Re: Scrollbar thumbs

["grischka" <grishka@gmx.de>]

>> I guess it is just that these GUI toolkit people usually are trained to
>> deliver good looking and pixel-precise artwork and in consequence might
>> have some difficulties to imagine how it can be "pretty much impossibe"
>> for some editor to know how many lines it is actually displaying (or
>> anyway that such editor would still want to use their scrollbars).
> 
> Emacs _does_ know how many lines it's displaying.
> 
> What it doesn't know is how many lines are in the entire file, or more
> precisely, the "height" of the entire file as rendered, which
> essentially requires rendering the _entire thing_ (it can't be
> calculated from logical number of lines because it depends on the exact
> characters rendered).  That's a pretty nasty requirement for a non-toy
> editor...

The simple rule is:  First do it right, then do it fast.  Try to make
it work for small files and then you can still think about how to get
equally good results with larger ones.

--- grischka