[Xr] Dealing with groups in Xr

[Carl Worth]

On Apr 24, Owen Taylor wrote:
 > It strikes me that making the user worry about the bounding
 > box of primitives drawn onto the temporary group is wrong; if creating
 > larger empty pixmaps becomes a time or memory bottleneck, it can
 > certainly be optimized out, at the cost of a moderate amount
 > of complexity. (For instance, with a tiled representation of the
 > surface.)

Good point. I think we're close to understanding what the three new
functions should do now. And we just need the names...

 > Just as a thought, perhaps Enter/Leave is better than Push/Pop?
 > Push/Pop seems to indicate tat

Owen, did you forget to finish this thought? I'm curious what you were
going to say.

I'd at least like a name that suggests that the groups can be nested
and I don't know if Enter/Leave does that for me, (though I'm not sure
why). Maybe Begin/End?

 > Though something even stronger would be appreciated; I'd like to be able
 > to set an OOM  handler that simply aborted the program, so that you
 > didn't have to check your XrCreateSurface() and nothing else in the GTK+
 > program.

This seems reasonable.

As of yet, Xr doesn't have any callbacks. If we add some we'll also
have to address the issue of locking within Xr.

-Carl

-- 
Carl Worth                                        
USC Information Sciences Institute                      cworth at isi.edu