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Diffstat (limited to 'doc/src/snippets/persistentindexes/model.cpp')
-rw-r--r-- | doc/src/snippets/persistentindexes/model.cpp | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/doc/src/snippets/persistentindexes/model.cpp b/doc/src/snippets/persistentindexes/model.cpp new file mode 100644 index 0000000..7158f34 --- /dev/null +++ b/doc/src/snippets/persistentindexes/model.cpp @@ -0,0 +1,169 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/* + model.cpp + + A simple model that uses a QStringList as its data source. +*/ + +#include <qdebug.h> + +#include "model.h" + +/*! + Returns the number of items in the string list as the number of rows + in the model. +*/ + +int StringListModel::rowCount(const QModelIndex &parent) const +{ + return stringList.count(); +} + +/*! + Returns an appropriate value for the requested data. + If the view requests an invalid index, an invalid variant is returned. + If a header is requested then we just return the column or row number, + depending on the orientation of the header. + Any valid index that corresponds to a string in the list causes that + string to be returned. +*/ + +QVariant StringListModel::data(const QModelIndex &index, int role) const +{ + if (!index.isValid()) + return QVariant(); + + if (index.row() < 0 || index.row() >= stringList.size()) + return QVariant(); + + if (role == Qt::DisplayRole) + return stringList.at(index.row()); + else + return QVariant(); +} + +/*! + Returns the appropriate header string depending on the orientation of + the header and the section. If anything other than the display role is + requested, we return an invalid variant. +*/ + +QVariant StringListModel::headerData(int section, Qt::Orientation orientation, + int role) const +{ + if (role != Qt::DisplayRole) + return QVariant(); + + if (orientation == Qt::Horizontal) + return QString("Column %1").arg(section); + else + return QString("Row %1").arg(section); +} + +/*! + Returns an appropriate value for the item's flags. Valid items are + enabled, selectable, and editable. +*/ + +Qt::ItemFlags StringListModel::flags(const QModelIndex &index) const +{ + if (!index.isValid()) + return Qt::ItemIsEnabled; + + return QAbstractItemModel::flags(index) | Qt::ItemIsEditable; +} + +/*! + Changes an item in the string list, but only if the following conditions + are met: + + * The index supplied is valid. + * The index corresponds to an item to be shown in a view. + * The role associated with editing text is specified. + + The dataChanged() signal is emitted if the item is changed. +*/ + +bool StringListModel::setData(const QModelIndex &index, + const QVariant &value, int role) +{ + if (index.isValid() && role == Qt::EditRole) { + + stringList.replace(index.row(), value.toString()); + emit dataChanged(index, index); + return true; + } + return false; +} + +/*! + Inserts a number of rows into the model at the specified position. +*/ + +bool StringListModel::insertRows(int position, int rows, const QModelIndex &parent) +{ + beginInsertRows(parent, position, position + rows - 1); + + for (int row = 0; row < rows; ++row) { + stringList.insert(position, ""); + } + + endInsertRows(); + return true; +} + +/*! + Removes a number of rows from the model at the specified position. +*/ + +bool StringListModel::removeRows(int position, int rows, const QModelIndex &parent) +{ + beginRemoveRows(parent, position, position + rows - 1); + + for (int row = 0; row < rows; ++row) { + stringList.removeAt(position); + } + + endRemoveRows(); + return true; +} |