[css3-page][css3-background] Canvas background painting and positioning area


Section 3.11 of css3-background says

> The background of the root element becomes the background of the
> canvas and its background painting area extends to cover the entire
> canvas

But where exactly is the canvas in Paged Media?

In css3-page, section 7 defined precisely where the @page background is
drawn and how it is positioned. It could be updated to the Background 3 
terminology (painting area, positioning area) but it is not ambiguous is 
it stand.

> The page background covers the entire page box, including the page
> margins. Background images are positioned as for any other box, by
> default anchored within the page area (i.e. the page box's content
> box); however if ‘background-attachment’ is ‘fixed’ then the image is
> positioned relative to the page box including its margins.

Section 4.2 talks about the root element and the canvas, but is more 

> The root element then paints the canvas and the document contents
> within the page padding box.

I think this implies that the background painting area is the page 
padding box, but it should be more explicit. As above, consider using 
the Background 3 terminology.
(Note: why not the border edge instead, as on "normal" boxes?)

Simon Sapin

Received on Thursday, 26 January 2012 16:18:23 UTC