zoomer changes default axisscale vakues after Home key in a Qwtplot

[john_k]

Hi

I set my axes like

const QwtInterval xInterval = m_spectrogram->data()->interval( Qt::XAxis );
setAxisScale(xBottom, xInterval.minValue(), xInterval.maxValue(), 20);

const QwtInterval yInterval = m_spectrogram->data()->interval( Qt::YAxis );
setAxisScale(yLeft, yInterval.minValue(), yInterval.maxValue(), 5);

then I setup my zoomer

if(!m_zoomer)
{
m_zoomer = new MyZoomer(canvas());
}

m_zoomer->setKeyPattern( QwtEventPattern::KeyHome, Qt::Key_Home);

The plot has the X, Y axes I want when it starts but after zooming and returning to the default view through the Home key the axes do not return to the setting above.

This is all being done in a class derived from QwtPlot like in the Qwt examples.

[Uwe]

In cases where you don't create the zoomer - probably all beside the first one - you have to reinitialize the zoom base:

m_zoomer->setZoomBase( true );

m_zoomer->setZoomBase( true );

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Uwe

[john_k]

Hi Uwe, thanks again for your response.

Here is what I have done and it works.

void MySurfacePlott::keyReleaseEvent(QKeyEvent *event)
{
if (event->key() == Qt::Key_Home)
{
const QwtInterval xInterval = m_spectrogram->data()->interval( Qt::XAxis );
setAxisScale(xBottom, xInterval.minValue(), xInterval.maxValue(), 20);

const QwtInterval yInterval = m_spectrogram->data()->interval( Qt::YAxis );
setAxisScale(yLeft, yInterval.minValue(), yInterval.maxValue(), 5);

m_zoomer->setZoomBase( true );

}

QwtPlot::keyReleaseEvent(event);
}