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- /*
- * 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.accessibility;
-
- import java.io.StringWriter;
- import java.io.Writer;
- import java.util.ArrayList;
- import java.util.Iterator;
- import java.util.List;
-
- import javax.xml.transform.Transformer;
- import javax.xml.transform.TransformerFactory;
- import javax.xml.transform.dom.DOMSource;
- import javax.xml.transform.stream.StreamResult;
-
- import org.w3c.dom.Node;
- import org.w3c.dom.NodeList;
-
- /**
- * A reduced version of the document's FO tree, containing only its logical
- * structure. Used by accessible output formats.
- */
- public final class StructureTree {
-
- private final List pageSequenceStructures = new ArrayList();
-
- /**
- * Package-private default constructor.
- */
- public StructureTree() { }
-
- private static boolean flowOrStaticContentNodes(NodeList nodes) {
- for (int i = 0; i < nodes.getLength(); i++) {
- Node node = nodes.item(i);
- if (node.getNodeType() != Node.ELEMENT_NODE) {
- return false;
- }
- String name = node.getLocalName();
- if (!(name.equals("flow") || name.equals("static-content"))) {
- return false;
- }
- }
- return true;
- }
-
- void addPageSequenceStructure(NodeList structureTree) {
- assert flowOrStaticContentNodes(structureTree);
- pageSequenceStructures.add(structureTree);
- }
-
- /**
- * Returns the list of nodes that are the children of the given page sequence.
- *
- * @param index index of the page sequence, 0-based
- * @return its children nodes
- */
- public NodeList getPageSequence(int index) {
- return (NodeList) pageSequenceStructures.get(index);
- }
-
- /**
- * Returns an XML-like representation of the structure trees.
- * <p>
- * <strong>Note:</strong> use only for debugging purpose, as this method
- * performs non-trivial operations.
- * </p>
- * @return a string representation of this object
- */
- public String toString() {
- try {
- Transformer t = TransformerFactory.newInstance().newTransformer();
- Writer str = new StringWriter();
- for (Iterator iter = pageSequenceStructures.iterator(); iter.hasNext();) {
- NodeList nodes = (NodeList) iter.next();
- for (int i = 0, c = nodes.getLength(); i < c; i++) {
- t.transform(new DOMSource(nodes.item(i)), new StreamResult(str));
- }
- }
- return str.toString();
- } catch (Exception e) {
- return e.toString();
- }
- }
-
- }
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