How to paint a selection rectangle on a pixmap?

**SkripT** · 8th January 2006, 19:11

Ok, I understand. But this solution will cause a lot of flickering when I move the scroll bars. It' wouldn't be more simple just inserting the image as the background of the QScrollArea with setPalette?

**axeljaeger** · 8th January 2006, 19:20

It will not cause a lot of flickering if done right, e.g. using double buffering

**SkripT** · 8th January 2006, 19:29

Yes you are right. But I will be very grateful if you can give me some more details of how to do this double buffering (I haven't much practice working with images...)

**axeljaeger** · 8th January 2006, 19:48

If you are using Qt4, you're fine: Just draw the pixmap using QPainter::drawPixmap. If you use Qt3, first draw in a QPixmap and then bitBlt the QPixmap to the screen.

I think Johan's pixmap view provides source that could be helpfull:

http://www.digitalfanatics.org/e8joh...ies/index.html