Re: menclose: several values in the "notation" attribute

On Tue, Jan 20, 2009 at 6:31 PM, Karl Tomlinson <w3@karlt.net> wrote:

> Neil Soiffer writes:
>
> > The current draft spec ...
>
> Is the editor's draft publicly available?


There were plans to do that, but I'm not sure what happened to those plans.
David Carlisle has been doing tons of work on the production system used to
generate drafts, so I'll leave an answer up to him.

>
>
> > ... says:
> >
> > "Any number of values can be given for notation separated by whitespace;
> all
> > of those given and understood by a MathML renderer should be rendered.
> Each
> > should be rendered as if the others were not present; they should not
> nest
> > one inside of the other. For example, notation="circle box" should result
> in
> > circle and a box around the contents of menclose; the circle and box may
> > overlap. This is shown in the first example below."
>
> "Each should be rendered as if the others were not present" I
> think addresses my question, thank you.
>
> I think it clearly implies that the position and size of each
> notation relative to child elements depend only on the child
> elements (not on other notations).
>
> I assume that implementations are permitted to position and size
> the menclose (as a whole), thus positioning all the notations,
> relative to the menclose's sibling and ancestor elements, in a
> manner that depends on (the maximum extents of) the particular set
> of notations.  But I don't think a reader would be likely to infer
> otherwise from the text above.
>

Yes (and a little no).  The amount of space used by the notations is not
defined so renderers are free to draw what looks best in their opinion.  I
think though that the baseline for every element should be defined so that
users and implementers know what will/should happen for horizontal
alignment.  This should be the case for all elements, so if it is missing,
I'd appreciate someone pointing out the elements on which this isn't said.
Does saying that the baseline of the meclose element should be the same as
the baseline of its child (which might be an implied mrow) seem right?  It
is what MathPlayer does.

Neil Soiffer
Senior Scientist
Design Science, Inc.
www.dessci.com
~ Makers of Equation Editor, MathType, MathPlayer and MathFlow ~