Re: gtk scroll bar deficiency

[Stefan Monnier]

>> Some toolkits call it the "thumb".
> thanks.  what is a "slider" (is there such a word?)

I believe "slider" is an alternative term for the same thing.

>> I'm pretty sure it's intentional.  It's not perfect, but the perfect
>> behavior (which you get with the non-toolkit build)
> does this mean that you agree that the first behavior is better?

Yes, of course.

>> tends to be difficult to get with current toolkits because toolkit
>> writers are boneheaded
> somehow gedit got it right - and it appears to be pretty minimalist by
> design ("notepad" for gnome).

That's the problem: the toolkit only cater to the simple case.  To "do it
right" in Emacs we'd be forced to *render* the whole buffer in order to
compute its total pixel size so as to precisely set the thumb size.
And then we'd still be stuck with the design constraint that you cannot
bring point-max higher than the bottom of the window (a very common
limitation in most other applications, often construed as a feature by
GUI-zealots).

Given that we cannot "do it right" without major performance problems (and
usually this is only due to an over-eager test in the toolkit: fixing the
toolkit in the case of Xaw3d amounts to removing 2-3 lines), we end up
having to choose between various hacks and problems.

Since the problem mostly affects operation when dragging the slider and this
only when the slider gets near the bottom, another solution (which I tend to
prefer) is to set the thumb size to something artificially small (e.g. 0)
during dragging.  This way the thumb size can still be correct at all
other times.


        Stefan