- Qt 5.5
- Qt WebEngine Widgets
- WebEngine Tab Browser Example
- modelmenu.cpp Example File
- Qt 5.5.1 Reference Documentation

# modelmenu.cpp Example File

browser/modelmenu.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the demonstration applications of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:LGPL$
    ** Commercial License Usage
    ** Licensees holding valid commercial Qt licenses may use this file in
    ** accordance with the commercial license agreement provided with the
    ** Software or, alternatively, in accordance with the terms contained in
    ** a written agreement between you and The Qt Company. For licensing terms
    ** and conditions see http://www.qt.io/terms-conditions. For further
    ** information use the contact form at http://www.qt.io/contact-us.
    **
    ** GNU Lesser General Public License Usage
    ** Alternatively, this file may be used under the terms of the GNU Lesser
    ** General Public License version 2.1 as published by the Free Software
    ** Foundation and appearing in the file LICENSE.LGPL included in the
    ** packaging of this file. Please review the following information to
    ** ensure the GNU Lesser General Public License version 2.1 requirements
    ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
    **
    ** As a special exception, The Qt Company gives you certain additional
    ** rights. These rights are described in The Qt Company LGPL Exception
    ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
    **
    ** GNU General Public License Usage
    ** Alternatively, this file may be used under the terms of the GNU
    ** General Public License version 3.0 as published by the Free Software
    ** Foundation and appearing in the file LICENSE.GPL included in the
    ** packaging of this file. Please review the following information to
    ** ensure the GNU General Public License version 3.0 requirements will be
    ** met: http://www.gnu.org/copyleft/gpl.html.
    **
    **
    ** $QT_END_LICENSE$
    **
    ****************************************************************************/

    #include "modelmenu.h"

    #include <QtCore/QAbstractItemModel>
    #include <qdebug.h>

    ModelMenu::ModelMenu(QWidget * parent)
        : QMenu(parent)
        , m_maxRows(7)
        , m_firstSeparator(-1)
        , m_maxWidth(-1)
        , m_hoverRole(0)
        , m_separatorRole(0)
        , m_model(0)
    {
        connect(this, SIGNAL(aboutToShow()), this, SLOT(aboutToShow()));
    }

    bool ModelMenu::prePopulated()
    {
        return false;
    }

    void ModelMenu::postPopulated()
    {
    }

    void ModelMenu::setModel(QAbstractItemModel *model)
    {
        m_model = model;
    }

    QAbstractItemModel *ModelMenu::model() const
    {
        return m_model;
    }

    void ModelMenu::setMaxRows(int max)
    {
        m_maxRows = max;
    }

    int ModelMenu::maxRows() const
    {
        return m_maxRows;
    }

    void ModelMenu::setFirstSeparator(int offset)
    {
        m_firstSeparator = offset;
    }

    int ModelMenu::firstSeparator() const
    {
        return m_firstSeparator;
    }

    void ModelMenu::setRootIndex(const QModelIndex &index)
    {
        m_root = index;
    }

    QModelIndex ModelMenu::rootIndex() const
    {
        return m_root;
    }

    void ModelMenu::setHoverRole(int role)
    {
        m_hoverRole = role;
    }

    int ModelMenu::hoverRole() const
    {
        return m_hoverRole;
    }

    void ModelMenu::setSeparatorRole(int role)
    {
        m_separatorRole = role;
    }

    int ModelMenu::separatorRole() const
    {
        return m_separatorRole;
    }

    Q_DECLARE_METATYPE(QModelIndex)
    void ModelMenu::aboutToShow()
    {
        if (QMenu *menu = qobject_cast<QMenu*>(sender())) {
            QVariant v = menu->menuAction()->data();
            if (v.canConvert<QModelIndex>()) {
                QModelIndex idx = qvariant_cast<QModelIndex>(v);
                createMenu(idx, -1, menu, menu);
                disconnect(menu, SIGNAL(aboutToShow()), this, SLOT(aboutToShow()));
                return;
            }
        }

        clear();
        if (prePopulated())
            addSeparator();
        int max = m_maxRows;
        if (max != -1)
            max += m_firstSeparator;
        createMenu(m_root, max, this, this);
        postPopulated();
    }

    void ModelMenu::createMenu(const QModelIndex &parent, int max, QMenu *parentMenu, QMenu *menu)
    {
        if (!menu) {
            QString title = parent.data().toString();
            menu = new QMenu(title, this);
            QIcon icon = qvariant_cast<QIcon>(parent.data(Qt::DecorationRole));
            menu->setIcon(icon);
            parentMenu->addMenu(menu);
            QVariant v;
            v.setValue(parent);
            menu->menuAction()->setData(v);
            connect(menu, SIGNAL(aboutToShow()), this, SLOT(aboutToShow()));
            return;
        }

        int end = m_model->rowCount(parent);
        if (max != -1)
            end = qMin(max, end);

        connect(menu, SIGNAL(triggered(QAction*)), this, SLOT(triggered(QAction*)));
        connect(menu, SIGNAL(hovered(QAction*)), this, SLOT(hovered(QAction*)));

        for (int i = 0; i < end; ++i) {
            QModelIndex idx = m_model->index(i, 0, parent);
            if (m_model->hasChildren(idx)) {
                createMenu(idx, -1, menu);
            } else {
                if (m_separatorRole != 0
                    && idx.data(m_separatorRole).toBool())
                    addSeparator();
                else
                    menu->addAction(makeAction(idx));
            }
            if (menu == this && i == m_firstSeparator - 1)
                addSeparator();
        }
    }

    QAction *ModelMenu::makeAction(const QModelIndex &index)
    {
        QIcon icon = qvariant_cast<QIcon>(index.data(Qt::DecorationRole));
        QAction *action = makeAction(icon, index.data().toString(), this);
        QVariant v;
        v.setValue(index);
        action->setData(v);
        return action;
    }

    QAction *ModelMenu::makeAction(const QIcon &icon, const QString &text, QObject *parent)
    {
        QFontMetrics fm(font());
        if (-1 == m_maxWidth)
            m_maxWidth = fm.width(QLatin1Char('m')) * 30;
        QString smallText = fm.elidedText(text, Qt::ElideMiddle, m_maxWidth);
        return new QAction(icon, smallText, parent);
    }

    void ModelMenu::triggered(QAction *action)
    {
        QVariant v = action->data();
        if (v.canConvert<QModelIndex>()) {
            QModelIndex idx = qvariant_cast<QModelIndex>(v);
            emit activated(idx);
        }
    }

    void ModelMenu::hovered(QAction *action)
    {
        QVariant v = action->data();
        if (v.canConvert<QModelIndex>()) {
            QModelIndex idx = qvariant_cast<QModelIndex>(v);
            QString hoveredString = idx.data(m_hoverRole).toString();
            if (!hoveredString.isEmpty())
                emit hovered(hoveredString);
        }
    }