Initial support for XMP metadata (PDF 1.4) under fo:declarations. Both xmpmeta and RDF elements can be used as root elements for XMP metadata.

Extracted DOM2SAX functionality from XMLXMLHandler into utility class since it is now reused elsewhere.
New DOMBuilderContentHandlerFactory is used to create ContentHandlers that build generic DOMs.
New DelegatingContentHandler is a convenience base class modelled after XMLFilterImpl but as passive SAX receiver. It is used by DOMBuilderContentHandlerFactory.
Refactored FOTreeBuilder. FO tree building is now in a special ContentHandler which can be replaced temporarily when handling foreign XML like SVG or XMP. Extension Elements wanting the set their own ContentHandlers (instead of using the standard FO tree building mechanism) return a non-null value in getContentHandlerFactory(). The old mechanism is still supported (MathML, Plan and Barcode4J still use that). However, SVG support is changed to use a ContentHandlerFactory.
Extension elements for xmpmeta and RDF elements making use of the new DOM build-up using ContentHandlerFactory.
XMP metadata is passed to the renderer as ExtensionAttachment to the document. Only PDFRenderer uses the XMP extension attachment at this time.
The PDFRenderer automatically builds XMP metadata based on the basic metadata information in the PDFInfo object if no explicit XMP metadata has been added to the XSL-FO document.
XMP metadata merging is not implemented because this would involve a more sophisticated XMP infrastructure. That also means that XMP metadata is not validated. It's passed into the PDF as is.
The PDF library now provides the PDFMetadata class to embed XMP metadata in PDFs version >=1.4. stream contents use a special filter list which is initially empty, so non-PDF-aware XMP readers can extract (and optionally modify) the XMP metadata.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@378482 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 162 insertions, 83 deletions

diff --git a/src/java/org/apache/fop/fo/FOTreeBuilder.java b/src/java/org/apache/fop/fo/FOTreeBuilder.java
index f674d58c8..d5d03b7b7 100644
--- a/src/java/org/apache/fop/fo/FOTreeBuilder.java
+++ b/src/java/org/apache/fop/fo/FOTreeBuilder.java
@@ -29,7 +29,11 @@ import org.apache.fop.area.AreaTreeHandler;
 import org.apache.fop.fo.ElementMapping.Maker;
 import org.apache.fop.fo.pagination.Root;
 import org.apache.fop.image.ImageFactory;
+import org.apache.fop.util.ContentHandlerFactory;
+import org.apache.fop.util.ContentHandlerFactory.ObjectSource;
+import org.apache.fop.util.ContentHandlerFactory.ObjectBuiltListener;
 import org.xml.sax.Attributes;
+import org.xml.sax.ContentHandler;
 import org.xml.sax.Locator;
 import org.xml.sax.SAXException;
 import org.xml.sax.SAXParseException;
@@ -56,16 +60,12 @@ public class FOTreeBuilder extends DefaultHandler {
      */
     protected Root rootFObj = null;
 
-    /**
-     * Current formatting object being handled
-     */
-    protected FONode currentFObj = null;
-
-    /**
-     * Current propertyList for the node being handled.
-     */
-    protected PropertyList currentPropertyList;
-
+    /** Main DefaultHandler that handles the FO namespace. */
+    protected MainFOHandler mainFOHandler;
+    
+    /** Current delegate ContentHandler to receive the SAX events */
+    protected ContentHandler delegate;
+    
     /**
      * The class that handles formatting and rendering to a stream
      * (mark-fop@inomial.com)
@@ -80,6 +80,8 @@ public class FOTreeBuilder extends DefaultHandler {
     
     private boolean used = false;
     
+    private int depth;
+    
     /**
      * FOTreeBuilder constructor
      * @param outputFormat the MIME type of the output format to use (ex. "application/pdf").
@@ -135,11 +137,8 @@ public class FOTreeBuilder extends DefaultHandler {
      * @see org.xml.sax.ContentHandler#characters(char[], int, int)
      */
     public void characters(char[] data, int start, int length) 
-        throws FOPException {
-            if (currentFObj != null) {
-                currentFObj.addCharacters(data, start, start + length, 
-                        currentPropertyList, getEffectiveLocator());
-            }
+                throws SAXException {
+        delegate.characters(data, start, length);
     }
 
     /**
@@ -157,6 +156,9 @@ public class FOTreeBuilder extends DefaultHandler {
             log.debug("Building formatting object tree");
         }
         foEventHandler.startDocument();
+        this.mainFOHandler = new MainFOHandler(); 
+        this.mainFOHandler.startDocument();
+        this.delegate = this.mainFOHandler;
     }
 
     /**
@@ -164,8 +166,8 @@ public class FOTreeBuilder extends DefaultHandler {
      * @see org.xml.sax.ContentHandler#endDocument()
      */
     public void endDocument() throws SAXException {
+        this.delegate.endDocument();
         rootFObj = null;
-        currentFObj = null;
         if (log.isDebugEnabled()) {
             log.debug("Parsing of document complete");
         }
@@ -181,55 +183,8 @@ public class FOTreeBuilder extends DefaultHandler {
      */
     public void startElement(String namespaceURI, String localName, String rawName,
                              Attributes attlist) throws SAXException {
-
-        /* the node found in the FO document */
-        FONode foNode;
-        PropertyList propertyList;
-
-        // Check to ensure first node encountered is an fo:root
-        if (rootFObj == null) {
-            if (!namespaceURI.equals(FOElementMapping.URI) 
-                || !localName.equals("root")) {
-                throw new SAXException(new ValidationException(
-                    "Error: First element must be the fo:root formatting object. Found " 
-                        + FONode.getNodeString(namespaceURI, localName) + " instead."
-                        + " Please make sure you're producing a valid XSL-FO document."));
-            }
-        } else { // check that incoming node is valid for currentFObj
-            if (namespaceURI.equals(FOElementMapping.URI)) {
-                // currently no fox: elements to validate
-                // || namespaceURI.equals(ExtensionElementMapping.URI) */) {
-                try {
-                    currentFObj.validateChildNode(locator, namespaceURI, localName);
-                } catch (ValidationException e) {
-                    throw e;
-                }
-            }
-        }
-        
-        ElementMapping.Maker fobjMaker = findFOMaker(namespaceURI, localName);
-//      log.debug("found a " + fobjMaker.toString());
-
-        try {
-            foNode = fobjMaker.make(currentFObj);
-            propertyList = foNode.createPropertyList(currentPropertyList, foEventHandler);
-            foNode.processNode(localName, getEffectiveLocator(), attlist, propertyList);
-            foNode.startOfNode();
-        } catch (IllegalArgumentException e) {
-            throw new SAXException(e);
-        }
-
-        if (rootFObj == null) {
-            rootFObj = (Root) foNode;
-            rootFObj.setFOEventHandler(foEventHandler);
-        } else {
-            currentFObj.addChildNode(foNode);
-        }
-
-        currentFObj = foNode;
-        if (propertyList != null) {
-            currentPropertyList = propertyList;
-        }
+        this.depth++;
+        delegate.startElement(namespaceURI, localName, rawName, attlist);
     }
 
     /**
@@ -237,25 +192,17 @@ public class FOTreeBuilder extends DefaultHandler {
      * @see org.xml.sax.ContentHandler#endElement(String, String, String)
      */
     public void endElement(String uri, String localName, String rawName)
-                throws FOPException {
-        if (currentFObj == null) {
-            throw new IllegalStateException(
-                    "endElement() called for " + rawName + " where there is no current element.");
-        } else if (!currentFObj.getLocalName().equals(localName) 
-                || !currentFObj.getNamespaceURI().equals(uri)) {
-            log.warn("Mismatch: " + currentFObj.getLocalName() 
-                    + " (" + currentFObj.getNamespaceURI() 
-                    + ") vs. " + localName + " (" + uri + ")");
-        }
-        currentFObj.endOfNode();
-
-        if (currentPropertyList.getFObj() == currentFObj) {
-            currentPropertyList = currentPropertyList.getParentPropertyList();
-        }
-        if (currentFObj.getParent() == null) {
-            log.debug("endElement for top-level " + currentFObj.getName());
+                throws SAXException {
+        this.delegate.endElement(uri, localName, rawName);
+        this.depth--;
+        if (depth == 0) {
+            if (delegate != mainFOHandler) {
+                //Return from sub-handler back to main handler
+                delegate.endDocument();
+                delegate = mainFOHandler;
+                delegate.endElement(uri, localName, rawName);
+            }
         }
-        currentFObj = currentFObj.getParent();
     }
 
     /**
@@ -309,5 +256,137 @@ public class FOTreeBuilder extends DefaultHandler {
         }
     }
     
+    /**
+     * Main DefaultHandler implementation which builds the FO tree.
+     */
+    private class MainFOHandler extends DefaultHandler {
+        
+        /**
+         * Current formatting object being handled
+         */
+        protected FONode currentFObj = null;
+
+        /**
+         * Current propertyList for the node being handled.
+         */
+        protected PropertyList currentPropertyList;
+
+        /**
+         * SAX Handler for the start of an element
+         * @see org.xml.sax.ContentHandler#startElement(String, String, String, Attributes)
+         */
+        public void startElement(String namespaceURI, String localName, String rawName,
+                                 Attributes attlist) throws SAXException {
+
+            /* the node found in the FO document */
+            FONode foNode;
+            PropertyList propertyList;
+
+            // Check to ensure first node encountered is an fo:root
+            if (rootFObj == null) {
+                if (!namespaceURI.equals(FOElementMapping.URI) 
+                    || !localName.equals("root")) {
+                    throw new SAXException(new ValidationException(
+                        "Error: First element must be the fo:root formatting object. Found " 
+                            + FONode.getNodeString(namespaceURI, localName) + " instead."
+                            + " Please make sure you're producing a valid XSL-FO document."));
+                }
+            } else { // check that incoming node is valid for currentFObj
+                if (namespaceURI.equals(FOElementMapping.URI)) {
+                    // currently no fox: elements to validate
+                    // || namespaceURI.equals(ExtensionElementMapping.URI) */) {
+                    try {
+                        currentFObj.validateChildNode(locator, namespaceURI, localName);
+                    } catch (ValidationException e) {
+                        throw e;
+                    }
+                }
+            }
+            
+            ElementMapping.Maker fobjMaker = findFOMaker(namespaceURI, localName);
+
+            try {
+                foNode = fobjMaker.make(currentFObj);
+                propertyList = foNode.createPropertyList(currentPropertyList, foEventHandler);
+                foNode.processNode(localName, getEffectiveLocator(), attlist, propertyList);
+                foNode.startOfNode();
+            } catch (IllegalArgumentException e) {
+                throw new SAXException(e);
+            }
+
+            ContentHandlerFactory chFactory = foNode.getContentHandlerFactory();
+            if (chFactory != null) {
+                ContentHandler subHandler = chFactory.createContentHandler();
+                if (subHandler instanceof ObjectSource 
+                        && foNode instanceof ObjectBuiltListener) {
+                    ((ObjectSource)subHandler).setObjectBuiltListener((ObjectBuiltListener)foNode);
+                }
+                
+                subHandler.startDocument();
+                subHandler.startElement(namespaceURI, localName, rawName, attlist);
+                depth = 1;
+                delegate = subHandler;
+            }
+            
+            if (rootFObj == null) {
+                rootFObj = (Root) foNode;
+                rootFObj.setFOEventHandler(foEventHandler);
+            } else {
+                currentFObj.addChildNode(foNode);
+            }
+
+            currentFObj = foNode;
+            if (propertyList != null) {
+                currentPropertyList = propertyList;
+            }
+        }
+
+        /**
+         * SAX Handler for the end of an element
+         * @see org.xml.sax.ContentHandler#endElement(String, String, String)
+         */
+        public void endElement(String uri, String localName, String rawName)
+                    throws SAXException {
+            if (currentFObj == null) {
+                throw new IllegalStateException(
+                        "endElement() called for " + rawName 
+                            + " where there is no current element.");
+            } else if (!currentFObj.getLocalName().equals(localName) 
+                    || !currentFObj.getNamespaceURI().equals(uri)) {
+                log.warn("Mismatch: " + currentFObj.getLocalName() 
+                        + " (" + currentFObj.getNamespaceURI() 
+                        + ") vs. " + localName + " (" + uri + ")");
+            }
+            currentFObj.endOfNode();
+
+            if (currentPropertyList.getFObj() == currentFObj) {
+                currentPropertyList = currentPropertyList.getParentPropertyList();
+            }
+            if (currentFObj.getParent() == null) {
+                log.debug("endElement for top-level " + currentFObj.getName());
+            }
+            currentFObj = currentFObj.getParent();
+        }
+
+        /**
+         * SAX Handler for characters
+         * @see org.xml.sax.ContentHandler#characters(char[], int, int)
+         */
+        public void characters(char[] data, int start, int length) 
+            throws FOPException {
+                if (currentFObj != null) {
+                    currentFObj.addCharacters(data, start, start + length, 
+                            currentPropertyList, getEffectiveLocator());
+                }
+        }
+
+        public void endDocument() throws SAXException {
+            currentFObj = null;
+        }
+
+        
+        
+    }
+    
 }