View Javadoc

1   /***
2    * Redistribution  and use  in source  and binary  forms, with  or without
3    * modification, are permitted provided  that the following conditions are
4    * met :
5    *
6    * . Redistributions  of  source  code  must  retain  the  above copyright
7    *   notice, this list of conditions and the following disclaimer.
8    *
9    * . Redistributions in  binary form  must reproduce  the above  copyright
10   *   notice, this list of conditions  and the following disclaimer in  the
11   *   documentation and/or other materials provided with the distribution.
12   *
13   * . The name of the author may not be used to endorse or promote products
14   *   derived from this software without specific prior written permission.
15   *
16   * THIS SOFTWARE IS  PROVIDED BY THE  AUTHOR ``AS IS''  AND ANY EXPRESS  OR
17   * IMPLIED  WARRANTIES,  INCLUDING,  BUT   NOT  LIMITED  TO,  THE   IMPLIED
18   * WARRANTIES OF MERCHANTABILITY AND  FITNESS FOR A PARTICULAR  PURPOSE ARE
19   * DISCLAIMED.  IN NO  EVENT SHALL  THE AUTHOR  BE LIABLE  FOR ANY  DIRECT,
20   * INDIRECT,  INCIDENTAL,  SPECIAL,  EXEMPLARY,  OR  CONSEQUENTIAL  DAMAGES
21   * (INCLUDING,  BUT  NOT LIMITED  TO,  PROCUREMENT OF  SUBSTITUTE  GOODS OR
22   * SERVICES;  LOSS  OF USE,  DATA,  OR PROFITS;  OR  BUSINESS INTERRUPTION)
23   * HOWEVER CAUSED  AND ON  ANY THEORY  OF LIABILITY,  WHETHER IN  CONTRACT,
24   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25   * ANY  WAY  OUT OF  THE  USE OF  THIS  SOFTWARE, EVEN  IF  ADVISED OF  THE
26   * POSSIBILITY OF SUCH DAMAGE.
27   *
28   * $Id: LinearTileIterator.java,v 1.2 2005/09/09 18:19:41 mat007 Exp $
29   */
30  
31  package jtge.util.grid;
32  
33  import java.util.Iterator;
34  import java.util.NoSuchElementException;
35  
36  /***
37   * Provides a linear iterator from the top left to the bottom right tile.
38   * <p>
39   * This iterator returns all the non null tile within the grid.
40   *
41   * @author Jean-Laurent Fabre de Morlhon
42   * @version $Id: LinearTileIterator.java,v 1.2 2005/09/09 18:19:41 mat007 Exp $
43   */
44  public class LinearTileIterator implements Iterator
45  {
46      private final IGrid grid;
47      private Coordinate next;
48  
49      /***
50       * Create a linear tile iterator.
51       *
52       * @param grid the grid
53       */
54      public LinearTileIterator( final IGrid grid )
55      {
56          this( grid, new Coordinate( 0, 0 ) );
57      }
58  
59      /***
60       * Create a linear tile iterator starting a the given coordinate.
61       *
62       * @param grid the grid
63       * @param coordinate the coordinate to start from
64       */
65      public LinearTileIterator( final IGrid grid, final Coordinate coordinate )
66      {
67          if( !grid.isValid( coordinate ) )
68              throw new OutOfBoundException( coordinate );
69          this.grid = grid;
70          this.next = coordinate;
71      }
72  
73      /***
74       * {@inheritDoc}
75       */
76      public final boolean hasNext()
77      {
78          return findNext() != null;
79      }
80  
81      private void increment( final Coordinate coordinate )
82      {
83          coordinate.setX( coordinate.getX() + 1 );
84          if( coordinate.getX() == grid.getWidth() )
85          {
86              coordinate.setY( coordinate.getY() + 1 );
87              coordinate.setX( 0 );
88          }
89      }
90  
91      private Coordinate findNext()
92      {
93          final Coordinate start = (Coordinate)next.clone();
94          while( start.getY() < grid.getHeight() ) // FIXME wrong when starting coordinate is not Coordinate.ORIGIN
95          {
96              if( grid.getTile( start ) != null )
97                  return start;
98              increment( start );
99          }
100         return null;
101     }
102 
103     /***
104      * {@inheritDoc}
105      */
106     public final Object next()
107     {
108         final Coordinate coordinate = findNext();
109         if( coordinate != null )
110         {
111             next = (Coordinate)coordinate.clone();
112             increment( next );
113             return grid.getTile( coordinate );
114         }
115         throw new NoSuchElementException( "iterator exausted" );
116     }
117 
118     /***
119      * {@inheritDoc}
120      */
121     public final void remove()
122     {
123         throw new UnsupportedOperationException();
124     }
125 }