TextWrapper.java

/*******************************************************************************
 * Copyright (c) 2004, 2008 John Krasnay 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:
 *     John Krasnay - initial API and implementation
 *******************************************************************************/
package net.sf.vex.dom;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * Wraps text to a given width.
 */
public class TextWrapper {

    private List parts = new ArrayList();

    private boolean lastIsWhite = true;
    
    /**
     * Class constructor.
     */
    public TextWrapper() {
    }

    /**
     * Adds text to the list of things to be wrapped.
     *
     * @param s Text to be added.
     */
    public void add(String s) {
	int i = 0;
	int j = 0;
	boolean thisIsWhite = true;
	while (j < s.length()) {

	    // skip non-whitespace
	    while (j < s.length() && !Character.isWhitespace(s.charAt(j))) {
		j++;
		thisIsWhite = false;
	    }

	    // skip whitespace
	    while (j < s.length() && Character.isWhitespace(s.charAt(j))) {
		j++;
		thisIsWhite = true;
	    }
	    
	    if (lastIsWhite)
	    	this.parts.add(s.substring(i, j));
	    else
	    	this.parts.add(((String)this.parts.remove(this.parts.size()-1)) +
	    			s.substring(i, j));
	    i = j;
	    lastIsWhite = thisIsWhite;
	}
    }

    /**
     * Adds text to the list of things to be wrapped. The given text
     * will be treated as a single unit and will not be split across
     * lines.
     *
     * @param s Text to be added.
     */
    public void addNoSplit(String s) {
	this.parts.add(s);
    }

    /**
     * Clears any added text.
     */
    public void clear() {
	this.parts.clear();
    }

    /**
     * Wraps the text into the given width. The text is only
     * broken at spaces, meaning the returned lines will not
     * necessarily fit within width.
     *
     * @param width
     */
    public String[] wrap(int width) {
	List lines = new ArrayList();
	StringBuffer line = new StringBuffer();

	Iterator iter = this.parts.iterator();
	while (iter.hasNext()) {
	    String s = (String) iter.next();
	    if (line.length() > 0 &&
		line.length() + s.length() > width) {
		// part won't fit on the current line
		lines.add(line.toString());
		line.setLength(0);

		if (s.length() > width) {
		    lines.add(s);
		} else {
		    line.append(s);
		}
	    } else {
		line.append(s);
	    }
	}

	if (line.length() > 0) {
	    lines.add(line.toString());
	}

	return (String[]) lines.toArray(new String[lines.size()]);
    }
								

    //====================================================== PRIVATE


}