Hans-Peter Diettrich wrote:
Mark Morgan Lloyd schrieb:
Hans-Peter Diettrich wrote:
Mark Morgan Lloyd schrieb:
OK, so assuming an OS similar to X, can a single app support two
forms on different displays, and/or move forms between displays?
That's the job of the desktop/window manager, on every OS. When a
form shall be updated on screen, the manager determines the monitor
from the form's screen coordinates, then asks the form to paint
itself. Moving forms means nothing but changing their screen
coordinates, then request an screen update.
My understanding is that moving forms *between* *displays* requires
rather more than that, in fact I'm not sure it's doable on X (if it
were then we wouldn't need Xinerama, Xdmx etc.).
Try to move a form with the mouse to an different monitor. This works on
Linux without additional libraries. Linux also can show the same form on
all desktops, without additional code or libraries.
Oh no it doesn't. You need something like Xinerama (RandR, Xdmx)
installed, or hardware/drivers that support multiheaded operation.
Otherwise the two monitors are separate *screens* (specific, technocal
term- go look at your xorg.conf) identified as :0, :1 and so on.
If you mean "desktops" for "displays", or different X sessions, that's a
bit different. But even then it's only a process property, on which
desktop or X session a form is shown.
You're jumbling terms up badly there. "Desktop" has no meaning in
classic X organisation, these days it's roughly synonymous with "window
manager" where a window manager operates on a single screen (i.e.
identified as display :0, display :1 and so on). Where a desktop has
some sort of pager then forms can be moved around trivially: my
understanding is that on unix this is handled by minimisation/hiding (on
Windows there is the windowstation layer, which is somewhat different).
So I stick to my position that it's at best unclear whether forms can be
moved around between displays (I think you'd like to call those
sessions, in any event corresponding to a screen) and whether an app can
distribute forms over multiple displays (e.g. one form on display :0,
another on :1 and so on).
For completeness, displays are usually identified as :0 etc. but there's
actually another layer hence :0.0 :0.1 etc. I've not come across this
being used even on e.g. Xinerama, and I don't know what it's supposed to
represent.
--
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk
[Opinions above are the author's, not those of his employers or colleagues]
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