[Interest] application appearance changing when laptop goes in saving energy mode

[Robert Iakobashvili]

On Mon, Nov 9, 2015 at 7:54 AM, maitai <maitai at virtual-winds.org> wrote:
>
> Hello
>
> On Windows, some users are reporting that the application style (font? palette?) is changing when laptop goes in energy saving mode, and becomes more or less unreadable (white font on white background, etc). I have seen that myself also a couple of times but I'm unable to reproduce it.
>
> When it occurs, putting the laptop back on power does not fix anything, and the only way to get back the proper appearance is to restart the application. If you start the application when in battery saving mode, no problem. The application is widget-based (QMainWindow, QGraphicalScene, QMenubar, etc), Qt is 5.5.1 but that was reported also with previous Qt versions.
>
> As I said this occurs only for a few users, and I cannot reproduce it. Maybe it's connected with the laptop changing GPU, I don't know.
>
> Does anyone knows what could possibly trigger this, and if I can catch it somehow either to avoid it or reload style/palette/font/etc when it occurs?
>
> Thanks
> Philippe Lelong


Hi,

With which options Qt was configured and built?

Any plugins your software is using?

Is it correlating with any particular Windows versions
like on Windows-10 or 8.1?

That sounds like an aggressive memory optimization by OS.
Locking in memory sometimes could help against.

There is a Qt signal

QGuiApplication::on_applicationStateChanged(Qt::ApplicationState state);

and using it on Android.

Perhaps, coming to the state:Qt::ApplicationActive from
somewhere else and reloading fonts, etc could be a work-around?

Kind regards,
Robert