Added new AbstractXMLRenderer base class.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@674484 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 263 insertions, 0 deletions

diff --git a/src/java/org/apache/fop/render/xml/AbstractXMLRenderer.java b/src/java/org/apache/fop/render/xml/AbstractXMLRenderer.java
new file mode 100644
index 000000000..e0667815d
--- /dev/null
+++ b/src/java/org/apache/fop/render/xml/AbstractXMLRenderer.java
@@ -0,0 +1,263 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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: $ */
+
+package org.apache.fop.render.xml;
+
+import java.awt.geom.Rectangle2D;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.List;
+
+import javax.xml.transform.TransformerConfigurationException;
+import javax.xml.transform.sax.SAXTransformerFactory;
+import javax.xml.transform.sax.TransformerHandler;
+import javax.xml.transform.stream.StreamResult;
+
+import org.apache.fop.area.BookmarkData;
+import org.apache.fop.area.OffDocumentExtensionAttachment;
+import org.apache.fop.area.OffDocumentItem;
+import org.apache.fop.area.PageViewport;
+import org.apache.fop.fo.extensions.ExtensionAttachment;
+import org.apache.fop.render.PrintRenderer;
+import org.apache.fop.render.RendererContext;
+import org.apache.xmlgraphics.util.QName;
+import org.xml.sax.Attributes;
+import org.xml.sax.ContentHandler;
+import org.xml.sax.SAXException;
+import org.xml.sax.ext.LexicalHandler;
+import org.xml.sax.helpers.AttributesImpl;
+
+public abstract class AbstractXMLRenderer extends PrintRenderer {
+    /** Main namespace in use. */
+    public static final String NS = "";
+
+    /** CDATA type */
+    public static final String CDATA = "CDATA";
+
+    /** An empty Attributes object used when no attributes are needed. */
+    public static final Attributes EMPTY_ATTS = new AttributesImpl();
+
+    /** AttributesImpl instance that can be used during XML generation. */
+    protected AttributesImpl atts = new AttributesImpl();
+
+    /** ContentHandler that the generated XML is written to */
+    protected ContentHandler handler;
+
+    /** The OutputStream to write the generated XML to. */
+    protected OutputStream out;
+
+    protected RendererContext context;
+
+    /** A list of ExtensionAttachements received through processOffDocumentItem() */
+    protected List extensionAttachments;
+
+    /**
+     * Handles SAXExceptions.
+     * @param saxe the SAXException to handle
+     */
+    protected void handleSAXException(SAXException saxe) {
+        throw new RuntimeException(saxe.getMessage());
+    }
+
+    /**
+     * Handles page extension attachments
+     * @param page the page viewport
+     */
+    protected void handlePageExtensionAttachments(PageViewport page) {
+        handleExtensionAttachments(page.getExtensionAttachments());
+    }
+
+    /**
+     * Writes a comment to the generated XML.
+     * @param comment the comment
+     */
+    protected void comment(String comment) {
+        if (handler instanceof LexicalHandler) { 
+            try {
+                ((LexicalHandler) handler).comment(comment.toCharArray(), 0, comment.length());
+            } catch (SAXException saxe) {
+                handleSAXException(saxe);
+            }
+        }
+    }
+    
+    /**
+     * Starts a new element (without attributes).
+     * @param tagName tag name of the element
+     */
+    protected void startElement(String tagName) {
+        startElement(tagName, EMPTY_ATTS);
+    }
+
+    /**
+     * Starts a new element.
+     * @param tagName tag name of the element
+     * @param atts attributes to add
+     */
+    protected void startElement(String tagName, Attributes atts) {
+        try {
+            handler.startElement(NS, tagName, tagName, atts);
+        } catch (SAXException saxe) {
+            handleSAXException(saxe);
+        }
+    }
+
+    /**
+     * Ends an element.
+     * @param tagName tag name of the element
+     */
+    protected void endElement(String tagName) {
+        try {
+            handler.endElement(NS, tagName, tagName);
+        } catch (SAXException saxe) {
+            handleSAXException(saxe);
+        }
+    }
+
+    /**
+     * Sends plain text to the XML
+     * @param text the text
+     */
+    protected void characters(String text) {
+        try {
+            char[] ca = text.toCharArray();
+            handler.characters(ca, 0, ca.length);
+        } catch (SAXException saxe) {
+            handleSAXException(saxe);
+        }
+    }
+
+    /**
+     * Adds a new attribute to the protected member variable "atts".
+     * @param name name of the attribute
+     * @param value value of the attribute
+     */
+    protected void addAttribute(String name, String value) {
+        atts.addAttribute(NS, name, name, CDATA, value);
+    }
+
+    /**
+     * Adds a new attribute to the protected member variable "atts".
+     * @param name name of the attribute
+     * @param value value of the attribute
+     */
+    protected void addAttribute(QName name, String value) {
+        atts.addAttribute(name.getNamespaceURI(), name.getLocalName(), name.getQName(), 
+                CDATA, value);
+    }
+
+    /**
+     * Adds a new attribute to the protected member variable "atts".
+     * @param name name of the attribute
+     * @param value value of the attribute
+     */
+    protected void addAttribute(String name, int value) {
+        addAttribute(name, Integer.toString(value));
+    }
+
+    private String createString(Rectangle2D rect) {
+        return "" + (int) rect.getX() + " " + (int) rect.getY() + " "
+                  + (int) rect.getWidth() + " " + (int) rect.getHeight();
+    }
+    
+    /**
+     * Adds a new attribute to the protected member variable "atts".
+     * @param name name of the attribute
+     * @param rect a Rectangle2D to format and use as attribute value
+     */
+    protected void addAttribute(String name, Rectangle2D rect) {
+        addAttribute(name, createString(rect));
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void startRenderer(OutputStream outputStream)
+                throws IOException {
+        if (this.handler == null) {
+            SAXTransformerFactory factory
+                = (SAXTransformerFactory)SAXTransformerFactory.newInstance();
+            try {
+                TransformerHandler transformerHandler = factory.newTransformerHandler();
+                setContentHandler(transformerHandler);
+                StreamResult res = new StreamResult(outputStream);
+                transformerHandler.setResult(res);
+            } catch (TransformerConfigurationException tce) {
+                throw new RuntimeException(tce.getMessage());
+            }
+            this.out = outputStream;
+        }
+
+        try {
+            handler.startDocument();
+        } catch (SAXException saxe) {
+            handleSAXException(saxe);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public void stopRenderer() throws IOException {
+        try {
+            handler.endDocument();
+        } catch (SAXException saxe) {
+            handleSAXException(saxe);
+        }
+        if (this.out != null) {
+            this.out.flush();
+        }
+    }
+
+    /** {@inheritDoc} */
+    public void processOffDocumentItem(OffDocumentItem oDI) {
+        if (oDI instanceof BookmarkData) {
+            renderBookmarkTree((BookmarkData) oDI);
+        } else if (oDI instanceof OffDocumentExtensionAttachment) {
+            ExtensionAttachment attachment = ((OffDocumentExtensionAttachment)oDI).getAttachment();
+            if (extensionAttachments == null) {
+                extensionAttachments = new java.util.ArrayList();
+            }
+            extensionAttachments.add(attachment);
+        } else {
+            String warn = "Ignoring OffDocumentItem: " + oDI;
+            log.warn(warn);
+        }
+    }
+
+    protected void handleDocumentExtensionAttachments() {
+        if (extensionAttachments != null && extensionAttachments.size() > 0) {
+            handleExtensionAttachments(extensionAttachments);
+            extensionAttachments.clear();
+        }
+    }
+
+    /**
+     * Sets an outside TransformerHandler to use instead of the default one
+     * create in this class in startRenderer().
+     * @param handler Overriding TransformerHandler
+     */
+    public void setContentHandler(ContentHandler handler) {
+        this.handler = handler;
+    }
+
+    protected abstract void handleExtensionAttachments(List attachments);
+    
+    protected abstract void renderBookmarkTree(BookmarkData odi);
+}