LuaWordFinder.java

/*
* Copyright (C) 2003-2007 Kepler Project.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package org.keplerproject.ldt.ui.text.lua;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.Region;


/**
 * Provides a mechanism for finding a word within the lua source code
 * 
 * @author jasonsantos
 * @version $Id$
 */
public class LuaWordFinder {

	/**
	 * Find a word within a document, given an offset
	 */
	public static IRegion findWord(IDocument document, int offset) {

		int start= -2;
		int end= -1;
		
		try {
			int pos= offset;
			char c;

			while (pos >= 0) {
				c= document.getChar(pos);
				if (!Character.isJavaIdentifierPart(c) && c!='.'&& c!=':')
					break;
				--pos;
			}
			start= pos;

			pos= offset;
			int length= document.getLength();

			while (pos < length) {
				c= document.getChar(pos);
				if (!Character.isJavaIdentifierPart(c)&& c!='.'&& c!=':')
					break;
				++pos;
			}
			end= pos;

		} catch (BadLocationException x) {
		}

		if (start >= -1 && end > -1) {
			if (start == offset && end == offset)
				return new Region(offset, 0);
			else if (start == offset)
				return new Region(start, end - start);
			else
				return new Region(start + 1, end - start - 1);
		}

		return null;
	}
	
}