Re: [css3-images] Impl feedback requested - detached elements in element()

On 4/28/11 9:20 PM, Tab Atkins Jr. wrote:
> Hixie was recently tweaking the HTML side of this (you need a
> mechanism to refer to the detached elements, since Selectors can't
> target them), and was curious why I excluded other replaced elements
> like<iframe>.  I don't have a very good answer to this question, so I
> wanted to see what reasoning there was in Gecko to not allow other
> detached replaced elements to be used.

In Gecko, detached iframe's can't be rendered at all.  The data 
structures that compute style data and create a box tree are only 
allowed to exist when the iframe itself has a box.

> (The best I've got so far is that all the data necessary to display
> img/video/canvas is present automatically, as part of the elements'
> natures, so it's easy to present that data via element() even if the
> element's not in the DOM.

Precisely.

> However, an<iframe>  needs to actually do
> layout on its contents to be displayed; this *can* be done without a
> surrounding document.

In Gecko at the moment it cannot.

-Boris