1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package org.apache.harmony.xml.dom;
18
19import org.w3c.dom.DOMException;
20import org.w3c.dom.Node;
21import org.w3c.dom.Text;
22
23/**
24 * Provides a straightforward implementation of the corresponding W3C DOM
25 * interface. The class is used internally only, thus only notable members that
26 * are not in the original interface are documented (the W3C docs are quite
27 * extensive). Hope that's ok.
28 * <p>
29 * Some of the fields may have package visibility, so other classes belonging to
30 * the DOM implementation can easily access them while maintaining the DOM tree
31 * structure.
32 */
33public class TextImpl extends CharacterDataImpl implements Text {
34
35    public TextImpl(DocumentImpl document, String data) {
36        super(document, data);
37    }
38
39    @Override
40    public String getNodeName() {
41        return "#text";
42    }
43
44    @Override
45    public short getNodeType() {
46        return Node.TEXT_NODE;
47    }
48
49    public final Text splitText(int offset) throws DOMException {
50        Text newText = document.createTextNode(
51                substringData(offset, getLength() - offset));
52        deleteData(0, offset);
53
54        Node refNode = getNextSibling();
55        if (refNode == null) {
56            getParentNode().appendChild(newText);
57        } else {
58            getParentNode().insertBefore(newText, refNode);
59        }
60
61        return this;
62    }
63
64    public final boolean isElementContentWhitespace() {
65        // Undefined because we don't validate. Whether whitespace characters
66        // constitute "element content whitespace" is defined by the containing
67        // element's declaration (DTD) and we don't parse that.
68        // TODO: wire this up when we support document validation
69        return false;
70    }
71
72    public final String getWholeText() {
73        // TODO: support entity references. This code should expand through
74        // the child elements of entity references.
75        //     http://code.google.com/p/android/issues/detail?id=6807
76
77        StringBuilder result = new StringBuilder();
78        for (TextImpl n = firstTextNodeInCurrentRun(); n != null; n = n.nextTextNode()) {
79            n.appendDataTo(result);
80        }
81        return result.toString();
82    }
83
84    public final Text replaceWholeText(String content) throws DOMException {
85        // TODO: support entity references. This code should expand and replace
86        // the child elements of entity references.
87        //     http://code.google.com/p/android/issues/detail?id=6807
88
89        Node parent = getParentNode();
90        Text result = null;
91
92        // delete all nodes in the current run of text...
93        for (TextImpl n = firstTextNodeInCurrentRun(); n != null; ) {
94
95            // ...except the current node if we have content for it
96            if (n == this && content != null && content.length() > 0) {
97                setData(content);
98                result = this;
99                n = n.nextTextNode();
100
101            } else {
102                Node toRemove = n; // because removeChild() detaches siblings
103                n = n.nextTextNode();
104                parent.removeChild(toRemove);
105            }
106        }
107
108        return result;
109    }
110
111    /**
112     * Returns the first text or CDATA node in the current sequence of text and
113     * CDATA nodes.
114     */
115    private TextImpl firstTextNodeInCurrentRun() {
116        TextImpl firstTextInCurrentRun = this;
117        for (Node p = getPreviousSibling(); p != null; p = p.getPreviousSibling()) {
118            short nodeType = p.getNodeType();
119            if (nodeType == Node.TEXT_NODE || nodeType == Node.CDATA_SECTION_NODE) {
120                firstTextInCurrentRun = (TextImpl) p;
121            } else {
122                break;
123            }
124        }
125        return firstTextInCurrentRun;
126    }
127
128    /**
129     * Returns the next sibling node if it exists and it is text or CDATA.
130     * Otherwise returns null.
131     */
132    private TextImpl nextTextNode() {
133        Node nextSibling = getNextSibling();
134        if (nextSibling == null) {
135            return null;
136        }
137
138        short nodeType = nextSibling.getNodeType();
139        return nodeType == Node.TEXT_NODE || nodeType == Node.CDATA_SECTION_NODE
140                ? (TextImpl) nextSibling
141                : null;
142    }
143
144    /**
145     * Tries to remove this node using itself and the previous node as context.
146     * If this node's text is empty, this node is removed and null is returned.
147     * If the previous node exists and is a text node, this node's text will be
148     * appended to that node's text and this node will be removed.
149     *
150     * <p>Although this method alters the structure of the DOM tree, it does
151     * not alter the document's semantics.
152     *
153     * @return the node holding this node's text and the end of the operation.
154     *     Can be null if this node contained the empty string.
155     */
156    public final TextImpl minimize() {
157        if (getLength() == 0) {
158            parent.removeChild(this);
159            return null;
160        }
161
162        Node previous = getPreviousSibling();
163        if (previous == null || previous.getNodeType() != Node.TEXT_NODE) {
164            return this;
165        }
166
167        TextImpl previousText = (TextImpl) previous;
168        previousText.buffer.append(buffer);
169        parent.removeChild(this);
170        return previousText;
171    }
172}
173