Adding addPopupMenuListener to JCombo Box through Mouse Event

[Tim Jones]

UPDATE: Perhaps there is more elegant/better way to do this?

When comboBox (line 34) is clicked the MouseListener (line 38) calls method "userNames()" (line 51), which sets up a connection to the database and returns an ArrayList. PopupMenuListener "srcListener" (line 8) calls the method "userNames()" and adds it to the comboBox (line 34). Problem: When Mouse Listener activates, combo box population occurs multiple time (should be only once). Another problem is that everytime mouse listener is triggered it appends the ArrayList to the combo box, should delete the existing list before adding the new combo box.

	public class infoJDialog extends JDialog{
	
	
	public infoJDialog(final DefaultController controller) {
		this.controller = controller;
		
		//PopupMenuListener Methods display list of all user objects inside a JComboBox
		PopupMenuListener srcListener = new PopupMenuListener(){
			boolean initialized = false;

			@Override
			public void popupMenuCanceled(PopupMenuEvent e) {
				System.out.print("popupMenuCanceled");
			}

			@Override
			public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
				System.out.print("popupMenuWillBecomeInvisible");
				
			}

			@Override
			public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
				System.out.print("popupMenuWillBecomeVisible");
				JComboBox cBox = (JComboBox) e.getSource();
				if(!userNames().isEmpty()){
				cBox.setModel(new DefaultComboBoxModel(userNames().toArray()));			
				initialized = true;
				}
			}
			
		};
	
			comboBox_4 = new JComboBox();
			comboBox_4.setFont(new Font("SansSerif", Font.PLAIN, 10));
			comboBox_4.addMouseListener(new MouseAdapter() {
				@Override
				public void mousePressed(MouseEvent arg0) {
					
					userNames();	
					
				}
			});
		//Add addPopupMenuListener(srcListener) to combo Box
			if(rdbtnTnsConnection.isSelected()){
				comboBox_4.addPopupMenuListener(srcListener);				
		}
		userNames();
		}
	
	public ArrayList<String> userNames(){
		
		ArrayList<String> names = new ArrayList<String>();
		if(rdbtnTnsConnection.isSelected()){
			String usernameSrc = textField.getText().trim();
			char[] passwordSrc = passwordField.getPassword();
		if(serviceSrc != null && usernameSrc != null && passwordSrc != null){
			
			controller.setSrcTnsConn("localhost", "1521", serviceSrc, usernameSrc, passwordSrc);
			names = controller.getNames();
			
		}
		
		}else if(rdbtnManualConnection.isSelected()){
			String host = textField_2.getText().trim();
			String port = textField_3.getText().trim();
			String database = textField_4.getText().trim();
			String username = textField_5.getText().trim();
			char[] password = passwordField_2.getPassword();
			if(host != null && port != null && database != null && username != null && password != null){
			
				controller.setSrcConn(host, port, database, username, password);
				schemaNames = controller.getNames();
				
			}
			
		}
		
		return names;	
		
}
}