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Editorial Team
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Asked: 2026-05-30T02:08:08+00:00

There is a problem in my application when trying to set focus on a

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There is a problem in my application when trying to set focus on a JEditorPane using the tab key. I did not understand why at first, but I manage to make a small test case that demonstrates the issue.

public class JEditorPaneFocusTest
{
    public static void main(String... args) throws Exception
    {
        JFrame jFrame = new JFrame();
        jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Container container = jFrame.getContentPane();
        container.setLayout(new BorderLayout());

        container.add(new JTextField(), BorderLayout.NORTH);

        JEditorPane editorPane = new JEditorPane();
        editorPane.setEditorKit(new HTMLEditorKit());
        editorPane.setText("<html><body>Hello World</body></html>");
        container.add(editorPane, BorderLayout.CENTER);

        jFrame.setSize(new Dimension(400, 400));
        jFrame.setVisible(true);
    }
}

(Tested on Windows 7 and Mac OS X Lion.) The application will start with focus on the JTextField. Using the tab key won’t set focus to the JEditorPane. But if you comment the setText line, it seems to work…

Any idea?

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1 Answer

  1. Editorial Team
    • short answer

    delay this event by wraping to the invokeLater()

    • longer answer

    Focus / Focus Subsystem is asynchronous, in most cases hard to manage/timing this/these even(s), for better understanding about this issue you have to read linked tutorials,

    example about Focus issue 

    import java.awt.*;
import java.awt.event.*;
import java.awt.font.TextAttribute;
import java.math.RoundingMode;
import java.text.NumberFormat;
import java.util.Map;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import javax.swing.event.*;

public class TextAttributeSTRIKETHROUGH {

    private JFrame frame = new JFrame();
    private JPanel pnl = new JPanel();
    private JLabel focusLabel = new JLabel(" focusLost Handle ");
    private JFormattedTextField formTextField;
    private JLabel docLabel = new JLabel(" document Handle ");
    private JFormattedTextField formTextField1;
    private NumberFormat formTextFieldFormat;
    private double amount = 10000.00;
    private Map attributes;

    @SuppressWarnings("unchecked")
    public TextAttributeSTRIKETHROUGH() {
        formTextFieldFormat = NumberFormat.getNumberInstance();
        formTextFieldFormat.setMinimumFractionDigits(2);
        formTextFieldFormat.setMaximumFractionDigits(2);
        formTextFieldFormat.setRoundingMode(RoundingMode.HALF_UP);

        focusLabel.setFont(new Font("Serif", Font.BOLD, 14));
        focusLabel.setForeground(Color.blue);
        focusLabel.setPreferredSize(new Dimension(120, 27));
        formTextField = new JFormattedTextField(formTextFieldFormat);
        formTextField.setValue(amount);
        formTextField.setFont(new Font("Serif", Font.BOLD, 22));
        formTextField.setForeground(Color.black);
        formTextField.setBackground(Color.yellow);
        formTextField.setPreferredSize(new Dimension(120, 27));
        formTextField.setHorizontalAlignment(SwingConstants.RIGHT);
        formTextField.addFocusListener(new FocusListener() {

            @Override
            public void focusGained(FocusEvent e) {
                formTextField.requestFocus();
                formTextField.setText(formTextField.getText());
                formTextField.selectAll();
            }

            public void focusLost(FocusEvent e) {
                //Runnable doRun = new Runnable() {

                //@Override
                //public void run() {
                double t1a1 = (((Number) formTextField.getValue()).doubleValue());
                if (t1a1 < 1000) {
                    formTextField.setValue(amount);
                }
                //}
                // };
                //SwingUtilities.invokeLater(doRun);
            }
        });

        docLabel.setFont(new Font("Serif", Font.BOLD, 14));
        docLabel.setForeground(Color.blue);
        docLabel.setPreferredSize(new Dimension(120, 27));

        formTextField1 = new JFormattedTextField(formTextFieldFormat);
        formTextField1.setValue(amount);
        formTextField1.setFont(new Font("Serif", Font.BOLD, 22));
        formTextField1.setForeground(Color.black);
        formTextField1.setBackground(Color.yellow);
        formTextField1.setPreferredSize(new Dimension(120, 27));
        formTextField1.setHorizontalAlignment(SwingConstants.RIGHT);
        formTextField1.addFocusListener(new FocusListener() {

            @Override
            public void focusGained(FocusEvent e) {
                formTextField1.requestFocus();
                formTextField1.setText(formTextField1.getText());
                formTextField1.selectAll();
            }

            @Override
            public void focusLost(FocusEvent e) {
            }
        });
        formTextField1.getDocument().addDocumentListener(docListener);

        attributes = (new Font("Serif", Font.BOLD, 24)).getAttributes();
        attributes.put(TextAttribute.STRIKETHROUGH, TextAttribute.STRIKETHROUGH_ON);

        pnl = new JPanel();
        pnl.setBorder(new EmptyBorder(2, 2, 2, 2));
        pnl.setLayout(new GridLayout(2, 2));
        pnl.add(focusLabel);
        pnl.add(formTextField);
        pnl.add(docLabel);
        pnl.add(formTextField1);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(pnl, BorderLayout.CENTER);
        frame.setLocation(200, 200);
        frame.pack();
        frame.setVisible(true);
        formTextFieldFocus1();
    }
    //
    private DocumentListener docListener = new DocumentListener() {

        @Override
        public void changedUpdate(DocumentEvent documentEvent) {
            printIt(documentEvent);
        }

        @Override
        public void insertUpdate(DocumentEvent documentEvent) {
            printIt(documentEvent);
        }

        @Override
        public void removeUpdate(DocumentEvent documentEvent) {
            printIt(documentEvent);
        }

        private void printIt(DocumentEvent documentEvent) {
            DocumentEvent.EventType type = documentEvent.getType();
            double t1a1 = (((Number) formTextField1.getValue()).doubleValue());
            if (t1a1 < 1000) {
                Runnable doRun = new Runnable() {

                    @Override
                    public void run() {
                        formTextField1.setFont(new Font(attributes));
                    }
                };
                SwingUtilities.invokeLater(doRun);
            } else {
                Runnable doRun = new Runnable() {

                    @Override
                    public void run() {
                        formTextField1.setFont(new Font("Serif", Font.BOLD, 22));
                    }
                };
                SwingUtilities.invokeLater(doRun);
            }
        }
    };

    private void formTextFieldFocus1() {
        Runnable doRun = new Runnable() {

            @Override
            public void run() {
                formTextField1.grabFocus();
                formTextField1.requestFocus();
                formTextField1.setText(formTextField1.getText());
                formTextField1.selectAll();
            }
        };
        SwingUtilities.invokeLater(doRun);
    }

    private void formTextFieldFocus() {
        Runnable doRun = new Runnable() {

            @Override
            public void run() {
                formTextField.grabFocus();
                formTextField.requestFocus();
                formTextField.setText(formTextField.getText());
                formTextField.selectAll();
                formTextFieldFocus1();
            }
        };
        SwingUtilities.invokeLater(doRun);
    }

    public static void main(String args[]) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                TextAttributeSTRIKETHROUGH fl = new TextAttributeSTRIKETHROUGH();
            }
        });
    }
}
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