@Override
    public void actionPerformed(final ActionEvent event) {
      // Switch the caret status at every timer click.
      m_isCaretVisible = !m_isCaretVisible;

      notifyListeners();
    }
This function is called every time the caret timer ticks.
java/zylib/src/main/java/com/google/security/zynamics/zylib/gui/JCaret/JCaret.java