<!-- $Id: HOTSPOT.DTD 1.7 1996/08/23 13:01:52 mag Exp $ -->
<!-- Version 3.2 -->
<!-- DTD fragment for hotspots -->
<!-- This DTD reflects the output of the current Hotspot Editor.
The Hotspot Editor is currently in Beta release.  This DTD is subject
to change. -->

<!-- here are some entities useful in describing attribute values. -->
<!ENTITY % f.points   "CDATA"             -- a list of points -->

<!-- entity listing all types of region elements. -->
<!-- initial support for rectangles only. -->
<!ENTITY % f.region   "rect | polyline | ellipse" >

<!-- entity listing possible contents of a region.  (for searching) -->
<!-- a region could be given arbitrarily complex data to search on. 
Typically, a region element would contain the text visible in the region. -->
<!ENTITY % f.text     "#PCDATA" >



<!-- the GRAPHIC element surrounds all the hotspot information 
for a graphic.  Its ENTITY attribute refers to the graphic file itself. -->
<!--      ELEMENTS    MIN  CONTENT (EXCEPTIONS)                      -->
<!ELEMENT HotspotGraphic     - o  (%f.region)*         >

<!--      ELEMENTS    NAME     VALUE       DEFAULT                   -->
<!ATTLIST HotspotGraphic     entity   ENTITY      #IMPLIED
                      filename CDATA       #REQUIRED
                      EbtName  NAME        #FIXED "EBTgraphic"   >


<!-- a REGION is a specification of an area on the graphic.
ID is the region's identifier.  ENTITY identifies the graphic it is in. -->
<!--      ELEMENTS    MIN  CONTENT (EXCEPTIONS)                      -->
<!ELEMENT (%f.region) - o  (%f.text)         >

<!-- The region elements have several elements in common, including
points and numpoints, used to define their shape.  In addition, they
have the ebtName attribute which will (eventually) allow publishers
to use different element GIs -->
<!--      ELEMENTS    NAME     VALUE       DEFAULT                   -->
<!ATTLIST polyline    ebtName  NAME        #FIXED    "EBTpolyline"
                      id       ID          #REQUIRED
                      idref    IDREF       #IMPLIED
                      TEI      CDATA       #IMPLIED
                      book     CDATA       #IMPLIED
                      coll     CDATA       #IMPLIED
                      points   (%f.points) #REQUIRED
                      numpoints CDATA      #REQUIRED>
<!ATTLIST rect        ebtName  NAME        #FIXED    "EBTrect"
                      id       ID          #REQUIRED
                      idref    IDREF       #IMPLIED
                      TEI      CDATA       #IMPLIED
                      book     CDATA       #IMPLIED
                      coll     CDATA       #IMPLIED
                      points   (%f.points) #REQUIRED
                      numpoints CDATA      #REQUIRED>
<!ATTLIST ellipse     ebtName  NAME        #FIXED    "EBTellipse"     
                      id       ID          #REQUIRED
                      idref    IDREF       #IMPLIED
                      TEI      CDATA       #IMPLIED
                      book     CDATA       #IMPLIED
                      coll     CDATA       #IMPLIED
                      points   (%f.points) #REQUIRED
                      numpoints CDATA      #REQUIRED>

<!-- NOTES:
The idref attribute is intended to be used as a pointer to a link end element.
The TEI attribute is intended to be a TEI locator for a link end.  Either
the TEI attribute or the idref attribute should be used, not both.
The book and coll attributes are for specifiying a collection and book for
cross book links.

Coordinates are expressed in units relative to each axis of each graphic.
Coordinates are real numbers between 0.0 and 1.0.  (Exponential notation is not
supported.) Thus the point (0.5 0.5) is in the center (vertically and
horizontally) of any graphic, no matter what its shape or size.  (0.0 0.0) is
the upper left corner.  (1.0 1.0) is the lower right.

Each point is expressed as two coordinates (horizontal followed by vertical), 
separated by a space, and surrounded by parentheses.

A list of points is a space-separated concatination of points.

This DTD shows region elements which can contain only #PCDATA.  It could be
modified so that regions contain any valid SGML.  I show this to indicate how
we could store such information to enable searching within a graphic.
-->