Re: NSPasteboard on X, what to do?

[Richard Frith-Macdonald]

On Wednesday, January 9, 2002, at 09:53 AM, Robert Slover wrote:

> The X Window System supports one or more screens containing overlap-
> ping windows or subwindows.  A screen is a physical monitor and 
> hardware,
> which can be either color, grayscale or monochrome.  There can be 
> multiple
> screens for each display or workstation.  A single X server can provide 
> display
> services for any number of screens.  A set of screens for a single user 
> with one
> keyboard and one pointer (usually a mouse) is called a display.
>
> So I had always assumed that in a multi-screen environment (Xinerama?) 
> there
> was still only one DISPLAY variable per user session.  If that 
> assumption is
> correct, that seems to be the thing to group by, and in that case I 
> don't see why
> there's anything special to be done to support multiple screens.  It 
> seems like
> each backend should have some idea of what a user session key might be, 
> for
> X it is DISPLAY, and the pasteboard server should be set up uniquely per
> session key.  If my understanding is naive, please correct me.

Sounds very reasonable to me ... at the moment there is one pasteboard 
server
per machine ... but I have never actually encountered a case where there 
is was
not a one to one mapping between machine and DISPLAY (as described 
above).

I'm sure there must exist some setups (corporate/academic?) where they 
have mainframe
systems with multiple DISPLAYs, but I think they must be pretty rare.

So ... we should probably modify stuff as follows -
1. Extend the pasteboard server so we can tell it to advertise itsself 
to the network
using a name corresponding to the display it is started for.
2. Modify the NSPasteboard class to get it to connect to the correct 
pasteboard rather
than using the default name on the local host.
3. Define a user default to specify which host/DISPLAY an app is 
supposed to use and/or
an API for the backend to tell the frontend about this.