Qt 5.11 | Qt Core | MIME Type Browser Example | mimetypemodel.cpp Example File

Qt 5.11.3 Reference Documentation

# mimetypemodel.cpp Example File

mimetypes/mimetypebrowser/mimetypemodel.cpp

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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;
      }