Is it possible to stop a listener and start a listener alternatively,in java frames?

[Karri Tata Rao]

I was developed a simple GUI, in that it requires modification of jtextfield content while JComboBox item selected and vice-versa. I was used itemListener on JComboBox and Document Listener on JTextField.
It was gives exception while running the code. Because one listener source effected by another one. Please help me.

Thank you...
Exceptions are like this:

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: Attempt to mutate in notification
at javax.swing.text.AbstractDocument.writeLock(Unknown Source)
at javax.swing.text.AbstractDocument.replace(Unknown Source)
at javax.swing.text.JTextComponent.setText(Unknown Source)
at ronanki.swing.pcahostsimUI$5.itemStateChanged(pcahostsimUI.java:368)
at javax.swing.JComboBox.fireItemStateChanged(Unknown Source)
at javax.swing.JComboBox.selectedItemChanged(Unknown Source)
at javax.swing.JComboBox.setSelectedItem(Unknown Source)
at ronanki.swing.pcahostsimUI$6.textboxlisten(pcahostsimUI.java:398)
at ronanki.swing.pcahostsimUI$6.insertUpdate(pcahostsimUI.java:382)
at javax.swing.text.AbstractDocument.fireInsertUpdate(Unknown Source)
at javax.swing.text.AbstractDocument.handleInsertString(Unknown Source)
at javax.swing.text.AbstractDocument.insertString(Unknown Source)
at javax.swing.text.PlainDocument.insertString(Unknown Source)
at javax.swing.text.AbstractDocument.replace(Unknown Source)
at javax.swing.text.JTextComponent.setText(Unknown Source)
at ronanki.swing.pcahostsimUI$5.itemStateChanged(pcahostsimUI.java:368)
at javax.swing.JComboBox.fireItemStateChanged(Unknown Source)
at javax.swing.JComboBox.selectedItemChanged(Unknown Source)
at javax.swing.JComboBox.contentsChanged(Unknown Source)
at javax.swing.AbstractListModel.fireContentsChanged(Unknown Source)
at javax.swing.DefaultComboBoxModel.setSelectedItem(Unknown Source)
at javax.swing.JComboBox.setSelectedItem(Unknown Source)
at javax.swing.JComboBox.setSelectedIndex(Unknown Source)
at javax.swing.plaf.basic.BasicComboPopup$Handler.mouseReleased(Unknown Source)
at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at javax.swing.plaf.basic.BasicComboPopup$1.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

[Maneesh Godbole]

Welcome to the Ranch.

Looks like a threading issue.

at ronanki.swing.pcahostsimUI$5.itemStateChanged(pcahostsimUI.java:368) 

Can you post your relevant code?

[Karri Tata Rao]

	MsgSelCombo = new JComboBox(msgs);
		while(it2.hasNext())
		{
			final Map.Entry me1=(Map.Entry)it2.next();
				MsgSelCombo.addItemListener(new ItemListener()
			       {
			       public void itemStateChanged(ItemEvent ie)
			       {			          
			    	   if(ButtonConDiscon.getText()!="  CONNECT   ")
			    	   {
			            if(MsgSelCombo.getSelectedItem()==me1.getValue())
			            {
			            TextFieldMsgID.setText(me1.getKey().toString());
			            }
			    	   }
			       }
			  }); 		
		} // Reading messages and linking of textfield and combobox ending....
		TextFieldMsgID.getDocument().addDocumentListener(new DocumentListener() {
				
			public void removeUpdate(DocumentEvent e) {
				textboxlisten();				
			}
			
			public void insertUpdate(DocumentEvent e) {	
						
					textboxlisten();		
			}
			
			public void changedUpdate(DocumentEvent e) {		
					textboxlisten();	
			}
			public void textboxlisten()
			{
				if(TextFieldMsgID.getText().length()==3)
				{	
				int n=Integer.parseInt(TextFieldMsgID.getText());
				
					for(int i=0;i<dd;i++)
					{												
			   			if(n==msgsid[i])
						{
							MsgSelCombo.setSelectedItem(msgs[i]);
							TextFieldMsgID.setFocusable(true);
							System.out.println(msgs[i]);
						}	
			   			else
			   			flg++;
					}
					System.out.println(flg);
/*					for(int i=0;i<dd;i++)
					{
					if(flg==1 && n!=msgid[i])
		   			{
		   				MsgSelCombo.setSelectedItem(msgs[0]);
		   				JOptionPane.showMessageDialog(null, "Message ID you selected not exist, Try another one");
		   			}
					}*/
				}
				       else if(TextFieldMsgID.getText().length()!=3){
					  MsgSelCombo.setSelectedItem(null);
				     }			
			}
		});
	

[Karri Tata Rao]

Please help me any one...I had posted my code and problem above..

[Ranganathan Kaliyur Mannar]

PatienceIsAVirtue. You have to remember that people here volunteer their time for free to try and help. Expecting reply in few hours is unfair (and that too when you have actually got the first one within minutes).

The code has several problems. First of all, why do you add the ItemListener within a while loop? This doesn't make any sense and will have as many listeners. Instead, the loop should be within the item listener. Alternatively, you should think about using the contains() method of a collection. Secondly, you have to remember that ItemListener fires twice for a combo box (once for the old item and once for the new item). I don't think you need this in the current scenario. Would be better served by using ActionListener. Thirdly, your code doesn't look good with comparing with a String with spaces (ButtonConDiscon.getText()). You seem to be trying to see if the scenario is in a particular state. You should maintain the state separately in a variable (preferrably in a Enum) and use that.

Also, I would suggest you create a SSCCE and post the same for people here to run and reproduce the problem.

[Campbell Ritchie]

And welcome to the Ranch

[Darryl Burke]

Your code is difficult to read because you haven't followed the Java convention that variable names should start with a lowercase letter.

That said, the error message says it all: Attempt to mutate in notification

You probably need to use a DocumentFilter instead of a DocumentListener.

[Karri Tata Rao]

Thank you for your suggestions.

This is the actual code that i feel you can understand. In this, Item Listener works but raises exceptions and DocumentListener does not work. I know the reason why it raises exceptions. But i don't know how to solve it. If any one know the solution, please answer my problem.

Solution should be like:

1. TextField value modification should change the ComboBox item.

2.ComboBox item modification should change the TextField value.

Thank you.

My code is:

import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;

public class Listener_example extends JFrame{
    /**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	JPanel jPanel1 = new JPanel();
    JTextField TextFieldMsgID = new JTextField();
    JComboBox<String> MsgSelCombo = new JComboBox<String>();
	String[] list = { " SELECT YOUR MESSAGE ", " EMERGENCY:TAKE POSITION ", " EMERGENCY:ALERT ALL " };    
	Integer[] id ={000, 320 ,540 };
 	public Listener_example(){
       TextFieldMsgID = new JTextField("         ");      
       MsgSelCombo = new JComboBox<String>(list);
		jPanel1.add(TextFieldMsgID);
 		jPanel1.add(MsgSelCombo);
       this.add(jPanel1);
				MsgSelCombo.addItemListener(new ItemListener()
			       {
			       public void itemStateChanged(ItemEvent ie)
			       {			          
			    	  for(int i=0;i<list.length;i++)
			    	  {
			            if(MsgSelCombo.getSelectedItem()==list[i])
			            {
			            TextFieldMsgID.setText(id[i].toString());
			            }
			    	  }
			       }
			  }); 		
			TextFieldMsgID.getDocument().addDocumentListener(new DocumentListener() {
				
			public void removeUpdate(DocumentEvent e) {
				textboxlisten();				
			}
			
			public void insertUpdate(DocumentEvent e) {	
						
					textboxlisten();		
			}
			
			public void changedUpdate(DocumentEvent e) {		
					textboxlisten();	
			}
			public void textboxlisten()
			{
				
				if(TextFieldMsgID.getText().length()==3)
				{
					int n=Integer.parseInt(TextFieldMsgID.getText());
					for(int i=0;i<id.length;i++)
					{			
						System.out.println(id[i]);
			   			if(n==id[i])						
							MsgSelCombo.setSelectedItem(list[i]);							
			   		}
				}
				else
				{
					MsgSelCombo.setSelectedItem(list[0]);
				}
			}
		});
    }
    public static void main(String args[])
    {
    	Listener_example le = new Listener_example();
		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
		le.setTitle("Host");
		le.setBounds(0, 0, screenSize.width, screenSize.height);
		le.pack();
		le.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		le.setVisible(true);
    	
    }

}

[Campbell Ritchie]

I have added code tags to your last post, otherwise it is illegible. Please always use them.

[Karri Tata Rao]

Thank You friends..

I was resolved my self my problem by using Thread.sleep() in each listener

[Rob Spoor]

That sounds like a bad idea. You should read Concurrency in Swing.