qstringlistmodel.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

/*
  A simple model that uses a QStringList as its data source.
*/

#include "qstringlistmodel.h"

#ifndef QT_NO_STRINGLISTMODEL
/*!
  \class QStringListModel
  \brief The QStringListModel class provides a model that supplies strings to views.

  \ingroup model-view
  \mainclass

  QStringListModel is an editable model that can be used for simple cases
  where you need to display a number of strings in a view widget, such as
  a QListView or a QComboBox.

  The model provides all the standard functions of an editable model,
  representing the data in the string list as a model with one column and
  a number of rows equal to the number of items in the list.

  Model indexes corresponding to items are obtained with the
  \l{QAbstractListModel::index()}{index()} function, and item flags are
  obtained with flags().
  Item data is read with the data() function and written with setData().
  The number of rows (and number of items in the string list) can be found
  with the rowCount() function.

  The model can be constructed with an existing string list, or strings can
  be set later with the setStringList() convenience function. Strings can
  also be inserted in the usual way with the insertRows() function, and
  removed with removeRows(). The contents of the string list can be
  retrieved with the stringList() convenience function.
    
    An example usage of QStringListModel:
    \code
        QStringListModel *model = new QStringListModel();
        QStringList list;
        list << "a" << "b" << "c";
        model->setStringList(list);
    \endcode
    
  \sa QAbstractListModel, QAbstractItemModel, {Model/View Programming}
*/

/*!
  Constructs a string list model with the given \a parent.
*/

QStringListModel::QStringListModel(QObject *parent)
    : QAbstractListModel(parent)
{
}

/*!
  Constructs a string list model containing the specified \a strings with
  the given \a parent.
*/

QStringListModel::QStringListModel(const QStringList &strings, QObject *parent)
    : QAbstractListModel(parent), lst(strings)
{
}

/*!
    Returns the number of rows in the model. This value corresponds to the
    number of items in the model's internal string list.

    The optional \a parent argument is used in most models to specify the
    parent of the rows to be counted. Because this is a list if a 
    valid parent is specified the result will always be 0.

    \sa insertRows(), removeRows(), QAbstractItemModel::rowCount()
*/

int QStringListModel::rowCount(const QModelIndex &parent) const
{
    if (parent.isValid())
        return 0;
    
    return lst.count();
}

/*!
    Returns data from the item with the given \a index for the specified \a role.

    If the view requests an invalid index, an invalid variant is returned.

    \sa setData()
*/

QVariant QStringListModel::data(const QModelIndex &index, int role) const
{
    if (index.row() < 0 || index.row() >= lst.size())
        return QVariant();

    if (role == Qt::DisplayRole || role == Qt::EditRole)
        return lst.at(index.row());

    return QVariant();
}

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

    Valid items are enabled, selectable, and editable.
*/

Qt::ItemFlags QStringListModel::flags(const QModelIndex &index) const
{
    if (index.isValid())
        return QAbstractItemModel::flags(index) | Qt::ItemIsEditable;
    else
        return QAbstractItemModel::flags(index) | Qt::ItemIsDropEnabled;
}

/*!
    Sets the data for the item corresponding to the given \a index in the
    model to the \a value for the specifed \a role.

    The dataChanged() signal is emitted if the item is changed.

    \sa Qt::ItemDataRole, data()
*/

bool QStringListModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    if (index.isValid() && role == Qt::EditRole) {
        lst.replace(index.row(), value.toString());
        emit dataChanged(index, index);
        return true;
    }
    return false;
}

/*!
    Inserts \a count rows into the model beginning at the given \a row.

    The \a parent index of the rows is optional and is only used for
    consistency with QAbstractItemModel. By default, a null index is
    specified, indicating that the rows are inserted in the top level of
    the model.

    \sa QAbstractItemModel::insertRows()
*/

bool QStringListModel::insertRows(int row, int count, const QModelIndex &parent)
{
    Q_UNUSED(parent);
    if (count < 1 || row < 0 || row > rowCount(parent))
        return false;

    beginInsertRows(QModelIndex(), row, row + count - 1);

    for (int r = 0; r < count; ++r)
        lst.insert(row, QString());

    endInsertRows();

    return true;
}

/*!
    Removes \a count rows from the model beginning at the given \a row.

    The \a parent index of the rows is optional and is only used for
    consistency with QAbstractItemModel. By default, a null index is
    specified, indicating that the rows are removed in the top level of
    the model.

    \sa QAbstractItemModel::removeRows()
*/

bool QStringListModel::removeRows(int row, int count, const QModelIndex &parent)
{
    Q_UNUSED(parent);
    if (count <= 0 || row < 0 || (row + count) > rowCount(parent))
        return false;
    
    beginRemoveRows(QModelIndex(), row, row + count - 1);

    for (int r = 0; r < count; ++r)
        lst.removeAt(row);

    endRemoveRows();

    return true;
}

/*!
  \reimp
*/
void QStringListModel::sort(int, Qt::SortOrder order)
{
    if (order == Qt::AscendingOrder)
        qSort(lst.begin(), lst.end(), qLess<QString>());
    else
        qSort(lst.begin(), lst.end(), qGreater<QString>());
}

/*!
    Returns the string list used by the model to store data.
*/
QStringList QStringListModel::stringList() const
{
    return lst;
}

/*!
    Sets the model's internal string list to \a strings. The model will
    notify any attached views that its underlying data has changed.

    \sa dataChanged()
*/
void QStringListModel::setStringList(const QStringList &strings)
{
    lst = strings;
    reset();
}

#endif // QT_NO_STRINGLISTMODEL