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

[Robert Iakobashvili]

Perhaps, there are issues reported as
switch-over between monitors or graphical cards?

Sorry, no clues.

Regards,
Robert


On Mon, Nov 9, 2015 at 5:45 PM, maitai <maitai at virtual-winds.org> wrote:
> Thanks Robert for your reply,
>
> In fact I succeeded to reproduce partly the problem. I have a laptop with 2
> graphic cards, switchable. Whenever the PC goes in power-saving mode, it
> switches to the intel one. When this happens, my menubar (regular QMenuBar)
> is changing font and becomes ugly, and the only way to get it back to normal
> is to restart the application. It seems to happen also from time to time if
> I switch from external monitor to laptop monitor.
>
> This app is not using opengl, it's just a plain QWidget app.
>
> No signal or event as far as I can see is triggered when this happens, just
> a paintEvent it seems.
>
> The funny thing is that even QtCreator is impacted by that... It also
> changes font or style.
>
> Any clue on what is going on there?
>
> Thanks
> Philippe Lelong
>
>
> Le 09-11-2015 12:03, Robert Iakobashvili a écrit :
>>
>> 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