X+Twinview: Can xscreensaver independently blank/unblank only one monitor at a time??
 

So, running two monitors using twinview, on KDE, on Slackware 11, with X 6.9.x.

When my screensaver kicks in, it puts a screensaver on each monitor. It's the same screensaver on each monitor, but not in sync; they are each independently doing their thing.

Now, let's say my mouse cursor is on Screen A or Monitor A, under the screensaver, and I move the mouse. I would like for ONLY that monitor to unblank.

By the same note, let's say I'm working only on one screen for a while, and I do not mouse onto the second screen; can I have the second screen go blank by itself? And then unblank when I mouse over onto it?

I did some looking into this before my motherboard died, but came up empty handed, and now that I'm back into things again, this idea came back to me.

I'll do the work, but if anyone has a new direction to point me in while I continue to google myself silly, please do -- I'd be thankful :)

Well, in the Xorg version of dual head this should be possible.

But twinview is supposed to be like one big screen. I suspect that the running of one saver per screen is a workaround until a screensaver engine is written that will run across both.

The corollary would be just that: how to have a single screensaver across all screens in multi-head. Solve that one and you've solved your problem.

I think you'd need to explicitly run the screensaver twice, one for each screen. But it does more thanjust blank the screen or put up pretty graphics... it also handles power management: you don't want the whole machine asleep just 'cause screen A has been inactive.

I suppose one issue too, is that the signal to unblank is dependant on input; i.e. movement of the mouse, regardless where the cursor is, causes an unblank. Therefore the screensaver engine would need to not only listen for that trigger, but then see where the cursor is to decide what to unblank, rather than saying "ok, the mouse moved, so I'll unblank everything".

I know that xscreensaver is for all intents a separate application in its own right, but figuring on that regarding the rest of the desktop operates somewhat independently (different resolutions per screen, different wallpaper, semi-independent screensavers, ...) I figured there may be a way to do this too.

You're quite right that twinview (or Xinerama for that matter) is seen as 'one big desktop/screen' so this needs to be looked at from the point of view of the MONITORS themselves, or even the VGA adapters outputs themselves, rather than 'screen blanking'

Also, in my case anyhow, the machine doesn't sleep, only the monitors, so while some people might consider your last point about the whole machine sleeping because one screen went inactive, I can evade that aspect of it.

Thank you for the reply Simon.

Any other info is welcome, and if I get anywhere on this, I'll be sure to update.

With the xorg method, though, each monitor is treated separately - each has it's own x-session. You have to start apps explicitly to a particular screen... though I've never done this, which monitor has the input is clear.

Definitely, I understand what you're saying. Two X-Sessions, That would be simple huh? :)