import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

class GUIFlow extends JFrame{
	JTextField jtf1, jtf2, jtf3, jtf4;
	JLabel jl1, jl2, jl3, jl4;
	
	public GUIFlow(){
		setTitle("GUIFlow");
		addComponents(getContentPane());
		setSize(new Dimension(200,150));
		setDefaultLookAndFeelDecorated(true);
		setVisible(true);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
	}
	
	public void addComponents(Container c){
		c.setLayout(new FlowLayout());
		jtf1 = new JTextField(10);
		jtf2 = new JTextField(10);
		jtf3 = new JTextField(10);
		jtf4 = new JTextField(10);
		
		jl1 = new JLabel("Label1");
		jl2 = new JLabel("Label2");
		jl3 = new JLabel("Label3");
		jl4 = new JLabel("Label4");
		
		c.add(jl1);
		c.add(jtf1);
		c.add(jl2);
		c.add(jtf2);
		c.add(jl3);
		c.add(jtf3);
		c.add(jl4);
		c.add(jtf4);
	}
	
	public static void main(String[] args) {
		GUIFlow gf = new GUIFlow();
	}
}

class GUIGrid extends JFrame{
	JTextField jtf1, jtf2;
	JButton jb1, jb2, jb3, jb4;
	
	public GUIGrid(){
		setTitle("GUIGrid");
		addComponents(getContentPane());
		pack();
		setDefaultLookAndFeelDecorated(true);
		setVisible(true);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
	}
	
	public void addComponents(Container c){
		c.setLayout(new GridLayout(0,3));
		jtf1 = new JTextField(10);
		jtf2 = new JTextField(10);
		
		jb1 = new JButton("Button1");
		jb2 = new JButton("Button2");
		jb3 = new JButton("Button3");
		jb4 = new JButton("Button4");
		
		c.add(jb1);
		c.add(jb2);
		c.add(jb3);
		c.add(jtf1);
		c.add(jb4);
		c.add(jtf2);
	}
	
	public static void main(String[] args) {
		GUIGrid gg = new GUIGrid();
	}
}

class GUIBorder extends JFrame{
	JTextField jtf1, jtf2, jtf3, jtf4;
	JButton jb1;
	
	public GUIBorder(){
		setTitle("GUIBorder");
		addComponents(getContentPane());
		pack();
		setDefaultLookAndFeelDecorated(true);
		setVisible(true);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
	}
	
	public void addComponents(Container c){
		c.setLayout(new BorderLayout(0,3));
		jtf1 = new JTextField(10);
		jtf2 = new JTextField(10);
		jtf3 = new JTextField(10);
		jtf4 = new JTextField(10);
		
		jb1 = new JButton("Button1");

		c.add(jb1, BorderLayout.CENTER);
		c.add(jtf1, BorderLayout.NORTH);
		c.add(jtf2, BorderLayout.SOUTH);
		c.add(jtf3, BorderLayout.EAST);
		c.add(jtf4, BorderLayout.WEST);
	}
	
	public static void main(String[] args) {
		GUIBorder gb = new GUIBorder();
	}
}


class Calculator extends JFrame{
	JTextArea screen;
	JTextField input;
	JMenuBar jmb;
	JMenu jm1;
	JMenuItem jmi1, jmi2, jmi3;
	JButton add, subtract, divide, multiply, mod, clear, enter;

	double currentValue;
	int currentOperation;

	public Calculator() {
		setTitle("Calculator");
		Container c = getContentPane();
		addComponents(c);
	  
		pack();
	  
		setDefaultLookAndFeelDecorated(true);
		setVisible(true);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
	}	
	
	public void addComponents(Container c){
		c.setLayout(new BoxLayout(c,BoxLayout.Y_AXIS));
		  
		add = new JButton("+");
		subtract = new JButton("-");
		divide = new JButton("/");
		multiply = new JButton("*");
		mod = new JButton("%");
		clear = new JButton("Clear");
		enter = new JButton("=");
	  
		JPanel p1 = new JPanel();
		p1.setLayout(new GridLayout(0,5));
		p1.add(add);
		p1.add(subtract);
		p1.add(multiply);
		p1.add(divide);
		p1.add(mod);
	
		JPanel p2 = new JPanel(new GridLayout(0,1));
		p2.add(clear);
		JPanel p3 = new JPanel(new GridLayout(0,1));
		p3.add(enter);
	  
		input = new JTextField(10);
		screen = new JTextArea(5,20);
		screen.setEditable(false);
	  
		c.add(screen);
		c.add(p2);
		c.add(p1);
		c.add(p3);
		c.add(input);
		
	}
	
	public static void main(String[] args) {
		Calculator calculator1 = new Calculator();
	}
}