qwt_plot_shapeitem.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_SHAPE_ITEM_H
#define QWT_PLOT_SHAPE_ITEM_H

#include "qwt_global.h"
#include "qwt_plot_item.h"
#include <qpainterpath.h>

/*!
  \brief A plot item, which displays any graphical shape, 
         that can be defined by a QPainterPath

  A QPainterPath is a shape composed from intersecting and uniting
  regions, rectangles, ellipses or irregular areas defined by lines, and curves.
  QwtPlotShapeItem displays a shape with a pen and brush.

  QwtPlotShapeItem offers a couple of optimizations like clipping or weeding.
  These algorithms need to convert the painter path into polygons that might be
  less performant for paths built from curves and ellipses.

  \sa QwtPlotZone
*/
class QWT_EXPORT QwtPlotShapeItem: public QwtPlotItem
{
public:
    /*!
        Attributes to modify the drawing algorithm.
        The default disables all attributes

        \sa setPaintAttribute(), testPaintAttribute()
    */
    enum PaintAttribute
    {
        /*!
          Clip polygons before painting them. In situations, where points
          are far outside the visible area (f.e when zooming deep) this
          might be a substantial improvement for the painting performance

          But polygon clipping will convert the painter path into
          polygons what might introduce a negative impact on the
          performance of paths composed from curves or ellipses.
         */
        ClipPolygons = 0x01,
    };

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

    //! Mode how to display the item on the legend
    enum LegendMode
    {
        //! Display a scaled down version of the shape
        LegendShape,

        //! Display a filled rectangle 
        LegendColor
    };

    explicit QwtPlotShapeItem( const QString &title = QString::null );
    explicit QwtPlotShapeItem( const QwtText &title );

    virtual ~QwtPlotShapeItem();

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

    void setLegendMode( LegendMode );
    LegendMode legendMode() const;

    void setRect( const QRectF & );
    void setPolygon( const QPolygonF & );

    void setShape( const QPainterPath & );
    QPainterPath shape() const;

    void setPen( const QColor &, qreal width = 0.0, Qt::PenStyle = Qt::SolidLine );
    void setPen( const QPen & );
    QPen pen() const;

    void setBrush( const QBrush & );
    QBrush brush() const;

    void setRenderTolerance( double );
    double renderTolerance() const;

    virtual QRectF boundingRect() const;

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

    virtual QwtGraphic legendIcon( int index, const QSizeF & ) const;

    virtual int rtti() const;

private:
    void init();

    class PrivateData;
    PrivateData *d_data;
};

#endif