10 #ifndef QWT_WIDGET_OVERLAY_H    11 #define QWT_WIDGET_OVERLAY_H    13 #include "qwt_global.h"   123     void updateOverlay();
   125     virtual bool eventFilter( QObject *, QEvent *);
   128     virtual void paintEvent( QPaintEvent* event );
   129     virtual void resizeEvent( QResizeEvent* event );
   131     virtual QRegion maskHint() 
const;
   137     virtual void drawOverlay( QPainter *painter ) 
const = 0;
   141     void draw( QPainter * ) 
const;