EDIT

/*******************************************************************************

 * Copyright (c) 2000, 2006 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.ui.internal.navigator;

import java.util.Vector;

/**

 * A string pattern matcher, suppporting "*" and "?" wildcards.

 */

public class StringMatcher {

	protected String fPattern;

	protected int fLength; // pattern length

	protected boolean fIgnoreWildCards;

	protected boolean fIgnoreCase;

	protected boolean fHasLeadingStar;

	protected boolean fHasTrailingStar;

	protected String fSegments[]; // the given pattern is split into *

	// separated segments

	/* boundary value beyond which we don't need to search in the text */

	protected int fBound = 0;

	protected static final char fSingleWildCard = '\u0000';

	/**

	 * 

	 */

	static class Position {

		int start; // inclusive

		int end; // exclusive

		Position(int start, int end) {

			this.start = start;

			this.end = end;

		}

		int getStart() {

			return start;

		}

		int getEnd() {

			return end;

		}

	}

	/**

	 * StringMatcher constructor takes in a String object that is a simple

	 * pattern which may contain '*' for 0 and many characters and '?' for

	 * exactly one character.

	 * 

	 * Literal '*' and '?' characters must be escaped in the pattern e.g., "\*"

	 * means literal "*", etc.

	 * 

	 * Escaping any other character (including the escape character itself),

	 * just results in that character in the pattern. e.g., "\a" means "a" and

	 * "\\" means "\"

	 * 

	 * If invoking the StringMatcher with string literals in Java, don't forget

	 * escape characters are represented by "\\".

	 * 

	 * @param pattern

	 *            the pattern to match text against

	 * @param ignoreCase

	 *            if true, case is ignored

	 * @param ignoreWildCards

	 *            if true, wild cards and their escape sequences are ignored

	 *            (everything is taken literally).

	 */

	public StringMatcher(String pattern, boolean ignoreCase,

			boolean ignoreWildCards) {

		if (pattern == null) {

			throw new IllegalArgumentException();

		}

		fIgnoreCase = ignoreCase;

		fIgnoreWildCards = ignoreWildCards;

		fPattern = pattern;

		fLength = pattern.length();

		if (fIgnoreWildCards) {

			parseNoWildCards();

		} else {

			parseWildCards();

		}

	}

	/**

	 * Find the first occurrence of the pattern between

	 * <code>start</code)(inclusive) 

	 * and <code>end</code>(exclusive).  

	 * @param  text  the String object to search in 

	 * @param  start  the starting index of the search range, inclusive

	 * @param  end  the ending index of the search range, exclusive

	 * @return an <code>StringMatcher.Position</code> object that keeps the starting 

	 * (inclusive) and ending positions (exclusive) of the first occurrence of the 

	 * pattern in the specified range of the text; return null if not found or subtext

	 * is empty (start==end). A pair of zeros is returned if pattern is empty string

	 * Note that for pattern like "*abc*" with leading and trailing stars, position of "abc"

	 * is returned. For a pattern like"*??*" in text "abcdf", (1,3) is returned

	 */

	public StringMatcher.Position find(String text, int start, int end) {

		if (text == null) {

			throw new IllegalArgumentException();

		}

		int tlen = text.length();

		if (start < 0) {

			start = 0;

		}

		if (end > tlen) {

			end = tlen;

		}

		if (end < 0 || start >= end) {

			return null;

		}

		if (fLength == 0) {

			return new Position(start, start);

		}

		if (fIgnoreWildCards) {

			int x = posIn(text, start, end);

			if (x < 0) {

				return null;

			}

			return new Position(x, x + fLength);

		}

		int segCount = fSegments.length;

		if (segCount == 0) {

			return new Position(start, end);

		}

		int curPos = start;

		int matchStart = -1;

		int i;

		for (i = 0; i < segCount && curPos < end; ++i) {

			String current = fSegments[i];

			int nextMatch = regExpPosIn(text, curPos, end, current);

			if (nextMatch < 0) {

				return null;

			}

			if (i == 0) {

				matchStart = nextMatch;

			}

			curPos = nextMatch + current.length();

		}

		if (i < segCount) {

			return null;

		}

		return new Position(matchStart, curPos);

	}

	/**

	 * match the given <code>text</code> with the pattern

	 * 

	 * @return true if matched eitherwise false

	 * @param text

	 *            a String object

	 */

	public boolean match(String text) {

		if (text == null) {

			return false;

		}

		return match(text, 0, text.length());

	}

	/**

	 * Given the starting (inclusive) and the ending (exclusive) positions in

	 * the <code>text</code>, determine if the given substring matches with

	 * aPattern

	 * 

	 * @return true if the specified portion of the text matches the pattern

	 * @param text

	 *            a String object that contains the substring to match

	 * @param start

	 *            marks the starting position (inclusive) of the substring

	 * @param end

	 *            marks the ending index (exclusive) of the substring

	 */

	public boolean match(String text, int start, int end) {

		if (null == text) {

			throw new IllegalArgumentException();

		}

		if (start > end) {

			return false;

		}

		if (fIgnoreWildCards) {

			return (end - start == fLength)

					&& fPattern.regionMatches(fIgnoreCase, 0, text, start,

							fLength);

		}

		int segCount = fSegments.length;

		if (segCount == 0 && (fHasLeadingStar || fHasTrailingStar)) {

			// contains

			// only

			// '*'(s)

			return true;

		}

		if (start == end) {

			return fLength == 0;

		}

		if (fLength == 0) {

			return start == end;

		}

		int tlen = text.length();

		if (start < 0) {

			start = 0;

		}

		if (end > tlen) {

			end = tlen;

		}

		int tCurPos = start;

		int bound = end - fBound;

		if (bound < 0) {

			return false;

		}

		int i = 0;

		String current = fSegments[i];

		int segLength = current.length();

		/* process first segment */

		if (!fHasLeadingStar) {

			if (!regExpRegionMatches(text, start, current, 0, segLength)) {

				return false;

			}

			++i;

			tCurPos = tCurPos + segLength;

		}

		if ((fSegments.length == 1) && (!fHasLeadingStar)

				&& (!fHasTrailingStar)) {

			// only one segment to match, no wildcards specified

			return tCurPos == end;

		}

		/* process middle segments */

		while (i < segCount) {

			current = fSegments[i];

			int currentMatch;

			int k = current.indexOf(fSingleWildCard);

			if (k < 0) {

				currentMatch = textPosIn(text, tCurPos, end, current);

				if (currentMatch < 0) {

					return false;

				}

			} else {

				currentMatch = regExpPosIn(text, tCurPos, end, current);

				if (currentMatch < 0) {

					return false;

				}

			}

			tCurPos = currentMatch + current.length();

			i++;

		}

		/* process final segment */

		if (!fHasTrailingStar && tCurPos != end) {

			int clen = current.length();

			return regExpRegionMatches(text, end - clen, current, 0, clen);

		}

		return i == segCount;

	}

	/**

	 * This method parses the given pattern into segments seperated by wildcard

	 * '*' characters. Since wildcards are not being used in this case, the

	 * pattern consists of a single segment.

	 */

	private void parseNoWildCards() {

		fSegments = new String[1];

		fSegments[0] = fPattern;

		fBound = fLength;

	}

	/**

	 * Parses the given pattern into segments seperated by wildcard '*'

	 * characters.

	 * 

	 */

	private void parseWildCards() {

		if (fPattern.startsWith("*")) { //$NON-NLS-1$

			fHasLeadingStar = true;

		}

		if (fPattern.endsWith("*")) {//$NON-NLS-1$

			/* make sure it's not an escaped wildcard */

			if (fLength > 1 && fPattern.charAt(fLength - 2) != '\\') {

				fHasTrailingStar = true;

			}

		}

		Vector temp = new Vector();

		int pos = 0;

		StringBuffer buf = new StringBuffer();

		while (pos < fLength) {

			char c = fPattern.charAt(pos++);

			switch (c) {

			case '\\':

				if (pos >= fLength) {

					buf.append(c);

				} else {

					char next = fPattern.charAt(pos++);

					/* if it's an escape sequence */

					if (next == '*' || next == '?' || next == '\\') {

						buf.append(next);

					} else {

						/* not an escape sequence, just insert literally */

						buf.append(c);

						buf.append(next);

					}

				}

				break;

			case '*':

				if (buf.length() > 0) {

					/* new segment */

					temp.addElement(buf.toString());

					fBound += buf.length();

					buf.setLength(0);

				}

				break;

			case '?':

				/* append special character representing single match wildcard */

				buf.append(fSingleWildCard);

				break;

			default:

				buf.append(c);

			}

		}

		/* add last buffer to segment list */

		if (buf.length() > 0) {

			temp.addElement(buf.toString());

			fBound += buf.length();

		}

		fSegments = new String[temp.size()];

		temp.copyInto(fSegments);

	}

	/**

	 * @param text

	 *            a string which contains no wildcard

	 * @param start

	 *            the starting index in the text for search, inclusive

	 * @param end

	 *            the stopping point of search, exclusive

	 * @return the starting index in the text of the pattern , or -1 if not

	 *         found

	 */

	protected int posIn(String text, int start, int end) {// no wild card in

		// pattern

		int max = end - fLength;

		if (!fIgnoreCase) {

			int i = text.indexOf(fPattern, start);

			if (i == -1 || i > max) {

				return -1;

			}

			return i;

		}

		for (int i = start; i <= max; ++i) {

			if (text.regionMatches(true, i, fPattern, 0, fLength)) {

				return i;

			}

		}

		return -1;

	}

	/**

	 * @param text

	 *            a simple regular expression that may only contain '?'(s)

	 * @param start

	 *            the starting index in the text for search, inclusive

	 * @param end

	 *            the stopping point of search, exclusive

	 * @param p

	 *            a simple regular expression that may contains '?'

	 * @return the starting index in the text of the pattern , or -1 if not

	 *         found

	 */

	protected int regExpPosIn(String text, int start, int end, String p) {

		int plen = p.length();

		int max = end - plen;

		for (int i = start; i <= max; ++i) {

			if (regExpRegionMatches(text, i, p, 0, plen)) {

				return i;

			}

		}

		return -1;

	}

	/**

	 * 

	 * @return boolean

	 * @param text

	 *            a String to match

	 * @param tStart

	 *            indicates the starting index of match, inclusive

	 * @param p

	 *            a simple regular expression that may contain '?'

	 * @param pStart

	 * @param plen

	 */

	protected boolean regExpRegionMatches(String text, int tStart, String p,

			int pStart, int plen) {

		while (plen-- > 0) {

			char tchar = text.charAt(tStart++);

			char pchar = p.charAt(pStart++);

			/* process wild cards */

			if (!fIgnoreWildCards) {

				/* skip single wild cards */

				if (pchar == fSingleWildCard) {

					continue;

				}

			}

			if (pchar == tchar) {

				continue;

			}

			if (fIgnoreCase) {

				if (Character.toUpperCase(tchar) == Character

						.toUpperCase(pchar)) {

					continue;

				}

				// comparing after converting to upper case doesn't handle all

				// cases;

				// also compare after converting to lower case

				if (Character.toLowerCase(tchar) == Character

						.toLowerCase(pchar)) {

					continue;

				}

			}

			return false;

		}

		return true;

	}

	/**

	 * @param text

	 *            the string to match

	 * @param start

	 *            the starting index in the text for search, inclusive

	 * @param end

	 *            the stopping point of search, exclusive

	 * @param p

	 *            a string that has no wildcard

	 * @return the starting index in the text of the pattern , or -1 if not

	 *         found

	 */

	protected int textPosIn(String text, int start, int end, String p) {

		int plen = p.length();

		int max = end - plen;

		if (!fIgnoreCase) {

			int i = text.indexOf(p, start);

			if (i == -1 || i > max) {

				return -1;

			}

			return i;

		}

		for (int i = start; i <= max; ++i) {

			if (text.regionMatches(true, i, p, 0, plen)) {

				return i;

			}

		}

		return -1;

	}

}