area (db.area)

area — A region defined for a callout in a graphic or code example.

Synopsis

area (db.area) ::=

Attributes

Common attributes (ID required).

Additional attributes:

  • coords
  • label
  • Exactly one of:
    • units (enumeration)
      • “calspair”
      • “linecolumn”
      • “linecolumnpair”
      • “linerange”
    • Each of:
      • units (enumeration)
        • “other”
      • otherunits (NMTOKEN)

Required attributes are shown in bold.

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 areas, or it may be added by some other process. (This is an interchange issue. See Appendix C, 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 callouts are likely to deserve special consideration for interchange. See Appendix C, 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

Common attributes (ID required).

coords

Provides the coordinates of the area. The coordinates must be interpreted using the units specified.

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 the coords attribute.

otherunits

Identifies the units used in the coords attribute when the units attribute is “other” . This attribute is forbidden otherwise.

units

Identifies the units used in the coords attribute. The default units vary according to the type of callout specified: calspair for graphics and linecolumn for line-oriented elements.

Enumerated values:
“calspair”

Coordinates expressed as a pair of CALS graphic coordinates.

“linecolumn”

Coordinates expressed as a line and column.

“linecolumnpair”

Coordinates expressed as a pair of lines and columns.

“linerange”

Coordinates expressed as a line range.

Parents

These elements contain area: areaspec.

Children

The following elements occur in area: alt.

See Also

area (db.area.inareaset)

Last revised by Norman Walsh on (git hash: 8efbb30ec1f2a59299576c057927c2032216aea4 f2da477a142b88c50ef9ceb6f54ce6b54fca5836)