Re: xmosaic experience
Fri, 26 Feb 1993 10:08:36 +0100

>What I think xmosaic does is: it creates both a fixed window as above,
>then creates a huge-ass window as a child window. It connects the
>scrollbar to the child window, and allows the user to scroll the child
>window around, instead of scrolling the text around. This is a *much*
>simpler way of doing things,

Yes. So far your story is correct.

>but now X *will* allocate an internal
>backing pixmap for that child window, even without backing store, and
>without all of it being exposed. So you're using one huge amount of

Wrong. X does NOT allocate pixmaps just because you create a giant
window. It remembers the size of the window and gives you expose
events when parts of the window become visible. It does not even
allocate a pixmap for the visible part (since that's put directly in
screen memory). What do you think exposure events were good for if
the server allocated a pixmap? Soure that would be getting the worst
of two worlds!

I'll let Marc answer your attacks on XMosaic, but your knowledge of X
is less than what I expected.

--Guido van Rossum, CWI, Amsterdam <>