I originally filed this as bug 4145135 and I am now re-filing
the problem as an RFE. In an email exchange with Tom Santos
he explained that the motivation for firing an ActionEvent on
focus lost is for when a combo box is part of a form and the
user is tabbing betweeen controls. I agree that this is a
sensible default.

My RFE here is for a property that controls this behaviour. I would like
to see a property that can be set such that losing focus does not
fire an ActionEvent. The workaround requires me to know
too much about the implementation of the combo box. Can I really be
sure that the Editor is a JTextField? To do it correctly, I should
implement my own editor so I know what kind of control it is. This
is requiring far too much just so I can stop getting an ActionEvent
when the focus is lost.


The original description:

I created an editable ComboBox and ran into a problem with the combo-box's
ActionListener (see bug 4145134). I then tried attaching an ActionListener
to the combo-box's editor component. This solved the original problem but
introduce a new problem. Now the ActionListener was being invoked when
the combox-box lost focus.

I was trying to use a combo-box for a search string in an editor.
The goal is for the user to type in search string, hit return in the
combo-box to find the first occurrence of the string. This was all
fine and working. Now, if the user clicks in the editor, the combox-box
loses focus, the ActionListener is invoked and second occurrence of the
string is searched for. Not good.

Here is small program that demostrates the problem. Run the program,
type something into the combox box and the move the ouse outside of
the program's frame. Notice that you get line of output everytime the
mouse leaves the program's frame.

import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import com.sun.java.swing.JFrame;
import com.sun.java.swing.JTextField;
import com.sun.java.swing.JComboBox;

public class ComboBoxBug2 {

    /**
     * Constructor.
     */
    public ComboBoxBug2 () {
    }

    public static void main(String args[]) {
JFrame frame = new JFrame("ComboBox Bug");
Container contentPane = frame.getContentPane();
JComboBox comboBox = new JComboBox();
comboBox.setEditable(true);
JTextField textField = (JTextField) comboBox.getEditor().getEditorComponent();
textField.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.err.println("actionPerformed invoked");
}
});
contentPane.setLayout(new FlowLayout());
contentPane.add(comboBox);
frame.setSize(300, 300);
frame.setVisible(true);
    }
}