[whatwg] scrollIntoView jarring?

[David Bolter]

I have a concern about "3.5.3 Scrolling elements into view":  
http://www.whatwg.org/specs/web-apps/current-work/multipage/section-interaction.html#scrollintoview

In addition to concerns expressed by Brad Fults 
(http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2007-October/012655.html), 
I want to raise a concern about the behaviour of scrollIntoView. 
Specifically I would ask that:

1. scrollIntoView not do anything in the case that the element is 
already fully visible (possibly in the middle of the viewport), or
2. ensureElementIsVisible to be added as described by Daniel Glazman 
(http://lists.w3.org/Archives/Public/public-html/2007Nov/0188.html)

My concern is that with the movement towards rich interactive web 
interfaces, we are going to be seeing complex widgets that will need to 
call such functions fairly often, which may lead to a jarring experience 
if the function always butts the element to the edge of the viewport. It 
would be a shame to jar users when unnecessary. I realize there is a 
(hairy) way to do this but it would be nice to have the convenience.

Aside: we would like to recommend authors call such a method when using 
ARIA's activedescendant (draft spec).

cheers,
David