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diff --git a/docs/design/understanding/fo_tree.xml b/docs/design/understanding/fo_tree.xml deleted file mode 100644 index cbe5e5f35..000000000 --- a/docs/design/understanding/fo_tree.xml +++ /dev/null @@ -1,184 +0,0 @@ -<?xml version="1.0"?> -<document> - <header> - <title>FO Tree</title> - <subtitle>All you wanted to know about FO Tree !</subtitle> - <authors> <person name="Keiron Liddle" email="keiron@aftexsw.com"/> - </authors> - </header> -<body><s1 title="FO Tree"> - <p> - The FO Tree is a representation of the XSL:FO document. This - represents the <strong>Objectify</strong> step from the - spec. The <strong>Refinement</strong> step is part of reading - and using the properties which may happen immediately or - during the layout process. - </p> - - - -<p>Each xml element is represented by a java object. For pagination the -classes are in <code>org.apache.fop.fo.pagination.*</code>, for elements in the flow -they are in <code>org.apache.fop.fo.flow.*</code> and some others are in -<code>org.apache.fop.fo.*.</code></p> - - - -<p>The base class for all objects in the tree is FONode. The base class for -all FO Objects is FObj.</p> - - - -<p>(insert diagram here)</p> - - - -<p>There is a class for each element in the FO set. An object is created for -each element in the FO Tree. This object holds the properties for the FO -Object.</p> - - - - <p> - When the object is created it is setup. It is given its - element name, the FOUserAgent - for resolving properties - etc. - the logger and the attributes. The methods - <code>handleAttributes()</code> and - <code>setuserAgent()</code>, common to <code>FONode</code>, - are used in this process. The object will then be given any - text data or child elements. Then the <code>end()</code> - method is called. The end method is used by a number of - elements to indicate that it can do certain processing since - all the children have been added. - </p> - - - -<p>Some validity checking is done during these steps. The user can be warned of the error and processing can continue if possible. -</p> - - - <p> - The FO Tree is simply a heirarchy of java objects that - represent the fo elements from xml. The traversal is done by - the layout or structure process only in the flow elements. - </p> - - - -<s2 title="Properties"> - - - -<p>The XML attributes on each element are passed to the object. The objects -that represent FO objects then convert the attributes into properties. -</p> - - -<p>Since properties can be inherited the PropertyList class handles resolving -properties for a particular element. -All properties are specified in an XML file. Classes are created -automatically during the build process. -</p> - - -<p>(insert diagram here)</p> - - - -<p>In some cases the element may be moved to have a different parent, for -example markers, or the inheritance could be different, for example -initial property set.</p></s2> - - - - -<s2 title="Foreign XML"> - - -<p>The base class for foreign XML is XMLObj. This class handles creating a -DOM Element and the setting of attributes. It also can create a DOM -Document if it is a top level element, class XMLElement. -This class must be extended for the namespace of the XML elements. For -unknown namespaces the class is UnknowXMLObj.</p> - - - -<p>(insert diagram here)</p> - - - -<p>If some special processing is needed then the top level element can extend -the XMLObj. For example the SVGElement makes the special DOM required for -batik and gets the size of the svg. -</p> - - -<p>Foreign XML will usually be in an fo:instream-foreign-object, the XML will -be passed to the render as a DOM where the render will be able to handle -it. Other XML from an unknwon namespace will be ignored. -</p> - - -<p>By using element mappings it is possible to read other XML and either</p> -<ul><li>set information on the area tree</li> -<li>create pseudo FO Objects that create areas in the area tree</li> -<li>create FO Objects</li></ul> -</s2> - - - -<s2 title="Unknown Elements"> -<p>If an element is in a known namespace but the element is unknown then an -Unknown object is created. This is mainly to provide information to the -user. -This could happen if the fo document contains an element from a different -version or the element is misspelt.</p> -</s2> - - -<s2 title="Page Masters"> - <p> - The first elements in a document are the elements for the - page master setup. This is usually only a small number and - will be used throughout the document to create new pages. - These elements are kept as a factory to create the page and - appropriate regions whenever a new page is requested by the - layout. The objects in the FO Tree that represent these - elements are themselves the factory. The root element keeps - these objects as a factory for the page sequences. - </p> -</s2> - - -<s2 title="Flow"> -<p>The elements that are in the flow of the document are a set of elements -that is needed for the layout process. Each element is important in the -creation of areas.</p> -</s2> - - - -<s2 title="Other Elements"> - - - - <p> - The remaining FO Objects are things like page-sequence, - title and color-profile. These are handled by their parent - element; i.e. the root looks after the declarations and the - declarations maintains a list of colour profiles. The - page-sequences are direct descendents of root. - </p> - </s2> - - - -<s2 title="Associated Tasks"> - - - -<ul><li>Create diagrams</li> -<li>Setup all properties and elements for XSL:FO</li> -<li>Setup user agent for property resolution</li> -<li>Verify all XML is handled appropriately</li></ul></s2></s1></body></document>
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