qinternal_p.h

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/****************************************************************************
** $Id: qinternal_p.h,v 1.2 2003/07/10 02:40:11 llornkcor Exp $
**
** Definition of some shared interal classes
**
** Created : 010427
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of the kernel module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
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**********************************************************************/

#ifndef QINTERNAL_P_H
#define QINTERNAL_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of a number of Qt sources files.  This header file may change from
// version to version without notice, or even be removed.
//
// We mean it.
//
//
#ifndef QT_H
#include <qnamespace.h>
#include <qrect.h>
#endif // QT_H

class QWidget;
class QPainter;
class QPixmap;

class Q_EXPORT QSharedDoubleBuffer
{
public:
    enum DoubleBufferFlags {
        NoFlags         = 0x00,
        InitBG          = 0x01,
        Force           = 0x02,
        Default         = InitBG | Force
    };
    typedef uint DBFlags;

    QSharedDoubleBuffer( DBFlags f = Default );
    QSharedDoubleBuffer( QWidget* widget,
                         int x = 0, int y = 0, int w = -1, int h = -1,
                         DBFlags f = Default );
    QSharedDoubleBuffer( QPainter* painter,
                         int x = 0, int y = 0, int w = -1, int h = -1,
                         DBFlags f = Default );
    QSharedDoubleBuffer( QWidget *widget, const QRect &r, DBFlags f = Default );
    QSharedDoubleBuffer( QPainter *painter, const QRect &r, DBFlags f = Default );
    ~QSharedDoubleBuffer();

    bool begin( QWidget* widget, int x = 0, int y = 0, int w = -1, int h = -1 );
    bool begin( QPainter* painter, int x = 0, int y = 0, int w = -1, int h = -1);
    bool begin( QWidget* widget, const QRect &r );
    bool begin( QPainter* painter, const QRect &r );
    bool end();

    QPainter* painter() const;

    bool isActive() const;
    bool isBuffered() const;
    void flush();

    static bool isDisabled() { return !dblbufr; }
    static void setDisabled( bool off ) { dblbufr = !off; }

    static void cleanup();

private:
    enum DoubleBufferState {
        Active          = 0x0100,
        BufferActive    = 0x0200,
        ExternalPainter = 0x0400
    };
    typedef uint DBState;

    QPixmap *getPixmap();
    void releasePixmap();

    QWidget *wid;
    int rx, ry, rw, rh;
    DBFlags flags;
    DBState state;

    QPainter *p, *external_p;
    QPixmap *pix;

    static bool dblbufr;
};

inline bool QSharedDoubleBuffer::begin( QWidget* widget, const QRect &r )
{ return begin( widget, r.x(), r.y(), r.width(), r.height() ); }

inline bool QSharedDoubleBuffer::begin( QPainter *painter, const QRect &r )
{ return begin( painter, r.x(), r.y(), r.width(), r.height() ); }

inline QPainter* QSharedDoubleBuffer::painter() const
{ return p; }

inline bool QSharedDoubleBuffer::isActive() const
{ return ( state & Active ); }

inline bool QSharedDoubleBuffer::isBuffered() const
{ return ( state & BufferActive ); }


class QVirtualDestructor {
public:
    virtual ~QVirtualDestructor() {}
};

template <class T>
class QAutoDeleter : public QVirtualDestructor {
public:
    QAutoDeleter( T* p ) : ptr( p ) {}
    ~QAutoDeleter() { delete ptr; }
private:
    T* ptr;
};

template <class T>
QAutoDeleter<T>* qAutoDeleter( T* p )
{
    return new QAutoDeleter<T>( p );
}
#endif // QINTERNAL_P_H

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