Re: Gtk scrollbar: thumb too short

[Richard Stallman <rms@gnu.org>]

    > I understand why the scrollbar thumb is shorter than I think it
    > should be: to allow for placing the last line of the buffer in the
    > top line of the window.
    > 
    > But still, I'm not so happy with the current look of the scrollbar.
    > It confuses me quite a bit.  Is there no way to make the thumb extend
    > to the bottom of the scrollbar area when end of buffer is visible, and
    > yet to also allow scrolling further down so that the last line of the
    > buffer can be moved to the top of the window?

    Not really.  The code in Emacs does not specify the length of the
    thumb, GTK calculates it.  Emacs tells GTK how big the buffer is, how
    big a page is and where we are in the buffer.

What happens if the app specifies a position that is less than one
page away from the end?  Is that considered invalid?

My suggestion is to display a thumb that rises from the bottom of the
scroll bar, but is shorter than normal, as if the bottom of the thumb
were hidden beyond the end of the scroll bar.  Others may think
of a better way to indicate this situation.

    When GTK decides that the thumb extends to the bottom it will not
    emit events for anymore downwards motion with the mouse, only upwards.

Perhaps GTK should have an option so the app can let the thumb move
further down.  What do people think of that?