Qt Code:
  1. class YourZoomer: public QwtPlotZoomer
  2. {
  3. ....
  4.  
  5. virtual void zoom( const QRectF &rect )
  6. {
  7. QwtPlotZoomer::zoom( rect & zoomBase() );
  8. }
  9. };
To copy to clipboard, switch view to plain text mode 
Uwe