qmenu.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

    if (d->scroll)
        d->scrollMenu(act, QMenuPrivate::QMenuScroller::ScrollCenter);
}


/*!
    Returns the currently highlighted action, or 0 if no
    action is currently highlighted.
*/
QAction *QMenu::activeAction() const
{
    return d_func()->currentAction;
}

/*!
    Removes all the menu's actions. Actions owned by the menu and not
    shown in any other widget are deleted.

    \sa removeAction()
*/
void QMenu::clear()
{
    QList<QAction*> acts = actions();
    for(int i = 0; i < acts.size(); i++) {
        removeAction(acts[i]);
        if (acts[i]->parent() == this && acts[i]->d_func()->widgets.isEmpty())
            delete acts[i];
    }
}

/*!
  If a menu does not fit on the screen it lays itself out so that it
  does fit. It is style dependent what layout means (for example, on
  Windows it will use multiple columns).

  This functions returns the number of columns necessary.
*/
int QMenu::columnCount() const
{
    return d_func()->ncols;
}

/*!
  Returns the item at \a pt; returns 0 if there is no item there.
*/
QAction *QMenu::actionAt(const QPoint &pt) const
{
    if (QAction *ret = d_func()->actionAt(pt))
        return ret;
    return 0;
}

/*!
  Returns the geometry of action \a act.
*/
QRect QMenu::actionGeometry(QAction *act) const
{
    return d_func()->actionRect(act);
}

/*!
    \reimp
*/
QSize QMenu::sizeHint() const
{
    Q_D(const QMenu);
    ensurePolished();
    QMap<QAction*, QRect> actionRects;
    QList<QAction*> actionList;
    d->calcActionRects(actionRects, actionList);

    QSize s;
    QStyleOption opt(0);
    opt.rect = rect();
    opt.palette = palette();
    opt.state = QStyle::State_None;
    for (QMap<QAction*, QRect>::const_iterator i = actionRects.begin();
         i != actionRects.constEnd(); ++i) {
        if (i.value().bottom() > s.height())
            s.setHeight(i.value().y()+i.value().height());
        if (i.value().right() > s.width())
            s.setWidth(i.value().right());
    }
    if (d->tearoff)
        s.rheight() += style()->pixelMetric(QStyle::PM_MenuTearoffHeight, &opt, this);
    if (const int fw = style()->pixelMetric(QStyle::PM_MenuPanelWidth, &opt, this)) {
        s.rwidth() += fw*2;
        s.rheight() += fw*2;
    }
    s.rwidth() += 2 * style()->pixelMetric(QStyle::PM_MenuHMargin, &opt, this);
    s.rheight() += 2 * style()->pixelMetric(QStyle::PM_MenuVMargin, &opt, this);

    s += QSize(d->leftmargin + d->rightmargin, d->topmargin + d->bottommargin);

    return style()->sizeFromContents(QStyle::CT_Menu, &opt,
                                    s.expandedTo(QApplication::globalStrut()), this);
}

/*!
    Displays the menu so that the action \a atAction will be at the
    specified \e global position \a p. To translate a widget's local
    coordinates into global coordinates, use QWidget::mapToGlobal().

    When positioning a menu with exec() or popup(), bear in mind that
    you cannot rely on the menu's current size(). For performance
    reasons, the menu adapts its size only when necessary, so in many
    cases, the size before and after the show is different. Instead,
    use sizeHint() which calculates the proper size depending on the
    menu's current contents.

    \sa QWidget::mapToGlobal(), exec()
*/
void QMenu::popup(const QPoint &p, QAction *atAction)
{
    Q_D(QMenu);
    if (d->scroll) { //reset scroll state from last popup
        d->scroll->scrollOffset = 0;
        d->scroll->scrollFlags = QMenuPrivate::QMenuScroller::ScrollNone;
    }
    d->tearoffHighlighted = 0;
    d->motions = 0;
    d->doChildEffects = true;

    ensurePolished(); // Get the right font
    emit aboutToShow();
    d->updateActions();
    QPoint pos = p;
    QSize size = sizeHint();
    QRect screen = QApplication::desktop()->availableGeometry(p);
    const int desktopFrame = style()->pixelMetric(QStyle::PM_MenuDesktopFrameWidth, 0, this);
    if (d->ncols > 1) {
        pos.setY(screen.top()+desktopFrame);
    } else if (atAction) {
        for(int i=0, above_height=0; i<(int)d->actionList.count(); i++) {
            QAction *action = d->actionList.at(i);
            if (action == atAction) {
                int newY = pos.y()-above_height;
                if (d->scroll && newY < desktopFrame) {
                    d->scroll->scrollFlags = d->scroll->scrollFlags
                                             | QMenuPrivate::QMenuScroller::ScrollUp;
                    d->scroll->scrollOffset = newY;
                    newY = desktopFrame;
                }
                pos.setY(newY);

                if (d->scroll && d->scroll->scrollFlags != QMenuPrivate::QMenuScroller::ScrollNone
                    && !style()->styleHint(QStyle::SH_Menu_FillScreenWithScroll, 0, this)) {
                    int below_height = above_height + d->scroll->scrollOffset;
                    for(int i2 = i; i2 < (int)d->actionList.count(); i2++)
                        below_height += d->actionRects.value(d->actionList.at(i2)).height();
                    size.setHeight(below_height);
                }
                break;
            } else {
                above_height += d->actionRects.value(action).height();
            }
        }
    }

    QPoint mouse = QCursor::pos();
    const bool snapToMouse = (p == mouse);

    //handle popup falling "off screen"
    if (qApp->layoutDirection() == Qt::RightToLeft) {
        if(snapToMouse) //position flowing left from the mouse
            pos.setX(mouse.x()-size.width());

        if (pos.x() < screen.left()+desktopFrame)
            pos.setX(qMax(p.x(), screen.left()+desktopFrame));
        else if (pos.x()+size.width() > screen.right()-desktopFrame)
            pos.setX(qMax(p.x()-size.width(), screen.right()-desktopFrame-size.width()));
    } else {
        if (pos.x()+size.width() > screen.right()-desktopFrame)
            pos.setX(qMin(p.x()-size.width(), screen.right()-desktopFrame-size.width()));
        else if (pos.x() < screen.left()+desktopFrame)
            pos.setX(p.x());
    }
    if (pos.y() + size.height() > screen.bottom() - desktopFrame) {
        if(snapToMouse)
            pos.setY(qMin(mouse.y() - (size.height() + desktopFrame), screen.bottom()-desktopFrame-size.height()));
        else
            pos.setY(qMax(p.y() - (size.height() + desktopFrame), screen.bottom()-desktopFrame-size.height()));
    } else if (pos.y() < screen.top() + desktopFrame) {
        pos.setY(screen.top() + desktopFrame);
    }

    if (d->scroll) {
        if(pos.y() < screen.top())
            pos.setY(screen.top());
        if(pos.y()+size.height() > screen.bottom() - desktopFrame) {
            d->scroll->scrollFlags |= uint(QMenuPrivate::QMenuScroller::ScrollDown);
            size.setHeight(screen.bottom()-desktopFrame-pos.y());
        }
    } else {
        if(pos.y()+size.height() > screen.bottom())
            pos.setY(desktopFrame+screen.top()+(screen.height()-desktopFrame-size.height()));
        else if(pos.y() < screen.top())
            pos.setY(screen.top());
    }
    setGeometry(QRect(pos, size));

#ifndef QT_NO_EFFECTS
    int hGuess = qApp->layoutDirection() == Qt::RightToLeft ? QEffects::LeftScroll : QEffects::RightScroll;
    int vGuess = QEffects::DownScroll;
    if (qApp->layoutDirection() == Qt::RightToLeft) {
        if ((snapToMouse && (pos.x() + size.width()/2 > mouse.x())) ||
           (qobject_cast<QMenu*>(d->causedPopup.widget) && pos.x() + size.width()/2 > d->causedPopup.widget->x()))
            hGuess = QEffects::RightScroll;
    } else {
        if ((snapToMouse && (pos.x() + size.width()/2 < mouse.x())) ||
           (qobject_cast<QMenu*>(d->causedPopup.widget) && pos.x() + size.width()/2 < d->causedPopup.widget->x()))
            hGuess = QEffects::LeftScroll;
    }

#ifndef QT_NO_MENUBAR
    if ((snapToMouse && (pos.y() + size.height()/2 < mouse.y())) ||
       (qobject_cast<QMenuBar*>(d->causedPopup.widget) &&
        pos.y() + size.width()/2 < d->causedPopup.widget->mapToGlobal(d->causedPopup.widget->pos()).y()))
       vGuess = QEffects::UpScroll;
#endif
    if (QApplication::isEffectEnabled(Qt::UI_AnimateMenu)) {
        bool doChildEffects = true;
#ifndef QT_NO_MENUBAR
        if (QMenuBar *mb = qobject_cast<QMenuBar*>(d->causedPopup.widget)) {
            doChildEffects = mb->d_func()->doChildEffects;
            mb->d_func()->doChildEffects = false;
        } else
#endif
        if (QMenu *m = qobject_cast<QMenu*>(d->causedPopup.widget)) {
            doChildEffects = m->d_func()->doChildEffects;
            m->d_func()->doChildEffects = false;
        }

        if (doChildEffects) {
            if (QApplication::isEffectEnabled(Qt::UI_FadeMenu))
                qFadeEffect(this);
            else if (d->causedPopup.widget)
                qScrollEffect(this, qobject_cast<QMenu*>(d->causedPopup.widget) ? hGuess : vGuess);
            else
                qScrollEffect(this, hGuess | vGuess);
        } else {
            // kill any running effect
            qFadeEffect(0);
            qScrollEffect(0);

            show();
        }
    } else
#endif
    {
        show();
    }

#ifndef QT_NO_ACCESSIBILITY
    QAccessible::updateAccessibility(this, 0, QAccessible::PopupMenuStart);
#endif
}

/*!
    Executes this menu synchronously.

    This is equivalent to \c{exec(pos())}.

    This returns the triggered QAction in either the popup menu or one
    of its submenus, or 0 if no item was triggered (normally because
    the user pressed Esc).

    In most situations you'll want to specify the position yourself,
    for example, the current mouse position:
    \code
      exec(QCursor::pos());
    \endcode
    or aligned to a widget:
    \code
      exec(somewidget.mapToGlobal(QPoint(0,0)));
    \endcode
    or in reaction to a QMouseEvent *e:
    \code
      exec(e->globalPos());
    \endcode
*/
QAction *QMenu::exec()
{
    return exec(pos());
}


/*!
    \overload

    Executes this menu synchronously.

    Pops up the menu so that the action \a action will be at the
    specified \e global position \a p. To translate a widget's local
    coordinates into global coordinates, use QWidget::mapToGlobal().

    This returns the triggered QAction in either the popup menu or one
    of its submenus, or 0 if no item was triggered (normally because
    the user pressed Esc).

    Note that all signals are emitted as usual. If you connect a
    QAction to a slot and call the menu's exec(), you get the result
    both via the signal-slot connection and in the return value of
    exec().

    Common usage is to position the menu at the current mouse
    position:
    \code
        exec(QCursor::pos());
    \endcode
    or aligned to a widget:
    \code
        exec(somewidget.mapToGlobal(QPoint(0, 0)));
    \endcode
    or in reaction to a QMouseEvent *e:
    \code
      exec(e->globalPos());
    \endcode

    When positioning a menu with exec() or popup(), bear in mind that
    you cannot rely on the menu's current size(). For performance
    reasons, the menu adapts its size only when necessary. So in many
    cases, the size before and after the show is different. Instead,
    use sizeHint() which calculates the proper size depending on the
    menu's current contents.

    \sa popup(), QWidget::mapToGlobal()
*/
QAction *QMenu::exec(const QPoint &p, QAction *action)
{
    Q_D(QMenu);
    QEventLoop eventLoop;
    d->eventLoop = &eventLoop;
    popup(p, action);

    QPointer<QObject> guard = this;
    (void) eventLoop.exec();
    if (guard.isNull())
        return 0;

    action = d->syncAction;
    d->syncAction = 0;
    d->eventLoop = 0;
    return action;
}

/*!
    \overload

    Executes this menu synchronously.

    The menu's actions are specified by the list of \a actions. The menu
    will pop up so that the specified action, \a at, appears at global
    position \a pos. If \a at is not specified then the menu appears
    at position \a pos.

    The function returns the triggered QAction in either the popup
    menu or one of its submenus, or 0 if no item was triggered
    (normally because the user pressed Esc).

    This is equivalent to:
    \code
       QMenu menu;
       QAction *at = actions[0]; // Assumes actions is not empty
       foreach (QAction *a, actions)
          menu.addAction(a);
       menu.exec(pos, at);
    \endcode

    \sa popup(), QWidget::mapToGlobal()
*/
QAction *QMenu::exec(QList<QAction*> actions, const QPoint &pos, QAction *at)
{
    QMenu menu;
    for(QList<QAction*>::Iterator it = actions.begin(); it != actions.end(); ++it)
        menu.addAction((*it));
    return menu.exec(pos, at);
}

/*!
  \reimp
*/
void QMenu::hideEvent(QHideEvent *)
{
    Q_D(QMenu);
#ifdef QT3_SUPPORT
    emit aboutToHide();
#endif