AddDocumentListener's variable scope when creating two titles (using TitledBorder) in Java Swing

Question

Hello I am trying to display one String ("Character Count: ") and one dynamic character count on the bottom of JTextArea. When I run this code below, there is a panel that opens up without characterCountTitle. Only when I start typing, characterCountTitle displays and the number is correctly dynamic.

My goal is to show characterCountTitle (string + character count) as soon as the panel is open to users.

private void initComponents() {
    this.notePanel.getNoteDocument().addDocumentListener(new DocumentListener() {

        TitledBorder characterCountTitle;
        Border emptyBorder;

        public void insertUpdate(DocumentEvent e) {
            displayEditInfo(e);
        }

        public void removeUpdate(DocumentEvent e) {
            displayEditInfo(e);
        }

        public void changedUpdate(DocumentEvent e) {
            displayEditInfo(e);
        }

        private void displayEditInfo(DocumentEvent e) {
            Document document = e.getDocument();

            emptyBorder = BorderFactory.createEmptyBorder();

            //displays a string of "Character Count: " and another string of dynamic character count 
            characterCountTitle = BorderFactory.createTitledBorder(emptyBorder, "Character Count: " +  document.getLength());
            characterCountTitle.setTitlePosition(TitledBorder.BOTTOM);
            panel.setBorder(characterCountTitle);
        }
    });

    this.panel.add(notePanel, BorderLayout.CENTER);
    this.panel.add(navigation.buildPanel(), BorderLayout.SOUTH);
}

Due to this issue, I was trying to create two titles; one for string(outside of addDocumentListener) and one for character count (inside displayEditInfo method), but it messes up the variable scope.

I'd greatly appreciate your input!

Answer 1

You may simply create and add your border outside of the DocumentListener, and just change the title text on document events :

private void initComponents() {


        Border emptyBorder = BorderFactory.createEmptyBorder();
        final TitledBorder characterCountTitle = BorderFactory.createTitledBorder(emptyBorder, "Character Count:");
        characterCountTitle.setTitlePosition(TitledBorder.BOTTOM);
        panel.setBorder(characterCountTitle);

        this.notePanel.getNoteDocument().addDocumentListener(new DocumentListener()                 {

        public void insertUpdate(DocumentEvent e) {
            displayEditInfo(e);
        }

        public void removeUpdate(DocumentEvent e) {
            displayEditInfo(e);
        }

        public void changedUpdate(DocumentEvent e) {
            displayEditInfo(e);
        }

        private void displayEditInfo(DocumentEvent e) {
            Document document = e.getDocument();


            //displays a string and dynamic character count
            characterCountTitle.setTitle("Character Count: " +  document.getLength());
            panel.repaint();

        }
    });

    this.panel.add(notePanel, BorderLayout.CENTER);
    this.panel.add(navigation.buildPanel(), BorderLayout.SOUTH);
}