qwt_legend_itemmanager.h

#pragma once

class QwtLegend;
class QWidget;
class QRectF;
class QPainter;

/*!
  \brief Abstract API to bind plot items to the legend
*/

class QwtLegendItemManager
{
public:
    //! Constructor
    QwtLegendItemManager()
    {
    }

    //! Destructor
    virtual ~QwtLegendItemManager()
    {
    }

    /*!
      Update the widget that represents the item on the legend
      \param legend Legend
      \sa legendItem()
     */
    virtual void updateLegend( QwtLegend *legend ) const = 0;

    /*!
      Allocate the widget that represents the item on the legend
      \return Allocated widget
      \sa updateLegend() QwtLegend()
     */

    virtual QWidget *legendItem() const = 0;

    /*!
      QwtLegendItem can display an icon-identifier followed
      by a text. The icon helps to identify a plot item on
      the plot canvas and depends on the type of information,
      that is displayed.

      The default implementation paints nothing.
     */
    virtual void drawLegendIdentifier( QPainter *, const QRectF & ) const
    {
    }
};