mimetypemodel.cpp Example File

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 #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;
 }