node.h

QT 开发环境里面一个很重要的文件

/****************************************************************************
**
** Copyright (C) 2006-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the example classes 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
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** If you are unsure which license is appropriate for your use, please
** review the following information:
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** sales department at [e-mail].
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** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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****************************************************************************/

#ifndef NODE_H
#define NODE_H

#include <QGraphicsItem>
#include <QList>

class Edge;
class GraphWidget;
class QGraphicsSceneMouseEvent;

class Node : public QGraphicsItem
{
public:
    Node(GraphWidget *graphWidget);

    void addEdge(Edge *edge);
    QList<Edge *> edges() const;

    enum { Type = UserType + 1 };
    int type() const { return Type; }

    void calculateForces();
    bool advance();

    QRectF boundingRect() const;
    QPainterPath shape() const;
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);

protected:
    QVariant itemChange(GraphicsItemChange change, const QVariant &value);

    void mousePressEvent(QGraphicsSceneMouseEvent *event);
    void mouseReleaseEvent(QGraphicsSceneMouseEvent *event);
    
private:
    QList<Edge *> edgeList;
    QPointF newPos;
    GraphWidget *graph;
};

#endif