GUI 1: simple button display

import javax.swing.*;
import java.awt.*;
/*
 * Container (= Content Pane): JFrame, JPanel
 * JFrame and JPanel Classes have INHERITED the Container Class.
 * JFrame is like a desk, JPanel is like a blank paper on the desk.
 */


public class Main extends JFrame {
	public Main() {
		setTitle("Hazel you're so cool");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		// closes the program when frame is exited
		// another way to exit any Java program:
		// System.exit(0);
		
		Container contentPane = getContentPane();
		// 컨텐트팬 (Container) 을 알아낸다
		contentPane.setBackground(Color.pink);
		contentPane.setLayout(new FlowLayout());
		// Layout manager just helped me arrange my components into a free-flow layout! From left to right.
		// 1. Always remember to add "new" layout.
		// 2. You can change the layout of both a container (content pane) OR a panel.
		contentPane.setLayout(new FlowLayout(FlowLayout.LEFT, 30, 40));
		// Can change 정렬방법 by:
		// FlowLayout(alignment, horizontal pixel gap, vertical pixel gap);
		// 3 alignments: FlowLayout.LEFT, FlowLayout.RIGHT, FlowLayout.CENTER (default)
		
		contentPane.add(new JButton("OK"));
		contentPane.add(new JButton("Cancel"));
		contentPane.add(new JButton("Ignore"));
		JButton omg = new JButton("OMG!!");
		omg.setForeground(Color.blue);
		contentPane.add(omg);
		JButton yippee = new JButton("Yippee~");
		contentPane.add(yippee);
		yippee.setForeground(Color.green);
		// buttonName.setForeground(Color.colorName);   <- changes text colour of the button!!
		
		setSize(300, 200);
		setVisible(true);
	}

	public static void main(String[] args) {
		new Main();
	}
}