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1   /*
2    * Copyright (c) 1998, 2005 Gargoyle Software Inc. All rights reserved.
3    *
4    * Redistribution and use in source and binary forms, with or without
5    * modification, are permitted provided that the following conditions are met:
6    *
7    * 1. Redistributions of source code must retain the above copyright notice,
8    *    this list of conditions and the following disclaimer.
9    * 2. Redistributions in binary form must reproduce the above copyright notice,
10   *    this list of conditions and the following disclaimer in the documentation
11   *    and/or other materials provided with the distribution.
12   * 3. The end-user documentation included with the redistribution, if any, must
13   *    include the following acknowledgment:
14   *
15   *       "This product includes software developed by Gargoyle Software Inc.
16   *        (http://www.GargoyleSoftware.com/)."
17   *
18   *    Alternately, this acknowledgment may appear in the software itself, if
19   *    and wherever such third-party acknowledgments normally appear.
20   * 4. The name "Gargoyle Software" must not be used to endorse or promote
21   *    products derived from this software without prior written permission.
22   *    For written permission, please contact info@GargoyleSoftware.com.
23   * 5. Products derived from this software may not be called "GSBase", nor may
24   *    "GSBase" appear in their name, without prior written permission of
25   *    Gargoyle Software Inc.
26   *
27   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
28   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
29   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GARGOYLE
30   * SOFTWARE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
31   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
32   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
33   * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
36   * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37   */
38  package com.gargoylesoftware.base.gui;
39  
40  import com.gargoylesoftware.base.util.DetailedNullPointerException;
41  import javax.swing.JScrollPane;
42  import javax.swing.JTextArea;
43  import java.io.PrintWriter;
44  import java.io.StringWriter;
45  
46  /***
47   * A panel that can display an exception stack trace.
48   *
49   * @version $Revision: 1.6 $
50   * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
51   */
52  public class ThrowablePanel extends JScrollPane {
53  	private static final long serialVersionUID = 1;
54      private Throwable throwable_ = null;
55      private final JTextArea textArea_;
56  
57      /***
58       * Create a new panel.
59       */
60      public ThrowablePanel() {
61          super( new JTextArea() );
62          textArea_ = (JTextArea)getViewport().getView();
63      }
64  
65      /***
66       * Create a new panel.
67       * @param t The exception to display.
68       */
69      public ThrowablePanel( final Throwable t ) {
70          this();
71          setException(t);
72      }
73  
74      /***
75       * Set the exception that is being displayed.
76       * @param t The new exception.
77       */
78      public void setException( final Throwable t ) {
79          assertNotNull("t", t);
80          throwable_ = t;
81          textArea_.setText( makeString(t) );
82      }
83  
84      /***
85       * Return the exception that is being displayed.
86       * @return The exception.
87       */
88      public Throwable getException() {
89          return throwable_;
90      }
91  
92      /***
93       * Make a string from the exception.
94       * @param t The throwable object
95       * @return A string containing the stack trace
96       */
97      private static String makeString( final Throwable t ) {
98          final StringWriter stringWriter = new StringWriter();
99          final PrintWriter printWriter = new PrintWriter(stringWriter);
100         t.printStackTrace(printWriter);
101 
102         return stringWriter.toString();
103     }
104 
105 
106     /***
107      * Verify that the specified value is not null.  If it is then throw an exception
108      *
109      * @param fieldName The name of the field to check
110      * @param fieldValue The value of the field to check
111      * @exception DetailedNullPointerException If fieldValue is null
112      */
113     protected final void assertNotNull( final String fieldName, final Object fieldValue )
114         throws DetailedNullPointerException {
115 
116         if( fieldValue == null ) {
117             throw new DetailedNullPointerException(fieldName);
118         }
119     }
120 }
121