On Thu, Jan 2, 2014 at 1:53 AM, <angedwa...@gmail.com> wrote: > I find that I have to re-paint the whole widget every time I call an > update(), as I have create a new QPainter() instance. Is there a way to > update only a small part of the widget, while retaining the rest of the > widget?
In general, it would help to say which windowing toolkit you're using :) Fortunately you mention something that implies you're using QT, so I'm going to forge ahead with that. When you call update(), you're effectively saying "the whole object needs to be repainted". If you can restrict that to just a particular rectangle, simply pass those coordinates to the update call: http://pyqt.sourceforge.net/Docs/PyQt4/qwidget.html#update-4 I'm not sure if you're using PyQt4 or not, but if you're using something else, look through its docs for a similar function. Same goes for pretty much any windowing toolkit; it's always possible to report that a small area needs updating. Once you then get the update event, you should be given a rectangle that tells you which part needs to be repainted. But painting outside that area will be reasonably fast, so don't stress too much about that part if it's a lot of trouble. For instance, I have a MUD client that will always attempt to draw complete lines, even if only part of a line needs to be redrawn - but it'll repaint only those lines which need repainting (so it looks at the Y coordinates of the "please repaint me" rectangle, but not the X coords). ChrisA -- https://mail.python.org/mailman/listinfo/python-list