JCheckBox/Action Listener help

Question

Hey
I'm trying to make an applet with two tabs, a PurchasePanel and a StorePanel, and have data altered in one of them affect the data in the other. On the StorePanel, the data is input infields and through a ButtonListener command it is stored as both a String in a text field on the StorePanel, and as a check box on the PurchasePanel. Now, from the PurchasePanel I need to make an ActionListener function that when the CheckBoxes are pressed, some data is added to another textfield, and when it is unchecked the data is removed. I'm not sure I implemented the actionlistener correctly as the buttonlistener and the actionlistener commands aren't recognizing variables from each other. Any help is appreciated.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.awt.Container;
import java.text.*;
public class StorePanel extends JPanel
private ArrayList compList;
private PurchasePanel purchasePanel;
private JLabel brandName, price, memory, cpuType, cpuSpeed, info;
private JTextArea cpuInfo;
private JTextField BTL, PTL, MTL, TTL, STL;
private JPanel smallPanel, leftPanel, rightPanel, wholePanel;
private JScrollPane scrollBox;
public int counter = 0;
public StorePanel(ArrayList compList, PurchasePanel pPanel)
this.compList = compList;
this.purchasePanel = pPanel;
brandName = new JLabel("Brand Name ");
price = new JLabel("Price");
memory = new JLabel("Memory");
cpuType = new JLabel("CPU Type");
cpuSpeed = new JLabel("CPU Speed");
BTL = new JTextField();
PTL = new JTextField();
MTL = new JTextField();
TTL = new JTextField();
STL = new JTextField();
JPanel smallPanel = new JPanel();
smallPanel.setLayout(new GridLayout(5,2));
smallPanel.add(brandName);
smallPanel.add(BTL);
smallPanel.add(price);
smallPanel.add(PTL);
smallPanel.add(memory);
smallPanel.add(MTL);
smallPanel.add(cpuType);
smallPanel.add(TTL);
smallPanel.add(cpuSpeed);
smallPanel.add(STL);
// organize components here
// here is an example
JButton button1 = new JButton("Store");
button1.setSize(1,1);
button1.addActionListener(new ButtonListener());
info = new JLabel("INFORMATION", SwingConstants.CENTER);
leftPanel = new JPanel();
leftPanel.setLayout(new BorderLayout());
leftPanel.add(info,BorderLayout.NORTH);
leftPanel.add(smallPanel,BorderLayout.CENTER);
leftPanel.add(button1,BorderLayout.SOUTH);
cpuInfo = new JTextArea("No Computer",19,27);
scrollBox = new JScrollPane(cpuInfo);
rightPanel = new JPanel();
rightPanel.add(scrollBox);
wholePanel = new JPanel();
wholePanel.setLayout(new BorderLayout());
wholePanel.add(leftPanel,BorderLayout.WEST);
wholePanel.add(rightPanel,BorderLayout.EAST);
this.add(wholePanel);
private class ButtonListener implements ActionListener
     public void actionPerformed(ActionEvent event)
          String BN = BTL.getText();
          String P = PTL.getText();
          String M = MTL.getText();
          String CT = TTL.getText();
          String CS = STL.getText();
          String error = "";
          String enter = "";
          String computerString = "";
          int speed = 0;
          int memory = 0;
          double price = 0;
          String status = "Yes";
          String bPrice = "";
          JCheckBox computer;
          try
               speed = Integer.parseInt(CS);
               memory = Integer.parseInt(M);
               price = Double.parseDouble(P);
          catch (NumberFormatException exception)
               info.setText("Enter a number for Price, Memory, or Speed.");
               info.setForeground(Color.red);
               status = "No";
          if(BN.length() == 0 || P.length() == 0 || M.length() == 0 || CT.length() == 0 || CS.length() == 0)
               error = "Please Enter All Fields.";
               status = "Empty";
          if(status == "Yes" || status == "Empty")
          if(error == "Please Enter All Fields.")
               info.setText(error);
               info.setForeground(Color.red);
          else
               DecimalFormat myFormatter = new DecimalFormat("0,000.00");
               bPrice = myFormatter.format(price);
               if(counter == 0)
                    cpuInfo.replaceRange("",0,11);
               enter = "\nBrandName:\t\t" + BN + "\nCPU:\t\t" + CT + "," + speed
                              + "HZ\nMemory:\t\t" + memory + "M\nprice:\t\t$" + bPrice + "\n";
               info.setText("Computer Added.");
               info.setForeground(Color.red);
               cpuInfo.append(enter);
               counter ++;
               computer = new JCheckBox("BrandName:"+BN+"CPU:"+CT+","+speed+"HZMemory:"+memory+"Mprice:$"+bPrice);
               computer.addItemListener(new PurchasePanel.CheckBoxListener());
               purchasePanel.leftPane.add(computer);
               compList.add(computer);
public class PurchasePanel extends JPanel
private ArrayList compList;
private JLabel CTP, Filler;
private JTextArea totalPrice;
protected JPanel rightPane, leftPane;
protected JSplitPane wholePane;
private JScrollPane scrollPane;
private JCheckBox checked;
private double TP = 0.00;
public PurchasePanel(ArrayList compList)
     this.compList = compList;
     // organize components for purchase panel
     CTP = new JLabel("Current Total Purchase");
     Filler = new JLabel(" ");
totalPrice = new JTextArea("$" + TP,18,22);
scrollPane = new JScrollPane(totalPrice);
     rightPane = new JPanel();
     rightPane.setLayout(new BorderLayout());
rightPane.add(CTP, BorderLayout.CENTER);
     rightPane.add(scrollPane, BorderLayout.SOUTH);
     leftPane = new JPanel();
     leftPane.setLayout(new BoxLayout(leftPane, BoxLayout.Y_AXIS));
     leftPane.setSize(800,700);
     leftPane.add(Filler);
     wholePane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, leftPane, rightPane);
     this.add(wholePane);
private class CheckBoxListener implements ItemListener
     public void itemStateChanged(ItemEvent event)
               if(StorePanel.ButtonListener.computer.getStateChange() == ItemEvent.SELECTED)
                    TP = TP + 10.05;
public class Assignment6 extends JApplet
private int APPLET_WIDTH = 650, APPLET_HEIGHT = 350;
private JTabbedPane tPane;
private StorePanel storePanel;
private PurchasePanel purchasePanel;
private ArrayList computerList;
//The method init initializes the Applet with a Pane with two tabs
public void init()
     //list of computers to be used in every panel
     computerList = new ArrayList();
     //customer purchase panel uses the list of computers
     purchasePanel = new PurchasePanel(computerList);
     //store inventory panel uses the list of computers and also
     //established a connection with purchasePanel
storePanel = new StorePanel(computerList, purchasePanel);
//create a tabbed pane with two tabs
tPane = new JTabbedPane();
tPane.addTab("Store Inventory", storePanel);
tPane.addTab("Customer Purchase", purchasePanel);
getContentPane().add(tPane);
setSize (APPLET_WIDTH, APPLET_HEIGHT); //set Applet size
}

Answer 1

If you pass along references to the appropriate panel to the Listeners, then they can update the right thing accordingly eg.
// To enable the StorePanel to add/erase data from a textfield by listening to a checkbox in the PurchasePanel class
// PurchasePanel class
checked.addItemListener(new CheckBoxListener(storePanel));
// CheckBoxListener class
public void itemStateChanged(ItemEvent e) {
    // When checkbox checked
    if(checked)
        storePanel.writeToTextField("blahblah");
    else
        storePanel.writeToTextField("");
}That was pseudocode of course! If you need the PurchasePanel to listen to the button in the StorePanel, you need to do the reverse.