Re: several messages regarding animation in XBL

Hi Ian.

Ian Hickson:
> I have added text to XBL2 that makes SVG animation elements that would 
> otherwise target an <xbl:template> element that is the root of a shadow 
> tree instead target the bound element's parent element, if any.

Ok thanks.  In our request however we asked for (in this case of the
animation element being at the top of the shadow tree) the targetting to
be the flattened tree parent of the bound element, rather than the DOM
Core parent.  This would handle the situation where the DOM Core parent
of the bound element was itself a template element.  Any chance of
getting this behaviour?

Cameron McCormack:
> > Ian previously stated that whether elements are in the flattened tree or 
> > not determines only whether they are rendered.  Also there is this text 
> > in 4.9.1:
> > 
> >   Shadow content is not considered part of a document, so elements that
> >   are defined to trigger when they are "inserted into the document" do
> >   not trigger during binding attachment.
> > 
> > However, in SMIL documents and SVG documents with SMIL animation 
> > elements in them, it is whether the element is in the document that 
> > determines if it is processed.
>
> Could you elaborate on where SVG and/or SMIL says that?

In the Introduction of SMIL Animation[1] it says:

  A document containing animation elements is referred to as a host
  document.

and later in section 5.2:

  In general, target elements may be any element in the document. Host
  language designers must specify any exceptions to this.

Now, I just took another look at section 19.2.4 of SVG 1.1[2] which says
of the xlink:href attribute on animation elements:

  The target element must be part of the current SVG document fragment.

where the definition of “current SVG document fragment” is:

  The XML document sub-tree which starts with the outermost ancestor
  'svg' element of a given SVG element, with the requirement that
  all container elements between the outermost 'svg' and this
  element are all elements in the SVG language.

And while there doesn’t seem to be a reference to this definition for
whether animation elements are processed, this does seem to be the
prevailing behaviour.

There was a W3C submission for Timesheets, which was to be used to
specify animations outside the current document, but in SMIL Animation
and SMIL 2.1 this isn’t addressed; they were defined before the concept
of shadow trees was well understood.

So we think the current definition of the document in XBL inadvertently
precludes both animation of elements across a shadow tree boundary (as
with the new animation related text you have introduced) and also within
a shadow tree (since it’s not in the document).  We therefore request
that a clarifying sentence be inserted in the section on animation to
ensure that such things will work.

Thanks,

Cameron
-for the SVG WG

[1] http://www.w3.org/TR/2001/REC-smil-animation-20010904/
[2] http://www.w3.org/TR/SVG11/animate.html#TargetElement

-- 
Cameron McCormack, http://mcc.id.au/
 xmpp:heycam@jabber.org  ▪  ICQ 26955922  ▪  MSN cam@mcc.id.au

Received on Sunday, 18 February 2007 23:00:14 UTC