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1   /*
2    * Copyright 2002,2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.jelly.tags.swing;
17  
18  import java.awt.BorderLayout;
19  import java.awt.Component;
20  
21  import org.apache.commons.jelly.JellyTagException;
22  import org.apache.commons.jelly.TagSupport;
23  import org.apache.commons.jelly.XMLOutput;
24  
25  /***
26   * Represents a layout of a child component within its parent <borderLayout> layout.
27   *
28   * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
29   * @version $Revision: 155420 $
30   */
31  public class BorderAlignTag extends TagSupport implements ContainerTag {
32  
33      private String align;
34  
35      // ContainerTag interface
36      //-------------------------------------------------------------------------
37  
38      /***
39       * Adds a child component to this parent
40       */
41      public void addChild(Component component, Object constraints) throws JellyTagException {
42          BorderLayoutTag tag = (BorderLayoutTag) findAncestorWithClass( BorderLayoutTag.class );
43          if (tag == null) {
44              throw new JellyTagException( "this tag must be nested within a <borderLayout> tag" );
45          }
46          tag.addLayoutComponent(component, getConstraints());
47      }
48  
49      // Tag interface
50      //-------------------------------------------------------------------------
51      public void doTag(final XMLOutput output) throws JellyTagException {
52          invokeBody(output);
53      }
54  
55      // Properties
56      //-------------------------------------------------------------------------
57  
58      /***
59       * Returns the align.
60       * @return String
61       */
62      public String getAlign() {
63          return align;
64      }
65  
66      /***
67       * Sets the alignment of the child component which is a case insensitive value
68       * of {NORTH, SOUTH, EAST, WEST, CENTER} which defaults to CENTER
69       */
70      public void setAlign(String align) {
71          this.align = align;
72      }
73  
74      // Implementation methods
75      //-------------------------------------------------------------------------
76  
77      protected Object getConstraints() {
78          if ("north".equalsIgnoreCase(align)) {
79              return BorderLayout.NORTH;
80          }
81          else if ("south".equalsIgnoreCase(align)) {
82              return BorderLayout.SOUTH;
83          }
84          else if ("east".equalsIgnoreCase(align)) {
85              return BorderLayout.EAST;
86          }
87          else if ("west".equalsIgnoreCase(align)) {
88              return BorderLayout.WEST;
89          }
90          else {
91              // default to CENTER
92              return BorderLayout.CENTER;
93          }
94      }
95  }
96