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if statements,lables and combo boxes

Ok my code has to pick route combo box (check) display in label(check) have a return and single ticket combobox(check) need it to display text(check) my problem is it only prints text related to one of my statments hope someone can tell me how to fix my if statments. The lable changes on a button .It reads code by lable.So far it only prints 15 and wont print 20 unless i had another label but this wouldnt make sense for the program
package learning;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList.*;
import java.util.Arrays.*;
import java.util.List.*;
#SuppressWarnings("unused")
public class test {
String[] items = {"Tipperary_to_cork","Cork_to_Dublin","Limerick_to_Tipperary","Dublin_to_Cork"};
JComboBox c = new JComboBox(items);
JButton b = new JButton("From");
JLabel l = new JLabel();
String[] items2 = {"window","aisle"};
JComboBox m = new JComboBox(items2);
JButton n = new JButton("Seat");
JLabel o = new JLabel();
String[] items3 = {"Single","return"};
JComboBox x = new JComboBox(items3);
JButton y= new JButton("Ticket");
JLabel z = new JLabel("choose Ticket");
String[] items4 = {"1","2","3","4","5","6","7","8","9","10"};
JComboBox<?> xx = new JComboBox(items4);
JButton yy = new JButton("seat");
JLabel zz = new JLabel("Choose a seat");
JLabel hh = new JLabel("cost");
JButton ccc = new JButton("comfirm");
JLabel hhh = new JLabel("");{
}
public test(){
frame();
}
public void frame(){
JFrame wolf = new JFrame();//frame
wolf.setVisible(true);
wolf.setSize(350,350);
wolf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE );
JPanel p = new JPanel();
p.add(hh);
p.add(c);//
p.add(b);//
p.add(l);//lable1
p.add(m);//
p.add(n);//
p.add(o);//lable 2
p.add(x);//
p.add(y);//
p.add(z);//lable 2
p.add(xx);//
p.add(yy);//
p.add(zz);//lable 2
p.add(ccc);
p.add(hhh);
wolf.add(p);
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
String s = c.getSelectedItem().toString();
l.setText(s);
}
});
n.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
String s = m.getSelectedItem().toString();
o.setText(s);
}
});
y.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
String s = x.getSelectedItem().toString();
z.setText(s);
}
});
yy.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
String s = xx.getSelectedItem().toString();
zz.setText(s);
}
});
}
{
if(l.getText().equals("Tipperary_to_cork")&&(z.getText().equals("single"))){
ccc.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
hh.setText("15"); //***
}});
if(l.getText().equals("Tipperary_to_cork")&&(z.getText().equals("return"))){
ccc.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
hh.setText("20"); //****
}
});
}}}
public static void main(String[]args){
new test();
}
}

You want to check "if some condition" when you click the button. So, start with one simple if statement inside one of the actionPerformed methods. You shouldn't add an action listener inside an if statement, you should always perform an action, and determine the event inside that action.
For example
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
String s = c.getSelectedItem().toString();
if (s.equals("Tipperary to cork")) {
// TODO: do something
}
}
});
Original answer
These line just happen to work because you have if(false==false)
if(l.equals("Tipperary to cork")==(z.equals("single"))) { ... }
if(l.equals("Tipperary to cork")==(z.equals("return"))) { ... }
The reason they evaluate to false is because you are comparing a JLabel.equals(String). You should use l.getText().equals("text here"), but...
The problem is that you have those if statements inside the constructor for your class, meaning that they are the first thing that is evaluated in your code. You should move the corrected if statements into the ActionListeners for the respective buttons.
Additional note: You seem to want "Tipperary to cork" AND "single". In that case, use && in place of ==. Alternatively, you could do this (psuedocode intentional)
if "Tipperary to cork" {
if "single" { ... }
else if "return" { ... }
}
In reality, though, you should compare c.getSelectedItem().toString() instead of the text of the label, but that's your decision.

Java swing CheckBox not selected while display Conformation Dialog

I am working on an application in which I have developed a window with three check boxes. When first and second check boxes are selected, new windows will be opened as desired. The third check box is for closing the application. When Exit check box is selected, it is showing the conformation Dialog as desired but Exit check box is not ticked.
I could not trace out the issue here. Please help me to resolve this issue!
package jcheckbox;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class InitiaaWindow extends JPanel {
static JFrame frame = new JFrame("Credit Contract Validation");
private static final long serialVersionUID = 1L;
JCheckBox jValidateECOUT;
JCheckBox jValidateSuperDeals;
JCheckBox jEXIT;
JLabel jlbPicture,jlbPicture1;
CheckBoxListener myListener = null;
public InitiaaWindow() {
myListener = new CheckBoxListener();
jValidateECOUT = new JCheckBox("ValidateECOUT");
jValidateECOUT.setMnemonic(KeyEvent.VK_C);
jValidateECOUT.setSelected(false);
jValidateECOUT.addItemListener(myListener);
jValidateSuperDeals = new JCheckBox("ValidateSuperDeals");
jValidateSuperDeals.setMnemonic(KeyEvent.VK_G);
jValidateSuperDeals.setSelected(false);
jValidateSuperDeals.addItemListener(myListener);
jEXIT = new JCheckBox("EXIT");
jEXIT.setMnemonic(KeyEvent.VK_G);
jEXIT.setSelected(false);
jEXIT.addItemListener(myListener);
jlbPicture = new JLabel(new ImageIcon("src/jcheckbox/image.jpg"));
jlbPicture1 = new JLabel(new ImageIcon("src/jcheckbox/image1.jpg"));
JPanel jplCheckBox = new JPanel();
jplCheckBox.setLayout(new GridLayout(0, 1));
jplCheckBox.add(jValidateECOUT);
jplCheckBox.add(jValidateSuperDeals);
jplCheckBox.add(jEXIT);
setLayout(new BorderLayout());
add(jplCheckBox, BorderLayout.WEST);
add(jlbPicture1, BorderLayout.CENTER);
add(jlbPicture, BorderLayout.EAST);
setBorder(BorderFactory.createEmptyBorder(40,40,40,40));
}
class CheckBoxListener implements ItemListener {
public void itemStateChanged(ItemEvent e) {
if (jValidateECOUT.isSelected())
{
try {
UIPack.UI.myMethod(null);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
else if (jValidateSuperDeals.isSelected())
{
try {
ValidateSuperDealsUIPack.UI.ValidateSuperDealsUI(null);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
else if (jEXIT.isSelected())
{
int dialogButton = JOptionPane.YES_NO_OPTION;
int dialogResult = JOptionPane.showConfirmDialog(null, "Would you like to close the application", "Conformation message",dialogButton);
if(dialogResult==0)
System.exit(1);
else
JOptionPane.getRootFrame().dispose();
}
}
}
public static void main(String s[]) {
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
frame.setContentPane(new InitiaaWindow());
frame.pack();
frame.setVisible(true);
}
}

Since showConfirmDialog creates a modal dialog until the dialog is closed the execution of item selection event may not propagate to other listeners which might be responsible for updating the display of the checkbox.
If you click 'No' in the dialog, does the checkbox update properly? If yes then you can create the dialog in a separate runnable task using SwingUtilities.invokeLater this will ensure the current processing of selection event completes before the modal dialog is opned.

You can add
jEXIT.setSelected(true);
before
int dialogButton = JOptionPane.YES_NO_OPTION;

1.Sorry, but your code style is really terrible (IMHO, I don't want you to be dissappointed of that).
2.Use ActionListener instead of ItemListener for JCheckBox. And check the source of action before process it:
ActionListener listener = new ActionListener({
#Override
public void actionPerfomed(ActionEvent ae) {
if (ae.getSource().equals(comboBox1) {
//process 1
} else if (ae.getSource().equals(comboBox2) {
//process 2
} else if (ae.getSource().equals(comboBox3) {
//process 3
}
}
});
comboBox1.add(listener);
comboBox2.add(listener);
comboBox3.add(listener);
3.If you want to show modal dialogs on action events, it is good to use SwingUtilities.invokeLater() for that, because your action' source should repaint after action perfomed.

multiple JComboBox in one JPanel

I have a JPanel with three JComboBox. Here is the code I wrote:
public class Main {
private static String pat_order;
private static String PS_selection;
private static String ovlp_selection;
public static void main(String args[]) throws FileNotFoundException, IOException {
Date start_time = new Date();
try {
GridBagConstraints gbc = new GridBagConstraints();
final JComboBox jc = new JComboBox();
jc.addItem("ARR");
jc.addItem("SRR");
final JComboBox jc1 = new JComboBox();
jc1.addItem("RR");
jc1.addItem("IQC");
final JComboBox jc2 = new JComboBox();
jc2.addItem("YES");
jc2.addItem("NO");
JPanel myPanel = new JPanel(new GridBagLayout());
myPanel.add(jc, gbc);
myPanel.add(jc1, gbc);
myPanel.add(jc2, gbc);
jc.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent ie) {
String order = (String) jc.getSelectedItem();
pat_order = order;
}
});
jc1.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent ie) {
String PS_method = (String) jc1.getSelectedItem();
PS_selection = PS_method;
}
});
jc2.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent ie) {
String ovlp_user = (String) jc2.getSelectedItem();
ovlp_selection = ovlp_user;
}
});
if (pat_order == "ARR") {
Arrays.sort(patterns_array, new ColumnComparator(0));
} else if (pat_order == "SRR") {
Arrays.sort(patterns_array, new ColumnComparator(1));
}
if (PS_selection == "RR") {
System.out.println("RR");
} else if (PS_selection == "IQC") {
System.out.println("IQC");
}
if (ovlp_selection == "YES") {
Overlap a = new Overlap(Xdisc, final_patterns, k, Yresid, Xresid, projectname, pat_order, PS_selection);
}
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
} finally {
}
}
}
The problem is that the first JComboBox is working fine, but the second and third is doing nothing. It would be great if you can help me in this problem.

You seem to be running your UI as if it was a console program. UI's don't work this way, they respond to events. These events may come in any order and at any time...
Dialogs are a great way of control the flow of the execution. They will block code until the dialog is closed, allowing you to ascertain the results and take appropriate action.
Take a look at How to use dialogs for more details...
While you there, you might also want to take a look through Creating a UI with Swing which will explain more of the concepts you need to understand.
Like the fact that a UI needs some kind of Window in order to be displayed on the screen

Try to add ActionListener instead of ItemListener

ListSelectionListener and CardLayout

I'm creating a program that reads data from a file, displays it on a GUI that has a JList and JButtons. I am trying to write it with CardLayout so the appropriate JPanel can be displayed when an item is selected from the JList or a JButton is clicked (i.e. next, previous, first and last). I am able to successfully read from the file and display data to the GUI. I've run into 2 problems and I've tried searching online for answers but cant seem to figure it out:
1) How do I get the JPanels to switch using CardLayout?
2) How do I get the data to be displayed in the GUI in text fields when a user clicks an item from the JList? The JList does appear and my ListSelectionListener is working because when I click on a particular item, it will print to the console (as a test).
If I comment out all of the JPanels except for 1, then it is correctly displayed but when I place all of them, then it does not switch.
So far, I have this for my ListSelectionListener (as an inner class):
public class CancerSelectionListener implements ListSelectionListener {
#Override
public void valueChanged(ListSelectionEvent e) {
Integer selection = (Integer)(((JList) e.getSource()).getSelectedIndex());
if(selection == 0) {
System.out.println("blah"); // works
// switch to the corresponding JPanel in CardLayout
}
}
}
String[] tester;
String teste;
listModel = new DefaultListModel();
for(int i = 0; i < 36; i++) {
tester = _controller.readCancer(i); // reads from the file, this part works!
teste = tester[0];
listModel.addElement(teste);
}
cancerList = new JList(listModel);
cancerList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
cancerList.setSelectedIndex(-1);
cancerList.setVisibleRowCount(5);
cancerListScroller = new JScrollPane(cancerList);
CardLayout myCardLayout;
myCardLayout = new CardLayout();
mainPanel2.setLayout(myCardLayout);
myCardLayout.show(mainPanel2, "test");
CancerPanels.aplPanel apl = new CancerPanels.aplPanel();
CancerPanels.fcPanels fc = new CancerPanels.fcPanels();
CancerPanels.vhlsPanels vhls = new CancerPanels.vhlsPanels();
CancerPanels.pdgPanels pdg = new CancerPanels.pdgPanels();
CancerPanels.cebpaPanels cebpa = new CancerPanels.cebpaPanels();
mainPanel2.add(apl.aplReturn(), "test");
mainPanel2.add(fc.fcReturn());
mainPanel2.add(vhls.vhlsReturn());
mainPanel2.add(pdg.pdgReturn());
mainPanel2.add(cebpa.cebpaReturn());
// I have 37 JPanels that are placed in the JPanel that uses CardLayout but I didn't post all of them as it would take up lots of space
The data for each JPanel is populated from static inner classes in the CancerPanels class (only showing 1 as each is very long!)
public class CancerPanels extends CancerGUI {
static JPanel cards;
static CancerController _cons = new CancerController();
static String[] cancerData;
static JScrollPane treatmentsScroller = new JScrollPane(txtTreatments, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
static JScrollPane causesScroller = new JScrollPane(txtCauses, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
static JScrollPane symptomsScroller = new JScrollPane(txtSymptoms, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
public static class aplPanel extends JPanel {
public JPanel aplReturn() {
treatmentsScroller.setViewportView(txtTreatments);
txtTreatments.setEditable(false);
causesScroller.setViewportView(txtCauses);
txtCauses.setEditable(false);
symptomsScroller.setViewportView(txtSymptoms);
txtSymptoms.setEditable(false);
cards = new JPanel(new GridLayout(6,1));
cancerData = _cons.readCancer(0);
resultName.setText(cancerData[0]);
txtSymptoms.setText(cancerData[1]);
txtCauses.setText(cancerData[2]);
txtTreatments.setText(cancerData[3]);
resultRate.setText(cancerData[4]);
resultPrognosis.setText(cancerData[5]);
cards.add(resultName);
cards.add(symptomsScroller);
cards.add(causesScroller);
cards.add(treatmentsScroller);
cards.add(resultRate);
cards.add(resultPrognosis);
return cards;
}
}
Edit:
Here is my most recent attempt. I can scroll through the JList but it doesn't properly display the correct corresponding JPanel (in fact it doesn't display anything, except whenever I click the last button, I don't know why that button works). I successfully managed to place an ItemListener on a JComboBox but ultimately, I want the CardLayout to work. Our instructor provided us with sample code to use but when I try it, the JPanels do not switch (or if they do they're hidden, not sure why).
Each of my listeners are public inner classes in the overall CancerGUI class.
public CancerGUI() {
CancerPanels.aplPanel apl = new CancerPanels.aplPanel();
CancerPanels.fcPanels fc = new CancerPanels.fcPanels();
CancerPanels.vhlsPanels vhls = new CancerPanels.vhlsPanels();
// more than 30 JPanels that I add to the JPanel that uses CardLayout, so I only posted 3
// each of them uses the GridLayout
mainPanel2 = new JPanel(new CardLayout());
mainPanel2.add(apl.aplReturn(), "1");
mainPanel2.add(fc.fcReturn(), "2");
mainPanel2.add(vhls.vhlsReturn(), "3");
CancerActionButtons _cab = new CancerActionButtons();
btnNext = new JButton("Next");
btnPrevious = new JButton("Previous");
btnFirst = new JButton("First");
btnLast = new JButton("Last");
btnClear = new JButton("Clear");
btnNext.addActionListener(_cab);
btnPrevious.addActionListener(_cab);
btnFirst.addActionListener(_cab);
btnLast.addActionListener(_cab);
CancerItemListener _item = new CancerItemListener(); // this listener works!
renalC.addItemListener(_item);
skinC.addItemListener(_item);
brainC.addItemListener(_item);
bladderC.addItemListener(_item);
ovarianC.addItemListener(_item);
pancC.addItemListener(_item);
breastC.addItemListener(_item);
String[] tester;
String teste;
listModel = new DefaultListModel();
for(int i = 0; i < 36; i++) {
tester = _controller.readCancer(i);
teste = tester[0];
listModel.addElement(teste);
}
cancerList = new JList(listModel);
cancerList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
cancerList.setSelectedIndex(-1);
cancerList.setVisibleRowCount(5);
cancerListScroller = new JScrollPane(cancerList);
ListSelection _list = new ListSelection();
cancerList.addListSelectionListener(_list);
JScrollPane treatmentsScroller = new JScrollPane(txtTreatments, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
treatmentsScroller.setViewportView(txtTreatments);
JScrollPane causesScroller = new JScrollPane(txtCauses, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
causesScroller.setViewportView(txtCauses);
JScrollPane symptomsScroller = new JScrollPane(txtSymptoms, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
symptomsScroller.setViewportView(txtSymptoms);
public class ListSelection implements ListSelectionListener {
#Override
public void valueChanged(ListSelectionEvent e) {
String selection = (String)(((JList)e.getSource()).getSelectedValue());
((CardLayout) mainPanel2.getLayout()).show(mainPanel2, selection);
((CardLayout) mainPanel2.getLayout()).show(mainPanel2, selection);
}
}
public class CancerActionButtons implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
switch(e.getActionCommand()) {
case "First":
((CardLayout) mainPanel2.getLayout()).first(mainPanel2);
cancerCount = 1;
break;
case "Last":
((CardLayout) mainPanel2.getLayout()).last(mainPanel2);
cancerCount = 11;
break;
case "Previous":
((CardLayout) mainPanel2.getLayout()).previous(mainPanel2);
cancerCount--;
cancerCount = cancerCount < 1 ? 11 : cancerCount;
break;
case "Next":
((CardLayout) mainPanel2.getLayout()).next(mainPanel2);
cancerCount++;
cancerCount = cancerCount > 11 ? 1 : cancerCount; //
break;
}
cancerList.setSelectedIndex(cancerCount-1);
}
}
/**
* Inner class that responds to any user interaction with a JComboBox for
* general types of cancers.
*/
public class CancerItemListener implements ItemListener {
#Override
public void itemStateChanged(ItemEvent e) {
JPanel showPanel = new JPanel();
if(e.getStateChange() == ItemEvent.SELECTED) {
String selection = (String) e.getItem();
if(selection.equalsIgnoreCase("skin cancer")) {
CancerPanels.skin skin = new CancerPanels.skin();
showPanel = skin.skinReturn();
} else if (selection.equalsIgnoreCase("bladder cancer")) {
CancerPanels.bladder bladder = new CancerPanels.bladder();
showPanel = bladder.bladderReturn();
} else if (selection.equalsIgnoreCase("pancreatic cancer")) {
CancerPanels.pancreatic pancreatic = new CancerPanels.pancreatic();
showPanel = pancreatic.returnPancreatic();
} else if (selection.equalsIgnoreCase("renal cancer")) {
CancerPanels.renal renal = new CancerPanels.renal();
showPanel = renal.returnRenal();
} else if (selection.equalsIgnoreCase("ovarian cancer")) {
CancerPanels.ovarian ovarian = new CancerPanels.ovarian();
showPanel = ovarian.ovarianReturn();
} else if (selection.equalsIgnoreCase("breast cancer")) {
CancerPanels.breast breast = new CancerPanels.breast();
showPanel = breast.returnBreast();
} else if (selection.equalsIgnoreCase("brain cancer")) {
CancerPanels.brain brain = new CancerPanels.brain();
showPanel = brain.returnBrain();
} else if (selection.equalsIgnoreCase("von hippel-lindau syndrome")) {
CancerPanels.vhlsPanels vhls = new CancerPanels.vhlsPanels();
showPanel = vhls.vhlsReturn();
}
JOptionPane.showMessageDialog(null, showPanel);
}
}
}
Seperate class where the JPanels are made before being added to CardLayout:
public class CancerPanels extends CancerGUI {
static String name;
static JPanel cards;
static CancerController _cons = new CancerController();
static String[] cancerData;
static JScrollPane treatmentsScroller = new JScrollPane(txtTreatments, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
static JScrollPane causesScroller = new JScrollPane(txtCauses, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
static JScrollPane symptomsScroller = new JScrollPane(txtSymptoms, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
public static class aplPanel extends JPanel {
public JPanel aplReturn() {
treatmentsScroller.setViewportView(txtTreatments);
txtTreatments.setEditable(false);
causesScroller.setViewportView(txtCauses);
txtCauses.setEditable(false);
symptomsScroller.setViewportView(txtSymptoms);
txtSymptoms.setEditable(false);
cards = new JPanel(new GridLayout(6,1));
cancerData = _cons.readCancer(0);
resultName.setText(cancerData[0]);
txtSymptoms.setText(cancerData[1]);
txtCauses.setText(cancerData[2]);
txtTreatments.setText(cancerData[3]);
resultRate.setText(cancerData[4]);
resultPrognosis.setText(cancerData[5]);
cards.add(resultName);
cards.add(symptomsScroller);
cards.add(causesScroller);
cards.add(treatmentsScroller);
cards.add(resultRate);
cards.add(resultPrognosis);
return cards;
}

In essence what you are trying to do is to change the state of one class from another.
How this is done with Swing GUI's is no different for how it is done for non-GUI programs: one class calls the public methods of another class.
One key is to have wiring to allow this to occur which means references for one class needs to be available to the other class so that appropriate methods can be called on appropriate references. The devil as they say is in the details.
"1) How do I get the JPanels to switch using CardLayout?" -- So the class that holds the CardLayout could for instance have the public methods, next(), previous(), and perhaps show(SOME_STRING_CONSTANT) or some other swapView(...) method.
"2) How do I get the data to be displayed in the GUI in text fields when a user clicks an item from the JList?" -- This will involve the use of listeners -- the class holding the JTextFields will listen for notification from the class that holds the JList, and when notified gets the necessary information from the list-displaying class. A PropertyChangeListener could work well here.
e.g.,
public class CancerSelectionListener implements ListSelectionListener {
private CardDisplayingView cardDisplayingView = null;
public CancerSelectionListener(CardDisplayingView cardDisplayingView) {
this.cardDisplayingView = cardDisplayingView;
}
#Override
public void valueChanged(ListSelectionEvent e) {
int selection = ((JList) e.getSource()).getSelectedIndex();
if(selection == 0) {
if (cardDisplayingView != null) {
cardDisplayingView.swapView(...);
}
}
}
}

Array of ImageIcons, change contents of array on drag and drop

I have an array of ImageIcons, and I can drag and drop other Icons onto them to replace them. When I hit a button a new JFrame is created from the array of ImageIcons.
If I do this without dragging any other Icons on to the original array, it works. However once I drop a different imageicon into the array, I get an error when I hit the button.
I'm just wondering if this is even possible at all?
I've considered other approaches of using a JTable for the top panel, or trying to use an ArrayList, but I'm not too comfortable using them. If anyone has any opinion on how this should be done, please let me know!
I shortened this example as much as possible(at 200 lines it's not exactly short). But this is exactly what my problem is...
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Properties;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import java.io.*;
import java.lang.String.*;
public class test extends JFrame {
JPanel storyPanel, rightStoryPanel, leftStoryPanel,centerStoryPanel, imageSelectPanel, CreatePanel, storyFramePanel, storycard;
TransferHandler handler;
MouseListener listener;
CardLayout cl3;
JLabel[] storyLabel = new JLabel[20];
JButton playStory, nextStory,addtargetbutton;
int count, start, i, j,stop, start1;
public test(){
CreatePanel = new JPanel(new BorderLayout());
storyPanel = new JPanel(new BorderLayout());
rightStoryPanel = new JPanel(new GridLayout(6,1));
leftStoryPanel = new JPanel(new GridLayout(6,1));
centerStoryPanel = new JPanel();
JScrollPane centerscroll = new JScrollPane(centerStoryPanel);
addtargetbutton = new JButton("Add Another Image Slot");
addtargetbutton.addActionListener(new createbuttons());
playStory = new JButton("Play your story!");
leftStoryPanel.add(playStory);
playStory.addActionListener(new createbuttons());
leftStoryPanel.add(addtargetbutton);
imageSelectPanel = new JPanel(new FlowLayout());
storyPanel.add(rightStoryPanel,BorderLayout.EAST);
storyPanel.add(leftStoryPanel, BorderLayout.WEST);
storyPanel.add(centerscroll, BorderLayout.CENTER);
CreatePanel.add(storyPanel, BorderLayout.NORTH);
CreatePanel.add(imageSelectPanel, BorderLayout.CENTER);
count= 3;
start= 0;
stop = 0;
start1= 0;
ImageSelection();
targetpanel();
getContentPane().add(CreatePanel);
}//End Create}
public void ImageSelection(){
int i = 0;
int j = 0;
TransferHandler handler = new TransferHandler("icon") {
#Override
public boolean canImport(TransferSupport support) {
return super.canImport(support)
&& support.getComponent().getParent() != imageSelectPanel;}
};
MouseListener listener = new MouseAdapter(){
public void mousePressed(MouseEvent e){
JComponent c = (JComponent) e.getSource();
TransferHandler handler = c.getTransferHandler();
handler.exportAsDrag(c, e, TransferHandler.COPY);
System.out.println(e);}
}; // Drag & Drop mouse
try{
String imagePath = "";
BufferedImage[] CreateImagesFromDB = new BufferedImage[40];
JLabel[] ImageLabel = new JLabel[40];
while (count > start1) {
i = 1;
CreateImagesFromDB[i] = ImageIO.read(new File("one.jpg"));
ImageLabel[i] = new JLabel(new ImageIcon(CreateImagesFromDB[i]));
imageSelectPanel.add(ImageLabel[i]);
ImageLabel[i].addMouseListener(listener);
ImageLabel[i].setTransferHandler(handler);
i++;
start1++;
}
}//EndTRY
catch(Exception e){
System.out.println("CATCH"+ e);
}//end catch
}
public void targetpanel(){
TransferHandler handler = new TransferHandler("icon") {
#Override
public boolean canImport(TransferSupport support) {
return super.canImport(support)
&& support.getComponent().getParent() != imageSelectPanel;
}
};
MouseListener listener = new MouseAdapter(){
public void mousePressed(MouseEvent e){
JComponent c = (JComponent) e.getSource();
TransferHandler handler = c.getTransferHandler();
handler.exportAsDrag(c, e, TransferHandler.COPY);
}
};
BufferedImage[] storyImages = new BufferedImage[20];
try{
while(count > start){
storyImages[j] = ImageIO.read(new File("TargetImg.jpg"));
storyLabel[j] = new JLabel(new ImageIcon(storyImages[j]));
centerStoryPanel.add(storyLabel[j]);
storyLabel[j].addMouseListener(listener);
storyLabel[j].setTransferHandler(handler);
j++;
start++;
centerStoryPanel.revalidate();
//validate();
System.out.println("J in Loop is: "+j );
}//end while Loop
//System.out.println("J is equalto: "+j);
} catch(Exception e) {};
}// End TargetPanel
public void storyFrame (JLabel[] storyArray){
int i = 0;
storyFramePanel = new JPanel(new BorderLayout());
nextStory = new JButton("Next Image");
nextStory.addActionListener(new createbuttons());
storycard = new JPanel();
cl3 = new CardLayout();
storycard.setLayout(cl3);
JPanel[] storyImgPanel = new JPanel[20];
JLabel[] imglab = new JLabel[20];
storyImgPanel[i]= new JPanel();
while( i < j){
storyImgPanel[i].add(new JLabel(storyArray[i].getIcon()));
storycard.add(storyImgPanel[i], ""+i);
i++;
}
JFrame story = new JFrame("Story");
story.setSize(500,500);
storyFramePanel.add(storycard, BorderLayout.CENTER);
storyFramePanel.add(nextStory, BorderLayout.EAST);
story.add(storyFramePanel);
cl3.show(storycard, "1");
story.setVisible(true);
}
public static void main(String[] args){
System.out.println("Application Running");
JFrame mainframe = new test();
mainframe.setTitle("Let Me Know!");
mainframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainframe.setSize(1000,1000);
mainframe.setVisible(true);
}
class createbuttons implements ActionListener{
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == addtargetbutton){
count++;
targetpanel();
System.out.println("Trying to add another TargetImg, count = "+count);
}
if(e.getSource() == playStory){
storyFrame(storyLabel);
}
if(e.getSource() == nextStory){
cl3.next(storycard);
System.out.println("button pressed");
}
}
}
}

I figured it out:
Firstly, each time you call targetpanel(), you create a new instance of storyLabel, but then you are behaving like you have it already populated from the previous calls. So the result is:
first call:
storyLabel[0] = something;
storyLabel[1] = something;
storyLabel[2] = something;
storyLabel[3] = null;
storyLabel[4] = null.... etc
second call (you added another image slot):
storyLabel[0] = null;
storyLabel[1] = null;
storyLabel[2] = null;
storyLabel[3] = something;
storyLabel[4] = null.... etc
So when you use this array in the storyboard, you get NullPointerException.
You need to create the array only once. So remove storyLabel = new JLabel[20] from targetpanel() and initialize the array in the constructor, or even better in the declaration:
...
CardLayout cl3;
JLabel[] storyLabel = new JLabel[20];
JButton playStory, nextStory, addtargetbutton;
...
Secondly, when displaying the images using the storyFrame(), you change the parent of the supplied JLabels and they subsequently disappear from the storyPanel. You must create new instances of JLabel for the storyboard.
In storyFrame(), instead of
storyImgPanel[i].add(storyArray[i]);
write
storyImgPanel[i].add(new JLabel(storyArray[i].getIcon()));
If I do all this the program is working.

There's not enough in your code to really give you a good answer. One of these two lines:
storyImgPanel[i].add(storyArray[i]);
storycard.add(storyImgPanel[i], ""+i);
would be my guess. The component you're adding in is null (either storyArray[i] or storyImgPanel[i]. Probably the first, since you're creating the second in the loop.
If you could post all your code, it would be easier. Or, (preferably) post a self-contained small example.