Description
Callouts, such as numbered bullets, are an annotation mechanism. In an
online system, these bullets are frequently "hot," and clicking on
them navigates to the corresponding annotation.
A ScreenCO is a wrapper around an AreaSpec and
a Screen. An AreaSpec identifies the locations
(coordinates)
in the Screen where the callouts occur.
The ScreenCO may also contain the list of annotations in
a CalloutList, although the CalloutList may also
occur outside of the wrapper, elsewhere in the document.
It is also possible to embed CO elements directly in the
verbatim text, in order to avoid the overhead of calculating the
correct coordinates. If you decide to follow this route, use a
Screen and a CalloutList without the
ScreenCO wrapper. A ScreenCO
must specify at least one coordinate.
For a complete description of callouts, see Callout.
Processing expectations
Formatted as a displayed block. This element is displayed "verbatim";
whitespace and linebreaks within this element are significant.
The mandatory processing expectations of a ScreenCO are
minimal: a system is expected to render the program listing and the
callout list, if present.
If explicit CO elements are embedded in a
Screen, they must generate appropriate
callout marks.
In online environments, the processing system may be able to instantiate
the linking relationships between the callout marks in the program listing and
the annotations.
Some systems may even be able to go a step further and generate
the callout marks automatically from the coordinate information,
but this level of sophistication is not mandatory.
Parents
These elements contain ScreenCO:
Answer, Appendix, Article, BiblioDiv, Bibliography, BlockQuote, Callout, Caption, Caution, Chapter, Colophon, Dedication, entry, Example, Figure, Footnote, Glossary, GlossDef, GlossDiv, Important, Index, IndexDiv, InformalExample, InformalFigure, LegalNotice, ListItem, MsgExplan, MsgText, Note, Para, PartIntro, Preface, Procedure, QandADiv, QandASet, Question, RefSect1, RefSect2, RefSect3, RefSynopsisDiv, Sect1, Sect2, Sect3, Sect4, Sect5, Section, SetIndex, Sidebar, SimpleSect, Step, TextObject, Tip, Warning.
Examples
<!DOCTYPE informalexample PUBLIC "-//OASIS//DTD DocBook V3.1//EN">
<informalexample>
<screen>
Volume in drive C is SYSTEM Serial number is 2350:717C
Directory of C:\
10/17/97 9:04 <DIR> bin
10/16/97 14:11 <DIR> DOS <co id="dos">
10/16/97 14:40 <DIR> Program Files
10/16/97 14:46 <DIR> TEMP
10/17/97 9:04 <DIR> tmp
10/16/97 14:37 <DIR> WINNT
10/16/97 14:25 119 AUTOEXEC.BAT <co id="autoexec.bat">
2/13/94 6:21 54,619 COMMAND.COM <co id="command.com">
10/16/97 14:25 115 CONFIG.SYS <co id="config.sys">
11/16/97 17:17 61,865,984 pagefile.sys
2/13/94 6:21 9,349 WINA20.386 <co id="wina20.386">
</screen>
<calloutlist>
<callout arearefs="dos">
<para>
This directory holds <trademark>MS-DOS</trademark>, the
operating system that was installed before <trademark>Windows
NT</trademark>.
</para>
</callout>
<callout arearefs="autoexec.bat command.com config.sys">
<para>
System startup code for DOS.
</para>
</callout>
<callout arearefs="wina20.386">
<para>
Some sort of <trademark>Windows 3.1</trademark> hack for some 386 processors,
as I recall.
</para>
</callout>
</calloutlist>
</informalexample>
For additional examples, see also Screen.
10/16/97 14:40 <DIR> Program Files 10/16/97 14:46 <DIR> TEMP 10/17/97 9:04 <DIR> tmp 10/16/97 14:37 <DIR> WINNT 10/16/97 14:25 119 AUTOEXEC.BAT
2/13/94 6:21 54,619 COMMAND.COM
10/16/97 14:25 115 CONFIG.SYS
11/16/97 17:17 61,865,984 pagefile.sys 2/13/94 6:21 9,349 WINA20.386
