FigureIterator.java

/**
 *
    Java Diagram Package; An extremely flexible and fast multipurpose diagram 
    component for Swing.
    Copyright (C) 2001  Eric Crahen <crahen@cse.buffalo.edu>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package diagram;

import java.lang.reflect.Array;
import java.util.Iterator;

/**
 * @class FigureIterator
 *
 * @date 08-20-2001
 * @author Eric Crahen
 * @version 1.0
 *
 * This class allows a particular class of figures to be iterated over
 */
public class FigureIterator implements Iterator {

  private Class figureClass;
  private Figure[] figures = new Figure[4];
  private int current = 0;

  /**
   * Create an iterator that will pull a certain class of Figures from the 
   * given DiagramModel
   *
   * @param DiagramModel
   * @param Class
   */
  public FigureIterator(DiagramModel model, Class figureClass) {

    Class c = Figure.class;
    if(!c.isAssignableFrom(figureClass))
      throw new RuntimeException("Can only scan a DiagramModel for Figures");

    this.figureClass = figureClass;

    // Copy the matching figures
    figures = (Figure[])Array.newInstance(figureClass, 4);
    figures = (Figure[])model.toArray((Object[])figures);

  }

  public Object next() {
    return figures[current++];
  }

  public boolean hasNext() {
    return current < figures.length && figures[current] != null;
  }

  public void remove() { }

}