CSS-SVG Task Force Teleconference

14 Mar 2011


See also: IRC log


heycam, ed, smfr, rik_cabanier, hober, anthony, TabAtkins, CL


<trackbot> Date: 14 March 2011

<scribe> scribenick: smfr

<scribe> Scribenick: smfr

CSS Animation


heycam: summarizes css transitoins and animations applying to svg attributes

first proposal: turn all attributes into properties with the same name

<heycam> http://www.w3.org/Graphics/SVG/WG/wiki/Talk:F2F/Auckland_2011/CSS_Animation#Promoting_attributes_to_properties

(sorry heycam)

(aussies all sound the same)

controvecial to convert all attributes to properties

may end up with property name conflicts; css properties are global, so property with name 'r' is not acceptable

<heycam> http://www.w3.org/Graphics/SVG/WG/wiki/Talk:F2F/Auckland_2011/CSS_Animation#Introducing_new_properties

second proposal: new properties for attributes, but use different names

e.g. r -> circle-radius

<heycam> <circle circle-radius="100"/>

but this breaks correspondence between properties and presentation attributes, so confusing

would need to define how e.g. circle-radius and r would interact

third option: add extra syntax to css transitions/animation to allow targeting attributes

<heycam> http://www.w3.org/Graphics/SVG/WG/wiki/Talk:F2F/Auckland_2011/CSS_Animation#Allowing_CSS_Transitions.2FAnimations_to_target_attributes_directly

<heycam> http://www.w3.org/Graphics/SVG/WG/wiki/Talk:F2F/Auckland_2011/CSS_Animation#Conclusions

SVG WG preferred the functional syntax in the conclusion section

wouldn't be able to transition svg attributes directly in css, because you can't use attr(x) on the LHS outside the keyframes

smfr: there should be nothing special about css parsing inside of keyframes, so i don't like this proposal
... functional syntax on LHS is weird

TabAtkins: points to dean's proposal in email

<ed> http://lists.w3.org/Archives/Public/public-fx/2011JanMar/0127.html

heycam: strange to extract special meaning out of "-attr-" identifiers on the LHS

<ed> http://lists.w3.org/Archives/Public/public-fx/2011JanMar/0128.html

heycam: prefer the second option
... it's more of a wholesale change to svg to make a bunch of attributes into newly named properties

TabAtkins: this proposal seems similar to -attr-r
... attribute-targeting as a magic hack is untenable if general enough for transitions as well as animations
... OK with option 2 or -attr-

smfr: -attr may conflict with vendor prefixes

TabAtkins: could use attr- and claim it as a unique prefix

anthony_work: can you use this to apply style to content?

TabAtkins: yes
... like setting HTML attributes which map to CSS

like the normal cascade; the presentational attribute loses

(who just spoke?)

<cabanier> is 'display' animatable?

TabAtkins: we talked about all properties being animatable

smfr: i was going to try it and see if there were perf issues

TabAtkins: there's an issue to change transiton-property default to 'none'

heycam: does it make sense to target every attribute, or only animatable ones?
... don't want to modify the DOM attribute property value on animations

TabAtkins: say that only subset of attributes are mapped to properties

heycam: limit to simple values; lengths, numbers etc
... we've heard concrete arguments about option 3
... haven't heard technical arguments against property promotion idea

ChrisL: CSS WG doesn't like adding lots of properties, and element-specific properties
... adding cx and cy properties that only apply to circles would not be liked

heycam: don't want to expand out property tables on every element

smfr: how many properties are we talking about?

<heycam> http://www.w3.org/Graphics/SVG/WG/wiki/F2F/Auckland_2011/CSS_Animation#Regular_Attributes

heycam: about 45 new properties
... roc suggested that rather than adding e.g. circle-radius and ellipse-x-radius, see where properties are similar and merge them

TabAtkins: but this list has cx, x, rx so this list hasn't been folded
... if implementations can only use memory for SVG elements, then the number of new properties shouldn't be an issue

heycam: was this the main objection?

ChrisL: yes

TabAtkins: do we want to go with the attr- prefix or more specialized property names

heycam: maybe don't need to decide now
... x can be a single value on rect, but a list on text
... so need to be careful with possibly conflicting values

<ed> dx,dy has the same issue (for filters vs text elements)

TabAtkins: mostly an issue for the spec, not authors

heycam: if we go the attr- route then we could not create new presentation attributes on the elements

TabAtkins: wouldn't add new attributes even with the specialized names

heycam: what to do with SVG DOM obects like SVGAnimatedLength

TabAtkins: issue seeing the animating value from JS

heycam: SVG is interested in something easier to use than SVGAnimatedLength

<scribe> ACTION: take attr- proposal to CSS WG [recorded in http://www.w3.org/2011/03/14-fx-minutes.html#action01]

<trackbot> Sorry, couldn't find user - take

<scribe> ACTION: TabAtkins take attr- proposal to CSS WG [recorded in http://www.w3.org/2011/03/14-fx-minutes.html#action02]

<trackbot> Sorry, couldn't find user - TabAtkins

<scribe> ACTION: Tab take attr- proposal to CSS WG [recorded in http://www.w3.org/2011/03/14-fx-minutes.html#action03]

<trackbot> Sorry, couldn't find user - Tab


<heycam> trackbot, users?

<trackbot> Sorry, heycam, I don't understand 'trackbot, users?'. Please refer to http://www.w3.org/2005/06/tracker/irc for help

<heycam> trackbot, who do you know about?

<trackbot> Sorry, heycam, I don't understand 'trackbot, who do you know about?'. Please refer to http://www.w3.org/2005/06/tracker/irc for help

<ChrisL> trackbot, status

<scribe> ACTION: cameron to take attr- proposal to SVG WG [recorded in http://www.w3.org/2011/03/14-fx-minutes.html#action04]

<trackbot> Created ACTION-26 - Take attr- proposal to SVG WG [on Cameron McCormack - due 2011-03-21].

2D transforms spec

<ed> http://www.w3.org/Graphics/SVG/WG/wiki/FX-Taskforce/2DTransformsToDoList

anthony_work: made a TODO list

heycam: how do we proceed through this list?

smfr: take to email, the discuss things we need to

anthony_work: if you see issues that are easy to address, go in and edit the wiki page or let me know

smfr: what is "add IDL" for?
... issue is that CSS OM is in flux, and the IDL that used to be there relied on something like CSSValues that were removed?

heycam: does transform become attr-transform?

anthony_work: was assuming it would stay as transform
... what does this mean for the SVG animation interfaces?
... some content uses them, we can't just drop them

heycam: we should discuss what happens with SVG DOM, and if it changes we will need IDL for it
... wiki should make it clear that we won't add the CSS OM interfaces, just the SVG ones
... SVG DOM interfaces could just be defined in SVG, and not in this spec

anthony_work: i like that

ed: i would like to see css2d transforms interfaces, e.g CSSMatrix interface compatible with svg objects

smfr: we should strive to make a single matrix class
... issue with 2d vs. 3d transform matrix

TabAtkins: we should start with a 4x4 matrix

smfr: you have to say what happens when you apply a 3d matrix to something that can only render 2d

TabAtkins: you can specify what happens (flatten or whatever)

anthony_work: would prefer the transform doesn't apply, to avoid behavioral differences

smfr describes issues around supporting 3d css properties but not being able to render 3d

<ed> trackbot, end telcon

Summary of Action Items

[NEW] ACTION: cameron to take attr- proposal to SVG WG [recorded in http://www.w3.org/2011/03/14-fx-minutes.html#action04]
[NEW] ACTION: Tab take attr- proposal to CSS WG [recorded in http://www.w3.org/2011/03/14-fx-minutes.html#action03]
[NEW] ACTION: TabAtkins take attr- proposal to CSS WG [recorded in http://www.w3.org/2011/03/14-fx-minutes.html#action02]
[NEW] ACTION: take attr- proposal to CSS WG [recorded in http://www.w3.org/2011/03/14-fx-minutes.html#action01]
[End of minutes]

Minutes formatted by David Booth's scribe.perl version 1.135 (CVS log)
$Date: 2011/03/14 21:00:17 $

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Guessing input format: RRSAgent_Text_Format (score 1.00)

Succeeded: s/properties/attributes/
Succeeded: s/anthony_work:/heycam:/
Succeeded: s/c-x and c-y/cx and cy/
Succeeded: s/css matrix/css2d transforms interfaces, e.g CSSMatrix/
Found ScribeNick: smfr
Found ScribeNick: smfr
Inferring Scribes: smfr
Present: heycam ed smfr rik_cabanier hober anthony TabAtkins CL
Agenda: http://lists.w3.org/Archives/Public/public-fx/2011JanMar/0124.html
Found Date: 14 Mar 2011
Guessing minutes URL: http://www.w3.org/2011/03/14-fx-minutes.html
People with action items: attr- cameron proposal tab tabatkins take

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