QwtPlotZoomer- problem with zoom out

Hallo,
Though there's been post previously on more or less similar issue I can't figure out my problem. Any help would be great.

In my plot I could use zoom-in perfectly okay using left mouse button. But while using right-button to zoom out there is some problem.
Say, I zoom 2 times: org->stage 1->stage 2. Then on right click once it gets back to stage 1. But when I right click again the plot vanishes, and
the y-axis scale shows 0-1000. Irrespective of how many times it was zoomed, the last click (right) always shows the same (i.e no plot & 0-1000 scale).

Code:

---

class Zoomer: public QwtPlotZoomer
{
public:
    Zoomer( int xAxis, int yAxis, QWidget *canvas ):
          QwtPlotZoomer( xAxis, yAxis, canvas )
    {
        setRubberBandPen( QColor( Qt::darkGreen ) );
        setTrackerMode( QwtPlotPicker::AlwaysOn ); 
 
        setMousePattern( QwtEventPattern::MouseSelect2,
            Qt::RightButton, Qt::ControlModifier );
        setMousePattern( QwtEventPattern::MouseSelect3,
            Qt::RightButton );
    }
...
};

---

0 -> 1000 is the default range of a scale , obviously you have initialized the zoomer before setting the scales. See QwtPlotZoomer::setZoomBase() for how to sync the zoomer with the modified scales.

Uwe

Thank you so much Uwe. That was indeed the problem i.e initializing the zoomer before setting the scale. Now it works fine.