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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: Flow.java,v 1.5 2005/09/10 23:59:42 mat007 Exp $
29   */
30  
31  package jtge.engine.command;
32  
33  import java.util.Iterator;
34  import java.util.Vector;
35  import jtge.engine.data.IContext;
36  import jtge.engine.user.IUser;
37  
38  /***
39   * Implements a composite of commands.
40   *
41   * @author Mathieu Champlon
42   * @version $Revision: 1.5 $ $Date: 2005/09/10 23:59:42 $
43   */
44  public class Flow implements ICommand
45  {
46      private static final long serialVersionUID = -6355047856538355697L;
47      private final Vector commands;
48  
49      /***
50       * Create a command composite.
51       */
52      public Flow()
53      {
54          commands = new Vector();
55      }
56  
57      /***
58       * Add a command to the composite.
59       *
60       * @param command the command to add
61       */
62      public final void add( final ICommand command )
63      {
64          if( command != null )
65              commands.add( command );
66      }
67  
68      /***
69       * {@inheritDoc}
70       */
71      public final boolean equals( final Object object )
72      {
73          if( object instanceof Flow )
74              return commands.equals( ((Flow)object).commands );
75          return false;
76      }
77  
78      /***
79       * {@inheritDoc}
80       */
81      public final int hashCode()
82      {
83          return commands.hashCode();
84      }
85  
86      /***
87       * {@inheritDoc}
88       */
89      public final boolean validate( final IUser user )
90      {
91          Iterator iterator = commands.iterator();
92          while( iterator.hasNext() )
93              if( !((ICommand)iterator.next()).validate( user ) )
94                  return false;
95          return true;
96      }
97  
98      /***
99       * {@inheritDoc}
100      */
101     public final void execute( final IContext context )
102     {
103         Iterator iterator = commands.iterator();
104         while( iterator.hasNext() )
105             ((ICommand)iterator.next()).execute( context );
106     }
107 
108     /***
109      * {@inheritDoc}
110      */
111     public final ICommand filter( final IFilter filter )
112     {
113         Flow result = new Flow();
114         Iterator iterator = commands.iterator();
115         while( iterator.hasNext() )
116             result.add( ((ICommand)iterator.next()).filter( filter ) );
117         if( !result.isEmpty() )
118             return result;
119         return null;
120     }
121 
122     /***
123      * Check whether the flow contains commands or not.
124      *
125      * @return whether the flow is empty
126      */
127     public final boolean isEmpty()
128     {
129         return commands.isEmpty();
130     }
131 
132     /***
133      * {@inheritDoc}
134      */
135     public final ICommand sort( final ISorter sorter )
136     {
137         Flow result = new Flow();
138         Iterator iterator = commands.iterator();
139         while( iterator.hasNext() )
140             result.insert( ((ICommand)iterator.next()), sorter );
141         return result;
142     }
143 
144     private void insert( final ICommand command, final ISorter sorter )
145     {
146         int position = commands.size();
147         // insertion point searched backwards to keep 'equal' elements order
148         while( position > 0 && sorter != null && sorter.lessThan( command, (ICommand)commands.get( position - 1 ) ) )
149             --position;
150         commands.add( position, command );
151     }
152 }