Comment 8 for bug 331918

The conversation moved on to a different but related issue, multiple screen scenarios, and I thought it worth recording here for future reference:

<smspillaz> IntuitiveNipple: out of curiousity, is there any reason to use multi-screen instead of multi-output?
<IntuitiveNipple> smspillaz: I'm not sure... what's the difference!? My aim is to have two independent views. This is the way the setup-tools have always done it.
<IntuitiveNipple> On this system, it's nvidia. I've done the same on a Matrox G450 too.
<smspillaz> IntuitiveNipple: with multi-output it is easier to have different output sizes, compiz handles it better and you can move windows between outputs
<IntuitiveNipple> Okay. The idea is *not* to be able to move windows between displays.
<IntuitiveNipple> I don't want xinerama/twinview
<crdlb> then I guess you're set :)
<smspillaz> why would you want that?
<IntuitiveNipple> Why do you prefer chocolate to bananas? :)
* smspillaz tried multi-screen once, it had more bugs than a fluro lantern
<smspillaz> IntuitiveNipple: I guess we could *emulate* that functionality by writing a plugin that doesn't allow you to move windows between outputs ;-)
<IntuitiveNipple> I use xdmx to run 4 screens (the other two on a 2nd PC) from the one PC
<smspillaz> ah interesting
<IntuitiveNipple> smspillaz: I think that might confuse some apps though since the screen size would be a larger 'virtual' and so windows placed beyond the right side of the primary screen would, if the other displays weren't in use, disappear.
<smspillaz> that is probably the reason you have multi-screen then ;-)
<IntuitiveNipple> In my scenario, I use a laptop. When I'm at home-base I want as many screens as possible but when travelling I only have the one.
<IntuitiveNipple> When I used twinview/xinerama the problem was that windows I'd had previously on the extra displays would remember their coordinates and when loaded, would be unreachable :)
<smspillaz> that is a bug worth filing
<IntuitiveNipple> You mean... it now has a 'use case' ?
<smspillaz> no, the fact that when you disconnect outputs windows become unreachable
<smspillaz> that shouldn't happen
<smspillaz> I don't know if there is an output disconnected event though that we can hook
IntuitiveNipple> That is a more general problem with metacity too, so I assumed it was an application-specific thing going on.
<IntuitiveNipple> There is a nuance to that though - very often the laptop will be running dual screens when the session starts. At some point it'll get suspended or hibernated and I'll go mobile. When it resumes it's still in the same user session with my work as it was, and unless I log-out/log-in it won't figure out the external display is no longer attached.