qsizegrip.cpp

奇趣公司比较新的qt/emd版本

    QWidget *tlw = qt_sizegrip_topLevelWidget(this);
    d->p = e->globalPos();
    d->gotMousePress = true;
    d->r = tlw->geometry();

#ifdef Q_WS_X11
    // Use a native X11 sizegrip for "real" top-level windows if supported.
    if (tlw->isWindow() && X11->isSupportedByWM(ATOM(_NET_WM_MOVERESIZE))) {
        XEvent xev;
        xev.xclient.type = ClientMessage;
        xev.xclient.message_type = ATOM(_NET_WM_MOVERESIZE);
        xev.xclient.display = X11->display;
        xev.xclient.window = tlw->winId();
        xev.xclient.format = 32;
        xev.xclient.data.l[0] = e->globalPos().x();
        xev.xclient.data.l[1] = e->globalPos().y();
        if (d->atBottom())
            xev.xclient.data.l[2] = d->atLeft() ? 6 : 4; // bottomleft/bottomright
        else
            xev.xclient.data.l[2] = d->atLeft() ? 0 : 2; // topleft/topright
        xev.xclient.data.l[3] = Button1;
        xev.xclient.data.l[4] = 0;
        XUngrabPointer(X11->display, X11->time);
        XSendEvent(X11->display, QX11Info::appRootWindow(x11Info().screen()), False,
                   SubstructureRedirectMask | SubstructureNotifyMask, &xev);
        return;
    }
#endif // Q_WS_X11

    // Find available desktop/workspace geometry.
    QRect availableGeometry;
    bool hasVerticalSizeConstraint = true;
    bool hasHorizontalSizeConstraint = true;
    if (tlw->isWindow())
        availableGeometry = QApplication::desktop()->availableGeometry(tlw);
    else {
        const QWidget *tlwParent = tlw->parentWidget();
        // Check if tlw is inside QAbstractScrollArea/QScrollArea.
        // If that's the case tlw->parentWidget() will return the viewport
        // and tlw->parentWidget()->parentWidget() will return the scroll area.
#ifndef QT_NO_SCROLLAREA
        QAbstractScrollArea *scrollArea = qobject_cast<QAbstractScrollArea *>(tlwParent->parentWidget());
        if (scrollArea) {
            hasHorizontalSizeConstraint = scrollArea->horizontalScrollBarPolicy() == Qt::ScrollBarAlwaysOff;
            hasVerticalSizeConstraint = scrollArea->verticalScrollBarPolicy() == Qt::ScrollBarAlwaysOff;
        }
#endif // QT_NO_SCROLLAREA
        availableGeometry = tlwParent->contentsRect();
    }

    // Find frame geometries, title bar height, and decoration sizes.
    const QRect frameGeometry = tlw->frameGeometry();
    const int titleBarHeight = qMax(tlw->geometry().y() - frameGeometry.y(), 0);
    const int bottomDecoration = qMax(frameGeometry.height() - tlw->height() - titleBarHeight, 0);
    const int leftRightDecoration = qMax((frameGeometry.width() - tlw->width()) / 2, 0);

    // Determine dyMax depending on whether the sizegrip is at the bottom
    // of the widget or not.
    if (d->atBottom()) {
        if (hasVerticalSizeConstraint)
            d->dyMax = availableGeometry.bottom() - d->r.bottom() - bottomDecoration;
        else
            d->dyMax = INT_MAX;
    } else {
        if (hasVerticalSizeConstraint)
            d->dyMax = availableGeometry.y() - d->r.y() + titleBarHeight;
        else
            d->dyMax = -INT_MAX;
    }

    // In RTL mode, the size grip is to the left; find dxMax from the desktop/workspace
    // geometry, the size grip geometry and the width of the decoration.
    if (d->atLeft()) {
        if (hasHorizontalSizeConstraint)
            d->dxMax = availableGeometry.x() - d->r.x() + leftRightDecoration;
        else
            d->dxMax = -INT_MAX;
    } else {
        if (hasHorizontalSizeConstraint)
            d->dxMax = availableGeometry.right() - d->r.right() - leftRightDecoration;
        else
            d->dxMax = INT_MAX;
    }
}


/*!
    \fn void QSizeGrip::mouseMoveEvent(QMouseEvent * event)
    Resizes the top-level widget containing this widget. The mouse
    move event is passed in the \a event parameter.
*/
void QSizeGrip::mouseMoveEvent(QMouseEvent * e)
{
    if (e->buttons() != Qt::LeftButton) {
        QWidget::mouseMoveEvent(e);
        return;
    }

    Q_D(QSizeGrip);
    QWidget* tlw = qt_sizegrip_topLevelWidget(this);
    if (!d->gotMousePress || tlw->testAttribute(Qt::WA_WState_ConfigPending))
        return;

#ifdef Q_WS_X11
    if (tlw->isWindow() && X11->isSupportedByWM(ATOM(_NET_WM_MOVERESIZE))
        && tlw->isTopLevel())
        return;
#endif
#ifdef Q_WS_WIN
    if (tlw->isWindow() && ::GetSystemMenu(tlw->winId(), FALSE) != 0) {
        MSG msg;
        while(PeekMessage(&msg, winId(), WM_MOUSEMOVE, WM_MOUSEMOVE, PM_REMOVE));
        return;
    }
#endif

    QPoint np(e->globalPos());

    // Don't extend beyond the available geometry; bound to dyMax and dxMax.
    QSize ns;
    if (d->atBottom())
        ns.rheight() = d->r.height() + qMin(np.y() - d->p.y(), d->dyMax);
    else
        ns.rheight() = d->r.height() - qMax(np.y() - d->p.y(), d->dyMax);

    if (d->atLeft())
        ns.rwidth() = d->r.width() - qMax(np.x() - d->p.x(), d->dxMax);
    else
        ns.rwidth() = d->r.width() + qMin(np.x() - d->p.x(), d->dxMax);

    ns = ns.expandedTo(tlw->minimumSize()).expandedTo(tlw->minimumSizeHint()).boundedTo(tlw->maximumSize());

    QPoint p;
    QRect nr(p, ns);
    if (d->atBottom()) {
        if (d->atLeft())
            nr.moveTopRight(d->r.topRight());
        else
            nr.moveTopLeft(d->r.topLeft());
    } else {
        if (d->atLeft())
            nr.moveBottomRight(d->r.bottomRight());
        else
            nr.moveBottomLeft(d->r.bottomLeft());
    }

    tlw->setGeometry(nr);
}

/*!
  \reimp
*/
void QSizeGrip::mouseReleaseEvent(QMouseEvent *mouseEvent)
{
    if (mouseEvent->button() == Qt::LeftButton) {
        Q_D(QSizeGrip);
        d->gotMousePress = false;
        d->p = QPoint();
    } else {
        QWidget::mouseReleaseEvent(mouseEvent);
    }
}

/*!
  \reimp
*/
void QSizeGrip::moveEvent(QMoveEvent * /*moveEvent*/)
{
    Q_D(QSizeGrip);
    // We're inside a resize operation; no update necessary.
    if (!d->p.isNull())
        return;

    d->m_corner = d->corner();
#if !defined(QT_NO_CURSOR) && !defined(Q_WS_MAC)
    setCursor(d->m_corner == Qt::TopLeftCorner || d->m_corner == Qt::BottomRightCorner
              ? Qt::SizeFDiagCursor : Qt::SizeBDiagCursor);
#endif
}

/*!
  \reimp
*/
void QSizeGrip::showEvent(QShowEvent *showEvent)
{
#ifdef Q_WS_MAC
    d_func()->updateMacSizer(false);
#endif
    QWidget::showEvent(showEvent);
}

/*!
  \reimp
*/
void QSizeGrip::hideEvent(QHideEvent *hideEvent)
{
#ifdef Q_WS_MAC
    d_func()->updateMacSizer(true);
#endif
    QWidget::hideEvent(hideEvent);
}

/*! \reimp */
void QSizeGrip::setVisible(bool visible)
{
    Q_D(QSizeGrip);
    d->hiddenByUser = !visible;
    QWidget::setVisible(visible);
}

/*! \reimp */
bool QSizeGrip::eventFilter(QObject *o, QEvent *e)
{
    Q_D(QSizeGrip);
    if (d->hiddenByUser || e->type() != QEvent::WindowStateChange)
        return QWidget::eventFilter(o, e);
    QWidget *tlw = qt_sizegrip_topLevelWidget(this);
    if (o != tlw)
        return QWidget::eventFilter(o, e);
    QWidget::setVisible((tlw->windowState() &
                             (Qt::WindowFullScreen
#ifndef Q_WS_MAC
                              | Qt::WindowMaximized
#endif
                              ))==0);
    return false;
}

/*!
    \reimp
*/
bool QSizeGrip::event(QEvent *event)
{
    return QWidget::event(event);
}

#ifdef Q_WS_WIN
/*! \reimp */
bool QSizeGrip::winEvent( MSG *m, long *result )
{
    if (m->message != WM_LBUTTONDOWN)
        return QWidget::winEvent(m, result);

    // toplevel windows use the native size grip on Windows
    QWidget *w = qt_sizegrip_topLevelWidget(this);
    if (!w->isWindow())
        return QWidget::winEvent(m, result);

    Q_D(QSizeGrip);
    uint orientation = 0;
    if (d->atBottom())
        orientation = d->atLeft() ? SZ_SIZEBOTTOMLEFT : SZ_SIZEBOTTOMRIGHT;
    else
        orientation = d->atLeft() ? SZ_SIZETOPLEFT : SZ_SIZETOPRIGHT;

    QT_WA_INLINE(PostMessageW(w->winId(), WM_SYSCOMMAND, orientation, 0),
                 PostMessageA(w->winId(), WM_SYSCOMMAND, orientation, 0));

    return true;
}
#endif

#endif //QT_NO_SIZEGRIP