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;
  }