Re: Do-not-disturb protocol

[Lubos Lunak <l lunak suse cz>]

On Wednesday 18 January 2006 23:10, Tuomo Valkonen wrote:
> On 2006-01-18, Nicolas George <nicolas george ens fr> wrote:
> > I wonder if anyone has considered a "do not disturb" protocol (according
> > to the archives, the answer seems to be no): a protocol that would allow
> > a video player to tell the instant-messaging clients to be quiet while
> > the user is watching a movie.
> >
> > Such a protocol would probably be rather simple to design and implement
> > (a simple property on the root window could almost do the trick), and it
> > seems to me a straightforward and useful extension to a modern multimedia
> > desktop environment.
>
> Aside from the screen saver, it's the window manager's job to stop programs
> from disturbing whatever is going on, and any other program that overrides
> the WM is already doing things completely wrong. A simple
> DO_NOT_DISTURB_HINT property on the window itself (or flag in some other
> property) suffices.
...
> However, are there any other uses for such a hint besides video players? In
> most cases not disturbing the user should be done differently from such a
> passive property. I think no window should be switch to if there's recently
> been user activity in the active window (_NET_WM_USER_TIME) unless the new
> window was opened by user action from this one (may be separate program!),
> but there's no protocol for that. (If there were such a generic protocol
> for passing hints to the wm between execs, Ion could do a lot of things
> more sanely. Not that I expect VerySpecificHintsForUnusableDesktops.org to
> ever cover such things.)

 Actually ... see 
http://standards.freedesktop.org/startup-notification-spec/startup-notification-0.1.txt . 
The feature is called focus stealing prevention in KDE, GNOME has an 
implementation of it too since some time ago.

 The spec itself is rather trivial, but implementing it so that it doesn't do 
more harm than good is not that simple (e.g. it still doesn't work with 
launching-new-mozilla-opens-window-using-the-already-running-instance feature 
of Mozilla - I haven't been able to find a way avoid the problem without 
Mozilla supporting the spec).

> A video player could in such case simply set the 
> user activity time frequently, although it does eat a bit of resources.

 A rather tiny bit.

> So, if there are no other uses of a DO_NOT_DISTURB property, it being set is
> linked to screensaver disablation also, and perhaps those could be fused
> somehow...

 Actually I wonder if this even should have anything to do with window 
managers. If there's running something that shouldn't be disturbed, just not 
showing some dialogs is not going to cut it. Screensaver/DPMS should be 
disabled too, notifications sound should be disabled and that's probably not 
all - should this really be handled by the WM? IMHO there rather should be 
some service running responsible for this. Which, in case of Ion, Windowmaker 
etc. could actually be the WM, but e.g. in KDE it should be something else 
than KWin.

-- 
Lubos Lunak
KDE developer
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