doc/src/snippets/updating-selections/model.cpp
changeset 0 1918ee327afb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/src/snippets/updating-selections/model.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,237 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*
+    model.cpp
+
+    Provides a table model for use in various examples.
+*/
+
+#include <QtGui>
+
+#include "model.h"
+
+/*!
+    Constructs a table model with at least one row and one column.
+*/
+
+TableModel::TableModel(int rows, int columns, QObject *parent)
+    : QAbstractTableModel(parent)
+{
+    QStringList newList;
+
+    for (int column = 0; column < qMax(1, columns); ++column) {
+        newList.append("");
+    }
+
+    for (int row = 0; row < qMax(1, rows); ++row) {
+        rowList.append(newList);
+    }
+}
+
+
+/*!
+    Returns the number of items in the row list as the number of rows
+    in the model.
+*/
+
+int TableModel::rowCount(const QModelIndex &/*parent*/) const
+{
+    return rowList.size();
+}
+
+/*!
+    Returns the number of items in the first list item as the number of
+    columns in the model. All rows should have the same number of columns.
+*/
+
+int TableModel::columnCount(const QModelIndex &/*parent*/) const
+{
+    return rowList[0].size();
+}
+
+/*!
+    Returns an appropriate value for the requested data.
+    If the view requests an invalid index, an invalid variant is returned.
+    Any valid index that corresponds to a string in the list causes that
+    string to be returned for the display role; otherwise an invalid variant
+    is returned.
+*/
+
+QVariant TableModel::data(const QModelIndex &index, int role) const
+{
+    if (!index.isValid())
+        return QVariant();
+
+    if (role == Qt::DisplayRole)
+        return rowList[index.row()][index.column()];
+    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 TableModel::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 TableModel::flags(const QModelIndex &index) const
+{
+    if (!index.isValid())
+        return Qt::ItemIsEnabled;
+
+    return Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsEditable;
+}
+
+/*!
+    Changes an item in the model, but only if the following conditions
+    are met:
+
+    * The index supplied is valid.
+    * The role associated with editing text is specified.
+
+    The dataChanged() signal is emitted if the item is changed.
+*/
+
+bool TableModel::setData(const QModelIndex &index,
+                         const QVariant &value, int role)
+{
+    if (!index.isValid() || role != Qt::EditRole)
+        return false;
+
+    rowList[index.row()][index.column()] = value.toString();
+    emit dataChanged(index, index);
+    return true;
+}
+
+/*!
+    Inserts a number of rows into the model at the specified position.
+*/
+
+bool TableModel::insertRows(int position, int rows, const QModelIndex &parent)
+{
+    int columns = columnCount();
+    beginInsertRows(parent, position, position + rows - 1);
+
+    for (int row = 0; row < rows; ++row) {
+        QStringList items;
+        for (int column = 0; column < columns; ++column)
+            items.append("");
+        rowList.insert(position, items);
+    }
+
+    endInsertRows();
+    return true;
+}
+
+/*!
+    Inserts a number of columns into the model at the specified position.
+    Each entry in the list is extended in turn with the required number of
+    empty strings.
+*/
+
+bool TableModel::insertColumns(int position, int columns, const QModelIndex &parent)
+{
+    int rows = rowCount();
+    beginInsertColumns(parent, position, position + columns - 1);
+
+    for (int row = 0; row < rows; ++row) {
+        for (int column = position; column < columns; ++column) {
+            rowList[row].insert(position, "");
+        }
+    }
+
+    endInsertColumns();
+    return true;
+}
+
+/*!
+    Removes a number of rows from the model at the specified position.
+*/
+
+bool TableModel::removeRows(int position, int rows, const QModelIndex &parent)
+{
+    beginRemoveRows(parent, position, position + rows - 1);
+
+    for (int row = 0; row < rows; ++row) {
+        rowList.removeAt(position);
+    }
+
+    endRemoveRows();
+    return true;
+}
+
+/*!
+    Removes a number of columns from the model at the specified position.
+    Each row is shortened by the number of columns specified.
+*/
+
+bool TableModel::removeColumns(int position, int columns, const QModelIndex &parent)
+{
+    int rows = rowCount();
+    beginRemoveColumns(parent, position, position + columns - 1);
+
+    for (int row = 0; row < rows; ++row) {
+        for (int column = 0; column < columns; ++column) {
+            rowList[row].removeAt(position);
+        }
+    }
+
+    endRemoveColumns();
+    return true;
+}