【QT事件】大致了解一下QT中控件响应流程

首先，了解一下事件循环：

http://blog.youkuaiyun.com/houwenbin1986/article/details/79078446

接着，来看看最简单的按钮的点击响应：

又是贴代码

//处理事件分发
void QWindowsGuiEventDispatcher::sendPostedEvents()
{
    QEventDispatcherWin32::sendPostedEvents();
    QWindowSystemInterface::sendWindowSystemEvents(m_flags);
}

//针对Windows事件分发
bool QWindowSystemInterface::sendWindowSystemEvents(QEventLoop::ProcessEventsFlags flags)
{
    int nevents = 0;

    while (QWindowSystemInterfacePrivate::windowSystemEventsQueued()) {
        QWindowSystemInterfacePrivate::WindowSystemEvent *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);//比如Windows下的事件
        }

        // 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.store(event->eventAccepted);

        delete event;
    }

    return (nevents > 0);
}

void QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent *e)
{
    switch(e->type) {
    case QWindowSystemInterfacePrivate::FrameStrutMouse:
    case QWindowSystemInterfacePrivate::Mouse://比如鼠标事件响应
        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::ApplicationStateChanged: {
        QWindowSystemInterfacePrivate::ApplicationStateChangedEvent * changeEvent = static_cast<QWindowSystemInterfacePrivate::ApplicationStateChangedEvent *>(e);
        QGuiApplicationPrivate::setApplicationState(changeEvent->newState, changeEvent->forcePropagate); }
        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::reportScreenOrientationChange(
                static_cast<QWindowSystemInterfacePrivate::ScreenOrientationEvent *>(e));
        break;
    case QWindowSystemInterfacePrivate::ScreenGeometry:
        QGuiApplicationPrivate::reportGeometryChange(
                static_cast<QWindowSystemInterfacePrivate::ScreenGeometryEvent *>(e));
        break;
    case QWindowSystemInterfacePrivate::ScreenLogicalDotsPerInch:
        QGuiApplicationPrivate::reportLogicalDotsPerInchChange(
                static_cast<QWindowSystemInterfacePrivate::ScreenLogicalDotsPerInchEvent *>(e));
        break;
    case QWindowSystemInterfacePrivate::ScreenRefreshRate:
        QGuiApplicationPrivate::reportRefreshRateChange(
                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;
    }
}

//响应鼠标事件啦！！！
void QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent *e)
{
    QEvent::Type type;
    Qt::MouseButtons stateChange = e->buttons ^ buttons;
    if (e->globalPos != QGuiApplicationPrivate::lastCursorPosition && (stateChange != Qt::NoButton)) {
        // A mouse event should not change both position and buttons at the same time. Instead we
        // should first send a move event followed by a button changed event. Since this is not the case
        // with the current event, we split it in two.
        QWindowSystemInterfacePrivate::MouseEvent mouseButtonEvent(
                    e->window.data(), e->timestamp, e->type, e->localPos, e->globalPos, e->buttons, e->modifiers, e->source);
        if (e->flags & QWindowSystemInterfacePrivate::WindowSystemEvent::Synthetic)
            mouseButtonEvent.flags |= QWindowSystemInterfacePrivate::WindowSystemEvent::Synthetic;
        e->buttons = buttons;
        processMouseEvent(e);
        processMouseEvent(&mouseButtonEvent);
        return;
    }

    QWindow *window = e->window.data();
    modifier_buttons = e->modifiers;

    QPointF localPoint = e->localPos;
    QPointF globalPoint = e->globalPos;

    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;
        }
    }

    Qt::MouseButton button = Qt::NoButton;
    bool doubleClick = false;
    const bool frameStrut = e->type == QWindowSystemInterfacePrivate::FrameStrutMouse;

    if (QGuiApplicationPrivate::lastCursorPosition != globalPoint) {
        type = frameStrut ? QEvent::NonClientAreaMouseMove : QEvent::MouseMove;
        QGuiApplicationPrivate::lastCursorPosition = globalPoint;
        if (qAbs(globalPoint.x() - mousePressX) > mouse_double_click_distance||
            qAbs(globalPoint.y() - mousePressY) > mouse_double_click_distance)
            mousePressButton = Qt::NoButton;
    } else { // Check to see if a new button has been pressed/released.
        for (int check = Qt::LeftButton;
            check <= int(Qt::MaxMouseButton);
             check = check << 1) {
            if (check & stateChange) {
                button = Qt::MouseButton(check);
                break;
            }
        }
        if (button == Qt::NoButton) {
            // Ignore mouse events that don't change the current state.
            return;
        }
        mouse_buttons = buttons = e->buttons;
        if (button & e->buttons) {
            ulong doubleClickInterval = static_cast<ulong>(QGuiApplication::styleHints()->mouseDoubleClickInterval());
            doubleClick = e->timestamp - mousePressTime < doubleClickInterval && button == mousePressButton;
            type = frameStrut ? QEvent::NonClientAreaMouseButtonPress : QEvent::MouseButtonPress;
            mousePressTime = e->timestamp;
            mousePressButton = button;
            const QPoint point = QGuiApplicationPrivate::lastCursorPosition.toPoint();
            mousePressX = point.x();
            mousePressY = point.y();
        } else {
            type = frameStrut ? QEvent::NonClientAreaMouseButtonRelease : QEvent::MouseButtonRelease;
        }
    }

    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, buttons, e->modifiers, e->source);
                ev.setTimestamp(e->timestamp);
                cursor->pointerEvent(ev);
            }
    }
#endif

    QMouseEvent ev(type, localPoint, localPoint, globalPoint, button, 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()
        && !frameStrut
        && 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 && (buttons & Qt::LeftButton)) {
            point.state = Qt::TouchPointMoved;
        } else {
            return;
        }

        points << point;

        QEvent::Type type;
        QList<QTouchEvent::TouchPoint> touchPoints = QWindowSystemInterfacePrivate::fromNativeTouchPoints(points, window, &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 = frameStrut ? QEvent::NonClientAreaMouseButtonDblClick : QEvent::MouseButtonDblClick;
            QMouseEvent dblClickEvent(doubleClickType, localPoint, localPoint, globalPoint,
                                      button, buttons, e->modifiers, e->source);
            dblClickEvent.setTimestamp(e->timestamp);
            QGuiApplication::sendSpontaneousEvent(window, &dblClickEvent);
        }
    }
}

//调用通知（回调）连接到槽函数
#ifndef QT_NO_QOBJECT
inline bool QCoreApplication::sendEvent(QObject *receiver, QEvent *event)
{  if (event) event->spont = false; return notifyInternal2(receiver, event); }

inline bool QCoreApplication::sendSpontaneousEvent(QObject *receiver, QEvent *event)
{ if (event) event->spont = true; return notifyInternal2(receiver, event); }//通知槽函数响应
#endif

//通知相应事件处理！！！
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;
    QScopedLoopLevelCounter loopLevelCounter(threadData);
    if (!selfRequired)
        return doNotify(receiver, event);//
    return self->notify(receiver, event);//转到应用程序的响应里去
}

//应用的响应！！！
bool QApplicationPrivate::notify_helper(QObject *receiver, QEvent * e)
{
    // send to all application event filters
    if (threadRequiresCoreApplication()
        && receiver->d_func()->threadData->thread == mainThread()
        && sendThroughApplicationEventFilters(receiver, e))
        return true;

    if (receiver->isWidgetType()) {
        QWidget *widget = static_cast<QWidget *>(receiver);

#if !defined(Q_OS_WINCE) || (defined(GWES_ICONCURS) && !defined(QT_NO_CURSOR))
        // toggle HasMouse widget state on enter and leave
        if ((e->type() == QEvent::Enter || e->type() == QEvent::DragEnter) &&
            (!QApplication::activePopupWidget() || QApplication::activePopupWidget() == widget->window()))
            widget->setAttribute(Qt::WA_UnderMouse, true);
        else if (e->type() == QEvent::Leave || e->type() == QEvent::DragLeave)
            widget->setAttribute(Qt::WA_UnderMouse, false);
#endif

        if (QLayout *layout=widget->d_func()->layout) {
            layout->widgetEvent(e);
        }
    }

    // send to all receiver event filters //注意多个连接槽函数！！！
    if (sendThroughObjectEventFilters(receiver, e))
        return true;

    // deliver the event
    bool consumed = receiver->event(e);//转到具体信号接收者的响应里去
    QCoreApplicationPrivate::setEventSpontaneous(e, false);
    return consumed;
}

//具体控件的事件响应里
bool QPushButton::event(QEvent *e)
{
    Q_D(QPushButton);
    if (e->type() == QEvent::ParentChange) {
        if (QDialog *dialog = d->dialogParent()) {
            if (d->defaultButton)
                dialog->d_func()->setMainDefault(this);
        }
    } else if (e->type() == QEvent::StyleChange
#ifdef Q_OS_MAC
               || e->type() == QEvent::MacSizeChange
#endif
               ) {
        d->resetLayoutItemMargins();
        updateGeometry();
    } else if (e->type() == QEvent::PolishRequest) {
        updateGeometry();
    }
    return QAbstractButton::event(e);
}

//做一些事情！！！
bool QAbstractButton::event(QEvent *e)
{
    // as opposed to other widgets, disabled buttons accept mouse
    // events. This avoids surprising click-through scenarios
    if (!isEnabled()) {
        switch(e->type()) {
        case QEvent::TabletPress:
        case QEvent::TabletRelease:
        case QEvent::TabletMove:
        case QEvent::MouseButtonPress:
        case QEvent::MouseButtonRelease:
        case QEvent::MouseButtonDblClick:
        case QEvent::MouseMove:
        case QEvent::HoverMove:
        case QEvent::HoverEnter:
        case QEvent::HoverLeave:
        case QEvent::ContextMenu:
#ifndef QT_NO_WHEELEVENT
        case QEvent::Wheel:
#endif
            return true;
        default:
            break;
        }
    }

#ifndef QT_NO_SHORTCUT
    if (e->type() == QEvent::Shortcut) {
        Q_D(QAbstractButton);
        QShortcutEvent *se = static_cast<QShortcutEvent *>(e);
        if (d->shortcutId != se->shortcutId())
            return false;
        if (!se->isAmbiguous()) {
            if (!d->animateTimer.isActive())
                animateClick();
        } else {
            if (focusPolicy() != Qt::NoFocus)
                setFocus(Qt::ShortcutFocusReason);
            window()->setAttribute(Qt::WA_KeyboardFocusChange);
        }
        return true;
    }
#endif
    return QWidget::event(e);
}

//再往下传递
bool QWidget::event(QEvent *event)
{
    Q_D(QWidget);

    // ignore mouse and key events when disabled
    if (!isEnabled()) {
        switch(event->type()) {
        case QEvent::TabletPress:
        case QEvent::TabletRelease:
        case QEvent::TabletMove:
        case QEvent::MouseButtonPress:
        case QEvent::MouseButtonRelease:
        case QEvent::MouseButtonDblClick:
        case QEvent::MouseMove:
        case QEvent::TouchBegin:
        case QEvent::TouchUpdate:
        case QEvent::TouchEnd:
        case QEvent::TouchCancel:
        case QEvent::ContextMenu:
        case QEvent::KeyPress:
        case QEvent::KeyRelease:
#ifndef QT_NO_WHEELEVENT
        case QEvent::Wheel:
#endif
            return false;
        default:
            break;
        }
    }
    switch (event->type()) {
    case QEvent::MouseMove:
        mouseMoveEvent((QMouseEvent*)event);
        break;

    case QEvent::MouseButtonPress:
        mousePressEvent((QMouseEvent*)event);
        break;

    case QEvent::MouseButtonRelease://这里响应一下
        mouseReleaseEvent((QMouseEvent*)event);
        break;

    case QEvent::MouseButtonDblClick:
        mouseDoubleClickEvent((QMouseEvent*)event);
        break;
#ifndef QT_NO_WHEELEVENT
    case QEvent::Wheel:
        wheelEvent((QWheelEvent*)event);
        break;
#endif
#ifndef QT_NO_TABLETEVENT
    case QEvent::TabletMove:
    case QEvent::TabletPress:
    case QEvent::TabletRelease:
        tabletEvent((QTabletEvent*)event);
        break;
#endif
    case QEvent::KeyPress: {
        QKeyEvent *k = (QKeyEvent *)event;
        bool res = false;
        if (!(k->modifiers() & (Qt::ControlModifier | Qt::AltModifier))) {  //### Add MetaModifier?
            if (k->key() == Qt::Key_Backtab
                || (k->key() == Qt::Key_Tab && (k->modifiers() & Qt::ShiftModifier)))
                res = focusNextPrevChild(false);
            else if (k->key() == Qt::Key_Tab)
                res = focusNextPrevChild(true);
            if (res)
                break;
        }
        keyPressEvent(k);
#ifdef QT_KEYPAD_NAVIGATION
        if (!k->isAccepted() && QApplication::keypadNavigationEnabled()
            && !(k->modifiers() & (Qt::ControlModifier | Qt::AltModifier | Qt::ShiftModifier))) {
            if (QApplication::navigationMode() == Qt::NavigationModeKeypadTabOrder) {
                if (k->key() == Qt::Key_Up)
                    res = focusNextPrevChild(false);
                else if (k->key() == Qt::Key_Down)
                    res = focusNextPrevChild(true);
            } else if (QApplication::navigationMode() == Qt::NavigationModeKeypadDirectional) {
                if (k->key() == Qt::Key_Up)
                    res = QWidgetPrivate::navigateToDirection(QWidgetPrivate::DirectionNorth);
                else if (k->key() == Qt::Key_Right)
                    res = QWidgetPrivate::navigateToDirection(QWidgetPrivate::DirectionEast);
                else if (k->key() == Qt::Key_Down)
                    res = QWidgetPrivate::navigateToDirection(QWidgetPrivate::DirectionSouth);
                else if (k->key() == Qt::Key_Left)
                    res = QWidgetPrivate::navigateToDirection(QWidgetPrivate::DirectionWest);
            }
            if (res) {
                k->accept();
                break;
            }
        }
#endif
#ifndef QT_NO_WHATSTHIS
        if (!k->isAccepted()
            && k->modifiers() & Qt::ShiftModifier && k->key() == Qt::Key_F1
            && d->whatsThis.size()) {
            QWhatsThis::showText(mapToGlobal(inputMethodQuery(Qt::ImCursorRectangle).toRect().center()), d->whatsThis, this);
            k->accept();
        }
#endif
    }
        break;

    case QEvent::KeyRelease:
        keyReleaseEvent((QKeyEvent*)event);
        // fall through
    case QEvent::ShortcutOverride:
        break;

    case QEvent::InputMethod:
        inputMethodEvent((QInputMethodEvent *) event);
        break;

    case QEvent::InputMethodQuery:
        if (testAttribute(Qt::WA_InputMethodEnabled)) {
            QInputMethodQueryEvent *query = static_cast<QInputMethodQueryEvent *>(event);
            Qt::InputMethodQueries queries = query->queries();
            for (uint i = 0; i < 32; ++i) {
                Qt::InputMethodQuery q = (Qt::InputMethodQuery)(int)(queries & (1<<i));
                if (q) {
                    QVariant v = inputMethodQuery(q);
                    if (q == Qt::ImEnabled && !v.isValid() && isEnabled())
                        v = QVariant(true); // special case for Qt4 compatibility
                    query->setValue(q, v);
                }
            }
            query->accept();
        }
        break;

    case QEvent::PolishRequest:
        ensurePolished();
        break;

    case QEvent::Polish: {
        style()->polish(this);
        setAttribute(Qt::WA_WState_Polished);
        if (!QApplication::font(this).isCopyOf(QApplication::font()))
            d->resolveFont();
        if (!QApplication::palette(this).isCopyOf(QApplication::palette()))
            d->resolvePalette();
    }
        break;

    case QEvent::ApplicationWindowIconChange:
        if (isWindow() && !testAttribute(Qt::WA_SetWindowIcon)) {
            d->setWindowIcon_sys();
            d->setWindowIcon_helper();
        }
        break;
    case QEvent::FocusIn:
        focusInEvent((QFocusEvent*)event);
        d->updateWidgetTransform(event);
        break;

    case QEvent::FocusOut:
        focusOutEvent((QFocusEvent*)event);
        break;

    case QEvent::Enter:
#ifndef QT_NO_STATUSTIP
        if (d->statusTip.size()) {
            QStatusTipEvent tip(d->statusTip);
            QApplication::sendEvent(const_cast<QWidget *>(this), &tip);
        }
#endif
        enterEvent(event);
        break;

    case QEvent::Leave:
#ifndef QT_NO_STATUSTIP
        if (d->statusTip.size()) {
            QString empty;
            QStatusTipEvent tip(empty);
            QApplication::sendEvent(const_cast<QWidget *>(this), &tip);
        }
#endif
        leaveEvent(event);
        break;

    case QEvent::HoverEnter:
    case QEvent::HoverLeave:
        update();
        break;

    case QEvent::Paint:
        // At this point the event has to be delivered, regardless
        // whether the widget isVisible() or not because it
        // already went through the filters
        paintEvent((QPaintEvent*)event);
        break;

    case QEvent::Move:
        moveEvent((QMoveEvent*)event);
        d->updateWidgetTransform(event);
        break;

    case QEvent::Resize:
        resizeEvent((QResizeEvent*)event);
        d->updateWidgetTransform(event);
        break;

    case QEvent::Close:
        closeEvent((QCloseEvent *)event);
        break;

#ifndef QT_NO_CONTEXTMENU
    case QEvent::ContextMenu:
        switch (data->context_menu_policy) {
        case Qt::PreventContextMenu:
            break;
        case Qt::DefaultContextMenu:
            contextMenuEvent(static_cast<QContextMenuEvent *>(event));
            break;
        case Qt::CustomContextMenu:
            emit customContextMenuRequested(static_cast<QContextMenuEvent *>(event)->pos());
            break;
#ifndef QT_NO_MENU
        case Qt::ActionsContextMenu:
            if (d->actions.count()) {
                QMenu::exec(d->actions, static_cast<QContextMenuEvent *>(event)->globalPos(),
                            0, this);
                break;
            }
            // fall through
#endif
        default:
            event->ignore();
            break;
        }
        break;
#endif // QT_NO_CONTEXTMENU

#ifndef QT_NO_DRAGANDDROP
    case QEvent::Drop:
        dropEvent((QDropEvent*) event);
        break;

    case QEvent::DragEnter:
        dragEnterEvent((QDragEnterEvent*) event);
        break;

    case QEvent::DragMove:
        dragMoveEvent((QDragMoveEvent*) event);
        break;

    case QEvent::DragLeave:
        dragLeaveEvent((QDragLeaveEvent*) event);
        break;
#endif

    case QEvent::Show:
        showEvent((QShowEvent*) event);
        break;

    case QEvent::Hide:
        hideEvent((QHideEvent*) event);
        break;

    case QEvent::ShowWindowRequest:
        if (!isHidden())
            d->show_sys();
        break;

    case QEvent::ApplicationFontChange:
        d->resolveFont();
        break;
    case QEvent::ApplicationPaletteChange:
        if (!(windowType() == Qt::Desktop))
            d->resolvePalette();
        break;

    case QEvent::ToolBarChange:
    case QEvent::ActivationChange:
    case QEvent::EnabledChange:
    case QEvent::FontChange:
    case QEvent::StyleChange:
    case QEvent::PaletteChange:
    case QEvent::WindowTitleChange:
    case QEvent::IconTextChange:
    case QEvent::ModifiedChange:
    case QEvent::MouseTrackingChange:
    case QEvent::ParentChange:
    case QEvent::LocaleChange:
    case QEvent::MacSizeChange:
    case QEvent::ContentsRectChange:
    case QEvent::ThemeChange:
    case QEvent::ReadOnlyChange:
        changeEvent(event);
        break;

    case QEvent::WindowStateChange: {
        const bool wasMinimized = static_cast<const QWindowStateChangeEvent *>(event)->oldState() & Qt::WindowMinimized;
        if (wasMinimized != isMinimized()) {
            QWidget *widget = const_cast<QWidget *>(this);
            if (wasMinimized) {
                // Always send the spontaneous events here, otherwise it can break the application!
                if (!d->childrenShownByExpose) {
                    // Show widgets only when they are not yet shown by the expose event
                    d->showChildren(true);
                    QShowEvent showEvent;
                    QCoreApplication::sendSpontaneousEvent(widget, &showEvent);
                }
                d->childrenHiddenByWState = false; // Set it always to "false" when window is restored
            } else {
                QHideEvent hideEvent;
                QCoreApplication::sendSpontaneousEvent(widget, &hideEvent);
                d->hideChildren(true);
                d->childrenHiddenByWState = true;
            }
            d->childrenShownByExpose = false; // Set it always to "false" when window state changes
        }
        changeEvent(event);
    }
        break;

    case QEvent::WindowActivate:
    case QEvent::WindowDeactivate: {
        if (isVisible() && !palette().isEqual(QPalette::Active, QPalette::Inactive))
            update();
        QList<QObject*> childList = d->children;
        for (int i = 0; i < childList.size(); ++i) {
            QWidget *w = qobject_cast<QWidget *>(childList.at(i));
            if (w && w->isVisible() && !w->isWindow())
                QApplication::sendEvent(w, event);
        }
        break; }

    case QEvent::LanguageChange:
        changeEvent(event);
        {
            QList<QObject*> childList = d->children;
            for (int i = 0; i < childList.size(); ++i) {
                QObject *o = childList.at(i);
                if (o)
                    QApplication::sendEvent(o, event);
            }
        }
        update();
        break;

    case QEvent::ApplicationLayoutDirectionChange:
        d->resolveLayoutDirection();
        break;

    case QEvent::LayoutDirectionChange:
        if (d->layout)
            d->layout->invalidate();
        update();
        changeEvent(event);
        break;
    case QEvent::UpdateRequest:
        d->syncBackingStore();
        break;
    case QEvent::UpdateLater:
        update(static_cast<QUpdateLaterEvent*>(event)->region());
        break;
    case QEvent::StyleAnimationUpdate:
        if (isVisible() && !window()->isMinimized()) {
            event->accept();
            update();
        }
        break;

    case QEvent::WindowBlocked:
    case QEvent::WindowUnblocked:
        if (!d->children.isEmpty()) {
            QWidget *modalWidget = QApplication::activeModalWidget();
            for (int i = 0; i < d->children.size(); ++i) {
                QObject *o = d->children.at(i);
                if (o && o != modalWidget && o->isWidgetType()) {
                    QWidget *w  = static_cast<QWidget *>(o);
                    // do not forward the event to child windows; QApplication does this for us
                    if (!w->isWindow())
                        QApplication::sendEvent(w, event);
                }
            }
        }
#if defined(Q_DEAD_CODE_FROM_QT4_WIN)
            setDisabledStyle(this, (event->type() == QEvent::WindowBlocked));
#endif
        break;
#ifndef QT_NO_TOOLTIP
    case QEvent::ToolTip:
        if (!d->toolTip.isEmpty())
            QToolTip::showText(static_cast<QHelpEvent*>(event)->globalPos(), d->toolTip, this, QRect(), d->toolTipDuration);
        else
            event->ignore();
        break;
#endif
#ifndef QT_NO_WHATSTHIS
    case QEvent::WhatsThis:
        if (d->whatsThis.size())
            QWhatsThis::showText(static_cast<QHelpEvent *>(event)->globalPos(), d->whatsThis, this);
        else
            event->ignore();
        break;
    case QEvent::QueryWhatsThis:
        if (d->whatsThis.isEmpty())
            event->ignore();
        break;
#endif
    case QEvent::EmbeddingControl:
        d->topData()->frameStrut.setCoords(0 ,0, 0, 0);
        data->fstrut_dirty = false;
#if defined(Q_DEAD_CODE_FROM_QT4_WIN) || defined(Q_DEAD_CODE_FROM_QT4_X11)
        d->topData()->embedded = 1;
#endif
        break;
#ifndef QT_NO_ACTION
    case QEvent::ActionAdded:
    case QEvent::ActionRemoved:
    case QEvent::ActionChanged:
        actionEvent((QActionEvent*)event);
        break;
#endif

    case QEvent::KeyboardLayoutChange:
        {
            changeEvent(event);

            // inform children of the change
            QList<QObject*> childList = d->children;
            for (int i = 0; i < childList.size(); ++i) {
                QWidget *w = qobject_cast<QWidget *>(childList.at(i));
                if (w && w->isVisible() && !w->isWindow())
                    QApplication::sendEvent(w, event);
            }
            break;
        }
#ifdef Q_DEAD_CODE_FROM_QT4_MAC
    case QEvent::MacGLWindowChange:
        d->needWindowChange = false;
        break;
#endif
    case QEvent::TouchBegin:
    case QEvent::TouchUpdate:
    case QEvent::TouchEnd:
    case QEvent::TouchCancel:
    {
        event->ignore();
        break;
    }
#ifndef QT_NO_GESTURES
    case QEvent::Gesture:
        event->ignore();
        break;
#endif
    case QEvent::ScreenChangeInternal:
        if (const QTLWExtra *te = d->maybeTopData()) {
            const QWindow *win = te->window;
            d->setWinId((win && win->handle()) ? win->handle()->winId() : 0);
        }
#ifndef QT_NO_OPENGL
        d->renderToTextureReallyDirty = 1;
#endif
        break;
#ifndef QT_NO_PROPERTIES
    case QEvent::DynamicPropertyChange: {
        const QByteArray &propName = static_cast<QDynamicPropertyChangeEvent *>(event)->propertyName();
        if (propName.length() == 13 && !qstrncmp(propName, "_q_customDpi", 12)) {
            uint value = property(propName.constData()).toUInt();
            if (!d->extra)
                d->createExtra();
            const char axis = propName.at(12);
            if (axis == 'X')
                d->extra->customDpiX = value;
            else if (axis == 'Y')
                d->extra->customDpiY = value;
            d->updateFont(d->data.fnt);
        }
        if (windowHandle() && !qstrncmp(propName, "_q_platform_", 12))
            windowHandle()->setProperty(propName, property(propName));
        // fall through
    }
#endif
    default:
        return QObject::event(event);
    }
    return true;
}

//
void QAbstractButton::mouseReleaseEvent(QMouseEvent *e)
{
    Q_D(QAbstractButton);
    d->pressed = false;

    if (e->button() != Qt::LeftButton) {
        e->ignore();
        return;
    }

    if (!d->down) {
        // refresh is required by QMacStyle to resume the default button animation
        d->refresh();
        e->ignore();
        return;
    }

    if (hitButton(e->pos())) {
        d->repeatTimer.stop();
        d->click();//触发点击事件
        e->accept();
    } else {
        setDown(false);
        e->ignore();
    }
}

//发送相关的按钮事件
void QAbstractButtonPrivate::click()
{
    Q_Q(QAbstractButton);

    down = false;
    blockRefresh = true;
    bool changeState = true;
    if (checked && queryCheckedButton() == q) {
        // the checked button of an exclusive or autoexclusive group cannot be unchecked
#ifndef QT_NO_BUTTONGROUP
        if (group ? group->d_func()->exclusive : autoExclusive)
#else
        if (autoExclusive)
#endif
            changeState = false;
    }

    QPointer<QAbstractButton> guard(q);
    if (changeState) {
        q->nextCheckState();
        if (!guard)
            return;
    }
    blockRefresh = false;
    refresh();
    q->repaint(); //flush paint event before invoking potentially expensive operation
    QApplication::flush();
    if (guard)
        emitReleased();
    if (guard)
        emitClicked();//点击事件
}

void QAbstractButtonPrivate::emitClicked()//发送点击事件
{
    Q_Q(QAbstractButton);
    QPointer<QAbstractButton> guard(q);
    emit q->clicked(checked);
#ifndef QT_NO_BUTTONGROUP
    if (guard && group) {
        emit group->buttonClicked(group->id(q));
        if (guard && group)
            emit group->buttonClicked(q);
    }
#endif
}

//核心关键点
void QAbstractButton::clicked(bool _t1)
{
    void *_a[] = { Q_NULLPTR, const_cast<void*>(reinterpret_cast<const void*>(&_t1)) };
    QMetaObject::activate(this, &staticMetaObject, 2, _a);//调用MetaCall！！！
}

//
void QMetaObject::activate(QObject *sender, const QMetaObject *m, int local_signal_index,
                           void **argv)
{
    activate(sender, QMetaObjectPrivate::signalOffset(m), local_signal_index, argv);
}

//QObject中具体调用那个槽函数了！！！
void QMetaObject::activate(QObject *sender, int signalOffset, int local_signal_index, void **argv)
{
    int signal_index = signalOffset + local_signal_index;

    if (!sender->d_func()->isSignalConnected(signal_index)
        && !qt_signal_spy_callback_set.signal_begin_callback
        && !qt_signal_spy_callback_set.signal_end_callback) {
        return; // nothing connected to these signals, and no spy
    }

    if (sender->d_func()->blockSig)
        return;

    if (sender->d_func()->declarativeData && QAbstractDeclarativeData::signalEmitted)
        QAbstractDeclarativeData::signalEmitted(sender->d_func()->declarativeData, sender,
                                                signal_index, argv);

    void *empty_argv[] = { 0 };
    if (qt_signal_spy_callback_set.signal_begin_callback != 0) {
        qt_signal_spy_callback_set.signal_begin_callback(sender, signal_index,
                                                         argv ? argv : empty_argv);
    }

    Qt::HANDLE currentThreadId = QThread::currentThreadId();

    {
    QMutexLocker locker(signalSlotLock(sender));
    struct ConnectionListsRef {
        QObjectConnectionListVector *connectionLists;
        ConnectionListsRef(QObjectConnectionListVector *connectionLists) : connectionLists(connectionLists)
        {
            if (connectionLists)
                ++connectionLists->inUse;
        }
        ~ConnectionListsRef()
        {
            if (!connectionLists)
                return;

            --connectionLists->inUse;
            Q_ASSERT(connectionLists->inUse >= 0);
            if (connectionLists->orphaned) {
                if (!connectionLists->inUse)
                    delete connectionLists;
            }
        }

        QObjectConnectionListVector *operator->() const { return connectionLists; }
    };
    ConnectionListsRef connectionLists = sender->d_func()->connectionLists;
    if (!connectionLists.connectionLists) {
        locker.unlock();
        if (qt_signal_spy_callback_set.signal_end_callback != 0)
            qt_signal_spy_callback_set.signal_end_callback(sender, signal_index);
        return;
    }

    const QObjectPrivate::ConnectionList *list;
    if (signal_index < connectionLists->count())
        list = &connectionLists->at(signal_index);
    else
        list = &connectionLists->allsignals;

    do {
        QObjectPrivate::Connection *c = list->first;
        if (!c) continue;
        // We need to check against last here to ensure that signals added
        // during the signal emission are not emitted in this emission.
        QObjectPrivate::Connection *last = list->last;

        do {
            if (!c->receiver)
                continue;

            QObject * const receiver = c->receiver;
            const bool receiverInSameThread = currentThreadId == receiver->d_func()->threadData->threadId;

            // determine if this connection should be sent immediately or
            // put into the event queue
            if ((c->connectionType == Qt::AutoConnection && !receiverInSameThread)
                || (c->connectionType == Qt::QueuedConnection)) {
                queued_activate(sender, signal_index, c, argv ? argv : empty_argv, locker);
                continue;
#ifndef QT_NO_THREAD
            } else if (c->connectionType == Qt::BlockingQueuedConnection) {
                if (receiverInSameThread) {
                    qWarning("Qt: Dead lock detected while activating a BlockingQueuedConnection: "
                    "Sender is %s(%p), receiver is %s(%p)",
                    sender->metaObject()->className(), sender,
                    receiver->metaObject()->className(), receiver);
                }
                QSemaphore semaphore;
                QMetaCallEvent *ev = c->isSlotObject ?
                    new QMetaCallEvent(c->slotObj, sender, signal_index, 0, 0, argv ? argv : empty_argv, &semaphore) :
                    new QMetaCallEvent(c->method_offset, c->method_relative, c->callFunction, sender, signal_index, 0, 0, argv ? argv : empty_argv, &semaphore);
                QCoreApplication::postEvent(receiver, ev);
                locker.unlock();
                semaphore.acquire();
                locker.relock();
                continue;
#endif
            }

            QConnectionSenderSwitcher sw;//这个很牛逼的样子

            if (receiverInSameThread) {//统一线程内
                sw.switchSender(receiver, sender, signal_index);
            }
            const QObjectPrivate::StaticMetaCallFunction callFunction = c->callFunction;
            const int method_relative = c->method_relative;
            if (c->isSlotObject) {
                c->slotObj->ref();
                QScopedPointer<QtPrivate::QSlotObjectBase, QSlotObjectBaseDeleter> obj(c->slotObj);
                locker.unlock();
                obj->call(receiver, argv ? argv : empty_argv);//调用

                // Make sure the slot object gets destroyed before the mutex is locked again, as the
                // destructor of the slot object might also lock a mutex from the signalSlotLock() mutex pool,
                // and that would deadlock if the pool happens to return the same mutex.
                obj.reset();

                locker.relock();
            } else if (callFunction && c->method_offset <= receiver->metaObject()->methodOffset()) {
                //we compare the vtable to make sure we are not in the destructor of the object.
                locker.unlock();
                const int methodIndex = c->method();
                if (qt_signal_spy_callback_set.slot_begin_callback != 0)
                    qt_signal_spy_callback_set.slot_begin_callback(receiver, methodIndex, argv ? argv : empty_argv);

                callFunction(receiver, QMetaObject::InvokeMetaMethod, method_relative, argv ? argv : empty_argv);//这里是默认的调用方式

                if (qt_signal_spy_callback_set.slot_end_callback != 0)
                    qt_signal_spy_callback_set.slot_end_callback(receiver, methodIndex);
                locker.relock();
            } else {
                const int method = method_relative + c->method_offset;
                locker.unlock();

                if (qt_signal_spy_callback_set.slot_begin_callback != 0) {
                    qt_signal_spy_callback_set.slot_begin_callback(receiver,
                                                                method,
                                                                argv ? argv : empty_argv);
                }

                metacall(receiver, QMetaObject::InvokeMetaMethod, method, argv ? argv : empty_argv);//调用

                if (qt_signal_spy_callback_set.slot_end_callback != 0)
                    qt_signal_spy_callback_set.slot_end_callback(receiver, method);

                locker.relock();
            }

            if (connectionLists->orphaned)
                break;
        } while (c != last && (c = c->nextConnectionList) != 0);

        if (connectionLists->orphaned)
            break;
    } while (list != &connectionLists->allsignals &&
        //start over for all signals;
        ((list = &connectionLists->allsignals), true));//全部分发完！！！

    }

    if (qt_signal_spy_callback_set.signal_end_callback != 0)
        qt_signal_spy_callback_set.signal_end_callback(sender, signal_index);

}

//上一步的call最终指向moc_widget::qt_static_metacall
void Widget::qt_static_metacall(QObject *_o, QMetaObject::Call _c, int _id, void **_a)
{
    if (_c == QMetaObject::InvokeMetaMethod) {
        Q_ASSERT(staticMetaObject.cast(_o));
        Widget *_t = static_cast<Widget *>(_o);
        Q_UNUSED(_t)
        switch (_id) {
        case 0: _t->onSlotClicked(); break;
        case 1: _t->onSlotClicked2(); break;
        default: ;
        }
    }
    Q_UNUSED(_a);
}

//最最终调用我们的代码实现
void Widget::onSlotClicked()
{
    qDebug()<<"点击了按钮go-----";
}

再来：核心就是QMetaObject元对象！！！

//关于如何连接信号槽的，主要看这个吧！！！
//如果使用SIGNAL和SLOT宏
//见qobjectdefs.h
Q_CORE_EXPORT const char *qFlagLocation(const char *method);//核心的哦！！！

#ifndef QT_NO_META_MACROS
#ifndef QT_NO_DEBUG
# define QLOCATION "\0" __FILE__ ":" QT_STRINGIFY(__LINE__)
# ifndef QT_NO_KEYWORDS
#  define METHOD(a)   qFlagLocation("0"#a QLOCATION)
# endif
# define SLOT(a)     qFlagLocation("1"#a QLOCATION)
# define SIGNAL(a)   qFlagLocation("2"#a QLOCATION)
#else
# ifndef QT_NO_KEYWORDS
#  define METHOD(a)   "0"#a
# endif
# define SLOT(a)     "1"#a
# define SIGNAL(a)   "2"#a
#endif

//qobject.cpp中
const char *qFlagLocation(const char *method)
{
    QThreadData *currentThreadData = QThreadData::current(false);//线程相关的！！！
    if (currentThreadData != 0)
        currentThreadData->flaggedSignatures.store(method);//应该就是注册相关的吧
    return method;
}

//以下是moc_widget.cpp
#include "../../TestQt/widget.h"
#include <QtCore/qbytearray.h>
#include <QtCore/qmetatype.h>
#if !defined(Q_MOC_OUTPUT_REVISION)
#error "The header file 'widget.h' doesn't include <QObject>."
#elif Q_MOC_OUTPUT_REVISION != 67
#error "This file was generated using the moc from 5.6.3. It"
#error "cannot be used with the include files from this version of Qt."
#error "(The moc has changed too much.)"
#endif

QT_BEGIN_MOC_NAMESPACE
struct qt_meta_stringdata_Widget_t {
    QByteArrayData data[4];
    char stringdata0[37];
};
#define QT_MOC_LITERAL(idx, ofs, len) \
    Q_STATIC_BYTE_ARRAY_DATA_HEADER_INITIALIZER_WITH_OFFSET(len, \
    qptrdiff(offsetof(qt_meta_stringdata_Widget_t, stringdata0) + ofs \
        - idx * sizeof(QByteArrayData)) \
    )
static const qt_meta_stringdata_Widget_t qt_meta_stringdata_Widget = {
    {
QT_MOC_LITERAL(0, 0, 6), // "Widget"
QT_MOC_LITERAL(1, 7, 13), // "onSlotClicked"
QT_MOC_LITERAL(2, 21, 0), // ""
QT_MOC_LITERAL(3, 22, 14) // "onSlotClicked2"

    },
    "Widget\0onSlotClicked\0\0onSlotClicked2"
};
#undef QT_MOC_LITERAL

static const uint qt_meta_data_Widget[] = {

 // content:
       7,       // revision
       0,       // classname
       0,    0, // classinfo
       2,   14, // methods
       0,    0, // properties
       0,    0, // enums/sets
       0,    0, // constructors
       0,       // flags
       0,       // signalCount

 // slots: name, argc, parameters, tag, flags
       1,    0,   24,    2, 0x0a /* Public */,
       3,    0,   25,    2, 0x0a /* Public */,

 // slots: parameters
    QMetaType::Void,
    QMetaType::Void,

       0        // eod
};

void Widget::qt_static_metacall(QObject *_o, QMetaObject::Call _c, int _id, void **_a)
{
    if (_c == QMetaObject::InvokeMetaMethod) {
        Q_ASSERT(staticMetaObject.cast(_o));
        Widget *_t = static_cast<Widget *>(_o);
        Q_UNUSED(_t)
        switch (_id) {
        case 0: _t->onSlotClicked(); break;
        case 1: _t->onSlotClicked2(); break;
        default: ;
        }
    }
    Q_UNUSED(_a);
}

const QMetaObject Widget::staticMetaObject = {
    { &QWidget::staticMetaObject, qt_meta_stringdata_Widget.data,
      qt_meta_data_Widget,  qt_static_metacall, Q_NULLPTR, Q_NULLPTR}
};


const QMetaObject *Widget::metaObject() const
{
    return QObject::d_ptr->metaObject ? QObject::d_ptr->dynamicMetaObject() : &staticMetaObject;
}

void *Widget::qt_metacast(const char *_clname)
{
    if (!_clname) return Q_NULLPTR;
    if (!strcmp(_clname, qt_meta_stringdata_Widget.stringdata0))
        return static_cast<void*>(const_cast< Widget*>(this));
    return QWidget::qt_metacast(_clname);
}

int Widget::qt_metacall(QMetaObject::Call _c, int _id, void **_a)
{
    _id = QWidget::qt_metacall(_c, _id, _a);
    if (_id < 0)
        return _id;
    if (_c == QMetaObject::InvokeMetaMethod) {
        if (_id < 2)
            qt_static_metacall(this, _c, _id, _a);
        _id -= 2;
    } else if (_c == QMetaObject::RegisterMethodArgumentMetaType) {
        if (_id < 2)
            *reinterpret_cast<int*>(_a[0]) = -1;
        _id -= 2;
    }
    return _id;
}
QT_END_MOC_NAMESPACE