org.fife.ui.rsyntaxtextarea.RTfToText Maven / Gradle / Ivy
/*
* 07/28/2008
*
* RtfToText.java - Returns the plain text version of RTF documents.
*
* This library is distributed under a modified BSD license. See the included
* RSyntaxTextArea.License.txt file for details.
*/
package org.fife.ui.rsyntaxtextarea;
import java.io.*;
/**
* Gets the plain text version of RTF documents.
*
* This is used by RtfTransferable to return the plain text
* version of the transferable when the receiver does not support RTF.
*
* @author Robert Futrell
* @version 1.0
*/
class RtfToText {
private Reader r;
private StringBuilder sb;
private StringBuilder controlWord;
private int blockCount;
private boolean inControlWord;
/**
* Private constructor.
*
* @param r The reader to read RTF text from.
*/
private RtfToText(Reader r) {
this.r = r;
sb = new StringBuilder();
controlWord = new StringBuilder();
blockCount = 0;
inControlWord = false;
}
/**
* Converts the RTF text read from this converter's Reader
* into plain text. It is the caller's responsibility to close the
* reader after this method is called.
*
* @return The plain text.
* @throws IOException If an IO error occurs.
*/
private String convert() throws IOException {
// Skip over first curly brace as the whole file is in '{' and '}'
int i = r.read();
if (i!='{') {
throw new IOException("Invalid RTF file");
}
while ((i=r.read())!=-1) {
char ch = (char)i;
switch (ch) {
case '{':
if (inControlWord && controlWord.length()==0) { // "\{"
sb.append('{');
controlWord.setLength(0);
inControlWord = false;
}
else {
blockCount++;
}
break;
case '}':
if (inControlWord && controlWord.length()==0) { // "\}"
sb.append('}');
controlWord.setLength(0);
inControlWord = false;
}
else {
blockCount--;
}
break;
case '\\':
if (blockCount==0) {
if (inControlWord) {
if (controlWord.length()==0) { // "\\"
sb.append('\\');
controlWord.setLength(0);
inControlWord = false;
}
else {
endControlWord();
inControlWord = true;
}
}
else {
inControlWord = true;
}
}
break;
case ' ':
if (blockCount==0) {
if (inControlWord) {
endControlWord();
}
else {
sb.append(' ');
}
}
break;
case '\r':
case '\n':
if (blockCount==0) {
if (inControlWord) {
endControlWord();
}
// Otherwise, ignore
}
break;
default:
if (blockCount==0) {
if (inControlWord) {
controlWord.append(ch);
}
else {
sb.append(ch);
}
}
break;
}
}
return sb.toString();
}
/**
* Ends a control word. Checks whether it is a common one that affects
* the plain text output (such as "par" or "tab")
* and updates the text buffer accordingly.
*/
private void endControlWord() {
String word = controlWord.toString();
if ("par".equals(word)) {
sb.append('\n');
}
else if ("tab".equals(word)) {
sb.append('\t');
}
controlWord.setLength(0);
inControlWord = false;
}
/**
* Converts the contents of the specified byte array representing
* an RTF document into plain text.
*
* @param rtf The byte array representing an RTF document.
* @return The contents of the RTF document, in plain text.
* @throws IOException If an IO error occurs.
*/
public static String getPlainText(byte[] rtf) throws IOException {
return getPlainText(new ByteArrayInputStream(rtf));
}
/**
* Converts the contents of the specified RTF file to plain text.
*
* @param file The RTF file to convert.
* @return The contents of the file, in plain text.
* @throws IOException If an IO error occurs.
*/
public static String getPlainText(File file) throws IOException {
return getPlainText(new BufferedReader(new FileReader(file)));
}
/**
* Converts the contents of the specified input stream to plain text.
* The input stream will be closed when this method returns.
*
* @param in The input stream to convert. This will be closed when this
* method returns.
* @return The contents of the stream, in plain text.
* @throws IOException If an IO error occurs.
*/
public static String getPlainText(InputStream in) throws IOException {
return getPlainText(new InputStreamReader(in, "US-ASCII"));
}
/**
* Converts the contents of the specified Reader to plain text.
*
* @param r The Reader. This will be closed when this method
* returns.
* @return The contents of the Reader, in plain text.
* @throws IOException If an IO error occurs.
*/
private static String getPlainText(Reader r) throws IOException {
try {
RtfToText converter = new RtfToText(r);
return converter.convert();
} finally {
r.close();
}
}
/**
* Converts the contents of the specified String to plain text.
*
* @param rtf A string whose contents represent an RTF document.
* @return The contents of the String, in plain text.
* @throws IOException If an IO error occurs.
*/
public static String getPlainText(String rtf) throws IOException {
return getPlainText(new StringReader(rtf));
}
}