$Revision: 3046 $
$Date: 2003-08-17 10:31:00 -0400 (Sun, 17 Aug 2003) $
area — A region defined for a
Callout in a graphic or code example
area ::= EMPTY
Area is an empty element holding information about a
region in a graphic, program listing, or screen.
The region is generally decorated with a number, symbol, or other
distinctive mark. The mark is usually used as the label for the
Callout in a
CalloutList, which allows the
reader to identify which callouts are associated with which regions.
The marks may be generated by the processing application from the
Areas, or it may be added by some other process. (This is
an interchange issue. See Appendix F, Interchanging DocBook Documents.)
For a complete description of callouts, see
Suppressed. This element provides data for processing but it is not expected to be rendered directly.
Coords, which are required, identify
the location of the region. The coordinates are CDATA;
how they are interpreted depends on the
The coordinates are expressed using the semantics of the CALS graphic attributes. The format of the coordinates is “x1,y1 x2,y2”. This identifies a rectangle with the lower-left corner at (x1,y1) and the upper-right corner at (x2,y2). The X and Y coordinates are integers in the range 0 to 10000; they express a percentage of the total distance from 0.00 to 100.00%. The lower-left corner is (0,0).
The coordinates are expressed using lines and columns. The format of the coordinates is “line column.” In a graphic context, the meaning of this unit is unspecified.
The coordinates are expressed using lines. The format of the coordinates is “startingline endingline.” In a graphic context, the meaning of this unit is unspecified.
The coordinates are expressed as a continuous flow of characters. The format of the coordinates is “line1 col1 line2 col2”. This identifies a flow of characters that begins at col1 of line1 and extends to col2 of line2. If line1 and line2 are different, then the region includes all of the intervening lines (including text that occurs before col1 and after col2). In other words, this unit does not specify a rectangle. In a graphic context, the meaning of this unit is unspecified.
If specified, then the
attribute is expected to identify the units in some
Units attribute is not required, if it
is not specified, the semantics of the coordinates must be inherited from
or implied in
some implementation-specific manner.
In processing systems in which the mark is inserted automatically, the
Label attribute is provided as a mechanism
for specifying what the mark should be.
The author may point to any relevant information with
Linkends. DocBook does not specify a semantic for
these links. One possible use would be for providing a link back to
Callout in an online environment.
Coords provides the coordinates of the
Area. The coordinates should be interpreted using the
Label specifies an identifying number or string
that may be used in presentation. The
Area label might be drawn
on top of the figure, for example, at the position indicated by
If none of the
Units are applicable, set
Other and set
OtherUnits to some application-specific
description of the desired units.
Units indicate how the specified
Coords are to be interpreted. The default
units vary according to the type of callout specified;
for graphics and
LineColumn for line-oriented elements.