qwt_plot_rasteritem.h

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#ifndef QWT_PLOT_RASTERITEM_H
#define QWT_PLOT_RASTERITEM_H

#include <qglobal.h>
#include <qstring.h>
#include <qimage.h>

#include "qwt_plot_item.h" 

class QWT_EXPORT QwtPlotRasterItem: public QwtPlotItem
{
public:
    enum CachePolicy
    {
        NoCache,
        PaintCache,
        ScreenCache
    };

    explicit QwtPlotRasterItem(const QString& title = QString::null);
    explicit QwtPlotRasterItem(const QwtText& title);
    virtual ~QwtPlotRasterItem();

    void setAlpha(int alpha);
    int alpha() const;

    void setCachePolicy(CachePolicy);
    CachePolicy cachePolicy() const;

    void invalidateCache();

    virtual void draw(QPainter *p,
        const QwtScaleMap &xMap, const QwtScaleMap &yMap,
        const QRect &rect) const;

    virtual QSize rasterHint(const QwtDoubleRect &) const;

protected:

    virtual QImage renderImage(const QwtScaleMap &xMap, 
        const QwtScaleMap &yMap, const QwtDoubleRect &area
        ) const = 0;

private:
    QwtPlotRasterItem( const QwtPlotRasterItem & );
    QwtPlotRasterItem &operator=( const QwtPlotRasterItem & );

    void init();

    class PrivateData;
    PrivateData *d_data;
};

#endif