Update the testfield when setSelectedItem() for editable JComboBox

Question

Hi,
I am having problem with setSelectedItem() and setSelectedIndex() methods of editable JComboBox.
I extended JComboBox with default dataModel. When I enter some string in the textfield of the combobox, I call insertItemAt() method to dynamically grow the list. The application requires to clear the textfield everytime I enter something and press "return" key. To make it work, I insert an empty string to the list at the very beginning and call the setSelectedItem("") method in the actionPerformed().
Now the problem is that I know the setSelectedItem("") is called since the getActionCommand() returns "comboBoxChanged" everytime I enter something in the textfield, but the testfield is not cleared. And if I select one item from the list and press "enter" key, the textfield is cleared. To make things more interesting, after I enter the first string and press "enter", the textfield really get cleared, but not for all other later input. Is this a bug? Can anyone please help me? Thanks a lot. Below is my code snippet.
public class MyComboBox extends JComboBox implements ActionListener
public GsISCommComboBox()
jbInit();
private void jbInit() throws Exception
this.setEditable(true);
this.addActionListener(this);
insertItemAt("",0);
public void actionPerformed(ActionEvent e)
String str=null;
String strrr=e.getActionCommand();
System.out.println("getActionCommand: "+strrr);
if(strrr.equalsIgnoreCase("comboBoxChanged"))
str=(String)this.getSelectedItem();
return;
else
str=strrr;
// other stuff to process the string and do things
setSelectedItem("");
repaint();
hidePopup();
insertItemAt(str,0);

Answer 1

Try inserting your string first and then, try clearing the combobox's textfield.
insertItemAt(str,0);
setSelectedItem("");
hidePopup();
repaint();
Since you add the "" string at the begining, it will have the index 0. Perhaps, you want to insert your string this way:
// insert string at the end
insertItemAt(str, this.getItemCount());
//Then use the
setSelectedIndex(0);
But you need to remember that if you add an item at the begining, index 0 may not be your '' '' string after that.
I hope that it helps.