1 /*
2 * TouchGraph LLC. Apache-Style Software License
3 *
4 *
5 * Copyright (c) 2001-2002 Alexander Shapiro. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 *
19 * 3. The end-user documentation included with the redistribution,
20 * if any, must include the following acknowledgment:
21 * "This product includes software developed by
22 * TouchGraph LLC (http://www.touchgraph.com/)."
23 * Alternately, this acknowledgment may appear in the software itself,
24 * if and wherever such third-party acknowledgments normally appear.
25 *
26 * 4. The names "TouchGraph" or "TouchGraph LLC" must not be used to endorse
27 * or promote products derived from this software without prior written
28 * permission. For written permission, please contact
29 * alex@touchgraph.com
30 *
31 * 5. Products derived from this software may not be called "TouchGraph",
32 * nor may "TouchGraph" appear in their name, without prior written
33 * permission of alex@touchgraph.com.
34 *
35 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
36 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
37 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
38 * DISCLAIMED. IN NO EVENT SHALL TOUCHGRAPH OR ITS CONTRIBUTORS BE
39 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
40 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
41 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
42 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
43 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
44 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
45 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
46 * ====================================================================
47 *
48 */
49
50 package com.touchgraph.graphlayout.graphelements;
51
52 import java.util.Vector;
53
54 import com.touchgraph.graphlayout.Node;
55
56 /*** TGNodeQueue: a very simple queue implementation for doing a breadth
57 * first search. Should probably be implemented with linked lists.
58 *
59 * @author Alexander Shapiro
60 * @version 1.21 $Id: TGNodeQueue.java,v 1.1.1.1 2004/02/06 08:44:07 keesj Exp $
61 */
62 public class TGNodeQueue {
63
64 Vector queue;
65
66 public TGNodeQueue() {
67 queue=new Vector();
68 }
69
70 public void push( Node n ) {
71 queue.addElement(n);
72 }
73
74 public Node pop() {
75 Node n = (Node)queue.elementAt(0);
76 queue.removeElementAt(0);
77 return n;
78 }
79
80 public boolean isEmpty() {
81 return queue.size() == 0;
82 }
83
84 public boolean contains( Node n ) {
85 return queue.contains(n);
86 }
87
88 } // end com.touchgraph.graphlayout.graphelements.TGNodeQueue