path: root/docs/design/fo_impl/fo_classes.xml

<?xml version="1.0"?>
<!--
  Copyright 1999-2004 The Apache Software Foundation

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<!-- $Id$ -->
<!DOCTYPE formattingObjects [
<!ELEMENT formattingObjects (title,usage,category+,notes?)>
<!ELEMENT title (#PCDATA)>
<!ELEMENT usage (para)*>
<!ELEMENT para (#PCDATA|em|term)*>
<!ELEMENT em (#PCDATA)>
<!ELEMENT term (#PCDATA)>
<!ELEMENT category (object)+>
<!ATTLIST category
          class CDATA #REQUIRED>
<!ELEMENT object (name,baseClass,specContent,generatedAreas,breaksKeeps?)>
<!ATTLIST object
          implemented (true|false) "true">
<!ELEMENT name (#PCDATA)>
<!ELEMENT baseClass (#PCDATA)>
<!ELEMENT specContent (#PCDATA)>
<!ELEMENT generatedAreas (type,multiplicity,currentLayout)?>
<!ATTLIST generatedAreas
          isReference (true|false) "false">
<!ELEMENT type (class,stacking)>
<!ELEMENT class (#PCDATA)>
<!ELEMENT stacking (#PCDATA)>
<!ELEMENT multiplicity (#PCDATA)>
<!ELEMENT currentLayout (#PCDATA)>
<!ATTLIST currentLayout
          intoParentArea (true|false) "false">
<!ELEMENT breaksKeeps (#PCDATA)>
<!ELEMENT notes (note)+>
<!ELEMENT note (#PCDATA)>
]>
<formattingObjects>
<title>FOP Implementation of Layout Formatting Objects</title>
<usage>
<para>
This table displays information concerning FOP implementation
of XSL formatting objects of the layout type.
</para>
<para>
The category classes refer to the XSL specification notation
<term>&#037;block;</term> and <term>&#037;inline;</term>. These
classifications are rather less useful in practical terms than
one might initially suppose.
</para>
<para>
The <em>Base Class</em> of each object is the FOP implementation
class.
</para>
<para>
The <em>Spec Content</em> is the BNF grammar describing
the content of each FO, as taken from the XSL specification.
</para>
<para>
The <em>Breaks and Keeps</em> describes what breaks and keeps apply
to each FO. <em>All</em> means all breaks and keeps, <em>All Keeps</em>
indicates that <term>keep-together</term>, <term>keep-with-next</term>,
and <term>keep-with-previous</term> all apply. The abbreviations
<term>kt</term>, <term>kwn</term>, and <term>kwp</term> specify
individual keep properties.
</para>
<para>
The information on generated areas describes what type of areas are
<em>generated</em> by a given FO, how many there are, whether or not
they are reference areas, and what FOP area class is being used for layout.
In some cases content is laid-out into the parent area; in others, the
content is laid-out in new areas that are constructed as required, then
added to the parent area - this is also noted in the table. In practise,
we should see that FOs that do not generate areas should layout into the
parent.
</para>
<para>
The Name, Spec Content, and Breaks &amp; Keeps information is definite.
The type and multiplicity of generated areas is definite, as well as whether
the generated areas are reference areas or not. The BaseClass and the
layout area information is FOP-implementation dependent.
</para>
<para><em>Note:</em> Numbers in parentheses refer to Notes. A * after
an FO name indicates that the object is not yet implemented.</para>
</usage>
<category class="block-level">
<object>
  <name>block</name>
  <baseClass>FObjMixed</baseClass>
  <specContent><![CDATA[(#PCDATA|%inline;|%block;)*]]></specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>block</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout>BlockArea</currentLayout>
  </generatedAreas>
  <breaksKeeps>All (2)</breaksKeeps>
</object>
<object>
  <name>block-container</name>
  <baseClass>FObj</baseClass>
  <specContent><![CDATA[(%block;)+]]></specContent>
  <generatedAreas isReference="true">
    <type><class>viewport/ref</class><stacking>block</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout>AreaContainer</currentLayout>
  </generatedAreas>
  <breaksKeeps>All</breaksKeeps>
</object>
<object implemented="false">
  <name>table-and-caption</name>
  <baseClass>FObj (1)</baseClass>
  <specContent>(table-caption?,table)</specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>block</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout>AreaContainer</currentLayout>
  </generatedAreas>
  <breaksKeeps>All keeps</breaksKeeps>
</object>
<object>
  <name>table</name>
  <baseClass>FObj</baseClass>
  <specContent>(table-column*,table-header?, table-footer?,table-body+)</specContent>
  <generatedAreas isReference="true">
    <type><class>normal</class><stacking>block</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout>AreaContainer</currentLayout>
  </generatedAreas>
  <breaksKeeps>All</breaksKeeps>
</object>
<object>
  <name>list-block</name>
  <baseClass>FObj</baseClass>
  <specContent>(list-item+)</specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>block</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout>BlockArea</currentLayout>
  </generatedAreas>
  <breaksKeeps>All</breaksKeeps>
</object>
</category>
<category class="inline-level">
<object implemented="false">
  <name>bidi-override</name>
  <baseClass>FObjMixed (1)</baseClass>
  <specContent><![CDATA[(#PCDATA|%inline;|%block;)*]]></specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>inline</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout/>
  </generatedAreas>
  <breaksKeeps/>
</object>
<object>
  <name>character</name>
  <baseClass>FObj</baseClass>
  <specContent>EMPTY</specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>inline</stacking></type>
    <multiplicity>1</multiplicity>
    <currentLayout intoParentArea="true">BlockArea</currentLayout>
  </generatedAreas>
  <breaksKeeps>kwn, kwp</breaksKeeps>
</object>
<object>
  <name>external-graphic</name>
  <baseClass>FObj</baseClass>
  <specContent>EMPTY</specContent>
  <generatedAreas>
    <type><class>viewport/ref</class><stacking>inline</stacking></type>
    <multiplicity>1</multiplicity>
    <currentLayout>ImageArea</currentLayout>
  </generatedAreas>
  <breaksKeeps>kwn, kwp</breaksKeeps>
</object>
<object implemented="false">
  <name>initial-property-set</name>
  <baseClass>FObj (1)</baseClass>
  <specContent>EMPTY</specContent>
  <generatedAreas/>
  <breaksKeeps/>
</object>
<object>
  <name>instream-foreign-object</name>
  <baseClass>FObj</baseClass>
  <specContent>XML</specContent>
  <generatedAreas>
    <type><class>viewport/ref</class><stacking>inline</stacking></type>
    <multiplicity>1</multiplicity>
    <currentLayout>ForeignObjectArea</currentLayout>
  </generatedAreas>
  <breaksKeeps>kwn, kwp</breaksKeeps>
</object>
<object>
  <name>inline</name>
  <baseClass>FObjMixed</baseClass>
  <specContent><![CDATA[(#PCDATA|%inline;|%block;)*]]></specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>inline</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout intoParentArea="true">Area</currentLayout>
  </generatedAreas>
  <breaksKeeps>All keeps</breaksKeeps>
</object>
<object implemented="false">
  <name>inline-container</name>
  <baseClass>FObj (1)</baseClass>
  <specContent><![CDATA[(%block;)+]]></specContent>
  <generatedAreas isReference="true">
    <type><class>viewport/ref</class><stacking>inline</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout/>
  </generatedAreas>
  <breaksKeeps>All keeps</breaksKeeps>
</object>
<object>
  <name>leader</name>
  <baseClass>FObjMixed</baseClass>
  <specContent><![CDATA[(#PCDATA|%inline;)*]]></specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>inline</stacking></type>
    <multiplicity>1</multiplicity>
    <currentLayout intoParentArea="true">BlockArea</currentLayout>
  </generatedAreas>
  <breaksKeeps/>
</object>
<object>
  <name>page-number</name>
  <baseClass>FObj</baseClass>
  <specContent>EMPTY</specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>inline</stacking></type>
    <multiplicity>1</multiplicity>
    <currentLayout intoParentArea="true">BlockArea (4)</currentLayout>
  </generatedAreas>
  <breaksKeeps>kwn, kwp</breaksKeeps>
</object>
<object>
  <name>page-number-citation</name>
  <baseClass>FObj</baseClass>
  <specContent>EMPTY</specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>inline</stacking></type>
    <multiplicity>1</multiplicity>
    <currentLayout intoParentArea="true">BlockArea (4)</currentLayout>
  </generatedAreas>
  <breaksKeeps>kwn, kwp</breaksKeeps>
</object>
<object>
  <name>basic-link</name>
  <baseClass>FObjMixed</baseClass>
  <specContent><![CDATA[(#PCDATA|%inline;|%block;)*]]></specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>inline</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout intoParentArea="true">Area (4)</currentLayout>
  </generatedAreas>
  <breaksKeeps>All keeps</breaksKeeps>
</object>
</category>
<category class="other">
<object>
  <name>list-item-body</name>
  <baseClass>FObj</baseClass>
  <specContent><![CDATA[(%block;)+]]></specContent>
  <generatedAreas>
    <type><class>None</class><stacking>None</stacking></type>
    <multiplicity/>
    <currentLayout intoParentArea="true">Area</currentLayout>
  </generatedAreas>
  <breaksKeeps>kt</breaksKeeps>
</object>
<object>
  <name>list-item</name>
  <baseClass>FObj</baseClass>
  <specContent>(list-item-label,list-item-body)</specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>block</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout>BlockArea</currentLayout>
  </generatedAreas>
  <breaksKeeps>All</breaksKeeps>
</object>
<object>
  <name>list-item-label</name>
  <baseClass>FObj</baseClass>
  <specContent><![CDATA[(%block;)*]]></specContent>
  <generatedAreas>
    <type><class>None</class><stacking>None</stacking></type>
    <multiplicity/>
    <currentLayout intoParentArea="true">Area</currentLayout>
  </generatedAreas>
  <breaksKeeps>kt</breaksKeeps>
</object>
<object>
  <name>table-body</name>
  <baseClass>FObj</baseClass>
  <specContent>(table-row+|table-cell+)</specContent>
  <generatedAreas>
    <type><class>None</class><stacking>None</stacking></type>
    <multiplicity/>
    <currentLayout>AreaContainer (3)</currentLayout>
  </generatedAreas>
  <breaksKeeps/>
</object>
<object implemented="false">
  <name>table-caption</name>
  <baseClass>FObj (1)</baseClass>
  <specContent><![CDATA[(%block;)+]]></specContent>
  <generatedAreas>
    <type><class>normal</class><stacking>block</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout/>
  </generatedAreas>
  <breaksKeeps>kt</breaksKeeps>
</object>
<object>
  <name>table-cell</name>
  <baseClass>FObj</baseClass>
  <specContent><![CDATA[(%block;)+]]></specContent>
  <generatedAreas isReference="true">
    <type><class>normal</class><stacking>block</stacking></type>
    <multiplicity>1..*</multiplicity>
    <currentLayout>AreaContainer</currentLayout>
  </generatedAreas>
  <breaksKeeps/>
</object>
<object>
  <name>table-column</name>
  <baseClass>FObj</baseClass>
  <specContent>EMPTY</specContent>
  <generatedAreas/>
  <breaksKeeps/>
</object>
<object>
  <name>table-footer</name>
  <baseClass>TableBody</baseClass>
  <specContent>(table-row+|table-cell+)</specContent>
  <generatedAreas>
    <type><class>None</class><stacking>None</stacking></type>
    <multiplicity/>
    <currentLayout>AreaContainer (3)</currentLayout>
  </generatedAreas>
  <breaksKeeps/>
</object>
<object>
  <name>table-header</name>
  <baseClass>TableBody</baseClass>
  <specContent>(table-row+|table-cell+)</specContent>
  <generatedAreas>
    <type><class>None</class><stacking>None</stacking></type>
    <multiplicity/>
    <currentLayout>AreaContainer (3)</currentLayout>
  </generatedAreas>
  <breaksKeeps/>
</object>
<object>
  <name>table-row</name>
  <baseClass>FObj</baseClass>
  <specContent>(table-cell+)</specContent>
  <generatedAreas/>
  <breaksKeeps>All</breaksKeeps>
</object>
</category>
<notes>
<note>not yet implemented; suggested base class</note>
<note>also widows &amp; orphans</note>
<note>This is being generated in FOP, but an fo:table-body, or fo:table-header,
or fo:table-footer, generate no areas.</note>
<note>Should generate an area.</note>
</notes>
</formattingObjects>