use window height for viewport height instead of document height

[DocX]

translation from relative to absolute coordinates should be (as it is in documentation and also it is somehow logical) relative to browser's viewport edges. Thus viewport height is not document height but browser's window inner height.

[Prinzhorn]

There are other bits of code that use documentElement.clientHeight. Do you have a failing test case/example for the old code? Since all pages use html {height:100%} for overflow scrolling, both values are the same.

[DocX]

I was trying with it in simple html without CSS styles. So I had not height:100% on html. So if it is mandatory for the right function, it could be ok. IMHO I would still prefer window.innerHeight since it is more verbose about what it should be :)

[Prinzhorn]

I agree. Now we need to make it work in IE http://stackoverflow.com/questions/10173236/window-innerheight-ie8-alternative

E.g. window.innerHeight || documentElement.clientHeight but then there's not point in using it if IE still uses the old value (in case you didn't set HTML to 100% height, it will fail in IE I guess).