JComboBox doesn't work properly. HELP.

[lck092580]

I'm out of ideas. I currently have a JComboBox set up but it doesn't seem to want to list more than one item (even when there's more than one).

What I did was create an applet that recieves input. Since I seem to have errors initializing a JComboBox with an empty array I've used the default constructor and whenever a new record is entered I simply use the .addItem("BLAH&quot to update the combobox. However, no matter how many items I put in.. it only displays one item. Does anyone know why?

Thanks.

T

 

[lck092580]

U'd probably want the code.. it's too long.. so i've snipped parts out of it:

import javax.swing.*;
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

public class ApplicationCentre extends Applet
{ private JButton inputButton, admitButton, displayButton, submitButton;
private JPanel buttonsPanel, defaultPanel, inputPanel, admitPanel, displayPanel, rightPanel;
private JPanel textFieldPanel;
private JList universitiesList;
private JTextArea inputTextArea;
private JLabel nameLabel, averageLabel, storageAmount;
private JTextField studentNameTextfield, studentAverageTextfield;
private JComboBox studentsComboBox;
private int count, capacity;
private Student[] studentArray;
public static final String[] UNIVERSITIES = {"Toronto", "York", "Western", "Brock", "Guelph", "Waterloo", "McGill", "Concordia", "Laval", "Macmaster"};

public void init()
{ int size = Integer.parseInt(JOptionPane.showInputDialog("Enter size of database&quot);
capacity = size;
studentArray = new Student[capacity];
count = 0;
setLayout(new BorderLayout());

// JPanel for action listener buttons (input, admit, display)
buttonsPanel = new JPanel(new GridLayout(3,1));
inputButton = new JButton("Input"
inputButton.addActionListener(new inputButtonListener());
admitButton = new JButton("Admit"
admitButton.addActionListener(new admitButtonListener());
displayButton = new JButton("Display"
displayButton.addActionListener(new displayButtonListener());
buttonsPanel.add(inputButton);
buttonsPanel.add(admitButton);
buttonsPanel.add(displayButton);

// constructs the defaultPanel, inputPanel, admitPanel, & displayPanel
defaultPanel();
inputPanel();
admitPanel();

rightPanel = new JPanel(new CardLayout());
rightPanel.add(defaultPanel, "DEFAULT"
rightPanel.add(inputPanel, "INPUT"
rightPanel.add(admitPanel, "ADMIT"

add(buttonsPanel, BorderLayout.WEST);
add(rightPanel, BorderLayout.CENTER);

}

private void defaultPanel()
{ // JPanel for default panel

}

private void inputPanel()
{ // JPanel for inputPanel
submitButton.addActionListener(new submitButtonListener());
}

private void admitPanel()
{ // JPanel for admitPanel
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints constraint = new GridBagConstraints();
admitPanel = new JPanel(gridbag);
studentsComboBox = new JComboBox();
admitPanel.add(studentsComboBox);
}


private class inputButtonListener implements ActionListener
{ public void actionPerformed(ActionEvent event)
{ CardLayout cl = (CardLayout)(rightPanel.getLayout());
cl.show(rightPanel, "INPUT"
}
}

private class submitButtonListener implements ActionListener
{ public void actionPerformed(ActionEvent event)
{ studentsComboBox.addItem(name);

}
}

private class admitButtonListener implements ActionListener
{ public void actionPerformed(ActionEvent event)
{ CardLayout cl = (CardLayout)(rightPanel.getLayout());
cl.show(rightPanel, "ADMIT"
System.out.println(studentsComboBox.getItemCount());
System.out.println(studentsComboBox.isVisible());
}
}

private class displayButtonListener implements ActionListener
{ public void actionPerformed(ActionEvent event)
{
}
}
}

 

[AlistairMonkeyFinger]

Not sure if thisis what you mean but......

import javax.swing.*;
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;

public class ApplicationCentre extends Applet
{    private JButton inputButton, admitButton, displayButton, submitButton;
    private JPanel buttonsPanel, defaultPanel, inputPanel, admitPanel, displayPanel, rightPanel;
    private JPanel textFieldPanel;
    private JList universitiesList;
    private JTextArea inputTextArea;
    private JLabel nameLabel, averageLabel, storageAmount;
    private JTextField studentNameTextfield, studentAverageTextfield;
    private JComboBox studentsComboBox;
    private int count, capacity;
    //private Student[] studentArray;
    public static final String[] UNIVERSITIES = {"Toronto", "York", "Western", "Brock", "Guelph", "Waterloo", "McGill", "Concordia", "Laval", "Macmaster"};


  public ApplicationCentre()
  {
  }
    
    public void init()
    {   // int size = Integer.parseInt(JOptionPane.showInputDialog("Enter size of database"));
        //capacity = size;
        //studentArray = new Student[capacity];
        //count = 0;
        setLayout(new BorderLayout());
        
        // JPanel for action listener buttons (input, admit, display)
        buttonsPanel = new JPanel(new GridLayout(3,1));
        inputButton = new JButton("Input");
        inputButton.addActionListener(new inputButtonListener());
        admitButton = new JButton("Admit");
        admitButton.addActionListener(new admitButtonListener());
        displayButton = new JButton("Display");
        displayButton.addActionListener(new displayButtonListener());
        buttonsPanel.add(inputButton);
        buttonsPanel.add(admitButton);
        buttonsPanel.add(displayButton);
        
        // constructs the defaultPanel, inputPanel, admitPanel, & displayPanel
        setdefaultPanel(); 
        setinputPanel();
        setadmitPanel();
        
        rightPanel = new JPanel(new CardLayout());
        rightPanel.add(defaultPanel, "DEFAULT");
        rightPanel.add(inputPanel, "INPUT");
        rightPanel.add(admitPanel, "ADMIT");
        
        add(buttonsPanel, BorderLayout.WEST);
        add(rightPanel, BorderLayout.CENTER);
                
    }


  public static void main(String[] args)
  {
    ApplicationCentre applet = new ApplicationCentre();
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add(applet, BorderLayout.CENTER);
    frame.setTitle("Applet Frame");
    applet.init();
    applet.start();
    frame.setSize(300, 300);
    Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
    Dimension frameSize = frame.getSize();
    frame.setLocation((d.width - frameSize.width) / 2, (d.height - frameSize.height) / 2);
    frame.setVisible(true);
  }

    
    private void setdefaultPanel()
    {    // JPanel for default panel
        defaultPanel = new JPanel();
        
    }

    private void setinputPanel()
    {    // JPanel for inputPanel
        inputPanel = new JPanel();
    }
    
    private void setadmitPanel()
    {    // JPanel for admitPanel
        GridBagLayout gridbag = new GridBagLayout();
        GridBagConstraints constraint = new GridBagConstraints();
        admitPanel = new JPanel(gridbag);
        studentsComboBox = new JComboBox(UNIVERSITIES);
        admitPanel.add(studentsComboBox);
    }

    
    private class inputButtonListener implements ActionListener
    {    public void actionPerformed(ActionEvent event)
        {    CardLayout cl = (CardLayout)(rightPanel.getLayout());
            cl.show(rightPanel, "INPUT");
            studentsComboBox.addItem((JOptionPane.showInputDialog("Enter name")));
        }
    }
    
    private class submitButtonListener implements ActionListener
    {    public void actionPerformed(ActionEvent event)
        {                        studentsComboBox.addItem((JOptionPane.showInputDialog("Enter name")));

        }
    }    
    
    private class admitButtonListener implements ActionListener
    {    public void actionPerformed(ActionEvent event)
        {    CardLayout cl = (CardLayout)(rightPanel.getLayout());
            cl.show(rightPanel, "ADMIT");
            System.out.println(studentsComboBox.getItemCount());
            System.out.println(studentsComboBox.isVisible());
        }
    }
    
    private class displayButtonListener implements ActionListener
    {    public void actionPerformed(ActionEvent event)
        {    
        }
    }
}

I added a main class so i didn't have to run it as an applet, probably doesn't do what you want but it demonstrates adding to a JComboBox