[mcclim-devel] One char patch to presentation-defs [Lisp listener problems]

[Andy Hefner]

On 8/9/05, rpgoldman at real-time.com <rpgoldman at real-time.com> wrote:

> There are two interesting things about the clim-listener "wholine"
> statusbar:
> 
> 1.  CLIM's layout algorithm seems inadequate --- it seems to require
>     special help to manage the wholine, since there needs to be
>     special compose-space and allocate-space methods.  Anyone have any
>     idea why that is?  Does this reflect problems with CLIM?

The compose-space method is only there because I'm picky about the
size and appearance of the wholine. I'm doing something unusual in the
wholine, drawing the beveled decoration behind the text in the
handle-repaint method (with output recording off) before replaying the
recorded output. This way the decoration does not pollute the output
history, and I can redraw the decoration without recomputing the
contents of the pane. If the size of the pane changes, the bevel
should adjust to fill it. The allocate-space method is there to make
this happen (repaint the window when the size changes).

A simpler approach might have been to use some kind of border pane
around a vanilla application-pane. Still, I think it's good to know
how to do this.
 
> 2.  Doesn't use incremental redisplay.  I would have thought that the
>     wholine, for example, would be a good application for this, since
>     most of the time the user ID won't change, and even the package
>     name is probably pretty stable.  Is this because of problems with
>     incremental redisplay?  Or is it just that rendering the wholine
>     is so cheap it's not worth the trouble?

I expect that rendering the wholine is very cheap.