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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.jface;
17  
18  import java.util.Map;
19  
20  import org.apache.commons.jelly.JellyTagException;
21  import org.apache.commons.jelly.XMLOutput;
22  import org.apache.commons.jelly.tags.swt.WidgetTag;
23  import org.eclipse.jface.viewers.Viewer;
24  import org.eclipse.swt.SWT;
25  import org.eclipse.swt.widgets.Composite;
26  import org.eclipse.swt.widgets.Widget;
27  
28  /***
29   * This tag creates an JFace Viewer
30   *
31   * @author <a href="mailto:ckl@dacelo.nl">Christiaan ten Klooster</a>
32   */
33  public class ViewerTag extends WidgetTag {
34  
35      private Composite parent;
36      private int style = SWT.NULL;
37  
38      /***
39       * @param widgetClass
40       */
41      public ViewerTag(Class tagClass) {
42          super(tagClass);
43      }
44  
45      /***
46       * @param widgetClass
47       * @param style
48       */
49      public ViewerTag(Class tagClass, int style) {
50          super(tagClass);
51          this.style = style;
52      }
53  
54      /*
55       * @see org.apache.commons.jelly.tags.core.UseBeanTag#newInstance(java.lang.Class, java.util.Map, org.apache.commons.jelly.XMLOutput)
56       */
57      protected Object newInstance(
58          Class theClass,
59          Map attributes,
60          XMLOutput output)
61          throws JellyTagException {
62  
63          int style = getStyle(attributes);
64  
65          // now lets call the constructor with the parent
66          Widget parent = getParentWidget();
67          Viewer viewer = (Viewer) createWidget(theClass, parent, style);
68  
69          return viewer;
70      }
71  
72      /***
73       * @return the visible viewer, if there is one.
74       */
75      public Viewer getViewer() {
76          Object bean = getBean();
77          if (bean instanceof Viewer) {
78              return (Viewer) bean;
79          }
80          return null;
81      }
82  
83  }