Re: Animating SVG attributes from Web Animations

On Jun 16, 2015, at 1:45 PM, Shane Stephens <shans@google.com<mailto:shans@google.com>> wrote:



On Tue, Jun 16, 2015 at 9:24 PM Dirk Schulze <dschulze@adobe.com<mailto:dschulze@adobe.com>> wrote:
On Jun 16, 2015, at 9:35 AM, Shane Stephens <shans@google.com<mailto:shans@google.com>> wrote:



On Tue, Jun 16, 2015 at 4:46 PM Dirk Schulze <dschulze@adobe.com<mailto:dschulze@adobe.com>> wrote:
On Jun 16, 2015, at 7:16 AM, Shane Stephens <shans@google.com<mailto:shans@google.com>> wrote:

Shall WebAnimation also animate HTML attributes at some point?

I don't know. We've talked in the past about animating class. I'd also like to be able to animate scroll offsets at some point.

If yes, shall these attributes be “html” prefixed as well?

Yes. I think that would make sense.

What happens with the “svg*” attribute animation once we promoted the attribute to a CSS property/ presentation attribute?

* If the promotion matches the syntax and name, then animating either svgFoo or foo will produce identical results.
* If the promition matches the syntax, but the name foo becomes bar when promoted, then animating svgFoo and animating bar will produce identical results.
etc..

What about the CSS properties width/height and the width/height attributes on an HTMLCanvasElement? Both can be applied at the same time and may have different meanings. I assume that this would justify the html* prefix but we would end up with a svgWidth and htmlWidth animation attribute.

Yes, these would also be properties that we would want to provide with an html prefix, if we choose to make them animatable. I'm not aware of any plans to do so right now though.

Is there maybe a way to explicitly state that you want to animate a property or an attribute? In case of a presentation attribute it would always fallback to the property? Similar to “attributeType”[1] in SVG animations?

svg/html as a prefix is an example of an explicit way :) Happy to consider others too. Do you have some ideas?

What about another animation parameter?


Note that it's probably a bad idea to restrict a single animation to only property animation or only attribute animation, because future promotion of attributes might then lead to the need for a large-scale refactor.

IMO the current experience with the latest presentation properties lead to a different conclusion. Still supporting attribute animations separate from property animations on a presentation attribute is quite a challenge and we agreed to not require this anymore.

Can you provide more context? e.g. who's 'we' and which animations are you talking about? What were the challenges?

I can't think of any particular difficulties that would prevent us supporting both property and attribute references within a single keyframe, but maybe I'm thinking wrong.

With attributeType, it was possible (according to SVG 1.1) to specify a animation on the attribute value of the presentation attribute. Meaning that you animated a value that comes after US stylesheet in the CSS cascade. Or you animated the CSS property which animated the value after the whole cascade. You were able to animate the attribute and the property at the same time, causing changes in different levels of the cascade. This was implementable but fairly complex. We agreed to get rid of this behavior and animate the property even though attributeType=“XML” was specified. With “we” I am basically speaking of WebKit, Blink, Gecko and the SVG WG.

Greetings,
Dirk


Cheers,
    -Shane


Greetings,
Dirk


Cheers,
    -Shane

Greetings,
Dirk

[1] http://www.w3.org/TR/SVG/animate.html#AttributeTypeAttribute



Cheers,
    -Shane

Dirk

>
> Cheers,
>     -Shane