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: Buffer.java,v 1.3 2005/08/26 18:09:36 mat007 Exp $
29 */
30
31 package jtge.engine.handler;
32
33 import jtge.engine.command.Flow;
34 import jtge.engine.command.ICommand;
35
36 /***
37 * Provides a handler to bufferize commands.
38 * <p>
39 * This handler bufferizes and multiplexes received commands and releases the resulting command when triggered.
40 *
41 * @author Mathieu Champlon
42 * @version $Revision: 1.3 $ $Date: 2005/08/26 18:09:36 $
43 */
44 public class Buffer extends AbstractHandler
45 {
46 private Flow composite;
47
48 /***
49 * Create a new buffer handler.
50 *
51 * @param consumer the target consumer
52 */
53 public Buffer( final IConsumer consumer )
54 {
55 super( consumer );
56 }
57
58 /***
59 * {@inheritDoc}
60 */
61 public final void handle( final ICommand command )
62 {
63 if( composite == null )
64 composite = new Flow();
65 composite.add( command );
66 }
67
68 /***
69 * Forward the bufferized resulting command to the target consumer.
70 */
71 public final void release()
72 {
73 forward( clear() );
74 }
75
76 private ICommand clear()
77 {
78 if( composite == null || composite.isEmpty() )
79 return null;
80 ICommand command = composite;
81 composite = null;
82 return command;
83 }
84 }