Hello!
I have a QwtPlotSpectrogramm item on my QwtPlot widget. I found out that it caches when I do it visible or invisible. Then some parameters of spectrogramm (more exactly parameters of subclassed QwtRasterData object) could change and I call replot(), but old spectrogram is painted (which is saved in cache).
Is there a way to clear cache or force qwt to repaint item?
