source: ntrip/trunk/BNC/qwtpolar/qwt_polar_canvas.h@ 5700

/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * QwtPolar Widget Library
 * Copyright (C) 2008   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_POLAR_CANVAS_H
#define QWT_POLAR_CANVAS_H 1

#include "qwt_polar_global.h"
#include <qwt_point_polar.h>
#include <qframe.h>

class QPainter;
class QwtPolarPlot;

/*!
  \brief Canvas of a QwtPolarPlot.

  The canvas is the widget, where all polar items are painted to.

  \note In opposite to QwtPlot all axes are painted on the canvas.
  \sa QwtPolarPlot
*/
class QWT_POLAR_EXPORT QwtPolarCanvas: public QFrame
{
    Q_OBJECT

public:
    /*!
      \brief Paint attributes

      The default setting enables BackingStore

      \sa setPaintAttribute(), testPaintAttribute(), backingStore()
     */

    enum PaintAttribute
    {
        /*!
          Paint double buffered and reuse the content of the pixmap buffer
          for some spontaneous repaints that happen when a plot gets unhidden,
          deiconified or changes the focus.
         */
        BackingStore = 0x01
    };

    //! Paint attributes
    typedef QFlags<PaintAttribute> PaintAttributes;

    explicit QwtPolarCanvas( QwtPolarPlot * );
    virtual ~QwtPolarCanvas();

    QwtPolarPlot *plot();
    const QwtPolarPlot *plot() const;

    void setPaintAttribute( PaintAttribute, bool on = true );
    bool testPaintAttribute( PaintAttribute ) const;

    const QPixmap *backingStore() const;
    void invalidateBackingStore();

    QwtPointPolar invTransform( const QPoint & ) const;
    QPoint transform( const QwtPointPolar & ) const;

protected:
    virtual void paintEvent( QPaintEvent * );
    virtual void resizeEvent( QResizeEvent * );

private:
    class PrivateData;
    PrivateData *d_data;
};

Q_DECLARE_OPERATORS_FOR_FLAGS( QwtPolarCanvas::PaintAttributes )

#endif