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Re: animate-elem-46-t.svg

From: Chris Lilley <chris@w3.org>
Date: Tue, 8 Jun 2010 07:28:17 +0200
Message-ID: <1301284756.20100608072817@w3.org>
To: Daniel Holbert <dholbert@mozilla.com>
CC: Robert Longson <longsonr@gmail.com>, www-svg@w3.org, Jeff Schiller <codedread@gmail.com>
On Monday, June 7, 2010, 10:32:54 PM, Daniel wrote:

DH> On 06/07/2010 04:48 AM, Chris Lilley wrote:
 >> RL>  and the
 >> RL>  default value for attributeType is "auto" which means use CSS if
 >> RL>  possible.
CL>> Not quite accurate either.
DH> [...]
CL>> So 'auto' here means 'is there is a property of that name, use it'.

DH> Right, I think that's basically what Robert said/meant. :)

Not exactly, which is why I took care to be precise.

CL>> There is indeed a property called 'font-size' so that is what is
CL>> being animated;

DH> Agreed so far...

CL>> and it is being animated with legal values for that
CL>> property.

DH> I don't think that's correct. "30" and "12" are *not* legal values for
DH> that property.

Not so. They are legal values for the property. But not, in a stylesheet, due to restrictions in the CSS syntax. They are however legal values when the property assignment happens with a presentation attribute.

DH> Those values would be legal for the font-size *presentational attribute*

A presentational attribute is a value assignment to a property, with a specificity of zero.

DH> (which would be selected if attributeType="XML" were added).

No, really it wouldn't.

DH>   But 
DH> they're not legal for the font-size *CSS property*.  As Boris mentioned
DH> earlier in this thread, CSS properties require units for all nonzero 
DH> <length>s (including font-size values).

Again, no. Please, re-read the explanation in my earlier mail.


DH> Note that http://www.w3.org/TR/SVG11/animate.html says attributeType 
DH> "specifies the namespace in which the target attribute and its 
DH> associated values are defined".  In this case, attributeType="auto" 
DH> makes us choose the CSS namespace (as you described above), and within
DH> that namespace, "30" and "12" are not valid values for 'font-size'.

 >> RL>  Can the three animations of font-size in the test be changed so 
DH> that either
 >> RL>  a) they specify attributeType="XML"

CL>> That doesn't do what you seem to think it does.

DH> I don't understand your response here -- can you elaborate? 

You seem to be working on the following assumptions, all incorrect

a) that properties can only be expressed in stylesheets (wrong, they can also be expressed in presentational attributes)

b) that presentational attributes are unrelated to properties

c) that setting attributeType="XML" means "animate the presentation attribute".

DH>  IIUC, that
DH> change would indeed fix the test (or, at worst, leave the rendering 
DH> unchanged, in browsers that accept unitless values for [effectively] 
DH> attributeType="CSS" animations)

No, it would specify that what is to be animated is an (unknown, non-existent) attribute called 'font-family' which is not a property. Therte is no such attribute.


-- 
 Chris Lilley                    mailto:chris@w3.org
 Technical Director, Interaction Domain
 W3C Graphics Activity Lead
 Co-Chair, W3C Hypertext CG
Received on Tuesday, 8 June 2010 13:56:34 GMT

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