area
area — A region defined for a Callout
in a graphic or code example
Synopsis
Content Model
area ::=
EMPTY
Attributes
Name | Type | Default | ||||||
coords | CDATA | Required | ||||||
otherunits | NMTOKEN | None | ||||||
label | CDATA | None | ||||||
units |
| None | ||||||
linkends | IDREFS | None |
Description
An 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 Area
s, 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 Callout
.
Processing expectations
Suppressed. This element provides data for processing but it is not expected to be rendered directly.
The processing expectations of Callout
s are likely to deserve special consideration for interchange. See Appendix F, Interchanging DocBook Documents.
The Coords
, which are required, identify the location of the region. The coordinates are CDATA; how they are interpreted depends on the Units
specified:
CALSPair
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).
LineColumn
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.
LineRange
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.
LineColumnPair
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.
OtherUnits
If specified, then the
OtherUnits
attribute is expected to identify the units in some implementation-specific way.
The Units
attribute is not required, if it is not specified, the semantics of the coordinates must be inherited from the surrounding AreaSpec
or AreaSet
element 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 the appropriate Callout
in an online environment.
Attributes
coords
Coords
provides the coordinates of theArea
. The coordinates should be interpreted using theUnits
(orOtherUnits
) specified.label
Label
specifies an identifying number or string that may be used in presentation. TheArea
label might be drawn on top of the figure, for example, at the position indicated byCoords
.linkends
Linkends
points to theCallout
(s) which refer to thisArea
. (This provides bidirectional linking, which may be useful in online presentation.)otherunits
If none of the
Units
are applicable, setUnits
toOther
and setOtherUnits
to some application-specific description of the desired units.units
Units
indicate how the specifiedCoords
are to be interpreted. The default units vary according to the type of callout specified;CALSPair
for graphics andLineColumn
for line-oriented elements.
Examples
For examples, see graphicco
, mediaobjectco
, programlistingco
.