m_prevy = m_y;
}
void QVxMouseHandler::readMouseData()
{
EV_DEV_EVENT buffer[32];
int n = 0;
bool posChanged = false, btnChanged = false;
bool pendingMouseEvent = false;
forever {
int result = QT_READ(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
if (result == 0) {
qCWarning(qLcVxMouse)<<"evdevmouse: Got EOF from the input device";
return;
} else if (result < 0) {
if (errno != EINTR && errno != EAGAIN) {
qCWarning(qLcVxMouse)<<"evdevmouse: Could not read from input device"<<errno;
// If the device got disconnected, stop reading, otherwise we get flooded
// by the above error over and over again.
if (errno == ENODEV) {
delete m_notify;
m_notify = nullptr;
qt_safe_close(m_fd);
m_fd = -1;
}
return;
}
} else {
n += result;
if (n % sizeof(buffer[0]) == 0)
break;
}
}
n /= sizeof(buffer[0]);
for (int i = 0; i < n; ++i) {
EV_DEV_EVENT *data = &buffer[i];
if (data->type == EV_DEV_REL) {
if (data->code == EV_DEV_PTR_REL_X) {
m_x += data->value;
posChanged = true;
} else if (data->code == EV_DEV_PTR_REL_Y) {
m_y += data->value;
posChanged = true;
}
} else if (data->type == EV_DEV_KEY && data->code >= EV_DEV_PTR_BTN_LEFT) {
Qt::MouseButton button = Qt::NoButton;
// BTN_LEFT == 0x110 in kernel's input.h
// The range of possible mouse buttons ends just before BTN_JOYSTICK, value 0x120.
switch (data->code) {
case 0x110: button = Qt::LeftButton; break; // BTN_LEFT
case 0x111: button = Qt::RightButton; break;
case 0x112: button = Qt::MiddleButton; break;
case 0x113: button = Qt::ExtraButton1; break; // AKA Qt::BackButton
case 0x114: button = Qt::ExtraButton2; break; // AKA Qt::ForwardButton
case 0x115: button = Qt::ExtraButton3; break; // AKA Qt::TaskButton
case 0x116: button = Qt::ExtraButton4; break;
case 0x117: button = Qt::ExtraButton5; break;
case 0x118: button = Qt::ExtraButton6; break;
case 0x119: button = Qt::ExtraButton7; break;
case 0x11a: button = Qt::ExtraButton8; break;
case 0x11b: button = Qt::ExtraButton9; break;
case 0x11c: button = Qt::ExtraButton10; break;
case 0x11d: button = Qt::ExtraButton11; break;
case 0x11e: button = Qt::ExtraButton12; break;
case 0x11f: button = Qt::ExtraButton13; break;
}
m_buttons.setFlag(button, data->value);
m_button = button;
m_eventType = data->value == 0 ? QEvent::MouseButtonRelease : QEvent::MouseButtonPress;
btnChanged = true;
} else if (data->type == EV_DEV_SYN) {
if (btnChanged) {
btnChanged = posChanged = false;
sendMouseEvent();
pendingMouseEvent = false;
} else if (posChanged) {
m_eventType = QEvent::MouseMove;
posChanged = false;
if (m_compression) {
pendingMouseEvent = true;
} else {
sendMouseEvent();
}
}
}
}
if (m_compression && pendingMouseEvent) {
int distanceSquared = (m_x - m_prevx)*(m_x - m_prevx) + (m_y - m_prevy)*(m_y - m_prevy);
if (distanceSquared > m_jitterLimitSquared)
sendMouseEvent();
}
}
QT_END_NAMESPACE
#include "moc_qvxmousehandler_p.cpp"