idea: screen-like utility for X11 / proxy server

[Glynn Clements]

Mildred wrote:

> > The proxy would introduce a layer of potential latency and decrease
> > in throughput.  What would be better is to have support in the X11 
> > libraries or toolkits for attaching and detaching, or at least not
> > dying when the X server dies.
> > 
> > I think the problem is that X clients have resources in the X server
> > and should the X server suddenly die, those resources would be gone.
> > The apps may or may not be able to recreate what was in the
> > resources.  At the very least, it puts a burden on X11 applications
> > and it would not be backward compatible with existing applications
> > that have expectations about what is stored on the server and whether
> > it is always available.
> 
> Thanks, I now understand why it was never done. And you're probably
> right, a toolkit support is probably better (but I don't think how
> that can be done though, it doesn't seems that easy any more).

Actually, it's much easier to do in a toolkit.

Most X-oriented toolkits have a distinct concept of "realisation",
which amounts to creating the server-side resources associated with a
widget.

An unrealised widget is just a "struct" in which various properties
are stored. The server-side window is only created when the widget is
realised. Many (most?) toolkits allow widgets to be explicitly
realised and unrealised; e.g. GTK+ has gtk_widget_realize() and
gtk_widget_unrealize(). It wouldn't be particularly hard to allow
widgets to be unrealised, then re-realised on another screen or
display.

The main issue is that any resources created by the client (e.g. 
pixmaps) may need to be explicitly re-created if the window is moved
to another display.

-- 
Glynn Clements <glynn at gclements.plus.com>