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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.myfaces.trinidad.change;
20  
21  import javax.faces.component.UIComponent;
22  import javax.faces.context.FacesContext;
23  import org.apache.myfaces.trinidad.logging.TrinidadLogger;
24  
25  /**
26   * Base class for specialized Change that when applied will add a component
27   *  instance to the component tree.
28   * @version $Name:  $ ($Revision: adfrt/faces/adf-faces-api/src/main/java/oracle/adf/view/faces/change/AddComponentChange.java#0 $) $Date: 10-nov-2005.19:09:55 $
29   */
30  abstract public class AddComponentChange extends ComponentChange
31  {
32    protected AddComponentChange(
33      UIComponent component)
34    {
35      if (component == null)
36        throw new IllegalArgumentException(_LOG.getMessage(
37          "COMPONENT_REQUIRED"));
38      
39      _proxy = new ChangeComponentProxy(FacesContext.getCurrentInstance(), 
40                                        component);
41    }
42    
43    /**
44     * Returns the component that is to be added either as a child or a facet 
45     *  while applying this Change. Returns <code>null</code> if the component cannot be 
46     *  successfully re-constructed.
47     */
48    public UIComponent getComponent()
49    {
50      return _proxy.createComponent();
51    }
52  
53    private final ChangeComponentProxy _proxy;
54    private static final TrinidadLogger _LOG = TrinidadLogger.createTrinidadLogger(
55      AddComponentChange.class);
56    private static final long serialVersionUID = 1L;
57  }