Re: Figure overlays in HTML+

Dave_Raggett <dsr@hplb.hpl.hp.com>
From: Dave_Raggett <dsr@hplb.hpl.hp.com>
Message-id: <9307151659.AA18273@manuel.hpl.hp.com>
Subject: Re: Figure overlays in HTML+
To: jay@bogle.eitech.com
Date: Thu, 15 Jul 93 17:59:46 BST
Cc: www-talk@nxoc01.cern.ch
Mailer: Elm [revision: 66.36.1.1]
Status: RO
Responding to Jay's Message-Id: <9307141846.AA09413@eitech.com> Wed, 14 Jul 93

>> FIGT as it stands is inappropriate outside a figure, since the attachment
>> mechanism is defined as an offset on the figure itself.

> True, so we would like to be able to define offsets relative to the
> document itself, either in coordinates or via "at" (as in PANELs as
> you suggest).

Due to the way word wrap depends on the font and window size etc. it is
impractical to use coordinates outside of figures (or perhaps PRE stuff).

> We'ld like to do annotations where someone can circle a section of text,
> draw arrows between sections of text, point to their own comments, etc.
> We see each user's comments being on a layer that sits on top of the
> original document

The idea of showing a circled portion of the original document is appealing
but doesn't work when you can't say where a line break will occur or which
words will be under each other. Just change the window size and it all
changes.

What one could do is to mark a particular sequence of words or characters
as being pertinent to a given comment. This could be done by inserting
the appropriate markup into document, in the same way that HTML+ handles
change bars. The PANEL tag can be held separately, but relies on there
being predefined anchors to attach to.

In the absence of write access to the document and any suitable anchors,
one is then forced to adopt character offset from known points or pattern
matching, as the basis for attaching comments.

> Understood, but then you go on to describe several ways to allow
> multiple comments on the same document.  I understand what the
> browser would do with multiple comments; what I don't know is the
> HTML+ syntax that could be used to specify them.

The HTML+ syntax permits multiple PANEL elements to be attached to the
same anchor using the AT attribute:

    <p id=z35>Some text that you want to comment on.

some where else:

    <panel at=z35>Thats daft, why don't you ... </panel>
    ...
    <panel at=z35>Another comment on the same paragraph</panel>

I think that a role attribute would clarify the use of the panel element
e.g. role=annotation.

We could extend the FIGT element to have an IDREF which names the figure
to which it applies. This would allow these to be kept separately as well.

Hoping thats clear.

Dave Raggett

p.s.

a) the latest version of the spect is at ftp://15.254.100.100/pub/html/.ps

b) What's you phone number? Perhaps a phone call would be more effective?