/*******************************************************************************
* Copyright (c) 2000, 2003 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Common Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package net.sourceforge.phpdt.internal.ui.text;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.eclipse.jface.text.Assert;
import org.eclipse.jface.text.rules.ICharacterScanner;
import org.eclipse.jface.text.rules.IRule;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.IWordDetector;
import org.eclipse.jface.text.rules.Token;
/**
* An implementation of IRule
capable of detecting words.
*
* Word rules also allow for the association of tokens with specific words. That * is, not only can the rule be used to provide tokens for exact matches, but * also for the generalized notion of a word in the context in which it is used. * A word rules uses a word detector to determine what a word is. *
** This word rule allows a word detector to be shared among different word * matchers. Its up to the word matchers to decide if a word matches and, in * this a case, which token is associated with that word. *
* * @see IWordDetector * @since 3.0 */ public class CombinedWordRule implements IRule { /** * Word matcher, that associates matched words with tokens. */ public static class WordMatcher { /** The table of predefined words and token for this matcher */ private Map fWords = new HashMap(); /** * Adds a word and the token to be returned if it is detected. * * @param word * the word this rule will search for, may not be *null
* @param token
* the token to be returned if the word has been found, may
* not be null
*/
public void addWord(String word, IToken token) {
Assert.isNotNull(word);
Assert.isNotNull(token);
fWords.put(new CharacterBuffer(word), token);
}
/**
* Returns the token associated to the given word and the scanner state.
*
* @param scanner
* the scanner
* @param word
* the word
* @return the token or null
if none is associated by
* this matcher
*/
public IToken evaluate(ICharacterScanner scanner, CharacterBuffer word) {
IToken token = (IToken) fWords.get(word);
if (token != null)
return token;
return Token.UNDEFINED;
}
/**
* Removes all words.
*/
public void clearWords() {
fWords.clear();
}
}
/**
* Character buffer, mutable or suitable for use as key in hash
* maps.
*/
public static class CharacterBuffer {
/** Buffer content */
private char[] fContent;
/** Buffer content size */
private int fLength = 0;
/** Is hash code cached? */
private boolean fIsHashCached = false;
/** The hash code */
private int fHashCode;
/**
* Initialize with the given capacity.
*
* @param capacity
* the initial capacity
*/
public CharacterBuffer(int capacity) {
fContent = new char[capacity];
}
/**
* Initialize with the given content.
*
* @param string
* the initial content
*/
public CharacterBuffer(String content) {
fContent = content.toCharArray();
fLength = content.length();
}
/**
* Empties this buffer.
*/
public void clear() {
fIsHashCached = false;
fLength = 0;
}
/**
* Appends the given character to the buffer.
*
* @param c
* the character
*/
public void append(char c) {
fIsHashCached = false;
if (fLength == fContent.length) {
char[] old = fContent;
fContent = new char[old.length << 1];
System.arraycopy(old, 0, fContent, 0, old.length);
}
fContent[fLength++] = c;
}
/**
* Returns the length of the content.
*
* @return the length
*/
public int length() {
return fLength;
}
/**
* Returns the content as string.
*
* @return the content
*/
public String toString() {
return new String(fContent, 0, fLength);
}
/**
* Returns the character at the given position.
*
* @param i
* the position
* @return the character at position i
*/
public char charAt(int i) {
return fContent[i];
}
/*
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
if (fIsHashCached)
return fHashCode;
int hash = 0;
for (int i = 0, n = fLength; i < n; i++)
hash = 29 * hash + fContent[i];
fHashCode = hash;
fIsHashCached = true;
return hash;
}
/*
* @see java.lang.Object#equals(java.lang.Object)
*/
public boolean equals(Object obj) {
if (obj == this)
return true;
if (!(obj instanceof CharacterBuffer))
return false;
CharacterBuffer buffer = (CharacterBuffer) obj;
int length = buffer.length();
if (length != fLength)
return false;
for (int i = 0; i < length; i++)
if (buffer.charAt(i) != fContent[i])
return false;
return true;
}
/**
* Is the content equal to the given string?
*
* @param string
* the string
* @return true
iff the content is the same character
* sequence as in the string
*/
public boolean equals(String string) {
int length = string.length();
if (length != fLength)
return false;
for (int i = 0; i < length; i++)
if (string.charAt(i) != fContent[i])
return false;
return true;
}
}
/** Internal setting for the uninitialized column constraint */
private static final int UNDEFINED = -1;
/** The word detector used by this rule */
private IWordDetector fDetector;
/**
* The default token to be returned on success and if nothing else has been
* specified.
*/
private IToken fDefaultToken;
/** The column constraint */
private int fColumn = UNDEFINED;
/** Buffer used for pattern detection */
private CharacterBuffer fBuffer = new CharacterBuffer(16);
/** List of word matchers */
private List fMatchers = new ArrayList();
/**
* Creates a rule which, with the help of an word detector, will return the
* token associated with the detected word. If no token has been associated,
* the scanner will be rolled back and an undefined token will be returned
* in order to allow any subsequent rules to analyze the characters.
*
* @param detector
* the word detector to be used by this rule, may not be
* null
*
* @see #addWord(String, IToken)
*/
public CombinedWordRule(IWordDetector detector) {
this(detector, null, Token.UNDEFINED);
}
/**
* Creates a rule which, with the help of an word detector, will return the
* token associated with the detected word. If no token has been associated,
* the specified default token will be returned.
*
* @param detector
* the word detector to be used by this rule, may not be
* null
* @param defaultToken
* the default token to be returned on success if nothing else is
* specified, may not be null
*
* @see #addWord(String, IToken)
*/
public CombinedWordRule(IWordDetector detector, IToken defaultToken) {
this(detector, null, defaultToken);
}
/**
* Creates a rule which, with the help of an word detector, will return the
* token associated with the detected word. If no token has been associated,
* the scanner will be rolled back and an undefined token will be returned
* in order to allow any subsequent rules to analyze the characters.
*
* @param detector
* the word detector to be used by this rule, may not be
* null
* @param matcher
* the initial word matcher
*
* @see #addWord(String, IToken)
*/
public CombinedWordRule(IWordDetector detector, WordMatcher matcher) {
this(detector, matcher, Token.UNDEFINED);
}
/**
* Creates a rule which, with the help of an word detector, will return the
* token associated with the detected word. If no token has been associated,
* the specified default token will be returned.
*
* @param detector
* the word detector to be used by this rule, may not be
* null
* @param matcher
* the initial word matcher
* @param defaultToken
* the default token to be returned on success if nothing else is
* specified, may not be null
*
* @see #addWord(String, IToken)
*/
public CombinedWordRule(IWordDetector detector, WordMatcher matcher,
IToken defaultToken) {
Assert.isNotNull(detector);
Assert.isNotNull(defaultToken);
fDetector = detector;
fDefaultToken = defaultToken;
if (matcher != null)
addWordMatcher(matcher);
}
/**
* Adds the given matcher.
*
* @param matcher
* the matcher
*/
public void addWordMatcher(WordMatcher matcher) {
fMatchers.add(matcher);
}
/**
* Sets a column constraint for this rule. If set, the rule's token will
* only be returned if the pattern is detected starting at the specified
* column. If the column is smaller then 0, the column constraint is
* considered removed.
*
* @param column
* the column in which the pattern starts
*/
public void setColumnConstraint(int column) {
if (column < 0)
column = UNDEFINED;
fColumn = column;
}
/*
* @see IRule#evaluate(ICharacterScanner)
*/
public IToken evaluate(ICharacterScanner scanner) {
int c = scanner.read();
if (fDetector.isWordStart((char) c)) {
if (fColumn == UNDEFINED || (fColumn == scanner.getColumn() - 1)) {
fBuffer.clear();
do {
fBuffer.append((char) c);
c = scanner.read();
} while (c != ICharacterScanner.EOF
&& fDetector.isWordPart((char) c));
scanner.unread();
for (int i = 0, n = fMatchers.size(); i < n; i++) {
IToken token = ((WordMatcher) fMatchers.get(i)).evaluate(
scanner, fBuffer);
if (!token.isUndefined())
return token;
}
if (fDefaultToken.isUndefined())
unreadBuffer(scanner);
return fDefaultToken;
}
}
scanner.unread();
return Token.UNDEFINED;
}
/**
* Returns the characters in the buffer to the scanner.
*
* @param scanner
* the scanner to be used
*/
private void unreadBuffer(ICharacterScanner scanner) {
for (int i = fBuffer.length() - 1; i >= 0; i--)
scanner.unread();
}
}