APL/APL2.1/TP11/Playlist/Playlist.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Playlist extends JPanel {
    private int elementCount;
    private Observer obs;

    public Playlist() {
        super();
        elementCount = 0;
        obs = new Observer();
    }

    public void add(String title) {
        elementCount += 1;
        this.setLayout(new GridLayout(elementCount, 1));

        JLabel l = new JLabel(title);
        l.addMouseListener(obs);
        l.setOpaque(true);
        this.add(l);
    }
}