RE: Comments on SVG 1.2 from a Gecko developer

Hi, Rob-

First, let me say that I, for one, am very interested to see analyses by
implementors. I'm sure that the WG is appreciative of your input (note that
I don't purport to even unofficially represent the SVG WG, of course ;). 

In addition to the comments by Antoine and Jim, I wanted to add another
rationale to why there is seeming duplication. Given the imprecision of
other Specs as regards SVG, and given the difficulting in coordinating
efforts and results with other WGs, I think it's quite prudent of the SVG WG
to define exactly how the language should behave, as much as possible. It is
better that features are well-defined, so that implementors all do things
the same way (avoiding a Browser Wars scenario). If and when substantial
overlap occurs with other Specs, future versions of both Specs can address
that. I don't think that it's reasonable for SVG to conform wholly to a CSS
spec, for example, that was designed for HTML; better that SVG explores its
own advantages and limitations, and a more neutral approach is developed for
both.

In addition, there seems to be an assumption on your part (totally natural,
since you are developing and extending an HTML UA), that all these parts
(HTML, CSS, SVG, SMIL, etc.) are always going to be working together.
Clearly, this isn't always going to be the case... witness Batik (a
standalone SVG viewer) and mobile players. Having a well-defined SVG Spec
helps those UAs tremendously, as they only have to implement SVG.

Similarly, there are some features of SVG that may need to be made into
their own Spec, or seem more suited to a different Spec. I personally don't
see any harm in their being developed in SVG, in a timely manner that lets
them be used sometime soon, with later revisions relocating and deprecating
them.
 
That being said, I'm looking forward to the day when a mixed-namespace
browser is prevalent, and I'm glad that the Mozilla project in trying to
bring that about. This was certainly not an attack on your observations, but
just my own take on the subject.

Regards-
-Doug

Robert O'Callahan wrote:
| 
| I was just looking through the spec at 
| http://www.w3.org/TR/2004/WD-SVG12-20040318/ and I want to make some 
| comments from the point of view of a browser implementor. I'm speaking 
| on my own behalf and don't purport to officially represent Mozilla. My 
| main concern is that this spec overlaps considerably with existing W3C
| recommendations:
| 
| -- The text flow elements in section 3 overlap considerably with 
| regular HTML/CSS text layout.
| -- "Focusable" seems like it should just resurrect the CSS3-UI 
| proposed "user-focus" property. I'm not sure why it was dropped from 
| CSS3-UI...
| -- The tooltip support could just reuse the HTML 'title' 
| attribute, as far as I can tell.
| -- Instead of copying parts of SMIL into SVG, why not create a 
| SMIL+SVG profile?
| -- The SVG page support seems to overlap with CSS3 Paged Media.
| 
| In these cases, it seems that referring to the appropriate W3C 
| recommendations (possibly using profiles to restrict what is 
| appropriate inside SVG), or slightly extending those recommendations, 
| would reduce work for implementors, authors and standards bodies. 
| (Case in point: a browser that already does HTML+CSS won't want to 
| reimplement text layout slightly differently for SVG.)
| 
| Some other features, such as the streaming attributes in section 9, 
| and the DOM enhancements in section 17, seem to fall into the charters 
| of SMIL and DOM if not the current SMIL and DOM recommendations. (The 
| DOM group per se may be inoperative, but the work on general purpose 
| DOM APIs still needs a venue of its own.)
| 
| Has the SVG WG given any thought to this problem? Is there any way we 
| can avoid this overlap and the difficulties it will cause for 
| implementors and authors?
| 
| Rob
| 
| --
| Robert O'Callahan <robert@ocallahan.org> "In the beginning was the 
| Word, and the Word was with God, and the Word was God. ... The Word 
| became flesh and made his dwelling among us. We have seen his glory, 
| the glory of the One and Only, who came from the Father, full of grace 
| and truth." 1 John 1:1,14

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Received on Friday, 14 May 2004 13:32:50 UTC