Need help with generic listeners

Sat Jan 24, 2009 2:04 am

Need help for my comp-sci class, I thought I had the code done, but I did something wrong and it won't compile. It must end up looking like this:

Driver:

Code:: import javax.swing.JFrame; public class Driver09 { public static void main(String[] args) { JFrame frame = new JFrame("Sum the Series"); frame.setSize(200, 200); frame.setLocation(200, 100); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setContentPane(new Panel09()); frame.setVisible(true); } }

Code:: import javax.swing.*; import java.awt.*; import java.awt.event.*; public class Panel09 extends JPanel { private JLabel label; private double total; private JButton we; public Panel09() { setLayout(new BorderLayout()); total = 0.0; JPanel panel = new JPanel(); panel.setLayout(new GridLayout(2, 3, 10, 0)); add(panel, BorderLayout.CENTER); addButton(panel, "+1.00", 1.0); addButton(panel, "+0.10", 0.1); addButton(panel, "+0.01", 0.01); addButton(panel, "-1.00", -1.0); addButton(panel, "-0.10", -0.1); addButton(panel, "-0.01", -0.01); label = new JLabel("$0.00"); label.setFont(new Font("Serif", Font.BOLD, 30)); label.setHorizontalAlignment(SwingConstants.CENTER); add(label, BorderLayout.NORTH); } private void addButton(JPanel panel, String s, double x) { we = new JButton(); we.addActionListener(Listener(x)); add(we); } private class Listener implements ActionListener { private double myX; public Listener(double x) { myX = x; } public void actionPerformed(ActionEvent e) { double s = Double.parseDouble(label.getText()); s = s + myX; label.setText("$:"+s); } } }

COMPILE ERROR:

Panel09.java:37: cannot find symbol
symbol : method Listener(double)
location: class Panel09
we.addActionListener(Listener(x));
^
1 error

Sat Jan 24, 2009 10:51 am

Reply the line

Code:: we.addActionListener(Listener(x));

with

Code:: we.addActionListener(new Listener(x));

Tue Jan 27, 2009 2:57 am

thank you so much, now it compiles
btw:i think my code has more problems, cause now it just gives me a big button that does nothing..so any more help with that would be greatly appreciated:)

Tue Jan 27, 2009 10:13 am

i think because you are using border layout .

Code:: setLayout(new BorderLayout());

Need help with generic listeners

Need help with generic listeners

Re: Need help with generic listeners

Re: Need help with generic listeners

Re: Need help with generic listeners