So it looks like people want file order and not graphical order. If there are no objections, I propose that we make sure the wording in the spec is clear and we go with that approach.

Thanks all,

-- Benoit mailto:ben...@itedo.com

Friday, October 8, 2004, 12:41:50 PM, David wrote:

CDW> All,

CDW> When I think of the structure of a CGM file with respect to CDW> hierarchy, I think in terms of SGML/XML hierarchy. That means CDW> first child to me means the first one in the order of the CDW> hierarchy, not the last one drawn graphically.

CDW> The question that remains in my mind is the graphical CDW> effect. If you have three children aps; foo:one, foo:two, and CDW> foo:three, and you change the style of foo:two, do all three have CDW> to be re-generated in the graphical display? Is there a CDW> difference depending on the choice of whether foo:one or foo:two CDW> is first child?

CDW> thx...dave

CDW> -----Original Message----- CDW> From: Benoit Bezaire [mailto:ben...@itedo.com] CDW> Sent: Thursday, October 07, 2004 8:38 AM CDW> To: CGM Open WebCGM TC CDW> Subject: [cgmo-webcgm] WebCGM traversal routines

CDW> Hi all,

CDW> I have a question regarding the WebCGM DOM traversal routines. I CDW> have to admit, this one took me by surprise. Let's take the CDW> following WebCGM document snippet as an example:

CDW> BEGAPS 'group' ... CDW> BEGAPSBODY; CDW> BEGAPS 'one' ... CDW> ... CDW> ENDAPS; CDW> BEGAPS 'two' ... CDW> ... CDW> ENDAPS; CDW> BEGAPS 'three' ... CDW> ... CDW> ENDAPS; CDW> BEGAPS 'four' ... CDW> ... CDW> ENDAPS; CDW> ENDAPS;

CDW> In your opinion; what is the firstChild of 'group'? Being accustomed CDW> to the XML world, I was convinced that the answer would be 'one'; CDW> but the existing Isodraw code tells me otherwise, it claims that CDW> 'four' is the firstChild. Dieter then explained that 'four' CDW> is the firstChild since it's the foremost object of the group. CDW> Ok, now it makes sense to me.

CDW> We believe (and please correct us if we are wrong) that other CDW> private APIs from vendors of this group behave like ours; that a CDW> firstChild of a group is not the first child based on file order but CDW> instead, the foremost element (visual tree order).

CDW> So the question is; do we want to adopt the XML/SVG approach (file CDW> order) or stick with current practices of CGM vendors (visual tree CDW> order)?

CDW> Note: if we do stick with current practices, I would recommend CDW> changing the names of these APIs or else they'll be confused with CDW> XML/SVG APIs.

CDW> I don't know what my preference is on this. I'm some times in CDW> favour of the XML/SVG approach (since script writers are used to CDW> this) but I could be convinced otherwise since WebCGM files are CDW> binary (so your are left with what you see on screen). What is CDW> problematic for me are the XML metadata nodes:

CDW> BEGAPS 'group' ... CDW> BEGAPSBODY; CDW> BEGAPS 'foo:simpleData' ... CDW> ... CDW> ENDAPS; CDW> BEGAPS 'foo:complexData' ... CDW> ... CDW> ENDAPS; CDW> ENDAPS;

CDW> Why would the firstChild of 'group' be 'foo:complexData'?

CDW> Obviously looking for your input,

CDW> Regards,