Remoting single applications

James [Wez] Weatherall jnw "at"
Thu, 10 Dec 1998 10:53:37 +0000

On Wed, 9 Dec 1998, walter kwaan wrote:

> >> [ ]"Remote" instances would not show up on the server computer (be hidden)
> >> screen, but only on remote computers?
> >
> >No.  Windows doesn't update any windows which aren't physically displayed
> >(i.e. on the visible desktop.)  Even under Windows Terminal Server, if a
> >virtual desktop isn't displayed then no graphics events occur for it.
[snip - stuff about NT desktops]
> That being said, are you saying that the graphic events dont happen on a
> hidden window??? i cant believe that is true since as i've composed this,
> i've used those tools to swap desktops and this emailer still seems to have
> been doing its auto-stuff (which all use window events...) or does it all
> refresh once the desktop becomes active??? 

Windows doesn't post WM_PAINT messages to windows on hidden desktops.
It is the Winstation, not the desktop, that is associated with the
graphics device, so only the currently displayed desktop actually has any
display memory to retrieve the graphical data from.  (This is set to
change under NT 5, of course, because it has multiple monitor support and
Terminal Server built in)

If you use a multi-desktop program on NT, you will notice that the hidden
desktops, when revealed, will flicker into life, as the applications are
posted paint messages, I believe.


James "Wez" Weatherall
Olivetti & Oracle Research Laboratory, Cambridge, UK - Tel : 343000
Laboratory for Communications Engineering, Cambridge - Tel : -

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