edge.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 EDGE_H
#define EDGE_H

#include <QGraphicsItem>

class Node;

class Edge : public QGraphicsItem
{
public:
    Edge(Node *sourceNode, Node *destNode);
    ~Edge();

    Node *sourceNode() const;
    void setSourceNode(Node *node);

    Node *destNode() const;
    void setDestNode(Node *node);

    void adjust();

    enum { Type = UserType + 2 };
    int type() const { return Type; }
    
protected:
    QRectF boundingRect() const;
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
    
private:
    Node *source, *dest;

    QPointF sourcePoint;
    QPointF destPoint;
    qreal arrowSize;
};

#endif