/*******************************************************************************
* Copyright (c) 2000, 2005 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
*******************************************************************************/
//copied directly from org.eclipse.jface.internal.text.link.contentassist.HTML2TextReader;
package com.aptana.ide.editors.unified.utils;
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.
*/
abstract class SubstitutionTextReader extends SingleCharReader
{
/**
* LINE_DELIM
*/
protected static final String LINE_DELIM = System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
private Reader fReader;
private boolean fWasWhiteSpace;
private int fCharAfterWhiteSpace;
/**
* Tells whether white space characters are skipped.
*/
private boolean fSkipWhiteSpace = true;
private boolean fReadFromBuffer;
private StringBuffer fBuffer;
private int fIndex;
/**
* SubstitutionTextReader
*
* @param reader
*/
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 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 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 Reader#read()
*/
public int read() throws IOException
{
int c;
do
{
c = nextChar();
while (!fReadFromBuffer)
{
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 Reader#ready()
*/
public boolean ready() throws IOException
{
return fReader.ready();
}
/**
* @see Reader#close()
*/
public void close() throws IOException
{
fReader.close();
}
/**
* @see Reader#reset()
*/
public void reset() throws IOException
{
fReader.reset();
fWasWhiteSpace = true;
fCharAfterWhiteSpace = -1;
fBuffer.setLength(0);
fIndex = 0;
}
/**
* setSkipWhitespace
*
* @param state
*/
protected final void setSkipWhitespace(boolean state)
{
fSkipWhiteSpace = state;
}
/**
* isSkippingWhitespace
*
* @return boolean
*/
protected final boolean isSkippingWhitespace()
{
return fSkipWhiteSpace;
}
}