DEV/DEV.2.1/TP/TP8-Evenements/2.Attente/Attente.java

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

public class Attente extends JComponent implements WindowListener {
    private boolean enArrierePlan = false;

    public Attente() {
        super();
    }

    @Override
    protected void paintComponent(Graphics pinceau) {
        Graphics secondPinceau = pinceau.create();
        secondPinceau.setColor(this.getForeground());

        if (enArrierePlan) {
            secondPinceau.setColor(Color.BLACK);
            int[] xHaut = {100, 150, 200};
            int[] yHaut = {100, 150, 100};
            int[] xBas = {100, 150, 200};
            int[] yBas = {250, 200, 250};
            secondPinceau.fillPolygon(xHaut, yHaut, 3);
            secondPinceau.fillPolygon(xBas, yBas, 3);
        } else {
            secondPinceau.setColor(Color.GREEN);
            secondPinceau.fillRect(0, 0, getWidth(), getHeight());
            secondPinceau.setColor(Color.MAGENTA);
            secondPinceau.fillOval(100, 100, 100, 100);
        }
    }

    @Override
    public void windowDeactivated(WindowEvent evenement) {
        System.out.println("Fenêtre mise en arrière-plan !");
        enArrierePlan = true;
        repaint();
    }

    @Override
    public void windowActivated(WindowEvent e) {
        System.out.println("Fenêtre active !");
        enArrierePlan = false;
        repaint();
    }

    @Override public void windowOpened(WindowEvent e) {}
    @Override public void windowClosing(WindowEvent e) {}
    @Override public void windowClosed(WindowEvent e) {}
    @Override public void windowIconified(WindowEvent e) {}
    @Override public void windowDeiconified(WindowEvent e) {}
}