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How do I highlight specific Label when selected from the comboBox?

So I have a database of users in my JComboBox and on the left side is a list of these users as well. What I want to do is write a program when this user is selected from the JComboBox, highlight him in the list(JLabel) on the left side. I hope I was specific enough.

public class Test2 extends JFrame {
private static final long serialVersionUID = 1L;
private JPanel panel;
private JComboBox<String> comboBox;
private JList<String> list;
public Test2() {
panel = new JPanel();
getContentPane().add(panel, BorderLayout.NORTH);
GridBagLayout gbl_panel = new GridBagLayout();
panel.setLayout(gbl_panel);
comboBox = new JComboBox<String>();
comboBox.addItem("User1");
comboBox.addItem("User2");
GridBagConstraints gbc_comboBox = new GridBagConstraints();
gbc_comboBox.weightx = 1.0;
gbc_comboBox.insets = new Insets(0, 0, 5, 0);
gbc_comboBox.fill = GridBagConstraints.HORIZONTAL;
gbc_comboBox.gridx = 0;
gbc_comboBox.gridy = 0;
panel.add(comboBox, gbc_comboBox);
DefaultListModel<String> listModel = new DefaultListModel<>();
listModel.addElement("User1");
listModel.addElement("User2");
list = new JList<String>(listModel);
GridBagConstraints gbc_lblNewLabel = new GridBagConstraints();
gbc_lblNewLabel.weightx = 1.0;
gbc_lblNewLabel.gridx = 1;
gbc_lblNewLabel.gridy = 0;
panel.add(list, gbc_lblNewLabel);
comboBox.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String selectedItem = String.valueOf(comboBox.getSelectedItem());
if (selectedItem.equals("User1"))
list.setSelectedValue("User1", true);
else if (selectedItem.equals("User2"))
list.setSelectedValue("User2", true);
}
});
}
public static void main(String[] args) {
Test2 myFrame = new Test2();
myFrame.setVisible(true);
myFrame.setSize(new Dimension(400, 500));
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Will this work for you?. I don't know why you are using JLabel inside JList. So i have changed the list from JList<JLabel> to JList<String>

Swing: how to get value from JTextfield in every JPanel?

My school project is to create a purchasing system for that I create a JPanel array to list out all the products information and also allow user to input something for every item. And I dont know how to get all the values from jtextfields by clicking one button. The actionPerformed() method always requires a final variable which is quite troublesome for me.
private JButton payBtn;
public void shoppingCartTab(Customer userIn){
contentPanel.removeAll();
bottomPanel.removeAll();
final Customer USER = userIn;
ArrayList<Product> pArray = new ArrayList<Product>();
pArray = loadCartFile.loadCartFile(userIn);
JLabel tabLabel = new JLabel("Shopping Cart");
JPanel cartItems = new JPanel();
cartItems.setLayout(new BoxLayout(cartItems, BoxLayout.Y_AXIS));
final JPanel CONSTANT_CART = cartItems;
JScrollPane scroller = new JScrollPane(cartItems);
if(pArray != null){
JPanel item[] = new JPanel[pArray.size()];
for(int i = 0; i< pArray.size(); i++){
item[i] = new JPanel();
final JPanel JPANEL_TO_DEL = item[i];
item[i].setLayout(new GridBagLayout());
GridBagConstraints gBC = new GridBagConstraints();
gBC.weightx = 0.3;
item[i].setBorder(BorderFactory.createLineBorder(Color.BLACK));
JLabel icon_small = new JLabel(new ImageIcon("Icons\\" + pArray.get(i).getID() + "_small.jpg"));
JLabel itemID = new JLabel(pArray.get(i).getID());
final String CONSTANT_ID = pArray.get(i).getID();
JLabel itemName = new JLabel(pArray.get(i).getName());
JLabel itemPrice = new JLabel("$" + pArray.get(i).getPrice());
JPanel setQuantity = new JPanel();
JButton plusBtn = new JButton("+");plusBtn.setPreferredSize(new Dimension(45,30));
final JTextField QUANTITY = new JTextField("0");QUANTITY.setColumns(3);
QUANTITY.setPreferredSize(new Dimension(45,30));QUANTITY.setHorizontalAlignment(JTextField.CENTER);
JButton minusBtn = new JButton("-");minusBtn.setPreferredSize(new Dimension(45,30));
plusBtn.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent event){
if(Integer.parseInt(QUANTITY.getText())<100)
QUANTITY.setText(Integer.toString(Integer.parseInt(QUANTITY.getText())+1));
}
});
minusBtn.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent event){
if(Integer.parseInt(QUANTITY.getText())>0)
QUANTITY.setText(Integer.toString(Integer.parseInt(QUANTITY.getText())-1));
}
});
setQuantity.add(plusBtn);
setQuantity.add(QUANTITY);
setQuantity.add(minusBtn);
JButton delBtn = new JButton("Delete");
delBtn.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent event){
int dialogResult = JOptionPane.showConfirmDialog(null, "Are you sure to remove this item from your cart?", "Confirm", JOptionPane.YES_NO_OPTION);
if(dialogResult == JOptionPane.YES_OPTION){
CONSTANT_CART.remove(JPANEL_TO_DEL);
revalidate();
repaint();
ShoppingCart.removeItem(USER, CONSTANT_ID);
}
}
});
gBC.gridx = 0;
gBC.gridy = 0;
item[i].add(icon_small,gBC);
gBC.gridx = 1;
gBC.gridy = 0;
item[i].add(itemID,gBC);
gBC.gridx = 2;
gBC.gridy = 0;
item[i].add(itemName,gBC);
gBC.gridx = 3;
gBC.gridy = 0;
item[i].add(itemPrice,gBC);
gBC.gridx = 4;
gBC.gridy = 0;
item[i].add(setQuantity,gBC);
gBC.gridx = 5;
gBC.gridy = 0;
item[i].add(delBtn,gBC);
cartItems.add(item[i]);
}
contentPanel.add(tabLabel);
contentPanel.add(scroller);
payBtn = new JButton("Pay");
bottomPanel.add(payBtn); payBtn.addActionListener(this);
}else{
JLabel emptyMsg = new JLabel("Your cart is empty!");
contentPanel.add(emptyMsg);
}
revalidate();
repaint();
}

One solution would be to create a type which extends JPanel, and exposes a public property, which when called returns the value stored in the JTextField. Something like:
public class TextFieldPanel extends JPanel {
private JTextField myTextField;
public TextFieldPanel()
{
//layout init code here
}
public String getText()
{
return myTextField.getText();
}
}
Then just use this class instead of a regular JPanel. Then when your button is clicked, iterate over each of the objects in your collection, and call getText() on them to get your values.

Need help making button relay information

Okay, so I have made a GUI with some input boxes and a combo box. I am wondering how I would go about having a listener know when the button is pressed then relay all the information in the imput boxes and combo box into different parts of the script...
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class dogedice extends JFrame implements ActionListener {
private static final long serialVersionUID = 1L;
private JPanel contentPane;
private JTextField textField;
private JComboBox combo;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
dogedice frame = new dogedice();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public dogedice() {
setTitle("DogeDice Bot");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
JPanel panel = new JPanel();
contentPane.add(panel, BorderLayout.WEST);
GridBagLayout gbl_panel = new GridBagLayout();
gbl_panel.columnWidths = new int[]{0, 0};
gbl_panel.rowHeights = new int[]{0, 0};
gbl_panel.columnWeights = new double[]{0.0, 1.0};
gbl_panel.rowWeights = new double[]{0.0, Double.MIN_VALUE};
panel.setLayout(gbl_panel);
//Every new Label however needs every part that says "user" or on the Password: "pass" changed to something unique.
JLabel userTag = new JLabel("Username:");
GridBagConstraints gbc_userTag = new GridBagConstraints();
gbc_userTag.insets = new Insets(0, 0, 0, 5);
gbc_userTag.anchor = GridBagConstraints.EAST;
gbc_userTag.gridx = 0;//Here are your x + y coords
gbc_userTag.gridy = 0;//Adding to x moves left, adding to y moves down
panel.add(userTag, gbc_userTag);
//Every new textfield needs only the * part to change for it to be valid. (gbc_* =)
textField = new JTextField();
GridBagConstraints gbc_Username = new GridBagConstraints();
gbc_textField.fill = GridBagConstraints.HORIZONTAL;
gbc_textField.gridx = 1;
gbc_textField.gridy = 0;
panel.add(textField, gbc_textField);
textField.setColumns(10);
JLabel startTag = new JLabel("Starting Bid:");
GridBagConstraints gbc_startTag = new GridBagConstraints();
gbc_startTag.insets = new Insets(0, 0, 0, 5);
gbc_startTag.anchor = GridBagConstraints.EAST;
gbc_startTag.gridx = 0;
gbc_startTag.gridy = 2;
panel.add(startTag, gbc_startTag);
textField = new JTextField();
GridBagConstraints gbc_StartBid = new GridBagConstraints();
gbc_textField.fill = GridBagConstraints.HORIZONTAL;
gbc_textField.gridx = 1;
gbc_textField.gridy = 2;
panel.add(textField, gbc_textField);
textField.setColumns(10);
JLabel multTag = new JLabel("Multiplier:");
GridBagConstraints gbc_multTag = new GridBagConstraints();
gbc_multTag.insets = new Insets(0, 0, 0, 5);
gbc_multTag.anchor = GridBagConstraints.EAST;
gbc_multTag.gridx = 0;
gbc_multTag.gridy = 3;
panel.add(multTag, gbc_multTag);
textField = new JTextField();
GridBagConstraints gbc_Multiplier = new GridBagConstraints();
gbc_textField.fill = GridBagConstraints.HORIZONTAL;
gbc_textField.gridx = 1;
gbc_textField.gridy = 3;
panel.add(textField, gbc_textField);
textField.setColumns(10);
JLabel minTag = new JLabel("Min Remaining:");
GridBagConstraints gbc_minTag = new GridBagConstraints();
gbc_minTag.insets = new Insets(0, 0, 0, 5);
gbc_minTag.anchor = GridBagConstraints.EAST;
gbc_minTag.gridx = 0;
gbc_minTag.gridy = 4;
panel.add(minTag, gbc_minTag);
textField = new JTextField();
GridBagConstraints gbc_MinRemaining = new GridBagConstraints();
gbc_textField.fill = GridBagConstraints.HORIZONTAL;
gbc_textField.gridx = 1;
gbc_textField.gridy = 4;
panel.add(textField, gbc_textField);
textField.setColumns(10);
textField = new JTextField();
GridBagConstraints gbc_Password = new GridBagConstraints();
gbc_textField.fill = GridBagConstraints.HORIZONTAL;
gbc_textField.gridx = 1;
gbc_textField.gridy = 1;
panel.add(textField, gbc_textField);
textField.setColumns(10);
JLabel passTag = new JLabel("Password:");
GridBagConstraints gbc_passTag = new GridBagConstraints();
gbc_passTag.insets = new Insets(0, 0, 0, 5);
gbc_passTag.anchor = GridBagConstraints.EAST;
gbc_passTag.gridx = 0;
gbc_passTag.gridy = 1;
panel.add(passTag, gbc_passTag);
textField = new JTextField();
GridBagConstraints gbc_Odds = new GridBagConstraints();
gbc_textField.fill = GridBagConstraints.HORIZONTAL;
gbc_textField.gridx = 1;
gbc_textField.gridy = 5;
panel.add(textField, gbc_textField);
textField.setColumns(10);
JLabel oddsTag = new JLabel("Odds %:");
GridBagConstraints gbc_oddsTag = new GridBagConstraints();
gbc_oddsTag.insets = new Insets(0, 0, 0, 5);
gbc_oddsTag.anchor = GridBagConstraints.EAST;
gbc_oddsTag.gridx = 0;
gbc_oddsTag.gridy = 5;
panel.add(oddsTag, gbc_oddsTag);
textField = new JTextField();
GridBagConstraints gbc_ComboBox = new GridBagConstraints();
gbc_textField.fill = GridBagConstraints.HORIZONTAL;
gbc_textField.gridx = 1;
gbc_textField.gridy = 6;
panel.add(textField, gbc_textField);
textField.setColumns(10);
//This is the Combo Box
combo = new JComboBox<String>(new String[]{"BTC","LTC","PPC","NMC","XPM","FTC","ANC","DOGE","NXT"});
combo.addActionListener(this);
GridBagConstraints gbc_list = new GridBagConstraints();
gbc_list.fill = GridBagConstraints.HORIZONTAL;
gbc_list.gridx = 1;
gbc_list.gridy = 7;
panel.add(combo, gbc_list);
JLabel maxTag = new JLabel("MaxBet:");
GridBagConstraints gbc_maxTag = new GridBagConstraints();
gbc_maxTag.insets = new Insets(0, 0, 0, 5);
gbc_maxTag.anchor = GridBagConstraints.EAST;
gbc_maxTag.gridx = 0;
gbc_maxTag.gridy = 6;
panel.add(maxTag, gbc_maxTag);
JPanel panel_1 = new JPanel();
contentPane.add(panel_1, BorderLayout.SOUTH);
panel_1.setLayout(new FlowLayout(FlowLayout.RIGHT, 5, 5));
JButton btnConfirm = new JButton("Turn Up");
panel_1.add(btnConfirm);
JScrollPane scrollPane = new JScrollPane();
contentPane.add(scrollPane, BorderLayout.CENTER);
JTextArea textArea = new JTextArea("Current Balance");
textArea.setColumns(1);
scrollPane.setViewportView(textArea);
JScrollPane scrollPanel = new JScrollPane();//This will hold the information the bot sends over such as win/loose or error
contentPane.add(scrollPane, BorderLayout.CENTER);
JTextArea textAreal = new JTextArea("Input bot information here...");
textArea.setColumns(20);
scrollPane.setViewportView(textArea);
pack();
}
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == combo) {
System.out.println(combo.getSelectedIndex()+1);
}
}
}

It's quite straightforward to add an ActionListener to a JButton.
// ...
btnConfirm = new JButton("Turn Up");
btnConfirm.addActionListener(this);
panel_1.add(btnConfirm);
// ...
Because you'll want to know when the button is triggering the callback, like so:
private JButton btnConfirm;
This way, you'll be able to tell when it's that button that triggered the actionListener() method:
if (event.getSource() == btnConfirm) {
// Handle "Turn Up" button press here
}

Start by taking a look at How to Use Buttons, Check Boxes, and Radio Buttons and How to Write an Action Listener
Essentially you need to register an ActionListener with your button...
There are a number of ways you might be able to achieve this...
You Could
Use the more traditional, purpose class...
public class ActionHandler implements ActionListener {
public void actionPerformed(ActionEvent evt) {
if ("Turn Up".evt.getActionCommand()) {
// Handle Turn Up...
}
}
}
In this context, you'll be required to provide a reference to the component you want to modify so that the ActionHandler can interact with it, personally, this is best done via an interface, but that's just me...
public class ActionHandler implements ActionListener {
private dogedice dice;
public ActionHandler(dogedice dice) {
this.dice = dice;
}
public void actionPerformed(ActionEvent evt) {
//...
}
}
The benefit of this is you can plug an play the action handler, changing what the action does depending on your needs. If you use an interface instead of an implementation reference, you further decouple the action from the program
You Could
Use use an anonymous class
btnConfirm = new JButton("Turn Up");
btnConfirm.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
// handle turn up action...
}
});
The benefit to this is, you don't end up with "another" class, the ActionListener can reference all the internal fields of the parent class and, because you've attached it directly, you can assume that the only thing that is going to generate the ActionEvent is the btnConfirm button.
The downside is you lose the flexibility to change how the action is handled without physically modifying the code
You Could
Take advantage of the Actions API, this is a little like the first option, in that you (should normally) create another class specifically designed to handle the "Turn Up" event, but these are self contained entities. That is, they carry all the information required to configure the UI element and perform the required action when triggered.
This is really good where the action may be repeated in the UI via menus, buttons or key strokes

can't change ImageIcon from anonymous class inside a JPanel

I'm currently building a picture sorter. I have a JList which has filenames, to the left of this I have an ImageIcon which should show the picture for the current file_chosen in the JList.
The problem is I can't find a way of updating the ImageIcon contained inside a JLabel; since the change appears inside the anonymous class where the ListSelectionListener() is.
Below is the code:
public class MemeList extends JPanel{
public MemeList(){
// load/update the file list.
updateFileList();
this.setLayout(new GridBagLayout());
JPanel east = new JPanel();
east.setLayout(new GridBagLayout());
gbc.gridx = 1;
gbc.gridy = 0;
this.add(east,gbc);
west = new JPanel();
west.setLayout(new GridBagLayout());
gbc.gridx = 0;
gbc.gridy = 0;
this.add(west,gbc);
filearray = flist.toArray(new String[flist.size()]);
list = new JList(filearray);
list.addListSelectionListener(new ListSelectionListener()
{
#Override
public void valueChanged(ListSelectionEvent e)
{
if (!e.getValueIsAdjusting())
{
file_chosen = (String) list.getSelectedValue();
System.out.println("selected = "+file_chosen);
}
}
});
meme_preview_icon = new ImageIcon(path + "/" + file_chosen); // file_chosen
label2 = new JLabel("", meme_preview_icon, JLabel.CENTER);
gbc.gridx = 0;
gbc.gridy = 0;
west.add(label2,gbc);
updateIcon();
JScrollPane pane = new JScrollPane();
pane.getViewport().add(list);
pane.setPreferredSize(new Dimension(320, 340));
gbc.gridx = 0;
gbc.gridy = 0;
gbc.insets = new Insets(0,0,0,0);
east.add(pane, gbc);
}
Below here is the method for changing ImageIcon
public void updateIcon(){
//west.removeAll();
meme_preview_icon = new ImageIcon(path + "/" + file_chosen); // file_chosen
label2.setIcon(meme_preview_icon);
west.revalidate();
west.repaint();
}

I figured out the problem with my flatmate.
I just needed to call the method updateIcon() inside the ListSelectionListener(). I got confused because it told me before it had to be static and then the listener can't be static. But there it is.
list.addListSelectionListener(new ListSelectionListener()
#Override
public void valueChanged(ListSelectionEvent e)
{
if (!e.getValueIsAdjusting())
{
file_chosen = (String) list.getSelectedValue();
System.out.println("selected = "+file_chosen);
updateIcon();
}
}
});

CardLayout panel display error in existing frame

I have designed a frame containing a few controls using the design view in Netbeans 6.9.1. Further, I have added an empty panel in which I am trying to toggle display of a couple of swing components on button click. The problem is that on button click, the panel displays nothing. The code is as follows:
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
JPanel txtPanel = new JPanel();
JPanel listPanel = new JPanel();
JTextField txtfield = new JTextField("ABCDEFGHIJ", 20);
txtPanel.add(txtfield);
JList<String> list = new JList<String>();
DefaultListModel<String> model = new DefaultListModel<String>();
for (int i = 0; i < userCommands.size(); i++){
model.addElement(userCommands.get(i));
}
list.setModel(model);
listPanel.add(list);
jPanel2.add(listPanel, "list");
jPanel2.add(txtPanel, "text");
//MainUI.getFrames()[0].add(jPanel2, BorderLayout.CENTER);
itemStateChanged("text");
}
Code for itemStateChanged is as follows:
public void itemStateChanged(String disp) {
CardLayout cl = (CardLayout)(jPanel2.getLayout());
cl.show(jPanel2, disp);
}
In the first piece of code, jPanel2 is dragged and dropped onto the frame containing other components, what i am trying to achieve here is that on button click, the jPanel2 should toggle between text field and list. But currently, the panel is not displaying anything on button click.

Before even considering if jPanel2 can switch between the different panels (the different cards), is jPanel2 on display at all anywhere? The only code I can see that displayes the jPanel2 is adding it to the MainUI but it is commented out?! So how do you know that the display inside jPanel2 isn't switching?

I did a quick example code for you .Have a look.You need to define the Card layout as global and try.
import javax.swing.AbstractAction;
public class TestPanel extends JPanel {
/**
* Create the panel.
*/
JPanel panel;
CardLayout cl = new CardLayout();
public TestPanel() {
GridBagLayout gridBagLayout = new GridBagLayout();
gridBagLayout.columnWidths = new int[]{0, 155, 0, 0};
gridBagLayout.rowHeights = new int[]{94, 0, 0};
gridBagLayout.columnWeights = new double[]{0.0, 0.0, 1.0, Double.MIN_VALUE};
gridBagLayout.rowWeights = new double[]{1.0, 1.0, Double.MIN_VALUE};
setLayout(gridBagLayout);
JButton btnNewButton = new JButton("New button");
GridBagConstraints gbc_btnNewButton = new GridBagConstraints();
gbc_btnNewButton.insets = new Insets(0, 0, 5, 5);
gbc_btnNewButton.gridx = 0;
gbc_btnNewButton.gridy = 0;
add(btnNewButton, gbc_btnNewButton);
btnNewButton.setAction(new AbstractAction("New button") {
#Override
public void actionPerformed(ActionEvent arg0) {
JPanel txtPanel = new JPanel();
JPanel listPanel = new JPanel();
JTextField txtfield = new JTextField("ABCDEFGHIJ", 20);
txtPanel.add(txtfield);
JList<String> list = new JList<String>();
DefaultListModel<String> model = new DefaultListModel<String>();
for (int i = 0; i < 3; i++){
model.addElement("Sanjaya");
}
list.setModel(model);
listPanel.add(list);
panel.add(listPanel, "list");
panel.add(txtPanel, "text");
//MainUI.getFrames()[0].add(jPanel2, BorderLayout.CENTER);
itemStateChanged("list");
}
});
JTextArea textArea = new JTextArea();
textArea.setLineWrap(true);
GridBagConstraints gbc_textArea = new GridBagConstraints();
gbc_textArea.insets = new Insets(0, 0, 5, 5);
gbc_textArea.fill = GridBagConstraints.BOTH;
gbc_textArea.gridx = 1;
gbc_textArea.gridy = 0;
add(textArea, gbc_textArea);
panel = new JPanel(cl);
GridBagConstraints gbc_panel = new GridBagConstraints();
gbc_panel.insets = new Insets(0, 0, 5, 0);
gbc_panel.fill = GridBagConstraints.BOTH;
gbc_panel.gridx = 2;
gbc_panel.gridy = 0;
add(panel, gbc_panel);
}
public void itemStateChanged(String disp) {
cl.show(panel, disp);
}
}