On Thursday 13 March 2008 05:02:36 pm Ted Drain wrote: > I'm working on improving the plotting speed of one of our applications. As > part of that, I was looking at how quickly the QtAgg backend is drawing. I > added some print out's to the backend and noticed that it seems to be > drawing everything twice. In the code: > > backend_qtagg.py: FigureCanvasQTAgg class: > > def draw( self ): > """ > Draw the figure when xwindows is ready for the update > """ > > if DEBUG: print "FigureCanvasQtAgg.draw", self > self.replot = True > FigureCanvasAgg.draw(self) > self.repaint( False ) > > > > FigureCanvasAgg.draw() will cause a draw the repaint call will cause a > draw. If I comment out the FCAgg.draw() call, my application (QtAgg > embedded in a PyQt program) works fine. I've also run several of the > various example scripts and they seem to work fine as well. Panning, > zooming, redraws, resize, and file saving seem to be unaffected. > > Does anyone know why the extra draw call might be necessary? Thank you for pointing this out, Ted. It actually solves a problem I was seeing with the qt4agg backend, where the widgets.Cursor crosshairs were not being drawn when blitting was disabled. I removed the lines from qtagg and qt4agg, and saw no problems in the examples or my own application, so I checked in the changes - svn 5002. Darren