Scrollbar thumbs (was: Customizing the mode line)

[Stefan Monnier <monnier@iro.umontreal.ca>]

>         I also find the scrollbar somewhat confusing: When the end of
>  buffer is visible in the window, I would expect the scrollbar to reach
>  all the way to the bottom, but it does not.

It does with some GUI and not with others.  In principle it should.
The only reason for it not to is to try and work around problems when
dragging the scrollbar thumb, where many GUI toolkits are absurdly
dogmatic and make it pretty much impossible for Emacs to do what
it should.

The more I see it, the more I think that rather than let the GUI code
make this choice, we should have it be in the generic part of the code
and the GUI code only chooses the default value, so users can choose to
have a half-working drag-scroll if they prefer it (because it gives them
proper display of the thumb size and position in return).


        Stefan