public class AdderApplet extends JApplet
1:
2: import javax.swing.JApplet;
3: import javax.swing.JButton;
4: import javax.swing.JPanel;
5: import javax.swing.JTextField;
6: import java.awt.Color;
7: import java.awt.Container;
8: import java.awt.BorderLayout;
9: import java.awt.FlowLayout;
10: import java.awt.event.ActionEvent;
11: import java.awt.event.ActionListener;
12:
13: public class AdderApplet extends JApplet
14: implements ActionListener
15: {
16: private JTextField inputOutputField;
17: private double sum = 0;
18:
19: public void init( )
20: {
21: Container contentPane = getContentPane( );
22: contentPane.setLayout(new BorderLayout( ));
23:
24: JPanel buttonPanel = new JPanel( );
25: buttonPanel.setBackground(Color.GRAY);
26: buttonPanel.setLayout(new FlowLayout( ));
27:
28: JButton addButton = new JButton("Add");
29: addButton.addActionListener(this);
30: buttonPanel.add(addButton);
31:
32: JButton resetButton = new JButton("Reset");
33: resetButton.addActionListener(this);
34: buttonPanel.add(resetButton);
35:
36: contentPane.add(buttonPanel, BorderLayout.SOUTH);
37:
38: JPanel textPanel = new JPanel( );
39: textPanel.setBackground(Color.BLUE);
40: textPanel.setLayout(new FlowLayout( ));
41:
42: inputOutputField =
43: new JTextField("Numbers go here.", 30);
44: inputOutputField.setBackground(Color.WHITE);
45: textPanel.add(inputOutputField);
46:
47: contentPane.add(textPanel, BorderLayout.CENTER);
48: }
49:
50: public void actionPerformed(ActionEvent e)
51: {
52: if (e.getActionCommand( ).equals("Add"))
53: {
54: sum = sum +
55: stringToDouble(inputOutputField.getText( ));
56: inputOutputField.setText(Double.toString(sum));
57: }
58: else if (e.getActionCommand( ).equals("Reset"))
59: {
60: sum = 0;
61: inputOutputField.setText("0.0");
62: }
63: else
64: inputOutputField.setText("Error in adder code.");
65: }
66:
67: private static double stringToDouble(String stringObject)
68: {
69: return Double.parseDouble(stringObject.trim( ));
70: }
71: }
72:
73:
74:
75:
76:
77: