model.h Example File

 /****************************************************************************
 **
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the demonstration applications of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Digia.  For licensing terms and
 ** conditions see http://qt.digia.com/licensing.  For further information
 ** use the contact form at http://qt.digia.com/contact-us.
 **
 ** 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, Digia gives you certain additional
 ** rights.  These rights are described in the Digia Qt LGPL Exception
 ** version 1.1, 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.
 **
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #ifndef MODEL_H
 #define MODEL_H

 #include <QAbstractItemModel>
 #include <QFileIconProvider>
 #include <QIcon>
 #include <QVector>

 class Model : public QAbstractItemModel
 {
     Q_OBJECT

 public:
     Model(int rows, int columns, QObject *parent = 0);
     ~Model();

     QModelIndex index(int row, int column, const QModelIndex &parent) const;
     QModelIndex parent(const QModelIndex &child) const;

     int rowCount(const QModelIndex &parent) const;
     int columnCount(const QModelIndex &parent) const;

     QVariant data(const QModelIndex &index, int role) const;
     QVariant headerData(int section, Qt::Orientation orientation, int role) const;

     bool hasChildren(const QModelIndex &parent) const;
     Qt::ItemFlags flags(const QModelIndex &index) const;

 private:

     struct Node
     {
         Node(Node *parent = 0) : parent(parent), children(0) {}
         ~Node() { delete children; }
         Node *parent;
         QVector<Node> *children;
     };

     Node *node(int row, Node *parent) const;
     Node *parent(Node *child) const;
     int row(Node *node) const;

     QIcon services;
     int rc, cc;
     QVector<Node> *tree;
     QFileIconProvider iconProvider;
 };

 #endif