qabstractitemmodel.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

    Returns a map with values for all predefined roles in the model
    for the item at the given \a index.

    Reimplemented this function if you want to extend the default behavior
    of this function to include custom roles in the map.

    \sa Qt::ItemDataRole, data()
*/
QMap<int, QVariant> QAbstractItemModel::itemData(const QModelIndex &index) const
{
    QMap<int, QVariant> roles;
    for (int i = 0; i < Qt::UserRole; ++i) {
        QVariant variantData = data(index, i);
        if (variantData.type() != QVariant::Invalid)
            roles.insert(i, variantData);
    }
    return roles;
}

/*!
    Sets the \a role data for the item at \a index to \a value.
    Returns true if successful; otherwise returns false.

    The dataChanged() signal should be emitted if the data was successfully set.

    The base class implementation returns false. This function and
    data() must be reimplemented for editable models. Note that the
    dataChanged() signal must be emitted explicitly when
    reimplementing this function.

    \sa Qt::ItemDataRole, data(), itemData()
*/
bool QAbstractItemModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    Q_UNUSED(index);
    Q_UNUSED(value);
    Q_UNUSED(role);
    return false;
}

/*!
    \fn QVariant QAbstractItemModel::data(const QModelIndex &index, int role) const = 0

    Returns the data stored under the given \a role for the item referred to
    by the \a index.

    \sa Qt::ItemDataRole, setData(), headerData()
*/

/*!
    For every Qt::ItemDataRole in \a roles, sets the role data for the item at
    \a index to the associated value in \a roles. Returns true if
    successful; otherwise returns false.

    \sa setData() data() itemData()
*/
bool QAbstractItemModel::setItemData(const QModelIndex &index, const QMap<int, QVariant> &roles)
{
    bool b = true;
    for (QMap<int, QVariant>::ConstIterator it = roles.begin(); it != roles.end(); ++it)
        b = b && setData(index, it.value(), it.key());
    return b;
}

/*!
    Returns a list of MIME types that can be used to describe a list of
    model indexes.

    \sa mimeData()
*/
QStringList QAbstractItemModel::mimeTypes() const
{
    QStringList types;
    types << "application/x-qabstractitemmodeldatalist";
    return types;
}

/*!
    Returns an object that contains serialized items of data corresponding to the
    list of \a indexes specified. The formats used to describe the encoded data
    is obtained from the mimeTypes() function.

    If the list of indexes is empty, 0 is returned rather than a serialized
    empty list.
*/
QMimeData *QAbstractItemModel::mimeData(const QModelIndexList &indexes) const
{
    if (indexes.count() <= 0)
        return 0;
    QMimeData *data = new QMimeData();
    QString format = mimeTypes().at(0);
    QByteArray encoded;
    QDataStream stream(&encoded, QIODevice::WriteOnly);
    encodeData(indexes, stream);
    data->setData(format, encoded);
    return data;
}

/*!
    Handles the \a data supplied by a drag and drop operation that ended with
    the given \a action.
    Although the specified \a row, \a column and \a parent indicate the location of
    an item in the model where the operation ended, it is the responsibility of the
    view to provide a suitable location for where the data should be inserted.

    For instance, a drop action on an item in a QTreeView can result in new items
    either being inserted as children of the item specified by \a row, \a column,
    and \a parent, or as siblings of the item.

    \sa supportedDropActions()
*/
bool QAbstractItemModel::dropMimeData(const QMimeData *data, Qt::DropAction action,
                                      int row, int column, const QModelIndex &parent)
{
    // check if the action is supported
    if (!data || action != Qt::CopyAction)
        return false;
    // check if the format is supported
    QString format = mimeTypes().at(0);
    if (!data->hasFormat(format))
        return false;
    if (row > rowCount(parent))
        row = rowCount(parent);
    if (row == -1)
        row = rowCount(parent);
    if (column == -1)
        column = 0;
    // decode and insert
    QByteArray encoded = data->data(format);
    QDataStream stream(&encoded, QIODevice::ReadOnly);
    return decodeData(row, column, parent, stream);
}

/*!
  Returns the drop actions supported by this model.

  The default implementation returns Qt::CopyAction. It is only necessary to reimplement
  this function in subclasses if you wish to support more types of drag and drop
  operation.

  \sa Qt::DropActions
*/
Qt::DropActions QAbstractItemModel::supportedDropActions() const
{
    return Qt::CopyAction;
}

/*!
  On models that support this, inserts \a count rows into the model before the
  given \a row.  The items in the new row will be children of the item
  represented by the \a parent model index.

  If \a row is 0, the rows are prepended to any existing rows in the parent.
  If \a row is rowCount(), the rows are appended to any existing rows in the
  parent.
  If \a parent has no children, a single column with \a count rows is inserted.

  Returns true if the rows were successfully inserted; otherwise returns
  false.

  The base class implementation does nothing and returns false.

  If you implement your own model, you can reimplement this function
  if you want to support insertions. Alternatively, you can provide
  you own API for altering the data.

  \sa insertColumns(), removeRows(), beginInsertRows(), endInsertRows()
*/
bool QAbstractItemModel::insertRows(int, int, const QModelIndex &)
{
    return false;
}

/*!
  On models that support this, inserts \a count new columns into the model
  before the given \a column.  The items in each new column will be children
  of the item represented by the \a parent model index.

  If \a column is 0, the columns are prepended to any existing columns.
  If \a column is columnCount(), the columns are appended to any existing
  columns.
  If \a parent has no children, a single row with \a count columns is inserted.

  Returns true if the columns were successfully inserted; otherwise returns
  false.

  The base class implementation does nothing and returns false.

  If you implement your own model, you can reimplement this function
  if you want to support insertions. Alternatively, you can provide
  you own API for altering the data.

  \sa insertRows(), removeColumns(), beginInsertColumns(), endInsertColumns()
*/
bool QAbstractItemModel::insertColumns(int, int, const QModelIndex &)
{
    return false;
}

/*!
    On models that support this, removes \a count rows starting with the given
    \a row under parent \a parent from the model. Returns true if the rows
    were successfully removed; otherwise returns false.

    The base class implementation does nothing and returns false.

    If you implement your own model, you can reimplement this function
    if you want to support removing. Alternatively, you can provide
    you own API for altering the data.

    \sa removeRow(), removeColumns(), insertColumns(), beginRemoveRows(), endRemoveRows()
*/
bool QAbstractItemModel::removeRows(int, int, const QModelIndex &)
{
    return false;
}

/*!
    On models that support this, removes \a count columns starting with the
    given \a column under parent \a parent from the model. Returns true if the
    columns were successfully removed; otherwise returns false.

    The base class implementation does nothing and returns false.

    If you implement your own model, you can reimplement this function
    if you want to support removing. Alternatively, you can provide
    you own API for altering the data.

    \sa removeColumn(), removeRows(), insertColumns(), beginRemoveColumns(), endRemoveColumns()
*/
bool QAbstractItemModel::removeColumns(int, int, const QModelIndex &)
{
    return false;
}

/*!
  Fetches any available data for the items with the parent specified by the
  \a parent index.

  Reimplement this if you have incremental data.

  The default implementation does nothing.

  \sa canFetchMore()
*/
void QAbstractItemModel::fetchMore(const QModelIndex &)
{
    // do nothing
}

/*!
  Returns true if there is more data available for \a parent,
  otherwise false.

  The default implementation always returns false.

  \sa fetchMore()
*/
bool QAbstractItemModel::canFetchMore(const QModelIndex &) const
{
    return false;
}

/*!
    Returns the item flags for the given \a index.

    The base class implementation returns a combination of flags that
    enables the item (\c ItemIsEnabled) and allows it to be
    selected (\c ItemIsSelectable).

    \sa Qt::ItemFlags
*/
Qt::ItemFlags QAbstractItemModel::flags(const QModelIndex &index) const
{
    if (!index.isValid())
        return 0;

    return Qt::ItemIsSelectable|Qt::ItemIsEnabled;
}

/*!
    Sorts the model by \a column in the given \a order.

    The base class implementation does nothing.
*/
void QAbstractItemModel::sort(int column, Qt::SortOrder order)
{
    Q_UNUSED(column);
    Q_UNUSED(order);
    // do nothing
}

/*!
  Returns a model index for the buddy of the item represented by \a index.
  When the user wants to edit an item, the view will call this function to
  check whether another item in the model should be edited instead, and
  construct a delegate using the model index returned by the buddy item.

  In the default implementation each item is its own buddy.
*/
QModelIndex QAbstractItemModel::buddy(const QModelIndex &index) const
{
    return index;
}

/*!
    Returns a list of indexes for the items where the data stored under
    the given \a role matches the specified \a value. The way the search
    is performed is defined by the \a flags given. The list that is
    returned may be empty.

    The search starts from the \a start index, and continues until the
    number of matching data items equals \a hits, the search reaches
    the last row, or the search reaches \a start again, depending on
    whether \c MatchWrap is specified in \a flags.
*/
QModelIndexList QAbstractItemModel::match(const QModelIndex &start, int role,
                                          const QVariant &value, int hits,
                                          Qt::MatchFlags flags) const
{
    QModelIndexList result;
    uint matchType = flags & 0x0F;
    bool caseSensitive = flags & Qt::MatchCaseSensitive;
    bool recurse = flags & Qt::MatchRecursive;
    bool wrap = flags & Qt::MatchWrap;
    bool allHits = (hits == -1);
    QString text; // only convert to a string if it is needed
    QModelIndex p = parent(start);
    int from = start.row();
    int to = rowCount(p);

    // iterates twice if wrapping
    for (int i = 0; (wrap && i < 2) || (!wrap && i < 1); ++i) {
        for (int r = from; (r < to) && (allHits || result.count() < hits); ++r) {
            QModelIndex idx = index(r, start.column(), p);
            if (!idx.isValid())
                 continue;
            QVariant v = data(idx, role);
            // QVariant based matching
            if (matchType == Qt::MatchExactly) {
                if (value == v)
                    result.append(idx);
            } else { // QString based matching
                if (text.isEmpty()) { // lazy conversion
                    text = value.toString();
                    if (!caseSensitive)
                        text = text.toLower();
                }
                QString t = v.toString();
                if (!caseSensitive)
                    t = t.toLower();
                switch (matchType) {
                case Qt::MatchRegExp:
                    if (QRegExp(text).exactMatch(t))
                        result.append(idx);
                    break;
                case Qt::MatchWildcard:
                    if (QRegExp(text, Qt::CaseSensitive, QRegExp::Wildcard).exactMatch(t))
                        result.append(idx);
                    break;
                case Qt::MatchStartsWith:
                    if (t.startsWith(text))
                        result.append(idx);
                    break;
                case Qt::MatchEndsWith:
                    if (t.endsWith(text))
                        result.append(idx);
                    break;
                case Qt::MatchContains:
                default:
                    if (t.contains(text))
                        result.append(idx);
                }
            }
            if (recurse && hasChildren(idx)) { // search the hierarchy
                result += match(index(0, idx.column(), idx), role,
                                (text.isEmpty() ? value : text),
                                (allHits ? -1 : hits - result.count()), flags);
            }
        }
        // prepare for the next iteration
        from = 0;
        to = start.row();
    }
    return result;
}

/*!
    Returns the row and column span of the item represented by \a index.

    Note: span is not used currently, but will be in the future.
*/

QSize QAbstractItemModel::span(const QModelIndex &) const
{