Power Management and Inhibition by Applications

[Matthieu Gallien]

Hello,

On samedi 19 janvier 2019 12:19:10 CET Elvis Angelaccio wrote:
> On 16/01/19 22:07, Matthieu Gallien wrote:
> > Hello,
> > 
> > I am trying to work on a feature request to add the ability to suppress
> > laptop sleep when playing music.
> > 
> > Currently, Juk is doing it via dbus calls to
> > "org.kde.Solid.PowerManagement".
> > 
> > I also had a look to Solid frameworks and the power classes that add an
> > asynchronous way to do that.
> > Currently, the Solid framework only conditionally provides those features
> > and it seems distributions (at least Debian) do not always build it.
> > 
> > I am also unsure about the current recommended solution that would work
> > for
> > most desktop environments.
> > 
> > What would be the best way forward ?
> 
> Hi,
> the "official" way to achieve that should be a dbus call to the
> org.freedesktop.ScreenSaver interface (methods Inhibit and UnInhibit).

I had thought that would only inhibit the screensaver instead of automatic 
sleep.
I did a quick test and in case I inhibit through org.freedesktop.ScreenSaver 
interface, the battery applet does not indicate any inhibit whereas through 
org.freedesktop.PowerManagement.Inhibit indicates that an inhibition is valid.

I wonder if I should not instead make usage of the Inhibit mechanism from 
logind coupled with powerdevil. I am not sure if this is desired.

I would forward inhibit request to logind and checks existing inhibition 
before allowing powerdecil to suspend.

> > I can also see some other features that could make sense to provide in
> > libraries that music players could use (lyrics fetching, album art
> > fetching, ...). This could be in a dedicated framework to help build
> > media players.
> > 
> > Best regards
> > 
> > --
> > Matthieu Gallien
> 
> Cheers,
> Elvis

Best regards