/*******************************************************************************
* Copyright (c) 2000, 2012 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.che.jdt.javadoc;
import java.io.IOException;
import java.io.Reader;
/**
* Reads the text contents from a reader and computes for each character
* a potential substitution. The substitution may eat more characters than
* only the one passed into the computation routine.
* <p>
* Moved into this package from <code>org.eclipse.jface.internal.text.revisions</code>.</p>
*/
public abstract class SubstitutionTextReader extends SingleCharReader {
protected static final String LINE_DELIM = System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
protected boolean fWasWhiteSpace;
private Reader fReader;
private int fCharAfterWhiteSpace;
/**
* Tells whether white space characters are skipped.
*/
private boolean fSkipWhiteSpace = true;
private boolean fReadFromBuffer;
private StringBuffer fBuffer;
private int fIndex;
protected SubstitutionTextReader(Reader reader) {
fReader = reader;
fBuffer = new StringBuffer();
fIndex = 0;
fReadFromBuffer = false;
fCharAfterWhiteSpace = -1;
fWasWhiteSpace = true;
}
/**
* Computes the substitution for the given character and if necessary
* subsequent characters. Implementation should use <code>nextChar</code>
* to read subsequent characters.
*
* @param c
* the character to be substituted
* @return the substitution for <code>c</code>
* @throws java.io.IOException
* in case computing the substitution fails
*/
protected abstract String computeSubstitution(int c) throws IOException;
/**
* Returns the internal reader.
*
* @return the internal reader
*/
protected Reader getReader() {
return fReader;
}
/**
* Returns the next character.
*
* @return the next character
* @throws java.io.IOException
* in case reading the character fails
*/
protected int nextChar() throws IOException {
fReadFromBuffer = (fBuffer.length() > 0);
if (fReadFromBuffer) {
char ch = fBuffer.charAt(fIndex++);
if (fIndex >= fBuffer.length()) {
fBuffer.setLength(0);
fIndex = 0;
}
return ch;
}
int ch = fCharAfterWhiteSpace;
if (ch == -1) {
ch = fReader.read();
}
if (fSkipWhiteSpace && Character.isWhitespace((char)ch)) {
do {
ch = fReader.read();
} while (Character.isWhitespace((char)ch));
if (ch != -1) {
fCharAfterWhiteSpace = ch;
return ' ';
}
} else {
fCharAfterWhiteSpace = -1;
}
return ch;
}
/**
* @see java.io.Reader#read()
*/
public int read() throws IOException {
int c;
do {
c = nextChar();
while (!fReadFromBuffer && c != -1) {
String s = computeSubstitution(c);
if (s == null)
break;
if (s.length() > 0)
fBuffer.insert(0, s);
c = nextChar();
}
} while (fSkipWhiteSpace && fWasWhiteSpace && (c == ' '));
fWasWhiteSpace = (c == ' ' || c == '\r' || c == '\n');
return c;
}
/**
* @see java.io.Reader#ready()
*/
public boolean ready() throws IOException {
return fReader.ready();
}
/**
* @see java.io.Reader#close()
*/
public void close() throws IOException {
fReader.close();
}
/**
* @see java.io.Reader#reset()
*/
public void reset() throws IOException {
fReader.reset();
fWasWhiteSpace = true;
fCharAfterWhiteSpace = -1;
fBuffer.setLength(0);
fIndex = 0;
}
protected final void setSkipWhitespace(boolean state) {
fSkipWhiteSpace = state;
}
protected final boolean isSkippingWhitespace() {
return fSkipWhiteSpace;
}
}