//PROGRAM 13-7
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class DemoTextField implements ActionListener {	
  public JLabel label1, label2, label3;
  public JTextField textField1, textField2, textField3;
  public JButton button1, button2, button3, button4;
		
  public DemoTextField() {	
		
    label1 = new JLabel("Nilai A");
    label1.setLocation(10, 10);
    label1.setSize(label1.getPreferredSize());	
		
    textField1 = new JTextField(20);
    textField1.setLocation(10, 25);
    textField1.setSize(textField1.getPreferredSize());	
		
    label2 = new JLabel("Nilai B");
    label2.setLocation(10, 45);
    label2.setSize(label2.getPreferredSize());	
				
    textField2 = new JTextField(20);
    textField2.setLocation(10, 60);
    textField2.setSize(textField2.getPreferredSize());	
		
    label3 = new JLabel("Hasil perhitungan antara A dan B");
    label3.setLocation(10, 90);
    label3.setSize(label3.getPreferredSize());
		
    textField3 = new JTextField(20);
    textField3.setLocation(10, 105);
    textField3.setSize(textField3.getPreferredSize());	
    textField3.setEditable(false);
		
    button1 = new JButton("Tambah");
    button1.setLocation(245, 10);
    button1.setSize(button1.getPreferredSize());
    button1.addActionListener(this);
    button1.setMnemonic('T');
	  
    button2 = new JButton("Kurang");
    button2.setLocation(245, 40);
    button2.setSize(button1.getPreferredSize());
    button2.addActionListener(this);
    button2.setMnemonic('u');
		
    button3 = new JButton("Kali");
    button3.setLocation(245, 70);
    button3.setSize(button1.getPreferredSize());
    button3.addActionListener(this);
    button3.setMnemonic('K');
		
    button4 = new JButton("Bagi");
    button4.setLocation(245, 100);
    button4.setSize(button1.getPreferredSize());  
    button4.addActionListener(this);
    button4.setMnemonic('B');    
  }
	
  public void createAndShowGUI() {
    JFrame.setDefaultLookAndFeelDecorated(true);
    JFrame frame = new JFrame("Demo JTextField");
    frame.setLayout(null);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    frame.getContentPane().add(label1);
    frame.getContentPane().add(textField1);
    frame.getContentPane().add(label2);
    frame.getContentPane().add(textField2);
    frame.getContentPane().add(label3);
    frame.getContentPane().add(textField3);
    frame.getContentPane().add(button1);
    frame.getContentPane().add(button2);
    frame.getContentPane().add(button3);
    frame.getContentPane().add(button4);
		
    frame.setBounds(0, 0, 350, 200);
    frame.setLocationRelativeTo(null);

    frame.setVisible(true);
  }
	
  public void actionPerformed(ActionEvent event) {
    double a=0.0, b=0.0, c=0.0;
		
    try {
      a = Double.parseDouble(textField1.getText());
      b = Double.parseDouble(textField2.getText());
    } catch (NumberFormatException nfe) {
      nfe.printStackTrace();
    }
		
    JButton btn = (JButton) event.getSource();
    if (btn == button1) {
      c = a + b;
    } else if (btn == button2) {
      c = a - b;
    } else if (btn == button3) {
      c = a * b;
    } else {
      c = a / b;
    }
		
    textField3.setText(new String().valueOf(c));	  
  }
	
  public static void main(String[] args) {		
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        DemoTextField app = new DemoTextField();
        app.createAndShowGUI();
      }
    });		
  }	
}