public class AdderApplet extends JApplet
1:
2: import javax.swing.*;
3: import java.awt.*;
4: import java.awt.event.*;
5:
6: public class AdderApplet extends JApplet
7: implements ActionListener
8: {
9: private JTextField inputOutputField;
10: private double sum = 0;
11:
12:
13: public void init( )
14: {
15: Container contentPane = getContentPane( );
16: contentPane.setLayout(new BorderLayout( ));
17:
18: JPanel buttonPanel = new JPanel( );
19: buttonPanel.setBackground(Color.GRAY);
20: buttonPanel.setLayout(new FlowLayout( ));
21: JButton addButton = new JButton("Add");
22: addButton.addActionListener(this);
23: buttonPanel.add(addButton);
24: JButton resetButton = new JButton("Reset");
25: resetButton.addActionListener(this);
26: buttonPanel.add(resetButton);
27: contentPane.add(buttonPanel, BorderLayout.SOUTH);
28:
29: JPanel textPanel = new JPanel( );
30: textPanel.setBackground(Color.BLUE);
31: textPanel.setLayout(new FlowLayout( ));
32: inputOutputField =
33: new JTextField("Numbers go here.", 30);
34: inputOutputField.setBackground(Color.WHITE);
35: textPanel.add(inputOutputField);
36: contentPane.add(textPanel, BorderLayout.CENTER);
37: }
38:
39: public void actionPerformed(ActionEvent e)
40: {
41: if (e.getActionCommand( ).equals("Add"))
42: {
43: sum = sum +
44: stringToDouble(inputOutputField.getText( ));
45: inputOutputField.setText(Double.toString(sum));
46: }
47: else if (e.getActionCommand( ).equals("Reset"))
48: {
49: sum = 0;
50: inputOutputField.setText("0.0");
51: }
52: else
53: inputOutputField.setText("Error in adder code.");
54: }
55:
56: private static double stringToDouble(String stringObject)
57: {
58: return Double.parseDouble(stringObject.trim( ));
59: }
60: }
61:
62:
63:
64:
65:
66: