1. Qt wayland initializes to receive mouse/case, touch screen and other events
QWaylandNativeInterface : public QPlatformNativeInterface
Inherit the qpa interface class QPlatformNativeInterface in QWaylandNativeInterface;
1.1 Initialize the mouse:
void *QWaylandNativeInterface::nativeResourceForIntegration(const QByteArray &resourceString)
{
QByteArray lowerCaseResource = resourceString.toLower();
if (lowerCaseResource == "display" || lowerCaseResource == "wl_display" || lowerCaseResource == "nativedisplay")
return m_integration->display()->wl_display();
if (lowerCaseResource == "compositor")
return const_cast<wl_compositor *>(m_integration->display()->wl_compositor());
if (lowerCaseResource == "server_buffer_integration")
return m_integration->serverBufferIntegration();
if (lowerCaseResource == "egldisplay" && m_integration->clientBufferIntegration())
return m_integration->clientBufferIntegration()->nativeResource(QWaylandClientBufferIntegration::EglDisplay);
if (lowerCaseResource == "wl_seat")
return m_integration->display()->defaultInputDevice()->wl_seat();
if (lowerCaseResource == "wl_keyboard") {
auto *keyboard = m_integration->display()->defaultInputDevice()->keyboard();
if (keyboard)
return keyboard->wl_keyboard();
return nullptr;
}
if (lowerCaseResource == "wl_pointer") {
auto *pointer = m_integration->display()->defaultInputDevice()->pointer();
if (pointer)
return pointer->wl_pointer();
return nullptr;
}
if (lowerCaseResource == "wl_touch") {
auto *touch = m_integration->display()->defaultInputDevice()->touch();
if (touch)
return touch->wl_touch();
return nullptr;
}
return nullptr;
}QWaylandInputDevice::Point mainly implements the QtWayland::wl_pointer class function
class Q_WAYLAND_CLIENT_WAYLAND_EXPORT wl_pointer
{
protected:
virtual void pointer_enter(uint32_t serial, struct ::wl_surface *surface, wl_fixed_t surface_x, wl_fixed_t surface_y);
virtual void pointer_leave(uint32_t serial, struct ::wl_surface *surface);
virtual void pointer_motion(uint32_t time, wl_fixed_t surface_x, wl_fixed_t surface_y);
virtual void pointer_button(uint32_t serial, uint32_t time, uint32_t button, uint32_t state);
virtual void pointer_axis(uint32_t time, uint32_t axis, wl_fixed_t value);
virtual void pointer_frame();
virtual void pointer_axis_source(uint32_t axis_source);
virtual void pointer_axis_stop(uint32_t time, uint32_t axis);
virtual void pointer_axis_discrete(uint32_t axis, int32_t discrete);
private:
void init_listener();
static const struct wl_pointer_listener m_wl_pointer_listener;
static void handle_enter(
void *data,
struct ::wl_pointer *object,
uint32_t serial,
struct ::wl_surface *surface,
wl_fixed_t surface_x,
wl_fixed_t surface_y);
static void handle_leave(
void *data,
struct ::wl_pointer *object,
uint32_t serial,
struct ::wl_surface *surface);
static void handle_motion(
void *data,
struct ::wl_pointer *object,
uint32_t time,
wl_fixed_t surface_x,
wl_fixed_t surface_y);
static void handle_button(
void *data,
struct ::wl_pointer *object,
uint32_t serial,
uint32_t time,
uint32_t button,
uint32_t state);
static void handle_axis(
void *data,
struct ::wl_pointer *object,
uint32_t time,
uint32_t axis,
wl_fixed_t value);
static void handle_frame(
void *data,
struct ::wl_pointer *object);
static void handle_axis_source(
void *data,
struct ::wl_pointer *object,
uint32_t axis_source);
static void handle_axis_stop(
void *data,
struct ::wl_pointer *object,
uint32_t time,
uint32_t axis);
static void handle_axis_discrete(
void *data,
struct ::wl_pointer *object,
uint32_t axis,
int32_t discrete);
struct ::wl_pointer *m_wl_pointer;
};2. The wl_pointer class registers with weston to monitor mouse events
const struct wl_pointer_listener wl_pointer::m_wl_pointer_listener = {
wl_pointer::handle_enter,
wl_pointer::handle_leave,
wl_pointer::handle_motion,
wl_pointer::handle_button,
wl_pointer::handle_axis,
wl_pointer::handle_frame,
wl_pointer::handle_axis_source,
wl_pointer::handle_axis_stop,
wl_pointer::handle_axis_discrete,
};
void wl_pointer::init_listener()
{
wl_pointer_add_listener(m_wl_pointer, &m_wl_pointer_listener, this);
}
The weston service calls the m_wl_pointer_listener function set when it receives the mouse event.
3. Event generation process: analyze the hand_enter mouse entry event as an example:
void wl_pointer::handle_enter(
void *data,
struct ::wl_pointer *object,
uint32_t serial,
struct ::wl_surface *surface,
wl_fixed_t surface_x,
wl_fixed_t surface_y)
{
Q_UNUSED(object);
static_cast<wl_pointer *>(data)->pointer_enter(
serial,
surface,
surface_x,
surface_y);
}
hand_enter handles calling the virtual function pointer_enter. The pointer_enter function is implemented in QWaylandInputDevice::Pointe.
void QWaylandInputDevice::Pointer::pointer_enter(uint32_t serial, struct wl_surface *surface,
wl_fixed_t sx, wl_fixed_t sy)
{
if (!surface)
return;
QWaylandWindow *window = QWaylandWindow::fromWlSurface(surface);
if (!window)
return; // Ignore foreign surfaces
if (mFocus) {
qCWarning(lcQpaWayland) << "The compositor sent a wl_pointer.enter event before sending a"
<< "leave event first, this is not allowed by the wayland protocol"
<< "attempting to work around it by invalidating the current focus";
invalidateFocus();
}
mFocus = window->waylandSurface();
connect(mFocus.data(), &QObject::destroyed, this, &Pointer::handleFocusDestroyed);
mSurfacePos = QPointF(wl_fixed_to_double(sx), wl_fixed_to_double(sy));
mGlobalPos = window->window()->mapToGlobal(mSurfacePos.toPoint());
mParent->mSerial = serial;
mEnterSerial = serial;
#if QT_CONFIG(cursor)
// Depends on mEnterSerial being updated
updateCursor();
#endif
printf("%s %d \n",__FUNCTION__,__LINE__);
QWaylandWindow *grab = QWaylandWindow::mouseGrab();
if (!grab)
setFrameEvent(new EnterEvent(window, mSurfacePos, mGlobalPos));
}setFrameEvent Sends the EnterEvent event.
void QWaylandInputDevice::Pointer::setFrameEvent(QWaylandPointerEvent *event)
{
qCDebug(lcQpaWaylandInput) << "Setting frame event " << event->type;
if (mFrameData.event && mFrameData.event->type != event->type) {
qCDebug(lcQpaWaylandInput) << "Flushing; previous was " << mFrameData.event->type;
flushFrameEvent();
}
mFrameData.event = event;
if (mParent->mVersion < WL_POINTER_FRAME_SINCE_VERSION) {
qCDebug(lcQpaWaylandInput) << "Flushing new event; no frame event in this version";
flushFrameEvent();
}
}
void QWaylandInputDevice::Pointer::flushFrameEvent()
{
if (auto *event = mFrameData.event) {
if (auto window = event->surface) {
window->handleMouse(mParent, *event);
} else if (mFrameData.event->type == QWaylandPointerEvent::Type::Release) {
// If the window has been destroyed, we still need to report an up event, but it can't
// be handled by the destroyed window (obviously), so send the event here instead.
QWindowSystemInterface::handleMouseEvent(nullptr, event->timestamp, event->local,
event->global, event->buttons, event->modifiers);
}
delete mFrameData.event;
mFrameData.event = nullptr;
}
//TODO: do modifiers get passed correctly here?
flushScrollEvent();
}
void QWaylandInputDevice::Pointer::flushFrameEvent()
{
if (auto *event = mFrameData.event) {
if (auto window = event->surface) {
window->handleMouse(mParent, *event);
} else if (mFrameData.event->type == QWaylandPointerEvent::Type::Release) {
// If the window has been destroyed, we still need to report an up event, but it can't
// be handled by the destroyed window (obviously), so send the event here instead.
QWindowSystemInterface::handleMouseEvent(nullptr, event->timestamp, event->local,
event->global, event->buttons, event->modifiers);
}
delete mFrameData.event;
mFrameData.event = nullptr;
}
//TODO: do modifiers get passed correctly here?
flushScrollEvent();
}
window->handleMouse
void QWaylandWindow::handleMouse(QWaylandInputDevice *inputDevice, const QWaylandPointerEvent &e)
{
if (e.type == QWaylandPointerEvent::Leave) {
if (mWindowDecoration) {
if (mMouseEventsInContentArea)
QWindowSystemInterface::handleLeaveEvent(window());
} else {
QWindowSystemInterface::handleLeaveEvent(window());
}
#if QT_CONFIG(cursor)
restoreMouseCursor(inputDevice);
#endif
return;
}
if (mWindowDecoration) {
handleMouseEventWithDecoration(inputDevice, e);
} else {
switch (e.type) {
case QWaylandPointerEvent::Enter:
QWindowSystemInterface::handleEnterEvent(window(), e.local, e.global);
break;
case QWaylandPointerEvent::Press:
case QWaylandPointerEvent::Release:
case QWaylandPointerEvent::Motion:
QWindowSystemInterface::handleMouseEvent(window(), e.timestamp, e.local, e.global, e.buttons, e.modifiers);
break;
case QWaylandPointerEvent::Wheel:
QWindowSystemInterface::handleWheelEvent(window(), e.timestamp, e.local, e.global,
e.pixelDelta, e.angleDelta, e.modifiers,
e.phase, e.source, false);
break;
}
}
#if QT_CONFIG(cursor)
if (e.type == QWaylandPointerEvent::Enter) {
QRect contentGeometry = windowContentGeometry().marginsRemoved(frameMargins());
if (contentGeometry.contains(e.local.toPoint()))
restoreMouseCursor(inputDevice);
}
#endif
}
Call QWindowSystemInterface::handleMouseEvent(window(). The handleMouseEvent function is implemented in the qtbase code.
QT_DEFINE_QPA_EVENT_HANDLER(void, handleMouseEvent, QWindow *window,
const QPointF &local, const QPointF &global, Qt::MouseButtons state,
Qt::MouseButton button, QEvent::Type type, Qt::KeyboardModifiers mods,
Qt::MouseEventSource source)
{
unsigned long time = QWindowSystemInterfacePrivate::eventTime.elapsed();
handleMouseEvent<Delivery>(window, time, local, global, state, button, type, mods, source);
}
QT_DEFINE_QPA_EVENT_HANDLER(void, handleMouseEvent, QWindow *window, ulong timestamp,
const QPointF &local, const QPointF &global, Qt::MouseButtons state,
Qt::MouseButton button, QEvent::Type type, Qt::KeyboardModifiers mods,
Qt::MouseEventSource source)
{
Q_ASSERT_X(type != QEvent::MouseButtonDblClick && type != QEvent::NonClientAreaMouseButtonDblClick,
"QWindowSystemInterface::handleMouseEvent",
"QTBUG-71263: Native double clicks are not implemented.");
auto localPos = QHighDpi::fromNativeLocalPosition(local, window);
auto globalPos = QHighDpi::fromNativePixels(global, window);
QWindowSystemInterfacePrivate::MouseEvent *e =
new QWindowSystemInterfacePrivate::MouseEvent(window, timestamp, localPos, globalPos,
state, mods, button, type, source);
QWindowSystemInterfacePrivate::handleWindowSystemEvent<Delivery>(e);
}
handleMouseEvent calls the handleWindowSystemEvent function.
template<>
bool QWindowSystemInterfacePrivate::handleWindowSystemEvent<QWindowSystemInterface::DefaultDelivery>(QWindowSystemInterfacePrivate::WindowSystemEvent *ev)
{
if (synchronousWindowSystemEvents)
return handleWindowSystemEvent<QWindowSystemInterface::SynchronousDelivery>(ev);
else
return handleWindowSystemEvent<QWindowSystemInterface::AsynchronousDelivery>(ev);
}
handleWindowSystemEvent synchronous processing and asynchronous processing
template<>
bool QWindowSystemInterfacePrivate::handleWindowSystemEvent<QWindowSystemInterface::AsynchronousDelivery>(WindowSystemEvent *ev)
{
windowSystemEventQueue.append(ev);
if (QAbstractEventDispatcher *dispatcher = QGuiApplicationPrivate::qt_qpa_core_dispatcher())
dispatcher->wakeUp();
return true;
}
异步处理实现：将事件加入到windowSystemEventQueue 队列处理。
Synchronous processing:
template<>
bool QWindowSystemInterfacePrivate::handleWindowSystemEvent<QWindowSystemInterface::SynchronousDelivery>(WindowSystemEvent *ev)
{
bool accepted = true;
if (QThread::currentThread() == QGuiApplication::instance()->thread()) {
// Process the event immediately on the current thread and return the accepted state.
QGuiApplicationPrivate::processWindowSystemEvent(ev);
accepted = ev->eventAccepted;
delete ev;
} else {
// Post the event on the Qt main thread queue and flush the queue.
// This will wake up the Gui thread which will process the event.
// Return the accepted state for the last event on the queue,
// which is the event posted by this function.
handleWindowSystemEvent<QWindowSystemInterface::AsynchronousDelivery>(ev);
accepted = QWindowSystemInterface::flushWindowSystemEvents();
}
return accepted;
}
/*!
Make Qt Gui process all events on the event queue immediately. Return the
accepted state for the last event on the queue.
*/
bool QWindowSystemInterface::flushWindowSystemEvents(QEventLoop::ProcessEventsFlags flags)
{
const int count = QWindowSystemInterfacePrivate::windowSystemEventQueue.count();
if (!count)
return false;
if (!QGuiApplication::instance()) {
qWarning().nospace()
<< "QWindowSystemInterface::flushWindowSystemEvents() invoked after "
"QGuiApplication destruction, discarding " << count << " events.";
QWindowSystemInterfacePrivate::windowSystemEventQueue.clear();
return false;
}
if (QThread::currentThread() != QGuiApplication::instance()->thread()) {
// Post a FlushEvents event which will trigger a call back to
// deferredFlushWindowSystemEvents from the Gui thread.
QMutexLocker locker(&QWindowSystemInterfacePrivate::flushEventMutex);
QWindowSystemInterfacePrivate::FlushEventsEvent *e = new QWindowSystemInterfacePrivate::FlushEventsEvent(flags);
QWindowSystemInterfacePrivate::handleWindowSystemEvent<AsynchronousDelivery>(e);
QWindowSystemInterfacePrivate::eventsFlushed.wait(&QWindowSystemInterfacePrivate::flushEventMutex);
} else {
sendWindowSystemEvents(flags);
}
return QWindowSystemInterfacePrivate::eventAccepted.loadRelaxed() > 0;
}
ool QWindowSystemInterface::sendWindowSystemEvents(QEventLoop::ProcessEventsFlags flags)
{
int nevents = 0;
while (QWindowSystemInterfacePrivate::windowSystemEventsQueued()) {
QWindowSystemInterfacePrivate::WindowSystemEvent *event = nullptr;
if (QWindowSystemInterfacePrivate::platformFiltersEvents) {
event = QWindowSystemInterfacePrivate::getWindowSystemEvent();
} else {
event = flags & QEventLoop::ExcludeUserInputEvents ?
QWindowSystemInterfacePrivate::getNonUserInputWindowSystemEvent() :
QWindowSystemInterfacePrivate::getWindowSystemEvent();
}
if (!event)
break;
if (QWindowSystemInterfacePrivate::eventHandler) {
if (QWindowSystemInterfacePrivate::eventHandler->sendEvent(event))
nevents++;
} else {
nevents++;
QGuiApplicationPrivate::processWindowSystemEvent(event);
}
// Record the accepted state for the processed event
// (excluding flush events). This state can then be
// returned by flushWindowSystemEvents().
if (event->type != QWindowSystemInterfacePrivate::FlushEvents)
QWindowSystemInterfacePrivate::eventAccepted.storeRelaxed(event->eventAccepted);
delete event;
}
return (nevents > 0);
}
void QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent *e)
{
Q_TRACE_SCOPE(QGuiApplicationPrivate_processWindowSystemEvent, e->type);
switch(e->type) {
case QWindowSystemInterfacePrivate::Mouse:
QGuiApplicationPrivate::processMouseEvent(static_cast<QWindowSystemInterfacePrivate::MouseEvent *>(e));
break;
case QWindowSystemInterfacePrivate::Wheel:
QGuiApplicationPrivate::processWheelEvent(static_cast<QWindowSystemInterfacePrivate::WheelEvent *>(e));
break;
case QWindowSystemInterfacePrivate::Key:
QGuiApplicationPrivate::processKeyEvent(static_cast<QWindowSystemInterfacePrivate::KeyEvent *>(e));
break;
case QWindowSystemInterfacePrivate::Touch:
QGuiApplicationPrivate::processTouchEvent(static_cast<QWindowSystemInterfacePrivate::TouchEvent *>(e));
break;
case QWindowSystemInterfacePrivate::GeometryChange:
QGuiApplicationPrivate::processGeometryChangeEvent(static_cast<QWindowSystemInterfacePrivate::GeometryChangeEvent*>(e));
break;
case QWindowSystemInterfacePrivate::Enter:
QGuiApplicationPrivate::processEnterEvent(static_cast<QWindowSystemInterfacePrivate::EnterEvent *>(e));
break;
case QWindowSystemInterfacePrivate::Leave:
QGuiApplicationPrivate::processLeaveEvent(static_cast<QWindowSystemInterfacePrivate::LeaveEvent *>(e));
break;
case QWindowSystemInterfacePrivate::ActivatedWindow:
QGuiApplicationPrivate::processActivatedEvent(static_cast<QWindowSystemInterfacePrivate::ActivatedWindowEvent *>(e));
break;
case QWindowSystemInterfacePrivate::WindowStateChanged:
QGuiApplicationPrivate::processWindowStateChangedEvent(static_cast<QWindowSystemInterfacePrivate::WindowStateChangedEvent *>(e));
break;
case QWindowSystemInterfacePrivate::WindowScreenChanged:
QGuiApplicationPrivate::processWindowScreenChangedEvent(static_cast<QWindowSystemInterfacePrivate::WindowScreenChangedEvent *>(e));
break;
case QWindowSystemInterfacePrivate::SafeAreaMarginsChanged:
QGuiApplicationPrivate::processSafeAreaMarginsChangedEvent(static_cast<QWindowSystemInterfacePrivate::SafeAreaMarginsChangedEvent *>(e));
break;
case QWindowSystemInterfacePrivate::ApplicationStateChanged: {
QWindowSystemInterfacePrivate::ApplicationStateChangedEvent * changeEvent = static_cast<QWindowSystemInterfacePrivate::ApplicationStateChangedEvent *>(e);
QGuiApplicationPrivate::setApplicationState(changeEvent->newState, changeEvent->forcePropagate); }
break;
case QWindowSystemInterfacePrivate::ApplicationTermination:
QGuiApplicationPrivate::processApplicationTermination(e);
break;
case QWindowSystemInterfacePrivate::FlushEvents: {
QWindowSystemInterfacePrivate::FlushEventsEvent *flushEventsEvent = static_cast<QWindowSystemInterfacePrivate::FlushEventsEvent *>(e);
QWindowSystemInterface::deferredFlushWindowSystemEvents(flushEventsEvent->flags); }
break;
case QWindowSystemInterfacePrivate::Close:
QGuiApplicationPrivate::processCloseEvent(
static_cast<QWindowSystemInterfacePrivate::CloseEvent *>(e));
break;
case QWindowSystemInterfacePrivate::ScreenOrientation:
QGuiApplicationPrivate::processScreenOrientationChange(
static_cast<QWindowSystemInterfacePrivate::ScreenOrientationEvent *>(e));
break;
case QWindowSystemInterfacePrivate::ScreenGeometry:
QGuiApplicationPrivate::processScreenGeometryChange(
static_cast<QWindowSystemInterfacePrivate::ScreenGeometryEvent *>(e));
break;
case QWindowSystemInterfacePrivate::ScreenLogicalDotsPerInch:
QGuiApplicationPrivate::processScreenLogicalDotsPerInchChange(
static_cast<QWindowSystemInterfacePrivate::ScreenLogicalDotsPerInchEvent *>(e));
break;
case QWindowSystemInterfacePrivate::ScreenRefreshRate:
QGuiApplicationPrivate::processScreenRefreshRateChange(
static_cast<QWindowSystemInterfacePrivate::ScreenRefreshRateEvent *>(e));
break;
case QWindowSystemInterfacePrivate::ThemeChange:
QGuiApplicationPrivate::processThemeChanged(
static_cast<QWindowSystemInterfacePrivate::ThemeChangeEvent *>(e));
break;
case QWindowSystemInterfacePrivate::Expose:
QGuiApplicationPrivate::processExposeEvent(static_cast<QWindowSystemInterfacePrivate::ExposeEvent *>(e));
break;
case QWindowSystemInterfacePrivate::Tablet:
QGuiApplicationPrivate::processTabletEvent(
static_cast<QWindowSystemInterfacePrivate::TabletEvent *>(e));
break;
case QWindowSystemInterfacePrivate::TabletEnterProximity:
QGuiApplicationPrivate::processTabletEnterProximityEvent(
static_cast<QWindowSystemInterfacePrivate::TabletEnterProximityEvent *>(e));
break;
case QWindowSystemInterfacePrivate::TabletLeaveProximity:
QGuiApplicationPrivate::processTabletLeaveProximityEvent(
static_cast<QWindowSystemInterfacePrivate::TabletLeaveProximityEvent *>(e));
break;
#ifndef QT_NO_GESTURES
case QWindowSystemInterfacePrivate::Gesture:
QGuiApplicationPrivate::processGestureEvent(
static_cast<QWindowSystemInterfacePrivate::GestureEvent *>(e));
break;
#endif
case QWindowSystemInterfacePrivate::PlatformPanel:
QGuiApplicationPrivate::processPlatformPanelEvent(
static_cast<QWindowSystemInterfacePrivate::PlatformPanelEvent *>(e));
break;
case QWindowSystemInterfacePrivate::FileOpen:
QGuiApplicationPrivate::processFileOpenEvent(
static_cast<QWindowSystemInterfacePrivate::FileOpenEvent *>(e));
break;
#ifndef QT_NO_CONTEXTMENU
case QWindowSystemInterfacePrivate::ContextMenu:
QGuiApplicationPrivate::processContextMenuEvent(
static_cast<QWindowSystemInterfacePrivate::ContextMenuEvent *>(e));
break;
#endif
case QWindowSystemInterfacePrivate::EnterWhatsThisMode:
QGuiApplication::postEvent(QGuiApplication::instance(), new QEvent(QEvent::EnterWhatsThisMode));
break;
default:
qWarning() << "Unknown user input event type:" << e->type;
break;
}
}
void QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent *e)
{
QEvent::Type type = QEvent::None;
Qt::MouseButton button = Qt::NoButton;
QWindow *window = e->window.data();
bool positionChanged = QGuiApplicationPrivate::lastCursorPosition != e->globalPos;
bool mouseMove = false;
bool mousePress = false;
if (e->enhancedMouseEvent()) {
type = e->buttonType;
button = e->button;
if (type == QEvent::NonClientAreaMouseMove || type == QEvent::MouseMove)
mouseMove = true;
else if (type == QEvent::NonClientAreaMouseButtonPress || type == QEvent::MouseButtonPress)
mousePress = true;
if (!mouseMove && positionChanged) {
QWindowSystemInterfacePrivate::MouseEvent moveEvent(window, e->timestamp,
e->localPos, e->globalPos, e->buttons ^ button, e->modifiers, Qt::NoButton,
e->nonClientArea ? QEvent::NonClientAreaMouseMove : QEvent::MouseMove,
e->source, e->nonClientArea);
if (e->synthetic())
moveEvent.flags |= QWindowSystemInterfacePrivate::WindowSystemEvent::Synthetic;
processMouseEvent(&moveEvent); // mouse move excluding state change
processMouseEvent(e); // the original mouse event
return;
}
} else {
Qt::MouseButtons stateChange = e->buttons ^ mouse_buttons;
if (positionChanged && (stateChange != Qt::NoButton)) {
QWindowSystemInterfacePrivate::MouseEvent moveEvent(window, e->timestamp, e->localPos,
e->globalPos, mouse_buttons, e->modifiers, Qt::NoButton, QEvent::None, e->source,
e->nonClientArea);
if (e->synthetic())
moveEvent.flags |= QWindowSystemInterfacePrivate::WindowSystemEvent::Synthetic;
processMouseEvent(&moveEvent); // mouse move excluding state change
processMouseEvent(e); // the original mouse event
return;
}
// In the compatibility path we deduce event type and button that caused the event
if (positionChanged) {
mouseMove = true;
type = e->nonClientArea ? QEvent::NonClientAreaMouseMove : QEvent::MouseMove;
} else {
// Check to see if a new button has been pressed/released.
for (uint mask = Qt::LeftButton; mask <= Qt::MaxMouseButton; mask <<= 1) {
if (stateChange & mask) {
button = Qt::MouseButton(mask);
break;
}
}
if (button == Qt::NoButton) {
// Ignore mouse events that don't change the current state. This shouldn't
// really happen, getting here can only mean that the stored button state
// is out of sync with the actual physical button state.
return;
}
if (button & e->buttons) {
mousePress = true;
type = e->nonClientArea ? QEvent::NonClientAreaMouseButtonPress
: QEvent::MouseButtonPress;
} else {
type = e->nonClientArea ? QEvent::NonClientAreaMouseButtonRelease
: QEvent::MouseButtonRelease;
}
}
}
modifier_buttons = e->modifiers;
QPointF localPoint = e->localPos;
QPointF globalPoint = e->globalPos;
bool doubleClick = false;
if (mouseMove) {
QGuiApplicationPrivate::lastCursorPosition = globalPoint;
const auto doubleClickDistance = e->source == Qt::MouseEventNotSynthesized ?
mouseDoubleClickDistance : touchDoubleTapDistance;
if (qAbs(globalPoint.x() - mousePressX) > doubleClickDistance ||
qAbs(globalPoint.y() - mousePressY) > doubleClickDistance)
mousePressButton = Qt::NoButton;
} else {
mouse_buttons = e->buttons;
if (mousePress) {
ulong doubleClickInterval = static_cast<ulong>(QGuiApplication::styleHints()->mouseDoubleClickInterval());
doubleClick = e->timestamp - mousePressTime < doubleClickInterval && button == mousePressButton;
mousePressTime = e->timestamp;
mousePressButton = button;
const QPoint point = QGuiApplicationPrivate::lastCursorPosition.toPoint();
mousePressX = point.x();
mousePressY = point.y();
}
}
if (e->nullWindow()) {
window = QGuiApplication::topLevelAt(globalPoint.toPoint());
if (window) {
// Moves and the release following a press must go to the same
// window, even if the cursor has moved on over another window.
if (e->buttons != Qt::NoButton) {
if (!currentMousePressWindow)
currentMousePressWindow = window;
else
window = currentMousePressWindow;
} else if (currentMousePressWindow) {
window = currentMousePressWindow;
currentMousePressWindow = 0;
}
QPointF delta = globalPoint - globalPoint.toPoint();
localPoint = window->mapFromGlobal(globalPoint.toPoint()) + delta;
}
}
if (!window)
return;
#ifndef QT_NO_CURSOR
if (!e->synthetic()) {
if (const QScreen *screen = window->screen())
if (QPlatformCursor *cursor = screen->handle()->cursor()) {
const QPointF nativeLocalPoint = QHighDpi::toNativePixels(localPoint, screen);
const QPointF nativeGlobalPoint = QHighDpi::toNativePixels(globalPoint, screen);
QMouseEvent ev(type, nativeLocalPoint, nativeLocalPoint, nativeGlobalPoint,
button, e->buttons, e->modifiers, e->source);
ev.setTimestamp(e->timestamp);
cursor->pointerEvent(ev);
}
}
#endif
QMouseEvent ev(type, localPoint, localPoint, globalPoint, button, e->buttons, e->modifiers, e->source);
ev.setTimestamp(e->timestamp);
if (window->d_func()->blockedByModalWindow && !qApp->d_func()->popupActive()) {
// a modal window is blocking this window, don't allow mouse events through
return;
}
if (doubleClick && (ev.type() == QEvent::MouseButtonPress)) {
// QtBUG-25831, used to suppress delivery in qwidgetwindow.cpp
setMouseEventFlags(&ev, ev.flags() | Qt::MouseEventCreatedDoubleClick);
}
QGuiApplication::sendSpontaneousEvent(window, &ev);
e->eventAccepted = ev.isAccepted();
if (!e->synthetic() && !ev.isAccepted()
&& !e->nonClientArea
&& qApp->testAttribute(Qt::AA_SynthesizeTouchForUnhandledMouseEvents)) {
if (!m_fakeTouchDevice) {
m_fakeTouchDevice = new QTouchDevice;
QWindowSystemInterface::registerTouchDevice(m_fakeTouchDevice);
}
QList<QWindowSystemInterface::TouchPoint> points;
QWindowSystemInterface::TouchPoint point;
point.id = 1;
point.area = QRectF(globalPoint.x() - 2, globalPoint.y() - 2, 4, 4);
// only translate left button related events to
// avoid strange touch event sequences when several
// buttons are pressed
if (type == QEvent::MouseButtonPress && button == Qt::LeftButton) {
point.state = Qt::TouchPointPressed;
} else if (type == QEvent::MouseButtonRelease && button == Qt::LeftButton) {
point.state = Qt::TouchPointReleased;
} else if (type == QEvent::MouseMove && (e->buttons & Qt::LeftButton)) {
point.state = Qt::TouchPointMoved;
} else {
return;
}
points << point;
QEvent::Type type;
QList<QTouchEvent::TouchPoint> touchPoints =
QWindowSystemInterfacePrivate::fromNativeTouchPoints(points, window, QTouchDevicePrivate::get(m_fakeTouchDevice)->id, &type);
QWindowSystemInterfacePrivate::TouchEvent fake(window, e->timestamp, type, m_fakeTouchDevice, touchPoints, e->modifiers);
fake.flags |= QWindowSystemInterfacePrivate::WindowSystemEvent::Synthetic;
processTouchEvent(&fake);
}
if (doubleClick) {
mousePressButton = Qt::NoButton;
if (!e->window.isNull() || e->nullWindow()) { // QTBUG-36364, check if window closed in response to press
const QEvent::Type doubleClickType = e->nonClientArea ? QEvent::NonClientAreaMouseButtonDblClick : QEvent::MouseButtonDblClick;
QMouseEvent dblClickEvent(doubleClickType, localPoint, localPoint, globalPoint,
button, e->buttons, e->modifiers, e->source);
dblClickEvent.setTimestamp(e->timestamp);
QGuiApplication::sendSpontaneousEvent(window, &dblClickEvent);
}
}
}
/*!
\internal
*/
bool QCoreApplication::sendSpontaneousEvent(QObject *receiver, QEvent *event)
{
Q_TRACE(QCoreApplication_sendSpontaneousEvent, receiver, event, event->type());
if (event)
event->spont = true;
return notifyInternal2(receiver, event);
}
/*!
\internal
*/
bool QCoreApplication::sendSpontaneousEvent(QObject *receiver, QEvent *event)
{
Q_TRACE(QCoreApplication_sendSpontaneousEvent, receiver, event, event->type());
if (event)
event->spont = true;
return notifyInternal2(receiver, event);
}
/*!
\internal
\since 5.6
This function is here to make it possible for Qt extensions to
hook into event notification without subclassing QApplication.
*/
bool QCoreApplication::notifyInternal2(QObject *receiver, QEvent *event)
{
bool selfRequired = QCoreApplicationPrivate::threadRequiresCoreApplication();
if (!self && selfRequired)
return false;
// Make it possible for Qt Script to hook into events even
// though QApplication is subclassed...
bool result = false;
void *cbdata[] = { receiver, event, &result };
if (QInternal::activateCallbacks(QInternal::EventNotifyCallback, cbdata)) {
return result;
}
// Qt enforces the rule that events can only be sent to objects in
// the current thread, so receiver->d_func()->threadData is
// equivalent to QThreadData::current(), just without the function
// call overhead.
QObjectPrivate *d = receiver->d_func();
QThreadData *threadData = d->threadData;
QScopedScopeLevelCounter scopeLevelCounter(threadData);
if (!selfRequired)
return doNotify(receiver, event);
return self->notify(receiver, event);
}
bool QCoreApplication::notify(QObject *receiver, QEvent *event)
{
// no events are delivered after ~QCoreApplication() has started
if (QCoreApplicationPrivate::is_app_closing)
return true;
return doNotify(receiver, event);
}
static bool doNotify(QObject *receiver, QEvent *event)
{
if (receiver == 0) { // serious error
qWarning("QCoreApplication::notify: Unexpected null receiver");
return true;
}
#ifndef QT_NO_DEBUG
QCoreApplicationPrivate::checkReceiverThread(receiver);
#endif
return receiver->isWidgetType() ? false : QCoreApplicationPrivate::notify_helper(receiver, event);
}
Helper function called by QCoreApplicationPrivate::notify() and qapplication.cpp
*/
bool QCoreApplicationPrivate::notify_helper(QObject *receiver, QEvent * event)
{
// Note: when adjusting the tracepoints in here
// consider adjusting QApplicationPrivate::notify_helper too.
Q_TRACE(QCoreApplication_notify_entry, receiver, event, event->type());
bool consumed = false;
bool filtered = false;
Q_TRACE_EXIT(QCoreApplication_notify_exit, consumed, filtered);
// send to all application event filters (only does anything in the main thread)
if (QCoreApplication::self
&& receiver->d_func()->threadData->thread.loadAcquire() == mainThread()
&& QCoreApplication::self->d_func()->sendThroughApplicationEventFilters(receiver, event)) {
filtered = true;
return filtered;
}
// send to all receiver event filters
if (sendThroughObjectEventFilters(receiver, event)) {
filtered = true;
return filtered;
}
// deliver the event
consumed = receiver->event(event);
return consumed;
}
receiver->event 指向QObject ；
It can be seen that two event filters are called in the process: sendThroughApplicationEventFilters and sendThroughObjectEventFilters. After the event filter is called, the receiver's event function is called.
The event filter of QApplication
The sendThroughApplicationEventFilters mentioned in the previous section is the event filter for processing app. All the event filters installed for the app will be called in the code (from the comments in the code, the event filters of the app can only be called in the main thread), and the event filters we installed for the app are executed at this stage of.
bool QCoreApplicationPrivate::sendThroughApplicationEventFilters(QObject *receiver, QEvent *event)
{
// We can't access the application event filters outside of the main thread (race conditions)
Q_ASSERT(receiver->d_func()->threadData->thread.loadAcquire() == mainThread());
if (extraData) {
// application event filters are only called for objects in the GUI thread
for (int i = 0; i < extraData->eventFilters.size(); ++i) {
QObject *obj = extraData->eventFilters.at(i);
...
if (obj->eventFilter(receiver, event))
return true;
}
}
return false;
}QObject's event filter
sendThroughObjectEventFilters is an event filter for processing objects. It will call all the event filters installed for the receiver. The event filter we installed for an object through installEventFilter is executed at this stage.
bool QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject *receiver, QEvent *event)
{
...
for (int i = 0; i < receiver->d_func()->extraData->eventFilters.size(); ++i) {
QObject *obj = receiver->d_func()->extraData->eventFilters.at(i);
...
if (obj->eventFilter(receiver, event))
return true;
}
}
return false;
}The event method of the object As
can be seen from the QCoreApplicationPrivate::notify_helper code, after the event filter of the event receiver is processed, the event method of the receiver will be called to process the event.
Each subclass inherited from QObject has an event method and can handle its own events.
Let's take a brief look at the event method of QWidget:
bool QWidget::event(QEvent *event)
{
...
switch (event->type()) {
...
case QEvent::MouseMove:
mouseMoveEvent((QMouseEvent*)event);
break;
case QEvent::MouseButtonPress:
mousePressEvent((QMouseEvent*)event);
break;
case QEvent::MouseButtonRelease:
mouseReleaseEvent((QMouseEvent*)event);
break;
case QEvent::MouseButtonDblClick:
mouseDoubleClickEvent((QMouseEvent*)event);
break;
...
}
到这里Are you familiar with it? Each specific event processing function is called at this stage.