source: other-projects/rsyntax-textarea/src/java/org/fife/ui/rsyntaxtextarea/RTfToText.java@ 25584

Last change on this file since 25584 was 25584, checked in by davidb, 12 years ago

Initial cut an a text edit area for GLI that supports color syntax highlighting
File size: 5.3 KB
Line 
1/*
2 * 07/28/2008
3 *
4 * RtfToText.java - Returns the plain text version of RTF documents.
5 *
6 * This library is distributed under a modified BSD license. See the included
7 * RSyntaxTextArea.License.txt file for details.
8 */
9package org.fife.ui.rsyntaxtextarea;
10
11import java.io.*;
12
13
14/**
15 * Gets the plain text version of RTF documents.<p>
16 *
17 * This is used by <code>RtfTransferable</code> to return the plain text
18 * version of the transferable when the receiver does not support RTF.
19 *
20 * @author Robert Futrell
21 * @version 1.0
22 */
23class RtfToText {
24
25 private Reader r;
26 private StringBuffer sb;
27 private StringBuffer controlWord;
28 private int blockCount;
29 private boolean inControlWord;
30
31
32 /**
33 * Private constructor.
34 *
35 * @param r The reader to read RTF text from.
36 */
37 private RtfToText(Reader r) {
38 this.r = r;
39 sb = new StringBuffer();
40 controlWord = new StringBuffer();
41 blockCount = 0;
42 inControlWord = false;
43 }
44
45
46 /**
47 * Converts the RTF text read from this converter's <code>Reader</code>
48 * into plain text. It is the caller's responsibility to close the
49 * reader after this method is called.
50 *
51 * @return The plain text.
52 * @throws IOException If an IO error occurs.
53 */
54 private String convert() throws IOException {
55
56 // Skip over first curly brace as the whole file is in '{' and '}'
57 int i = r.read();
58 if (i!='{') {
59 throw new IOException("Invalid RTF file");
60 }
61
62 while ((i=r.read())!=-1) {
63
64 char ch = (char)i;
65 switch (ch) {
66 case '{':
67 if (inControlWord && controlWord.length()==0) { // "\{"
68 sb.append('{');
69 controlWord.setLength(0);
70 inControlWord = false;
71 }
72 else {
73 blockCount++;
74 }
75 break;
76 case '}':
77 if (inControlWord && controlWord.length()==0) { // "\}"
78 sb.append('}');
79 controlWord.setLength(0);
80 inControlWord = false;
81 }
82 else {
83 blockCount--;
84 }
85 break;
86 case '\\':
87 if (blockCount==0) {
88 if (inControlWord) {
89 if (controlWord.length()==0) { // "\\"
90 sb.append('\\');
91 controlWord.setLength(0);
92 inControlWord = false;
93 }
94 else {
95 endControlWord();
96 }
97 }
98 inControlWord = true;
99 }
100 break;
101 case ' ':
102 if (blockCount==0) {
103 if (inControlWord) {
104 endControlWord();
105 }
106 else {
107 sb.append(' ');
108 }
109 }
110 break;
111 case '\r':
112 case '\n':
113 if (blockCount==0) {
114 if (inControlWord) {
115 endControlWord();
116 }
117 // Otherwise, ignore
118 }
119 break;
120 default:
121 if (blockCount==0) {
122 if (inControlWord) {
123 controlWord.append(ch);
124 }
125 else {
126 sb.append(ch);
127 }
128 }
129 break;
130 }
131
132 }
133
134 return sb.toString();
135
136 }
137
138
139 /**
140 * Ends a control word. Checks whether it is a common one that affects
141 * the plain text output (such as "<code>par</code>" or "<code>tab</code>")
142 * and updates the text buffer accordingly.
143 */
144 private void endControlWord() {
145 String word = controlWord.toString();
146 if ("par".equals(word)) {
147 sb.append('\n');
148 }
149 else if ("tab".equals(word)) {
150 sb.append('\t');
151 }
152 controlWord.setLength(0);
153 inControlWord = false;
154 }
155
156
157 /**
158 * Converts the contents of the specified byte array representing
159 * an RTF document into plain text.
160 *
161 * @param rtf The byte array representing an RTF document.
162 * @return The contents of the RTF document, in plain text.
163 * @throws IOException If an IO error occurs.
164 */
165 public static String getPlainText(byte[] rtf) throws IOException {
166 return getPlainText(new ByteArrayInputStream(rtf));
167 }
168
169
170 /**
171 * Converts the contents of the specified RTF file to plain text.
172 *
173 * @param file The RTF file to convert.
174 * @return The contents of the file, in plain text.
175 * @throws IOException If an IO error occurs.
176 */
177 public static String getPlainText(File file) throws IOException {
178 return getPlainText(new BufferedReader(new FileReader(file)));
179 }
180
181
182 /**
183 * Converts the contents of the specified input stream to plain text.
184 * The input stream will be closed when this method returns.
185 *
186 * @param in The input stream to convert.
187 * @return The contents of the stream, in plain text.
188 * @throws IOException If an IO error occurs.
189 */
190 public static String getPlainText(InputStream in) throws IOException {
191 return getPlainText(new InputStreamReader(in, "US-ASCII"));
192 }
193
194
195 /**
196 * Converts the contents of the specified <code>Reader</code> to plain text.
197 *
198 * @param r The <code>Reader</code>.
199 * @return The contents of the <code>Reader</code>, in plain text.
200 * @throws IOException If an IO error occurs.
201 */
202 private static String getPlainText(Reader r) throws IOException {
203 try {
204 RtfToText converter = new RtfToText(r);
205 return converter.convert();
206 } finally {
207 r.close();
208 }
209 }
210
211
212 /**
213 * Converts the contents of the specified String to plain text.
214 *
215 * @param rtf A string whose contents represent an RTF document.
216 * @return The contents of the String, in plain text.
217 * @throws IOException If an IO error occurs.
218 */
219 public static String getPlainText(String rtf) throws IOException {
220 return getPlainText(new StringReader(rtf));
221 }
222
223
224}
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