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Re: [css21] images without intrinsic properties

From: fantasai <fantasai.lists@inkedblade.net>
Date: Tue, 04 Mar 2008 16:40:08 -0800
Message-ID: <47CDEBE8.5010305@inkedblade.net>
To: Anne van Kesteren <annevk@opera.com>
CC: www-style@w3.org

fantasai wrote:
> 
> Anne van Kesteren wrote:
>>
>> The CSS 2.1 specification has detailed rules for replaced elements 
>> dealing with images that lack one or more of the following: intrinsic 
>> height, intrinsic width and intrinsic aspect ratio. ... 'background-image',
>> 'content', 'list-style-image' and 'cursor' ...

Ok, so based on
   http://lists.w3.org/Archives/Public/www-style/2008Jan/0448.html
and
   http://lists.w3.org/Archives/Public/www-style/2008Jan/0450.html
proposed text is:

In Section 14.2.1
-----------------

Append to the paragraph beginning "Intrinsic dimensions expressed
as percentages" the following:

   | If the image has one of either an intrinsic width or an
   | intrinsic height and an intrinsic aspect ratio, then the
   | missing dimension is calculated from the given dimension
   | and the ratio.
   |
   | If the image has one of either an intrinsic width or an
   | intrinsic height and no intrinsic aspect ratio, then the
   | missing dimension is assumed to be the size of the rectangle
   | that establishes the coordinate system for the
   | 'background-position' property.

In Section 18.1
---------------

Append to the definition for <uri> values for 'cursor':

   | Intrinsic sizes for cursors are calculated as for `background
   | images`_ except that a UA-defined rectangle is used in place
   | of the rectangle that establishes the coordinate system for
   | the 'background-image' property. This UA-defined rectangle
   | should be based on the size of a typical cursor on the UA's
   | operating system. If the resulting cursor size does not fit
   | within this rectangle, the UA may proportionally scale the
   | resulting cursor down until it fits within the rectangle.

   `background images` should link to colors.html#background-properties

In Section 12.5.1
-----------------

Add to the definition of 'list-style-image':

   | The size of the image is calculated from the following rules:
   |  1. If the image has an intrinsic width or height, then that
   |     intrinsic width/height becomes the image's used width/height.
   |  2. If the image's intrinsic width or height is given as a
   |     percentage, then that percentage is resolved against 1em.
   |  3. If the image has no intrinsic ratio and a ratio cannot be
   |     calculated from its width and height, then its intrinsic
   |     ratio is assumed to be 1:1.
   |  4. If the image has a width but no height, its height is
   |     calculated from the intrinsic ratio.
   |  5. If the image's height cannot be resolved from the rules
   |     above, then the image's height is assumed to be 1em.
   |  6. If the image has no intrinsic width, then its width is
   |     calculated from the resolved height and the intrinsic ratio.


~fantasai
Received on Wednesday, 5 March 2008 00:39:41 GMT

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