mimetypemodel.cpp Example File

/****************************************************************************
**
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** 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 https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "mimetypemodel.h"
#include <QIcon>
#include <QDebug>
#include <QMimeDatabase>
#include <QTextStream>
#include <QVariant>
#include <algorithm>
Q_DECLARE_METATYPE(QMimeType)
typedef QList<QStandardItem *> StandardItemList;
enum { mimeTypeRole = Qt::UserRole + 1, iconQueriedRole = Qt::UserRole + 2 };
bool operator<(const QMimeType &t1, const QMimeType &t2)
{
    return t1.name() < t2.name();
}
static StandardItemList createRow(const QMimeType &t)
{
    const QVariant v = QVariant::fromValue(t);
    QStandardItem *nameItem = new QStandardItem(t.name());
    const Qt::ItemFlags flags = Qt::ItemIsSelectable | Qt::ItemIsEnabled;
    nameItem->setData(v, mimeTypeRole);
    nameItem->setData(QVariant(false), iconQueriedRole);
    nameItem->setFlags(flags);
    nameItem->setToolTip(t.comment());
    return StandardItemList{nameItem};
}
MimetypeModel::MimetypeModel(QObject *parent)
    : QStandardItemModel(0, ColumnCount, parent)
{
    setHorizontalHeaderLabels(QStringList{tr("Name")});
    populate();
}
QVariant MimetypeModel::data(const QModelIndex &index, int role) const
{
    if (role != Qt::DecorationRole || !index.isValid() || index.data(iconQueriedRole).toBool())
        return QStandardItemModel::data(index, role);
    QStandardItem *item = itemFromIndex(index);
    const QString iconName = item->data(mimeTypeRole).value<QMimeType>().iconName();
    if (!iconName.isEmpty())
        item->setIcon(QIcon::fromTheme(iconName));
    item->setData(QVariant(true), iconQueriedRole);
    return item->icon();
}
QMimeType MimetypeModel::mimeType(const QModelIndex &index) const
{
    return index.data(mimeTypeRole).value<QMimeType>();
}
void MimetypeModel::populate()
{
    typedef QList<QMimeType>::Iterator Iterator;
    QMimeDatabase mimeDatabase;
    QList<QMimeType> allTypes = mimeDatabase.allMimeTypes();
    // Move top level types to rear end of list, sort this partition,
    // create top level items and truncate the list.
    Iterator end = allTypes.end();
    const Iterator topLevelStart =
        std::stable_partition(allTypes.begin(), end,
                              [](const QMimeType &t) { return !t.parentMimeTypes().isEmpty(); });
    std::stable_sort(topLevelStart, end);
    for (Iterator it = topLevelStart; it != end; ++it) {
        const StandardItemList row = createRow(*it);
        appendRow(row);
        m_nameIndexHash.insert(it->name(), indexFromItem(row.constFirst()));
    }
    allTypes.erase(topLevelStart, end);
    while (!allTypes.isEmpty()) {
        // Find a type inheriting one that is already in the model.
        end = allTypes.end();
        auto nameIndexIt = m_nameIndexHash.constEnd();
        for (Iterator it = allTypes.begin(); it != end; ++it) {
            nameIndexIt = m_nameIndexHash.constFind(it->parentMimeTypes().constFirst());
            if (nameIndexIt != m_nameIndexHash.constEnd())
                break;
        }
        if (nameIndexIt == m_nameIndexHash.constEnd()) {
            qWarning() << "Orphaned mime types:" << allTypes;
            break;
        }
        // Move types inheriting the parent type to rear end of list, sort this partition,
        // append the items to parent and truncate the list.
        const QString &parentName = nameIndexIt.key();
        const Iterator start =
            std::stable_partition(allTypes.begin(), end, [parentName](const QMimeType &t)
                                  { return !t.parentMimeTypes().contains(parentName); });
        std::stable_sort(start, end);
        QStandardItem *parentItem = itemFromIndex(nameIndexIt.value());
        for (Iterator it = start; it != end; ++it) {
            const StandardItemList row = createRow(*it);
            parentItem->appendRow(row);
            m_nameIndexHash.insert(it->name(), indexFromItem(row.constFirst()));
        }
        allTypes.erase(start, end);
    }
}
QTextStream &operator<<(QTextStream &stream, const QStringList &list)
{
    for (int i = 0, size = list.size(); i < size; ++i) {
        if (i)
            stream << ", ";
        stream << list.at(i);
    }
    return stream;
}
QString MimetypeModel::formatMimeTypeInfo(const QMimeType &t)
{
    QString result;
    QTextStream str(&result);
    str << "<html><head/><body><h3><center>" << t.name() << "</center></h3><br><table>";
    const QStringList &aliases = t.aliases();
    if (!aliases.isEmpty())
        str << "<tr><td>Aliases:</td><td>" << " (" << aliases << ')';
    str << "</td></tr>"
        << "<tr><td>Comment:</td><td>" << t.comment() << "</td></tr>"
        << "<tr><td>Icon name:</td><td>" << t.iconName() << "</td></tr>"
        << "<tr><td>Generic icon name</td><td>" << t.genericIconName() << "</td></tr>";
    const QString &filter = t.filterString();
    if (!filter.isEmpty())
        str << "<tr><td>Filter:</td><td>" << t.filterString() << "</td></tr>";
    const QStringList &patterns = t.globPatterns();
    if (!patterns.isEmpty())
        str << "<tr><td>Glob patterns:</td><td>" << patterns << "</td></tr>";
    const QStringList &parentMimeTypes = t.parentMimeTypes();
    if (!parentMimeTypes.isEmpty())
        str << "<tr><td>Parent types:</td><td>" << t.parentMimeTypes() << "</td></tr>";
    QStringList suffixes = t.suffixes();
    if (!suffixes.isEmpty()) {
        str << "<tr><td>Suffixes:</td><td>";
        const QString &preferredSuffix = t.preferredSuffix();
        if (!preferredSuffix.isEmpty()) {
            suffixes.removeOne(preferredSuffix);
            str << "<b>" << preferredSuffix << "</b> ";
        }
        str << suffixes << "</td></tr>";
    }
    str << "</table></body></html>";
    return result;
}