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1   /***
2    * Cecilia ADL Compiler
3    * Copyright (C) 2006-2007 STMicroelectronics
4    *
5    * This library is free software; you can redistribute it and/or
6    * modify it under the terms of the GNU Lesser General Public
7    * License as published by the Free Software Foundation; either
8    * version 2 of the License, or (at your option) any later version.
9    *
10   * This library is distributed in the hope that it will be useful,
11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   * Lesser General Public License for more details.
14   *
15   * You should have received a copy of the GNU Lesser General Public
16   * License along with this library; if not, write to the Free Software
17   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18   *
19   * Contact: fractal@objectweb.org
20   *
21   * Author: Matthieu Leclercq
22   */
23  
24  package org.objectweb.fractal.cecilia.adl.attributes;
25  
26  import java.util.List;
27  import java.util.Map;
28  
29  import org.objectweb.fractal.adl.ADLException;
30  import org.objectweb.fractal.adl.ComponentVisitor;
31  import org.objectweb.fractal.adl.Node;
32  import org.objectweb.fractal.adl.attributes.Attributes;
33  import org.objectweb.fractal.adl.attributes.AttributesContainer;
34  import org.objectweb.fractal.adl.components.ComponentContainer;
35  import org.objectweb.fractal.api.Component;
36  import org.objectweb.fractal.api.factory.InstantiationException;
37  import org.objectweb.fractal.task.core.AbstractTaskFactoryUser;
38  import org.objectweb.fractal.task.core.TaskException;
39  
40  /**
41   * Abstract visitor component that creates a task that depends on the attributes
42   * of the component (if any).
43   */
44  public abstract class AbstractAttributeVisitor extends AbstractTaskFactoryUser
45      implements
46        ComponentVisitor {
47  
48    /**
49     * Creates the task that is returned by this visitor.
50     * 
51     * @param container the component that is visited.
52     * @param attributes the {@link Attributes} node of the component.
53     * @return the created task.
54     * @throws InstantiationException if the instantiation of the task fails.
55     * @throws ADLException if the instantiation of the task fails.
56     */
57    protected abstract Component createTask(ComponentContainer container,
58        final Attributes attributes) throws ADLException, TaskException;
59  
60    // ---------------------------------------------------------------------------
61    // Implementation of the ComponentVisitor interface
62    // ---------------------------------------------------------------------------
63  
64    /**
65     * Visits {@link ComponentContainer} nodes and call
66     * {@link #createTask(ComponentContainer, Attributes) createTask} if the given
67     * component contains an {@link Attributes} sub-nodes.
68     */
69    public Component visit(final List<Node> path,
70        final ComponentContainer container, final Map<Object, Object> context)
71        throws ADLException, TaskException {
72      Attributes attributes = null;
73      if (container instanceof AttributesContainer) {
74        attributes = ((AttributesContainer) container).getAttributes();
75      }
76      if (attributes == null) return null;
77      return createTask(container, attributes);
78    }
79  }