vertical scrollbars: proposed extension to CSS

There is a lot of discussion about control of vertical scrollbars in 
web-browsers (see: http://bugzilla.mozilla.org/show_bug.cgi?id=72540), 
specifically for 2 different page layouts that are very popular: the 
centered table, and the width=100% table. In the scope of a website, many 
pages may have similar navigational elements, though page length may vary 
widely. Often, when going from a short page to a long page within a 
website, the rendering of the scrollbar causes the page to shift.

As I see it, there are three table-based HTML page layout paradigms that we 
need
to concern ourselves with, regarding vertical scrollbars:

1) the centered table with width less than 100% of the browser window (the 
width
is usually specified absolutely in pixels)
2) the left justified table with a width equal to 100% of the browser window
3) the left justified table with a width equal to 100% of the browser 
window,
containing centered elements (that should not shift between similar pages of
varying lengths).

For each of the three layout paradigms above, a *different* vertical 
scrollbar
behavior is called for---and I have a feeling that most web designers may 
not agree on which vertical scrollbar behavior is optimal for each of the 
cases above (and all those others that exist).

Which generally means, the decision should be left up to the web-designer 
(and
not the web-browser), through the following extension I propose to CSS:

vertical-scrollbar: auto | always-on | always-off | reserved

  auto - this is mozilla's current behavior, the scrollbar is rendered and 
the
page canvas resized when the page elements are taller than the page canvas. 
this
would probably remain the default behavior, optimal for pages without
table-based layout, and for tables with width=100% but without centered 
elements
(like navigation bars/menus) that might shift when the scrollbar is 
rendered for
longer pages.

  always-on - this is IE's current behavior, the scrollbar is shaded 
inactive
when not needed and is rendered when necessary. This would probably be 
optimal
for page designs that have centered elements within tables that occupy 100%
width of the page canvas.

  always-off - this would supress the rendering of the scrollbar regardless 
of
the height of the page elements

  reserved - in this alternative the "vertical scrollbar zone" is reserved 
and takes on the color/image of the page background, preventing page 
designs of the centered table variety from shifting when the scrollbar is 
rendered.

Received on Tuesday, 30 April 2002 07:54:20 UTC