[MeeGo-dev] QWidget::showEvent might be helpful for apps wanting to know if they should keep drawing.

[Javier]

Thiago Macieira (Fri, 12 Nov 2010 20:05:54 +0100):
> However, a window being deactivated in X doesn't mean it's no longer
> visible. Writing applications that stop painting when they get
> deactivated may lead to bizarre results, especially outside of MeeGo.

But that's exactly what's happening on Maemo (because as Arjan said 
there's a requirement to save power/cycles), and the net result is 
(obviously) that when the task switcher opens applications are not 
redrawn (thus you get old views: outdated time in clock application [1], 
outdated dynamic pages in browser, etc.).

This and the recent related discussion about the display off event [2] 
(which on Maemo btw is a separate D-Bus signal) is the reason I mentioned
the issue on irc.

[1] https://bugs.maemo.org/show_bug.cgi?id=5466
[2] http://lists.meego.com/pipermail/meego-dev/2010-November/479882.html