double clicking in the JComboBox results in a strange error

Question

I have a strange problem. I'm working on a long program and in that program I create a JComboBox the following way:

String[] s = {"aa", "bb", "cc"};
JComboBox try1 = new JComboBox(s);
try1.insertItemAt("", 0);
try1.setSelectedIndex(0);
AutoCompleteDecorator.decorate(try1);

When I run the program, if the user double clicks inside the text area of the combo box I get the following runtime error:

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: javax.swing.text.PlainDocument cannot be cast to javax.swing.text.StyledDocument
at org.jdesktop.swingx.autocomplete.AutoCompleteDocument.getParagraphElement(AutoCompleteDocument.java:309)
at javax.swing.text.Utilities.getParagraphElement(Utilities.java:850)
at javax.swing.text.Utilities.getWordStart(Utilities.java:631)
at javax.swing.text.DefaultEditorKit$BeginWordAction.actionPerformed(DefaultEditorKit.java:1750)
at javax.swing.text.DefaultEditorKit$SelectWordAction.actionPerformed(DefaultEditorKit.java:2163)
at javax.swing.text.DefaultCaret.selectWord(DefaultCaret.java:390)
at javax.swing.text.DefaultCaret.mousePressed(DefaultCaret.java:495)
at com.apple.laf.AquaCaret.mousePressed(AquaCaret.java:140)
at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:280)
at java.awt.Component.processMouseEvent(Component.java:6502)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4489)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: javax.swing.text.PlainDocument cannot be cast to javax.swing.text.StyledDocument
at org.jdesktop.swingx.autocomplete.AutoCompleteDocument.getParagraphElement(AutoCompleteDocument.java:309)
at javax.swing.text.Utilities.getParagraphElement(Utilities.java:850)
at javax.swing.text.Utilities.getWordStart(Utilities.java:631)
at javax.swing.text.DefaultEditorKit$BeginWordAction.actionPerformed(DefaultEditorKit.java:1750)
at javax.swing.text.DefaultEditorKit$SelectWordAction.actionPerformed(DefaultEditorKit.java:2163)
at javax.swing.text.DefaultCaret.selectWord(DefaultCaret.java:390)
at javax.swing.text.DefaultCaret.mouseClicked(DefaultCaret.java:415)
at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:270)
at java.awt.Component.processMouseEvent(Component.java:6508)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4501)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

However, if I create a very simple program that contains nothing but the same JComboBox I do not have the same problem. I find this very strange because the JComboBox is not being used anywhere so far in my program. Can someone please tell me what might be causing this behaviour. Thanks.

Answer 1

Solution:

The problem was caused by the AutoCompleteDecorator. I deactivated it and used instead the AutoCompletion.enable(employeeDelete). I appreciate all the comments that helped me.