W3C home > Mailing lists > Public > www-style@w3.org > November 1999

Re: The canvas

From: Ian Hickson <py8ieh@bath.ac.uk>
Date: Fri, 12 Nov 1999 23:06:06 +0000 (GMT)
To: Tantek Celik <tantek@cs.stanford.edu>
cc: www-style <www-style@w3.org>, "L. David Baron" <dbaron@fas.harvard.edu>
Message-ID: <Pine.GSO.4.04.9911122259001.19768-100000@amos.bath.ac.uk>
On Thu, 11 Nov 1999, Tantek Celik wrote:

>>> Section 14.2 of CSS2 says both of the following [1]:
>>> # Margins are always transparent so the background of the parent
>>> # box always shines through.
.>> # The background of the box generated by the root element covers
>>> # the entire canvas.
>> The root element `reverse inherits' its background up to the
>> canvas, in a similar way as you have the BODY element reverse
>> inheriting up to the HTML element, except that with the :root and
>> canvas backgrounds you inherit the computed value not the specified
>> value so that an image placed at the 'top left' of the :root box
>> will indeed be at the top left of the root box, not the top left of
>> the canvas (they could, with margins or positioning, be different).
> ... I propose the following:
> - A particularly specified background should only be drawn once.
> - If an element "reverse inherits" its background from one of its
> children, then the element then "takes over" drawing of that
> background, draws that background, and has its children *not* draw
> the background a second (or third) time.

Right -- once the value of 'background' has been "inherited", the
element from which it inherited it should have its 'background'
effectively set to 'transparent'.

This is only needed when "inheriting" the _specified_ value (the way
HTML does from BODY), when the _computed_ value is "inherited" (as is
effectively done when the HTML element gives it's background to the
canvas) it doesn't matter either way as the background would in any
case start at the same point (since it is the computed value that is
used, the starting point is relative to the HTML box not the canvas).

-- 
Ian Hickson
"So far, people have shown a reasonable amount of sense in evaluating
souls (whether they are properly priced)."
  -- Nick Gibbins; Author of http://totl.net/Soul/, 1999-10-05
Received on Friday, 12 November 1999 18:48:23 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 27 April 2009 13:54:01 GMT