I've implemented a Zoomer for a plot and it is working fine, except for the zoom out, that keeps inverting the x-axis when it reaches the zoom base. I mean, I click the mouse right bottom and it zooms out till the zoom base. Then, the next click inverts the x axis: it goes from [0 to 10000] to [10000 to 0]. When I click the right button again, it inverts the x-axis again, going back to [0-10000]

Qt Code:
  1. _zoomer = new QwtPlotZoomer(QwtPlot::xBottom, QwtPlot::yLeft, _canvas);
  2. _zoomer->setTrackerMode( QwtPicker::AlwaysOff );
  3. _zoomer->setRubberBand( QwtPicker::RectRubberBand );
  4. _zoomer->setRubberBandPen( QColor( Qt::green ) );
  5. _zoomer->setTrackerMode( QwtPicker::ActiveOnly );
  6. _zoomer->setTrackerPen( QColor( Qt::white ) );
  7. _zoomer->setMousePattern(QwtEventPattern::MouseSelect1,Qt::LeftButton); //zoom in
  8. _zoomer->setMousePattern( QwtEventPattern::MouseSelect3,Qt::RightButton ); //zoom out by 1
  9. _zoomer->setMousePattern( QwtEventPattern::MouseSelect2,Qt::RightButton, Qt::ControlModifier ); // Ctrl+RightButton: zoom out to full size
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Any ideas?