- From: Chris Lilley <chris@w3.org>
- Date: Thu, 30 Sep 1999 03:24:33 +0200
- To: Paul Topping <PaulT@mathtype.com>
- CC: "Hundiak, Arthur" <ahundiak@ingr.com>, www-svg@w3.org, svg-comments@w3.org
Paul Topping wrote:
> CAD systems often want groups to contain objects from several layers. A
> "geometry" layer might contain objects that form the boundary of a
> mechanical part and a "dimensioning" layer might contain the arrows,
> dimensions, and annotations applied to the part. Groups would be used to
> group the geometry of sub-parts; one for "bracket A", another for
> "subassembly B", for example.
>
> If SVG allows an object to be a member of more than one group, one can do
> this.
For that sort of structure, which cuts across hierarchical grouping, we
need the notion of set membership. thew class attribute is ideal for
this, since it is a space separated set of things. For example:
svg
g class="a"
g
g
circle class="a"
rect class="b c"
g
path class="a"
path class="c"
.a visibility: invisible
.b visibility: visible
If desired, the opacity property can be used to make semi-transparent
layers (eg, underlays).
--
Chris
Received on Wednesday, 29 September 1999 21:24:39 UTC