Prevent FocusEvents when Component is not focused

I have the following sample-code:

import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;

import javax.swing.BoxLayout;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.WindowConstants;

public class SampleFocus extends JFrame {

  public SampleFocus(String titel) {
    setTitle(titel);
    JTextField txtField1 = new JTextField("default-click");
    JTextField txtField2 = new JTextField("alternative-Text");
    JTextField txtField3 = new JTextField("own diaolog textfield");

    JTextArea dummyLabel = new JTextArea(10, 20);
    dummyLabel.setText("empty textarea, which is focusable");

    setLayout(new BoxLayout(getContentPane(), BoxLayout.Y_AXIS));
    add(txtField1);
    add(dummyLabel);
    add(txtField2);

    JDialog altDialog = new JDialog(this);
    altDialog.add(txtField3);
    altDialog.setVisible(true);
    altDialog.pack();

    FocusAdapter myFocusListner = new FocusAdapter() {

      @Override
      public void focusGained(FocusEvent e) {
        if (e.getComponent() instanceof JTextField) {
          System.out.println("gained for TextField: "
                             + ((JTextField) e.getComponent()).getText());
        } else {
          System.out.println("gained for component: " + e.getComponent());
        }
      }
    };

    txtField1.addFocusListener(myFocusListner);
    txtField2.addFocusListener(myFocusListner);
    txtField3.addFocusListener(myFocusListner);

    // dummyLabel.addFocusListener(myFocusListner);
  }

  public static void main(String[] args) {
    JFrame frame = new SampleFocus("FocusListener  - sample");
    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);

  }
}

When I switch from the Frame to the dialog I get the proper event. When I switch back to the Frame I get as well the proper FocusEvents. My problem is, that when I switch back, I get as well the FocusEvents for components 开发者_如何学Pythonwhich I am not interested in.

e.g.

Select 'default-click' ==> Dialog/Textfield ==> Frame/'empty textarea'

Result: I get a FocusGained-Event for 'default-click' although the component has NOT the focus.

Desired Result: Either

• Component 'default-click' does not get the FocusEvent OR

• distinguish if the component really received the Event properly (e.g. I could have clicked into it as well)

Workaround I found:

Attach to the JTextArea as well a FocusListener. Problem is, that this would mean, I need to attach to ALLLL of my components a Listener. Which is hardly possible. Any ideas?

Any ideas how to get the result?

Thx LeO

Its working as intended. You select "default-click". It gains focus. You select Dialog. Frame and "default-click" loses focus. You select Text area. Now, things becomes interesting. Dialog loses focus. Frame gets focus. "default-click" also gains focus, because he had it when Frame was active. And then "default-click" loses focus, textarea gains focus (because you clicked on text area).

Try combine focusGained and focusLost events.

Or tell me more what are you trying to accomplish, maybe I can help.

The way I found the workaround was to check in the focusGained-method if the current component is in an own JDialog and if previous component was a JTextField in a JFrame. If so, then I memorize the gained focused component, change the focus to another component and when I receive a focusLost I request it back to the previously memorized component.

Some kind of hack, but it works.... If there are any better ideas, I am interested in ...