This adds a basic library and support to dtsession and dtlogin to
support Xinerama/Twinview, where multimple monitors are used to make
up an X11 screen.
The main goal here is to draw dialogs and such centered on a monitor,
rather than spread out over multiple monitors.
Might need to add sorting - as on my test system, what I would
consider monitor 0, appears to actually be monitor 1. So a sort might
need to be added to sort the screens according to increasing x and y
offsets so it make sense to a user.
Also, this library is built statically and not documented. Maybe it
could be 'filled' out and refactored/redesigned in the futre if need
be and suppoerted.
It is enabled via a define, CDE_USEXINERAMA in site.def. It's a very
simple lib, so I do not expect any issues with the BSD's - it should
build and work fine, assuming your X server has the XINERAMA
extension, which I think pretty much all of them do at this point.
In order for this to work, dtsession must be setuid root. If
dtsession is not setuid root, then locking will be disabled, and a
message will be written to ~/.dt/errorlog with the message: "Unable to
lock display due to security restrictions".
