Detecting screen disconnection

[Ely Levy]

On Mon, 1 Nov 2004, Benjamin Herrenschmidt wrote:

> On Sun, 2004-10-31 at 16:44 +0100, Luc Verhaegen wrote:
>
> > It would be nice to have so that one can reattach a new monitor without
> > restarting X entirely (when there are bandwidth/frequency issues). X can
> > then revalidate modes and switchmode to get a usable display again. Or
> > attach a TV and see X initialise it, while reinitialising crt. That sort
> > of thing. From what i can see, it is not that hard a task.
> >
> > Polling all outputs all the time would be dreadful though (i'm not sure
> > if many CRT dacs can tell you if there is anything attached, dcc might
> > be an option then). Maybe a switchmode event could trigger it, maybe
> > some sort of keycombination, xrandr too, even though it's use might be
> > limited if your crt is unable to display the mode :).
>
> It would be nice indeed if X had the capability to dynamically
> add/remove displays ...
>
> I noticed that MacOS re-triggers a detection on wakeup from sleep (maybe
> we could do it in Resume() too ?) or via an explicit clic to a certain
> button in a control panel.

can it tell the diffrance between screen poweroff and disconnection?

Ely