package sec04.exam04_gridlayout;

import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class GridLayoutExample extends JFrame {
    private JButton[][] btn;

    public GridLayoutExample() {
        setTitle("GridLayoutExample");
        setSize(300, 100);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        // 2행 3열 GridLayout
        setLayout(new GridLayout(2, 3));
        
        for(int r = 0; r < 2; r++) {
            for(int c = 0; c < 3; c++) {
                getContentPane().add(getBtn()[r][c]);
            }
        }
    }

    public JButton[][] getBtn() {
        if(btn == null) {
            btn = new JButton[2][3];
            for(int r = 0; r < 2; r++) {
                for(int c = 0; c < 3; c++) {
                    btn[r][c] = new JButton("["+r+"][" + c + "]");
                }
            }
        }
        return btn;
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            GridLayoutExample jFrame = new GridLayoutExample();
            jFrame.setVisible(true);
        });
    }
}