qwt_plot_glcanvas.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_GLCANVAS_H
#define QWT_PLOT_GLCANVAS_H

#include "qwt_global.h"
#include <qframe.h>
#include <qgl.h>

class QwtPlot;

/*!
  \brief An alternative canvas for a QwtPlot derived from QGLWidget
  
  QwtPlotGLCanvas implements the very basics to act as canvas
  inside of a QwtPlot widget. It might be extended to a full
  featured alternative to QwtPlotCanvas in a future version of Qwt.

  Even if QwtPlotGLCanvas is not derived from QFrame it imitates
  its API. When using style sheets it supports the box model - beside
  backgrounds with rounded borders.

  \sa QwtPlot::setCanvas(), QwtPlotCanvas

  \note You might want to use the QPaintEngine::OpenGL paint engine
        ( see QGL::setPreferredPaintEngine() ). On a Linux test system 
        QPaintEngine::OpenGL2 shows very basic problems ( wrong
        geometries of rectangles ) but also more advanced stuff
        like antialiasing doesn't work.

  \note Another way to introduce OpenGL rendering to Qwt
        is to use QGLPixelBuffer or QGLFramebufferObject. Both
        type of buffers can be converted into a QImage and 
        used in combination with a regular QwtPlotCanvas.
*/
class QWT_EXPORT QwtPlotGLCanvas: public QGLWidget
{
    Q_OBJECT

    Q_ENUMS( Shape Shadow )

    Q_PROPERTY( Shadow frameShadow READ frameShadow WRITE setFrameShadow )
    Q_PROPERTY( Shape frameShape READ frameShape WRITE setFrameShape )
    Q_PROPERTY( int lineWidth READ lineWidth WRITE setLineWidth )
    Q_PROPERTY( int midLineWidth READ midLineWidth WRITE setMidLineWidth )
    Q_PROPERTY( int frameWidth READ frameWidth )
    Q_PROPERTY( QRect frameRect READ frameRect DESIGNABLE false )

public:
    /*!
        \brief Frame shadow

         Unfortunately it is not possible to use QFrame::Shadow
         as a property of a widget that is not derived from QFrame.
         The following enum is made for the designer only. It is safe
         to use QFrame::Shadow instead.
     */
    enum Shadow
    {
        //! QFrame::Plain
        Plain = QFrame::Plain,

        //! QFrame::Raised
        Raised = QFrame::Raised,

        //! QFrame::Sunken
        Sunken = QFrame::Sunken
    };

    /*!
        \brief Frame shape

        Unfortunately it is not possible to use QFrame::Shape
        as a property of a widget that is not derived from QFrame.
        The following enum is made for the designer only. It is safe
        to use QFrame::Shadow instead.

        \note QFrame::StyledPanel and QFrame::WinPanel are unsuported 
              and will be displayed as QFrame::Panel.
     */
    enum Shape
    {
        NoFrame = QFrame::NoFrame,

        Box = QFrame::Box,
        Panel = QFrame::Panel
    };

    explicit QwtPlotGLCanvas( QwtPlot * = NULL );
    virtual ~QwtPlotGLCanvas();

    void setFrameStyle( int style );
    int frameStyle() const;

    void setFrameShadow( Shadow );
    Shadow frameShadow() const;

    void setFrameShape( Shape );
    Shape frameShape() const;

    void setLineWidth( int );
    int lineWidth() const;

    void setMidLineWidth( int );
    int midLineWidth() const;

    int frameWidth() const;
    QRect frameRect() const;

    Q_INVOKABLE QPainterPath borderPath( const QRect & ) const;

    virtual bool event( QEvent * );

public Q_SLOTS:
    void replot();

protected:
    virtual void paintEvent( QPaintEvent * );

    virtual void drawBackground( QPainter * );
    virtual void drawBorder( QPainter * );
    virtual void drawItems( QPainter * );

private:
    class PrivateData;
    PrivateData *d_data;
};

#endif