There is an annoying bug in print_png (a’m using 1.1.0).
After saving figure it just stops redrawing on screen (gdk). It happens because the print_png calls the set_pixmap method of the canvas renderer which change the associated drawable forever. I’m using workaround saving canvas._renderer.gdkDrawable and restoring it after print_png call. Woud be nice to fix it in the upcoming release if possible.
Regards,
Oleg Volkov