[maemo-developers] Stopping QML update when not visible

[From: Thomas Perl]

Hi Andrew,

2011/5/30 Andrew Flegg <andrew at bleb.org>:
> Qt Quick 1.1 apparently features a "Qt.application.active" read-only
> property[1] which can be connected (somehow) to stopping animations,
> reading sensors and so on.
> [...]
> Thoughts welcome. To be honest, it's amazing (and disappointing) that
> there isn't a way of doing this in Qt Quick 1.0. Can anyone confirm
> whether or not it's at least not updating the screen when hidden (it
> does in the task manager), and it's only the accelerometer signalling
> I need to switch off?

As mentioned by someone else, try using QGLWidget as viewport or
simply use "-graphicssystem opengl" as command line arguments. As for
disabling something when the application is in the background, that
can be done by watching event() on the QDeclarativeView. As discussed
on IRC, I've sent a patch that implements that idea.

For anyone that's interested in how it's done (feedback and
improvement suggestions welcome!), you can find the patch against
Attitude here:

http://thp.io/2011/maemo/attitude_activemonitor.patch

HTH :)
Thomas