qmenu.cpp

奇趣公司比较新的qt/emd版本

/* This is poor-mans eventfilters. This avoids the use of
   eventFilter (which can be nasty for users of QMenuBar's). */
bool QMenuPrivate::mouseEventTaken(QMouseEvent *e)
{
    Q_Q(QMenu);
    QPoint pos = q->mapFromGlobal(e->globalPos());
    if (scroll && !activeMenu) { //let the scroller "steal" the event
        bool isScroll = false;
        if (pos.x() >= 0 && pos.x() < q->width()) {
            const int scrollerHeight = q->style()->pixelMetric(QStyle::PM_MenuScrollerHeight, 0, q);
            for(int dir = QMenuScroller::ScrollUp; dir <= QMenuScroller::ScrollDown; dir = dir << 1) {
                if (scroll->scrollFlags & dir) {
                    if (dir == QMenuScroller::ScrollUp)
                        isScroll = (pos.y() <= scrollerHeight);
                    else if (dir == QMenuScroller::ScrollDown)
                        isScroll = (pos.y() >= q->height()-scrollerHeight);
                    if (isScroll) {
                        scroll->scrollDirection = dir;
                        break;
                    }
                }
            }
        }
        if (isScroll) {
            if (!scroll->scrollTimer)
                scroll->scrollTimer = new QBasicTimer;
            scroll->scrollTimer->start(50, q);
            return true;
        } else if (scroll->scrollTimer && scroll->scrollTimer->isActive()) {
            scroll->scrollTimer->stop();
        }
    }

    if (tearoff) { //let the tear off thingie "steal" the event..
        QRect tearRect(0, 0, q->width(), q->style()->pixelMetric(QStyle::PM_MenuTearoffHeight, 0, q));
        if (scroll && scroll->scrollFlags & QMenuPrivate::QMenuScroller::ScrollUp)
            tearRect.translate(0, q->style()->pixelMetric(QStyle::PM_MenuScrollerHeight, 0, q));
        q->update(tearRect);
        if (tearRect.contains(pos) && hasMouseMoved(e->globalPos())) {
            setCurrentAction(0);
            tearoffHighlighted = 1;
            if (e->type() == QEvent::MouseButtonRelease) {
                if (!tornPopup)
                    tornPopup = new QTornOffMenu(q);
                tornPopup->setGeometry(q->geometry());
                tornPopup->show();
                hideUpToMenuBar();
            }
            return true;
        }
        tearoffHighlighted = 0;
    }

    if (q->frameGeometry().contains(e->globalPos())) //otherwise if the event is in our rect we want it..
        return false;

    for(QWidget *caused = causedPopup.widget; caused;) {
        bool passOnEvent = false;
        QWidget *next_widget = 0;
        QPoint cpos = caused->mapFromGlobal(e->globalPos());
#ifndef QT_NO_MENUBAR
        if (QMenuBar *mb = qobject_cast<QMenuBar*>(caused)) {
            passOnEvent = mb->rect().contains(cpos);
        } else
#endif
        if (QMenu *m = qobject_cast<QMenu*>(caused)) {
            passOnEvent = m->d_func()->actionAt(cpos);
            next_widget = m->d_func()->causedPopup.widget;
        }
        if (passOnEvent) {
            if(e->type() != QEvent::MouseButtonRelease || mouseDown == caused) {
            QMouseEvent new_e(e->type(), cpos, e->button(), e->buttons(), e->modifiers());
            QApplication::sendEvent(caused, &new_e);
            return true;
        }
        }
        if (!next_widget)
            break;
        caused = next_widget;
    }
    return false;
}

void QMenuPrivate::activateAction(QAction *action, QAction::ActionEvent action_e, bool self)
{
    Q_Q(QMenu);
#ifndef QT_NO_WHATSTHIS
    bool inWhatsThisMode = QWhatsThis::inWhatsThisMode();
#endif
    if (!action || !q->isEnabled()
        || (action_e == QAction::Trigger
#ifndef QT_NO_WHATSTHIS
            && !inWhatsThisMode
#endif
            && (action->isSeparator() ||!action->isEnabled())))
        return;

    /* I have to save the caused stack here because it will be undone after popup execution (ie in the hide).
       Then I iterate over the list to actually send the events. --Sam
    */
    const QList<QPointer<QWidget> > causedStack = calcCausedStack();
    if (action_e == QAction::Trigger) {
        for(QWidget *widget = qApp->activePopupWidget(); widget; ) {
            if (QMenu *qmenu = ::qobject_cast<QMenu*>(widget)) {
                if(qmenu == q)
                    hideUpToMenuBar();
                widget = qmenu->d_func()->causedPopup.widget;
            } else {
                break;
            }
        }
#ifndef QT_NO_WHATSTHIS
        if (inWhatsThisMode) {
            QString s = action->whatsThis();
            if (s.isEmpty())
                s = whatsThis;
            QWhatsThis::showText(q->mapToGlobal(actionRect(action).center()), s, q);
            return;
        }
#endif
    }

#ifdef QT3_SUPPORT
    const int actionId = q->findIdForAction(action);
#endif
    if(self)
        action->activate(action_e);

    for(int i = 0; i < causedStack.size(); ++i) {
        QPointer<QWidget> widget = causedStack.at(i);
        if (!widget)
            continue;
        //fire
        if (QMenu *qmenu = ::qobject_cast<QMenu*>(widget)) {
            widget = qmenu->d_func()->causedPopup.widget;
            if (action_e == QAction::Trigger) {
                emit qmenu->triggered(action);
#ifdef QT3_SUPPORT
                emit qmenu->activated(actionId);
#endif
            } else if (action_e == QAction::Hover) {
                emit qmenu->hovered(action);
#ifdef QT3_SUPPORT
                emit qmenu->highlighted(actionId);
#endif
            }
#ifndef QT_NO_MENUBAR
        } else if (QMenuBar *qmenubar = ::qobject_cast<QMenuBar*>(widget)) {
            if (action_e == QAction::Trigger) {
                emit qmenubar->triggered(action);
#ifdef QT3_SUPPORT
                emit qmenubar->activated(actionId);
#endif
            } else if (action_e == QAction::Hover) {
                emit qmenubar->hovered(action);
#ifdef QT3_SUPPORT
                emit qmenubar->highlighted(actionId);
#endif
            }
            break; //nothing more..
#endif
        }
    }

    if (action_e == QAction::Hover) {
#ifndef QT_NO_ACCESSIBILITY
        if (QAccessible::isActive()) {
            int actionIndex = indexOf(action) + 1;
            QAccessible::updateAccessibility(q, actionIndex, QAccessible::Focus);
            QAccessible::updateAccessibility(q, actionIndex, QAccessible::Selection);
        }
#endif
        QWidget *w = causedPopup.widget;
        while (QMenu *m = qobject_cast<QMenu*>(w))
            w = m->d_func()->causedPopup.widget;
        action->showStatusText(w);
    }
}

void QMenuPrivate::_q_actionTriggered()
{
    Q_Q(QMenu);
    if (QAction *action = qobject_cast<QAction *>(q->sender())) {
#ifdef QT3_SUPPORT
        //we store it here because the action might be deleted/changed by connected slots 
        const int id = q->findIdForAction(action);
#endif
        emit q->triggered(action);
#ifdef QT3_SUPPORT
        emit q->activated(id);
#endif
    }
}

void QMenuPrivate::_q_actionHovered()
{
    Q_Q(QMenu);
    if (QAction *action = qobject_cast<QAction *>(q->sender())) {
#ifdef QT3_SUPPORT
        //we store it here because the action might be deleted/changed by connected slots 
        const int id = q->findIdForAction(action);
#endif
        emit q->hovered(action);
#ifdef QT3_SUPPORT
        emit q->highlighted(id);
#endif
    }
}

bool QMenuPrivate::hasMouseMoved(const QPoint &globalPos)
{
    //determines if the mouse has moved (ie its intial position has 
    //changed by more than QApplication::startDragDistance()
    //or if there were at least 6 mouse motions)
    return motions > 6 || 
        QApplication::startDragDistance() < (mousePopupPos - globalPos).manhattanLength();
}


/*!
    Initialize \a option with the values from this menu and information from \a action. This method
    is useful for subclasses when they need a QStyleOptionMenuItem, but don't want
    to fill in all the information themselves.

    \sa QStyleOption::initFrom() QMenuBar::initStyleOption()
*/
void QMenu::initStyleOption(QStyleOptionMenuItem *option, const QAction *action) const
{
    if (!option || !action)
        return;

    Q_D(const QMenu);
    option->initFrom(this);
    option->palette = palette();
    option->state = QStyle::State_None;

    if (window()->isActiveWindow())
        option->state |= QStyle::State_Active;
    if (isEnabled() && action->isEnabled()
            && (!action->menu() || action->menu()->isEnabled()))
        option->state |= QStyle::State_Enabled;
    else
        option->palette.setCurrentColorGroup(QPalette::Disabled);

    option->font = action->font();

    if (d->currentAction && d->currentAction == action && !d->currentAction->isSeparator()) {
        option->state |= QStyle::State_Selected
                     | (d->mouseDown ? QStyle::State_Sunken : QStyle::State_None);
    }

    option->menuHasCheckableItems = d->hasCheckableItems;
    if (!action->isCheckable()) {
        option->checkType = QStyleOptionMenuItem::NotCheckable;
    } else {
        option->checkType = (action->actionGroup() && action->actionGroup()->isExclusive())
                            ? QStyleOptionMenuItem::Exclusive : QStyleOptionMenuItem::NonExclusive;
        option->checked = action->isChecked();
    }
    if (action->menu())
        option->menuItemType = QStyleOptionMenuItem::SubMenu;
    else if (action->isSeparator())
        option->menuItemType = QStyleOptionMenuItem::Separator;
    else if (d->defaultAction == action)
	    option->menuItemType = QStyleOptionMenuItem::DefaultItem;
    else
        option->menuItemType = QStyleOptionMenuItem::Normal;
    option->icon = action->icon();
    QString textAndAccel = action->text();
#ifndef QT_NO_SHORTCUT
    if (textAndAccel.indexOf(QLatin1Char('\t')) == -1) {
        QKeySequence seq = action->shortcut();
        if (!seq.isEmpty())
            textAndAccel += QLatin1Char('\t') + QString(seq);
    }
#endif
    option->text = textAndAccel;
    option->tabWidth = d->tabWidth;
    option->maxIconWidth = d->maxIconWidth;
    option->menuRect = rect();
}

/*!
    \class QMenu
    \brief The QMenu class provides a menu widget for use in menu
    bars, context menus, and other popup menus.

    \ingroup application
    \ingroup basicwidgets
    \mainclass
    
    A menu widget is a selection menu. It can be either a pull-down
    menu in a menu bar or a standalone context menu. Pull-down menus
    are shown by the menu bar when the user clicks on the respective
    item or presses the specified shortcut key. Use
    QMenuBar::addMenu() to insert a menu into a menu bar. Context
    menus are usually invoked by some special keyboard key or by
    right-clicking. They can be executed either asynchronously with
    popup() or synchronously with exec(). Menus can also be invoked in
    response to button presses; these are just like context menus
    except for how they are invoked.
    
    \raw HTML
    <table align="center" cellpadding="0">
    <tr>
        <td>
            \endraw
            \inlineimage plastique-menu.png
            \raw HTML
        </td>
        <td>
            \endraw
            \inlineimage windowsxp-menu.png
            \raw HTML
        </td>
        <td>
            \endraw
            \inlineimage macintosh-menu.png
            \raw HTML
        </td>

    </tr>
    <tr>
        <td colspan="3">
           \endraw
           A menu shown in \l{Plastique Style Widget Gallery}{Plastique widget style}, 
           \l{Windows XP Style Widget Gallery}{Windows XP widget style},
           and \l{Macintosh Style Widget Gallery}{Macintosh widget style}. 
           \raw HTML
        </td>
    </tr>
    </table>
    \endraw    
    
    A menu consists of a list of action items. Actions are added with
    addAction(). An action is represented vertically and rendered by
    QStyle. In addition, actions can have a text label, an optional
    icon drawn on the very left side, and shortcut key sequence such
    as "Ctrl+X".

    There are three kinds of action items: separators, actions that
    show a submenu, and actions that perform an action. Separators are
    inserted with addSeparator(). For submenus use addMenu(). All
    other items are considered action items.

    When inserting action items you usually specify a receiver and a
    slot. The receiver will be notifed whenever the item is
    \l{QAction::triggered()}{triggered()}. In addition, QMenu provides
    two signals, activated() and highlighted(), which signal the
    QAction that was triggered from the menu.

    You clear a menu with clear() and remove individual action items
    with removeAction().

    A QMenu can also provide a tear-off menu. A tear-off menu is a
    top-level window that contains a copy of the menu. This makes it
    possible for the user to "tear off" frequently used menus and
    position them in a convenient place on the screen. If you want
    this functionality for a particular menu, insert a tear-off handle
    with setTearOffEnabled(). When using tear-off menus, bear in mind
    that the concept isn't typically used on Microsoft Windows so
    some users may not be familiar with it. Consider using a QToolBar
    instead.

    See the \l{mainwindows/menus}{Menus} example for an example of how
    to use QMenuBar and QMenu in your application.

    Important inherited functions: addAction(), removeAction(), clear(),
    addSeparator(), and addMenu().

    \sa QMenuBar, {fowler}{GUI Design Handbook: Menu, Drop-Down and Pop-Up},
        {Application Example}, {Menus Example}, {Recent Files Example}
*/


/*!
    Constructs a menu with parent \a parent.

    Although a popup menu is always a top-level widget, if a parent is
    passed the popup menu will be deleted when that parent is
    destroyed (as with any other QObject).
*/
QMenu::QMenu(QWidget *parent)
    : QWidget(*new QMenuPrivate, parent, Qt::Popup)
{
    Q_D(QMenu);
    d->init();
}

/*!
    Constructs a menu with a \a title and a \a parent.

    Although a popup menu is always a top-level widget, if a parent is
    passed the popup menu will be deleted when that parent is