1 files changed, 190 insertions, 0 deletions
diff --git a/src/java/org/apache/fop/render/intermediate/IFStructureTreeBuilder.java b/src/java/org/apache/fop/render/intermediate/IFStructureTreeBuilder.java
new file mode 100644
index 000000000..66457681f
--- /dev/null
+++ b/src/java/org/apache/fop/render/intermediate/IFStructureTreeBuilder.java
@@ -0,0 +1,190 @@
+/*
+ * 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.intermediate;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+import org.xml.sax.Attributes;
+import org.xml.sax.ContentHandler;
+import org.xml.sax.SAXException;
+import org.xml.sax.helpers.DefaultHandler;
+
+import org.apache.fop.accessibility.StructureTree2SAXEventAdapter;
+import org.apache.fop.accessibility.StructureTreeEventHandler;
+
+/**
+ * Saves structure tree events as SAX events in order to replay them when it's
+ * time to stream the structure tree to the output.
+ */
+final class IFStructureTreeBuilder implements StructureTreeEventHandler {
+
+    private StructureTreeEventHandler delegate;
+
+    private final List<SAXEventRecorder> pageSequenceEventRecorders = new ArrayList<SAXEventRecorder>();
+
+    /**
+     * Replay SAX events for a page sequence.
+     * @param handler The handler that receives SAX events
+     * @param pageSequenceIndex The index of the page sequence
+     * @throws SAXException
+     */
+    public void replayEventsForPageSequence(ContentHandler handler,
+            int pageSequenceIndex) throws SAXException {
+        pageSequenceEventRecorders.get(pageSequenceIndex).replay(handler);
+    }
+
+    /** {@inheritDoc} */
+    public void startPageSequence(Locale locale) {
+        SAXEventRecorder eventRecorder = new SAXEventRecorder();
+        pageSequenceEventRecorders.add(eventRecorder);
+        delegate = StructureTree2SAXEventAdapter.newInstance(eventRecorder);
+        delegate.startPageSequence(locale);
+    }
+
+    /** {@inheritDoc} */
+    public void endPageSequence() {
+         delegate.endPageSequence();
+    }
+
+    /** {@inheritDoc} */
+    public void startNode(String name, Attributes attributes) {
+        delegate.startNode(name, attributes);
+    }
+
+    /** {@inheritDoc} */
+    public void endNode(String name) {
+        delegate.endNode(name);
+    }
+
+    /** A SAX handler that records events to replay them later. */
+    static class SAXEventRecorder extends DefaultHandler {
+
+        private final List<SAXEventRecorder.Event> events = new ArrayList<SAXEventRecorder.Event>();
+
+        private abstract static class Event {
+            abstract void replay(ContentHandler handler) throws SAXException;
+        }
+
+        private abstract static class Element extends SAXEventRecorder.Event {
+
+            protected final String uri;
+            protected final String localName;
+            protected final String qName;
+
+            private Element(String uri, String localName, String qName) {
+                this.uri = uri;
+                this.localName = localName;
+                this.qName = qName;
+            }
+        }
+
+        private static final class StartElement extends SAXEventRecorder.Element {
+
+            private final Attributes attributes;
+
+            private StartElement(String uri, String localName, String qName,
+                    Attributes attributes) {
+                super(uri, localName, qName);
+                this.attributes = attributes;
+            }
+
+            @Override
+            void replay(ContentHandler handler) throws SAXException {
+                handler.startElement(uri, localName, qName, attributes);
+            }
+        }
+
+        private static final class EndElement extends SAXEventRecorder.Element {
+
+            private EndElement(String uri, String localName, String qName) {
+                super(uri, localName, qName);
+            }
+
+            @Override
+            void replay(ContentHandler handler) throws SAXException {
+                handler.endElement(uri, localName, qName);
+            }
+        }
+
+        private static final class StartPrefixMapping extends SAXEventRecorder.Event {
+
+            protected final String prefix;
+            protected final String uri;
+
+            private StartPrefixMapping(String prefix, String uri) {
+                this.prefix = prefix;
+                this.uri = uri;
+            }
+
+            @Override
+            void replay(ContentHandler handler) throws SAXException {
+                handler.startPrefixMapping(prefix, uri);
+            }
+        }
+
+        private static final class EndPrefixMapping extends SAXEventRecorder.Event {
+
+            protected final String prefix;
+
+            private EndPrefixMapping(String prefix) {
+                this.prefix = prefix;
+            }
+
+            @Override
+            void replay(ContentHandler handler) throws SAXException {
+                handler.endPrefixMapping(prefix);
+            }
+        }
+
+        @Override
+        public void startElement(String uri, String localName, String qName,
+                Attributes attributes) throws SAXException {
+            events.add(new StartElement(uri, localName, qName, attributes));
+        };
+
+        @Override
+        public void endElement(String uri, String localName, String qName) throws SAXException {
+            events.add(new EndElement(uri, localName, qName));
+        };
+
+        @Override
+        public void startPrefixMapping(String prefix, String uri) throws SAXException {
+            events.add(new StartPrefixMapping(prefix, uri));
+        };
+
+        @Override
+        public void endPrefixMapping(String prefix) throws SAXException {
+            events.add(new EndPrefixMapping(prefix));
+        };
+
+        /**
+         * Replays the recorded events.
+         *
+         * @param handler {@code ContentHandler} to replay events on
+         */
+        public void replay(ContentHandler handler) throws SAXException {
+            for (SAXEventRecorder.Event e : events) {
+                e.replay(handler);
+            }
+        }
+    }
+}