Java Swing, lista

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package swingoceniane_1;

import java.awt.Color;
import java.awt.GridLayout;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

/**
 *
 * @author Hylus
 */
public class Okno_Frame extends JFrame implements ActionListener
{
    JPanel PANEL_1 = new JPanel(new GridLayout(5, 1));
    JPanel PANEL_2 = new JPanel(new GridLayout(2, 2));
    String[] napisy = { "Kot", "Pies", "Zebra" };
   // JList LIST_1 = new JList(napisy);
   // JScrollPane sp = new JScrollPane(LIST_1);

    JTextField TEXTFIELD_1 = new JTextField();
    JButton BUTTON_1 = new JButton("Dodaj");
    JButton BUTTON_2 = new JButton("Usun");
    JCheckBox CHECKBOX_1 = new JCheckBox ("Blokada");

    final DefaultListModel model = new DefaultListModel();
    JList list = new JList(model);
    JScrollPane sp = new JScrollPane(list);
    int licznik = 0;

    Okno_Frame()
    {
        BUTTON_1.addActionListener(this);
        BUTTON_2.addActionListener(this);
        TEXTFIELD_1.addActionListener(this);
        CHECKBOX_1.addActionListener(this);

        TEXTFIELD_1.addKeyListener(new KeyListener() {
            @Override
            public void keyTyped(KeyEvent e) {
                 System.out.print(("qqq"));
                 BUTTON_1.setEnabled(true);
            }

            @Override
            public void keyPressed(KeyEvent e) {
                System.out.print(("DFSFDSFSDFDFS"));
            }

            @Override
            public void keyReleased(KeyEvent e) {
                 System.out.print(("aaaa"));
            }
        });



        list.addListSelectionListener(new ListSelectionListener()
        {
          public void valueChanged(ListSelectionEvent e)
         {
            System.out.println("Zmiana w liscie");

            if (e.getSource().equals(BUTTON_2))
            {
                licznik++;
                model.removeAllElements();

            //    model.remove(licznik);
            }

         }
        });

        setTitle("Hello to ja");
        setSize (600,480);
        setResizable (false);
        setLayout(new GridLayout (2,1,10,10));
        setBackground(Color.yellow);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

      //  PANEL_2.add(LIST_1);
        PANEL_2.add(list);
        PANEL_1.add(TEXTFIELD_1);
        PANEL_1.add(BUTTON_1);
        PANEL_1.add(BUTTON_2);
        PANEL_1.add(CHECKBOX_1);

        BUTTON_1.setEnabled(false);
        BUTTON_2.setEnabled(false);

        add (PANEL_2);
        add (PANEL_1);
        setVisible(true);
    }



    @Override
    public void actionPerformed(ActionEvent e)
    {

        /*
        String b =TEXTFIELD_1.getText();
        if (b.length()> 0)
        {
                BUTTON_1.setEnabled(true);
        }
        */

        if (e.getSource().equals(BUTTON_1))
        {
            String a = TEXTFIELD_1.getText();
            model.addElement(a);
//            a = "";
            TEXTFIELD_1.setText("");
            licznik++;
            BUTTON_1.setEnabled(false);
        }

        if (e.getSource().equals(BUTTON_2))
        {
            licznik++;
            model.removeElementAt(model.size()-1);
        }

        if (e.getSource().equals(CHECKBOX_1))
        {
            boolean a = CHECKBOX_1.isFocusPainted();
            if (CHECKBOX_1.isSelected())
            {
                BUTTON_1.setEnabled(false);
                BUTTON_2.setEnabled(false);
                TEXTFIELD_1.setEnabled(false);
            }
            else
            {
                if (TEXTFIELD_1.getText().equals(""))
                {
                }
                else
                {
                    BUTTON_1.setEnabled(true);
                }
                if (licznik>0)
                {
                    BUTTON_2.setEnabled(true);
                }
                TEXTFIELD_1.setEnabled(true);
            }
        }



    }



}