[Pkg-xfce-devel] Bug#828204: Bug#828204: light-locker: Without chrome running, obeys xfce4-power-manager. With chrome, usually doesn't.

[Yves-Alexis Perez]

On Sun, Jun 26, 2016 at 03:51:01PM -0400, Fred Korz wrote:
> On 06/26/2016 03:07 PM, Yves-Alexis Perez wrote:
> > On sam., 2016-06-25 at 22:05 -0400, Fred Korz wrote:
> > > Since then, if google chrome (stable) is not running, power management on the
> > > display works just as set.
> > > 
> > > However, if google chrome is running, for a while display blanking and turndown
> > > works as configured, but eventually blanking doesn't work.
> > My first guess would be that google chrome uses inhibition to prevent screen
> > blanking/locking. Does it matter which tabs are open in google chrome?
> > 
> > Regards,
> 
> I had thought that too, that perhaps vlc were using inhibition, but shutting
> down vlc or not starting it had no effect.
> 
> As to chrome, not that I can tell if a particular tab is causing it.  With
> 20 windows averaging 10 tabs/window, and a minimum of 3 minutes wait per
> sample to tell the outcome, that's not really practical.  That would be
> O(10) hours worst case, O(5) hours if found half way through.  (Yes, I could
> use binary rather than linear search, but I'd have to figure out a way to
> store and restore the serious amount of state held in those windows and
> tabs.)
> 
> I suspect that there is a combination of (1) inhibition, which I don't know
> a practical way of finding, but hoped the package maintainers could suggest
> so I could chase it down,

No, I don't know any practical way of finding, but I'm pretty sure
Internet will know, sorry.

> and (2) an assumption in light-locker of an
> installed screen locking which is violated when there's no screensaver
> installed (which seems to run counter to the self-containment goal of
> light-locker and the lack of a package dependency on any screensaver).
> 
> To that second point:
> 
>    If I run 'light-locker-command --lock', I get blanking, light off, power
> minimization and locking.
> 
>    If I run 'light-locker-command --activate', which I believe the man page
> suggests will do all the above except lock, instead it goes through as if it
> expected to rely on a screen locker as a barrier but it comes back with the
> complaint, previously cited above, about locker failure.  I tried all the
> permutations on xfce4-power-manager-setting of "Automatically lock the
> session" in {"Never", "When screensaver is activated",
> "When screensaver is deactivated"} crossed with "Lock screen when system is
> going for sleep" in {checked, unchecked}.
> 

Yes, light-locker *is* the locker. When itself talks about screensaver,
it talks about the Xorg screensaver (so the screen blanking).

Light-locker can automagically locks when X11 screensaver engages
itself. It can also be called manually (through light-locker-command)
and (try to) force DPMS blanking as well, after doing the vt-switch to
the login screen.

Regards,
-- 
Yves-Alexis Perez
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