model.cpp Example File
demos/interview/model.cpp
/****************************************************************************
**
** Copyright (C) 2004-2005 Trolltech AS. All rights reserved.
**
** This file is part of the documentation 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
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** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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****************************************************************************/
#include "model.h"
#include <QIcon>
#include <QPixmap>
Model::Model(int rows, int columns, QObject *parent)
: QAbstractItemModel(parent),
rc(rows), cc(columns),
tree(new QVector<Node>(rows, Node(0)))
{
}
Model::~Model()
{
delete tree;
}
QModelIndex Model::index(int row, int column, const QModelIndex &parent) const
{
if (row < rc && row >= 0 && column < cc && column >= 0) {
Node *p = static_cast<Node*>(parent.internalPointer());
Node *n = node(row, p);
if (n)
return createIndex(row, column, n);
}
return QModelIndex();
}
QModelIndex Model::parent(const QModelIndex &child) const
{
if (child.isValid()) {
Node *n = static_cast<Node*>(child.internalPointer());
Node *p = parent(n);
if (p)
return createIndex(row(p), 0, p);
}
return QModelIndex();
}
int Model::rowCount(const QModelIndex &parent) const
{
Q_UNUSED(parent);
return rc;
}
int Model::columnCount(const QModelIndex &parent) const
{
Q_UNUSED(parent);
return cc;
}
QVariant Model::data(const QModelIndex &index, int role) const
{
static QIcon folder(QPixmap(":/images/folder.png"));
if (role == Qt::DisplayRole)
return "Item " + QString::number(index.row()) + ":" + QString::number(index.column());
if (role == Qt::DecorationRole)
return qVariantFromValue(folder);
return QVariant();
}
QVariant Model::headerData(int section, Qt::Orientation orientation, int role) const
{
static QIcon services(QPixmap(":/images/services.png"));
if (role == Qt::DisplayRole)
return QString::number(section);
if (role == Qt::DecorationRole)
return qVariantFromValue(services);
return QAbstractItemModel::headerData(section, orientation, role);
}
bool Model::hasChildren(const QModelIndex &parent) const
{
Q_UNUSED(parent);
return rc > 0 && cc > 0;
}
Qt::ItemFlags Model::flags(const QModelIndex &) const
{
return (Qt::ItemIsDragEnabled|Qt::ItemIsSelectable|Qt::ItemIsEnabled);
}
Model::Node *Model::node(int row, Node *parent) const
{
if (parent && !parent->children)
parent->children = new QVector<Node>(rc, Node(parent));
QVector<Node> *v = parent ? parent->children : tree;
return const_cast<Node*>(&(v->at(row)));
}
Model::Node *Model::parent(Node *child) const
{
return child ? child->parent : 0;
}
int Model::row(Node *node) const
{
const Node *first = node->parent ? &(node->parent->children->at(0)) : &(tree->at(0));
return (node - first);
}