CIS 260 TestCardLayout1.java

Code

/*
    TestCardLayout1.java
    CIS 260
    2/22/2006
    David Klick

    Demonstration of CardLayout using next and previous buttons.   
*/

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

public class TestCardLayout1 extends JFrame {
    JButton btnNext, btnPrev;
    JPanel pnlCard[], pnlCards, pnlControl;
    JButton btn[];
    int currentCard = 0;

    public static void main(String[] args) {
        TestCardLayout1 app = new TestCardLayout1();
        app.setDefaultCloseOperation(EXIT_ON_CLOSE);
        app.init();
    }

    public void init() {
        int i;

        pnlCard = new JPanel[3];
        btn = new JButton[12];

        pnlCards = new JPanel();
        pnlCards.setLayout(new CardLayout());

        for (i=0; i<pnlCard.length; i++) {
            pnlCard[i] = new JPanel();
            pnlCard[i].setLayout(new GridLayout(2, 2, 3, 3));
            pnlCards.add("Card"+i, pnlCard[i]);
        }

        for (i=0; i<btn.length; i++) {
            btn[i] = new JButton("Button #" + (i+1));
            pnlCard[i/4].add(btn[i]);
        }

        ButtonListener lstnr = new ButtonListener();
        btnNext = new JButton("Next");
        btnNext.addActionListener(lstnr);
        btnPrev = new JButton("Previous");
        btnPrev.addActionListener(lstnr);
        pnlControl = new JPanel();
        pnlControl.setLayout(new GridLayout(1, 2, 3, 3));
        pnlControl.add(btnPrev);
        pnlControl.add(btnNext);
        currentCard = 0;
        btnPrev.setEnabled(false);

        Container c = getContentPane();
        c.setLayout(new BorderLayout(10, 10));
        c.add(pnlControl, BorderLayout.NORTH);
        c.add(pnlCards, BorderLayout.CENTER);

        pack();
        setVisible(true);      
    }

    class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            if (e.getSource() == btnNext) {
                if (currentCard < pnlCard.length-1) {
                    currentCard++;
                    ((CardLayout) pnlCards.getLayout()).next(pnlCards);
                }
            } else if (e.getSource() == btnPrev) {
                if (currentCard > 0) {
                    currentCard--;
                    ((CardLayout) pnlCards.getLayout()).previous(pnlCards);
                }
            }
            if (currentCard <= 0) btnPrev.setEnabled(false);
            else btnPrev.setEnabled(true);
            if (currentCard >= pnlCard.length-1) btnNext.setEnabled(false);
            else btnNext.setEnabled(true);
        }
    }
}