We Keep Coding

How do I add an ActionListener to a JCheckBox?

Problem
So my program takes in a .csv file and loads the data and displays it. When data is loaded in, it creates a new JCheckBox for every column header there is in the data. How do I add an ActionListener such that when the user ticks/unticks any of the boxes, it should do a certain function?
When data is loaded in, it updates the JPanel by the code:
public void updateChecklistPanel(){
checklistPanel.removeAll();
checklistPanel.setLayout(new GridLayout(currentData.getColumnNames().length, 1, 10, 0));
for (String columnName : currentData.getColumnNames()){
JCheckBox checkBox = new JCheckBox();
checkBox.setText(columnName);
checklistPanel.add(checkBox);
}
checklistPanel.revalidate();
checklistPanel.repaint();
}
I also have the following at the bottom:
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == newDataFrameItem){
newFile();
System.out.println("New DataFrame Loaded in");
}
if (e.getSource() == loadDataFrameItem){
loadFile();
System.out.println(".csv Data loaded into DataFrame.");
}
if (e.getSource() == saveDataFrameItem){
System.out.println("Saved the data to a .csv file");
}
}
What I'm trying to do is that when a checkbox is unticked, it should hide a column in the JTable and when ticked, it should redisplay the column.
Current Solution
The solution that I have come up with is to make a variable allColumnHeaders that is an ArrayList of Strings. I then also have a variable shownColumnHeaders that is an ArrayList of Booleans. When the user wants to show/hide a column, the showColumn(String columnName) and hideColumn(String columnName) function finds the index of the column Name in allColumnHeaders and sets the Boolean value of the index in shownColumnHeaders to either true/false.
It the proceeds to create a new table model where the columns are only added if the Boolean value for that column is true. It will then set the model for the table to the new table model.
The code for the following is show below:
import java.awt.*;
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
public class MRE extends JPanel {
private static JTable table;
private static ArrayList<String> allColumnHeaders = new ArrayList<>();
private static ArrayList<Boolean> shownColumnHeaders = new ArrayList<>();
private static void createAndShowGUI()
{
table = new JTable(5, 7);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane( table );
JPanel buttons = new JPanel( new GridLayout(0, 1) );
for (int i = 0; i < table.getColumnCount(); i++) {
String column = table.getColumnName(i);
allColumnHeaders.add(column);
JCheckBox checkBox = new JCheckBox(column);
checkBox.addActionListener(event -> {
JCheckBox cb = (JCheckBox) event.getSource();
if (cb.isSelected()) {
System.out.println(checkBox.getText() + " is now being displayed");
showColumn(checkBox.getText());
} else {
System.out.println(checkBox.getText() + " is now being hidden");
hideColumn(checkBox.getText());
}
table.setModel(createTableModel());
});
checkBox.setSelected( true );
buttons.add( checkBox );
shownColumnHeaders.add(true);
}
JPanel wrapper = new JPanel();
wrapper.add( buttons );
JFrame frame = new JFrame("MRE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(scrollPane, BorderLayout.CENTER);
frame.add(wrapper, BorderLayout.LINE_END);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static DefaultTableModel createTableModel(){
DefaultTableModel tableModel = new DefaultTableModel(0, 0);
String[] columnValues = new String[1];
for (int i = 0; i < shownColumnHeaders.size(); i++){
if (shownColumnHeaders.get(i)){
tableModel.addColumn(allColumnHeaders.get(i), columnValues);
}
}
return tableModel;
}
public static void showColumn(String columnName){
for (int i = 0; i < allColumnHeaders.size(); i++) {
if (allColumnHeaders.get(i).equals(columnName)){
shownColumnHeaders.set(i, true);
}
}
}
public static void hideColumn(String columnName){
for (int i = 0; i < allColumnHeaders.size(); i++) {
if (allColumnHeaders.get(i).equals(columnName)){
shownColumnHeaders.set(i, false);
}
}
}
public static void main(String[] args) throws Exception
{
SwingUtilities.invokeLater( () -> createAndShowGUI() );
}
}

Introduction
It took me a while, but I came up with the following JTable GUI. Here's the starting display.
Here's the GUI after I remove the item description.
Here's the GUI after I remove the item price.
Here's the GUI after I add the columns back.
Explanation
I created an Item class to hold one item.
I created an Inventory class to hold a List of Item instances and a String array of the column headers.
I created the JFrame and two JPanels. One JPanel holds the JTable and the other holds the JCheckBoxes. I used Swing layout managers to create the JPanels.
So far, so basic. Creating the JTable took a bit of effort. I wanted to display the item price as currency, but that wasn't important for this example GUI.
I created an ActionListener to add and remove columns from the JTable. I had to experiment a bit. The TableColumnModel addColumn method appends the column to the table.
I had to create a DisplayTableColumn class to hold a TableColumn and a boolean that tells me whether or not to display the TableColumn. I wound up removing all the columns from the JTable and adding all the columns back to the JTable so that I could maintain the column sequence. I probably ran 100 tests before I could get this code to work.
Code
Here's the complete runnable code.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.BorderFactory;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;
public class JCheckBoxTableGUI implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new JCheckBoxTableGUI());
}
private final Inventory inventory;
private final InventoryTableModel tableModel;
private JFrame frame;
private JTable table;
public JCheckBoxTableGUI() {
this.tableModel = new InventoryTableModel();
this.inventory = new Inventory();
String[] columns = inventory.getTableHeader();
for (String column : columns) {
tableModel.addColumn(column);
}
List<Item> items = inventory.getInventory();
for (Item item : items) {
Object[] object = new Object[5];
object[0] = item.getItemNumber();
object[1] = item.getItemName();
object[2] = item.getItemDescription();
object[3] = item.getItemQuantity();
object[4] = item.getItemPrice();
tableModel.addRow(object);
}
}
#Override
public void run() {
frame = new JFrame("JCheckBox Table GUI");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createTablePanel(), BorderLayout.CENTER);
frame.add(createSelectionPanel(), BorderLayout.AFTER_LINE_ENDS);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private JPanel createTablePanel() {
JPanel panel = new JPanel(new BorderLayout());
panel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
table = new JTable(tableModel);
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
table.getColumnModel().getColumn(0).setPreferredWidth(100);
table.getColumnModel().getColumn(1).setPreferredWidth(150);
table.getColumnModel().getColumn(2).setPreferredWidth(150);
table.getColumnModel().getColumn(3).setPreferredWidth(100);
table.getColumnModel().getColumn(4).setPreferredWidth(100);
JScrollPane scrollPane = new JScrollPane(table);
scrollPane.setPreferredSize(new Dimension(620, 300));
panel.add(scrollPane, BorderLayout.CENTER);
return panel;
}
private JPanel createSelectionPanel() {
JPanel panel = new JPanel(new FlowLayout(FlowLayout.LEADING, 0, 0));
panel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
JPanel innerPanel = new JPanel(new GridLayout(0, 1, 5, 5));
ColumnListener listener = new ColumnListener(this);
String[] columns = inventory.getTableHeader();
for (String column : columns) {
JCheckBox checkBox = new JCheckBox("Display " + column);
checkBox.addActionListener(listener);
checkBox.setActionCommand(column);
checkBox.setSelected(true);
innerPanel.add(checkBox);
}
panel.add(innerPanel);
return panel;
}
public JTable getTable() {
return table;
}
public JFrame getFrame() {
return frame;
}
public class ColumnListener implements ActionListener {
private final JCheckBoxTableGUI frame;
private final List<DisplayTableColumn> displayColumns;
public ColumnListener(JCheckBoxTableGUI frame) {
this.frame = frame;
this.displayColumns = new ArrayList<>();
TableColumnModel tcm = frame.getTable().getColumnModel();
for (int index = 0; index < tcm.getColumnCount(); index++) {
TableColumn tc = tcm.getColumn(index);
displayColumns.add(new DisplayTableColumn(tc, true));
}
}
#Override
public void actionPerformed(ActionEvent event) {
JCheckBox checkBox = (JCheckBox) event.getSource();
String column = event.getActionCommand();
TableColumnModel tcm = frame.getTable().getColumnModel();
for (int index = 0; index < displayColumns.size(); index++) {
DisplayTableColumn dtc = displayColumns.get(index);
if (dtc.isShowTableColumn()) {
tcm.removeColumn(dtc.getTableColumn());
}
}
int columnIndex = getColumnIndex(column);
displayColumns.get(columnIndex).setShowTableColumn(
checkBox.isSelected());
for (int index = 0; index < displayColumns.size(); index++) {
DisplayTableColumn dtc = displayColumns.get(index);
if (dtc.isShowTableColumn()) {
tcm.addColumn(dtc.getTableColumn());
}
}
frame.getFrame().pack();
}
private int getColumnIndex(String column) {
for (int index = 0; index < displayColumns.size(); index++) {
DisplayTableColumn dtc = displayColumns.get(index);
if (column.equals(dtc.getTableColumn().getHeaderValue())) {
return index;
}
}
return -1;
}
}
public class DisplayTableColumn {
private boolean showTableColumn;
private final TableColumn tableColumn;
public DisplayTableColumn(TableColumn tableColumn, boolean showTableColumn) {
this.tableColumn = tableColumn;
this.showTableColumn = showTableColumn;
}
public boolean isShowTableColumn() {
return showTableColumn;
}
public void setShowTableColumn(boolean showTableColumn) {
this.showTableColumn = showTableColumn;
}
public TableColumn getTableColumn() {
return tableColumn;
}
}
public class InventoryTableModel extends DefaultTableModel {
private static final long serialVersionUID = 1L;
#Override
public Class<?> getColumnClass(int columnIndex) {
if (columnIndex <= 2) {
return String.class;
} else if (columnIndex == 3) {
return Integer.class;
} else {
return Integer.class;
}
}
}
public class Inventory {
private final List<Item> inventory;
private final String[] tableHeader;
public Inventory() {
this.tableHeader = new String[] { "Item Number", "Item Name",
"Item Description", "Item Quantity",
"Item Price" };
this.inventory = new ArrayList<>();
inventory.add(new Item("X101111", "Samsung Camera", " ", 20, 69.99));
inventory.add(new Item("X101112", "Samsung Monitor", " ", 10, 279.99));
inventory.add(new Item("X101113", "Samsung Smartphone", " ", 110, 599.99));
inventory.add(new Item("X101114", "Apple Watch", " ", 20, 1259.99));
inventory.add(new Item("X101115", "Sony Playstation 5", " ", 0, 399.99));
}
public String[] getTableHeader() {
return tableHeader;
}
public List<Item> getInventory() {
return inventory;
}
}
public class Item {
private int itemPrice;
private int itemQuantity;
private final String itemNumber;
private final String itemName;
private final String itemDescription;
public Item(String itemNumber, String itemName,
String itemDescription, int itemQuantity, double itemPrice) {
this.itemNumber = itemNumber;
this.itemName = itemName;
this.itemDescription = itemDescription;
this.itemQuantity = itemQuantity;
setItemPrice(itemPrice);
}
public int getItemPrice() {
return itemPrice;
}
public void setItemPrice(double itemPrice) {
this.itemPrice = (int) Math.round(itemPrice * 100.0);
}
public int getItemQuantity() {
return itemQuantity;
}
public void setItemQuantity(int itemQuantity) {
this.itemQuantity = itemQuantity;
}
public String getItemNumber() {
return itemNumber;
}
public String getItemName() {
return itemName;
}
public String getItemDescription() {
return itemDescription;
}
}
}

This only demonstrates how to create a basic MRE:
the csv file is irrelevant.
data in the model is irrelevant.
your loadFile, newFile and saveFile buttons are irrelevant.
the TableModel is irrelevant
Your question is about adding an ActionListener to dynamically created checkboxes based on the columns of the table.
So all you need is a table with some columns and the resulting checkboxes.
import java.awt.*;
import javax.swing.*;
public class MRE extends JPanel
{
private static void createAndShowGUI()
{
JTable table = new JTable(5, 7);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane( table );
JPanel buttons = new JPanel( new GridLayout(0, 1) );
for (int i = 0; i < table.getColumnCount(); i++)
{
String column = table.getColumnName(i);
JCheckBox checkBox = new JCheckBox("Display " + column);
checkBox.setSelected( true );
buttons.add( checkBox );
}
JPanel wrapper = new JPanel();
wrapper.add( buttons );
JFrame frame = new JFrame("MRE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(scrollPane, BorderLayout.CENTER);
frame.add(wrapper, BorderLayout.LINE_END);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args) throws Exception
{
SwingUtilities.invokeLater( () -> createAndShowGUI() );
}
}
If you can modify this to demonstrate how to use your "reusable class" to manage column visibility, then I will update the above code to use my reusable class with 4 additional lines of code.
Edit:
Suggested improvements to your code:
Make the code reusable and self contained
Don't use static methods
Don't change the data.
Your original question was:
How do I add an ActionListener to a JCheckBox?
So to do that you need a class that:
implements an ActionListener
is self contained to implement the functionality you require.
So the basic structure could be like the following:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class SomeFunction implements ActionListener
{
private JTable table;
public SomeFunction(JTable table)
{
this.table = table;
}
#Override
public void actionPerformed(ActionEvent e)
{
if (e.getSource() instanceof AbstractButton)
{
String command = e.getActionCommand();
AbstractButton button = (AbstractButton)e.getSource();
if (button.isSelected())
doSelected( command );
else
doUnselected( command );
}
}
private void doSelected(String command)
{
System.out.println(command + " selected");
}
private void doUnselected(String command)
{
System.out.println(command + " unselected");
}
private static void createAndShowGUI()
{
JTable table = new JTable(5, 7);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane( table );
JPanel buttons = new JPanel( new GridLayout(0, 1) );
SomeFunction listener = new SomeFunction( table ); // added
// TableColumnManager listener = new TableColumnManager(table, false);
// ColumnListener listener = new ColumnListener();
for (int i = 0; i < table.getColumnCount(); i++)
{
String column = table.getColumnName(i);
JCheckBox checkBox = new JCheckBox("Display " + column);
checkBox.setSelected( true );
checkBox.setActionCommand( column ); // added
checkBox.addActionListener( listener ); // added
buttons.add( checkBox );
}
JPanel wrapper = new JPanel();
wrapper.add( buttons );
JFrame frame = new JFrame("MRE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(scrollPane, BorderLayout.CENTER);
frame.add(wrapper, BorderLayout.LINE_END);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args) throws Exception
{
SwingUtilities.invokeLater( () -> createAndShowGUI() );
}
}
Whatever your function does it only needs to know about the table it should act upon.
So try to restructure your code into a reusable class.
If you want to use Gilberts code, then you need to restructure the ColumnListener class into a separate reusable self contained class.
Finally you can also try my reusable class. Check out Table Column Manager for the class to download.
Whatever reusable class you decide to use, you will only need to change a single line of code from the above example (once your functionality is contained in a reusable class).
Note the static methods would not be part of the final class. They are only there so simplify testing and posting of an MRE in a single class file.
Hope this helps with future design considerations.

JCombobox change another JCombobox values from mysql database

I use this code to display combobox in the search result in the database.
But I wanted a second combobox to show me a subcategory of the first.
How can I do this?
Thanks for help.
private void FillComboTipoEmpresas2(){
try{
String sql="select * from tiposempresa";
pst=(PreparedStatement) conexao.prepareStatement(sql);
rs=pst.executeQuery();
while(rs.next()){
String tiposempresa = rs.getString("descTipoEmpresa");
jComboBoxTipoEmpresas2.addItem(tiposempresa);
}
rs.close();
pst.close();
}
catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
private void jComboBoxTipoEmpresasPopupMenuWillBecomeInvisible(javax.swing.event.PopupMenuEvent evt) {
String tmp = (String) jComboBoxTipoEmpresas.getSelectedItem();
String sql = "select * from tiposempresa where descTipoEmpresa=?";
try{
pst=(PreparedStatement) conexao.prepareStatement(sql);
pst.setString(1, tmp);
rs=pst.executeQuery();
if(rs.next()){
String add2 = rs.getString("idTiposEmpresa");
jTTipoEmpresa.setText(add2);
}
rs.close();
pst.close();
}
catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
If someone doesnt understand the question I try to explain better.
Thanks again

jComboBoxTipoEmpresas2.addItem(tiposempresa);
I need a second JComboBox who list only the subcategory of the first Jcombobox...
It looks like you are just adding a new item. You first need to remove all the existing items from the model outside of the loop that adds new items to the model.
comboBox.removeAllItem();
Or the other approach is to create a new model and replace the existing model. Here is an example that show how this is done with hardcoded models:
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class ComboBoxTwo extends JPanel implements ActionListener
{
private JComboBox<String> mainComboBox;
private JComboBox<String> subComboBox;
private Hashtable<String, String[]> subItems = new Hashtable<String, String[]>();
public ComboBoxTwo()
{
String[] items = { "Select Item", "Color", "Shape", "Fruit" };
mainComboBox = new JComboBox<String>( items );
mainComboBox.addActionListener( this );
// prevent action events from being fired when the up/down arrow keys are used
mainComboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
add( mainComboBox );
// Create sub combo box with multiple models
subComboBox = new JComboBox<String>();
subComboBox.setPrototypeDisplayValue("XXXXXXXXXX"); // JDK1.4
add( subComboBox );
String[] subItems1 = { "Select Color", "Red", "Blue", "Green" };
subItems.put(items[1], subItems1);
String[] subItems2 = { "Select Shape", "Circle", "Square", "Triangle" };
subItems.put(items[2], subItems2);
String[] subItems3 = { "Select Fruit", "Apple", "Orange", "Banana" };
subItems.put(items[3], subItems3);
}
public void actionPerformed(ActionEvent e)
{
String item = (String)mainComboBox.getSelectedItem();
Object o = subItems.get( item );
if (o == null)
{
subComboBox.setModel( new DefaultComboBoxModel() );
}
else
{
subComboBox.setModel( new DefaultComboBoxModel( (String[])o ) );
}
}
private static void createAndShowUI()
{
JFrame frame = new JFrame("SSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( new ComboBoxTwo() );
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}

How to use Ctrl+Z and Ctrl+Y with all Text Components?

In fact i know how to implement using CTRL+Z (Undo) and CTRL+Y (Redo) with one JTextField. But i have hundreds of Text Components in my Swing application, so is there a way to apply this for all Text Components in my application, so when i click CTRL+Z in any Text Component it would undo the last entry in that Field ?
I have tried to implement it in EventQueue, but it did not work !

To make all your text components "undoable", you can simply create them using your own subclass like:
public class MyTextField extends JTextField {
public MyTextField() {
final UndoManager undoMgr = new UndoManager();
// Add listener for undoable events
getDocument().addUndoableEditListener(new UndoableEditListener() {
public void undoableEditHappened(UndoableEditEvent pEvt) {
undoMgr.addEdit(pEvt.getEdit());
}
});
// Add undo/redo actions
getActionMap().put(UNDO_ACTION, new AbstractAction(UNDO_ACTION) {
public void actionPerformed(ActionEvent pEvt) {
try {
if (undoMgr.canUndo()) {
undoMgr.undo();
}
} catch (CannotUndoException e) {
e.printStackTrace();
}
}
});
getActionMap().put(REDO_ACTION, new AbstractAction(REDO_ACTION) {
public void actionPerformed(ActionEvent pEvt) {
try {
if (undoMgr.canRedo()) {
undoMgr.redo();
}
} catch (CannotRedoException e) {
e.printStackTrace();
}
}
});
// Create keyboard accelerators for undo/redo actions (Ctrl+Z/Ctrl+Y)
getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_Z, InputEvent.CTRL_DOWN_MASK),
UNDO_ACTION);
getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_Y, InputEvent.CTRL_DOWN_MASK),
REDO_ACTION);
}
}
Then instead of creating JTextFields, create MyTextFields. The limitation is that you may also want to create another subclass for JTextArea and so on for other JTextComponents. So it is also possible to use an utility method to add Undo/Redo features to any existing JTextCompoent:
public final static String UNDO_ACTION = "Undo";
public final static String REDO_ACTION = "Redo";
public static void makeUndoable(JTextComponent pTextComponent) {
final UndoManager undoMgr = new UndoManager();
// Add listener for undoable events
pTextComponent.getDocument().addUndoableEditListener(new UndoableEditListener() {
public void undoableEditHappened(UndoableEditEvent evt) {
undoMgr.addEdit(evt.getEdit());
}
});
// Add undo/redo actions
pTextComponent.getActionMap().put(UNDO_ACTION, new AbstractAction(UNDO_ACTION) {
public void actionPerformed(ActionEvent evt) {
try {
if (undoMgr.canUndo()) {
undoMgr.undo();
}
} catch (CannotUndoException e) {
e.printStackTrace();
}
}
});
pTextComponent.getActionMap().put(REDO_ACTION, new AbstractAction(REDO_ACTION) {
public void actionPerformed(ActionEvent evt) {
try {
if (undoMgr.canRedo()) {
undoMgr.redo();
}
} catch (CannotRedoException e) {
e.printStackTrace();
}
}
});
// Create keyboard accelerators for undo/redo actions (Ctrl+Z/Ctrl+Y)
pTextComponent.getInputMap().put(
KeyStroke.getKeyStroke(KeyEvent.VK_Z, InputEvent.CTRL_DOWN_MASK), UNDO_ACTION);
pTextComponent.getInputMap().put(
KeyStroke.getKeyStroke(KeyEvent.VK_Y, InputEvent.CTRL_DOWN_MASK), REDO_ACTION);
}
The final and absolutely transparent solution would be to implement your own UI class using Lnf features, but you may want to think twice before making all TextComponents undoable, for memory consumptions reasons for example if you often perform huge text modifications to these components...

you can gel list of built_in KeyBindings short_cuts implemented in the API's
notice you have to check or prepare your code for all accesible Look and Feels
you can get built_in KeyBindings short_cuts and replace that as you expecting, System ClipBoard is very often modified,
never tried but on this forum you can foud out rellevant info How to change, replace KeyBindings short_cuts
list of built_in KeyBindings short_cuts
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
import javax.swing.filechooser.*;
public class KeyBindings implements ItemListener {
private static final String PACKAGE = "javax.swing.";
private static final String[] COLUMN_NAMES = {"Action", "When Focused", "When In Focused Window", "When Ancestor"};
private static String selectedItem;
private JComponent contentPane;
private JMenuBar menuBar;
private JTable table;
private JComboBox comboBox;
private Hashtable<String, DefaultTableModel> models;
/*
* Constructor
*/
public KeyBindings() {
models = new Hashtable<String, DefaultTableModel>();
contentPane = new JPanel(new BorderLayout());
contentPane.add(buildNorthComponent(), BorderLayout.NORTH);
contentPane.add(buildCenterComponent(), BorderLayout.CENTER);
resetComponents();
}
/*
* The content pane should be added to a high level container
*/
public JComponent getContentPane() {
return contentPane;
}
/*
* A menu can also be added which provides the ability to switch
* between different LAF's.
*/
public JMenuBar getMenuBar() {
if (menuBar == null) {
menuBar = createMenuBar();
}
return menuBar;
}
/*
* This panel is added to the North of the content pane
*/
private JComponent buildNorthComponent() {
comboBox = new JComboBox();
JLabel label = new JLabel("Select Component:");
label.setDisplayedMnemonic('S');
label.setLabelFor(comboBox);
JPanel panel = new JPanel();
panel.setBorder(new EmptyBorder(15, 0, 15, 0));
panel.add(label);
panel.add(comboBox);
return panel;
}
/*
* Check the key name to see if it is the UI property
*/
private String checkForUIKey(String key) {
if (key.endsWith("UI") && key.indexOf('.') == -1) {
String componentName = key.substring(0, key.length() - 2);// Ignore these components
if (componentName.equals("PopupMenuSeparator") || componentName.equals("ToolBarSeparator") || componentName.equals("DesktopIcon")) {
return null;
} else {
return componentName;
}
}
return null;
}
/*
** Build the emtpy table to be added in the Center
*/
private JComponent buildCenterComponent() {
DefaultTableModel model = new DefaultTableModel(COLUMN_NAMES, 0);
table = new JTable(model) {
private static final long serialVersionUID = 1L;
#Override
public boolean isCellEditable(int row, int column) {
return false;
}
};
table.setAutoCreateColumnsFromModel(false);
table.getColumnModel().getColumn(0).setPreferredWidth(200);
table.getColumnModel().getColumn(1).setPreferredWidth(200);
table.getColumnModel().getColumn(2).setPreferredWidth(200);
table.getColumnModel().getColumn(3).setPreferredWidth(200);
Dimension d = table.getPreferredSize();
d.height = 350;
table.setPreferredScrollableViewportSize(d);
table.getTableHeader().setFocusable(true);
return new JScrollPane(table);
}
/*
* When the LAF is changed we need to reset all the items
*/
private void resetComponents() {
models.clear();
((DefaultTableModel) table.getModel()).setRowCount(0);
Vector<String> comboBoxItems = new Vector<String>(50);// buildItemsMap();
UIDefaults defaults = UIManager.getLookAndFeelDefaults();
for (Object key : defaults.keySet()) { // All Swing components will have a UI property.
String componentName = checkForUIKey(key.toString());
if (componentName != null) {
comboBoxItems.add(componentName);
}
}
Collections.sort(comboBoxItems);
comboBox.removeItemListener(this);
comboBox.setModel(new DefaultComboBoxModel(comboBoxItems));
comboBox.setSelectedIndex(-1);
comboBox.addItemListener(this);
comboBox.requestFocusInWindow();
if (selectedItem != null) {
comboBox.setSelectedItem(selectedItem);
}
}
/**
* Create menu bar
*/
private JMenuBar createMenuBar() {
JMenuBar menuBar1 = new JMenuBar();
menuBar1.add(createFileMenu());
menuBar1.add(createLAFMenu());
return menuBar1;
}
/**
* Create menu items for the Application menu
*/
private JMenu createFileMenu() {
JMenu menu = new JMenu("Application");
menu.setMnemonic('A');
menu.addSeparator();
menu.add(new ExitAction());
return menu;
}
/**
* Create menu items for the Look & Feel menu
*/
private JMenu createLAFMenu() {
ButtonGroup bg = new ButtonGroup();
JMenu menu = new JMenu("Look & Feel");
menu.setMnemonic('L');
String lafId = UIManager.getLookAndFeel().getID();
UIManager.LookAndFeelInfo[] lafInfo = UIManager.getInstalledLookAndFeels();
for (int i = 0; i < lafInfo.length; i++) {
String laf = lafInfo[i].getClassName();
String name = lafInfo[i].getName();
Action action = new ChangeLookAndFeelAction(laf, name);
JRadioButtonMenuItem mi = new JRadioButtonMenuItem(action);
menu.add(mi);
bg.add(mi);
if (name.equals(lafId)) {
mi.setSelected(true);
}
}
return menu;
}
/*
* Implement the ItemListener interface
*/
#Override
public void itemStateChanged(ItemEvent e) {
String componentName = (String) e.getItem();
changeTableModel(getClassName(componentName));
selectedItem = componentName;
}
/*
* Use the component name to build the class name
*/
private String getClassName(String componentName) {
if (componentName.equals("TableHeader")) {// The table header is in a child package
return PACKAGE + "table.JTableHeader";
} else {
return PACKAGE + "J" + componentName;
}
}
/*
* Change the TabelModel in the table for the selected component
*/
private void changeTableModel(String className) {
DefaultTableModel model = models.get(className); // Check if we have already built the table model for this component
if (model != null) {
table.setModel(model);
return;
}
model = new DefaultTableModel(COLUMN_NAMES, 0); // Create an empty table to start with
table.setModel(model);
models.put(className, model);
JComponent component = null; // Create an instance of the component so we can get the default Action map and Input maps
try {
if (className.endsWith("JFileChooser")) {// Hack so I don't have to sign the jar file for usage in Java Webstart
component = new JFileChooser(new DummyFileSystemView());
} else {
Object o = Class.forName(className).newInstance();
component = (JComponent) o;
}
} catch (Exception e) {
Object[] row = {e.toString(), "", "", ""};
model.addRow(row);
return;
}
ActionMap actionMap = component.getActionMap(); // Not all components have Actions defined
Object[] keys = actionMap.allKeys();
if (keys == null) {
Object[] row = {"No actions found", "", "", ""};
model.addRow(row);
return;
}
// In some ActionMaps a key of type Object is found (I have no idea why)
// which causes a ClassCastExcption when sorting so we will ignore it
// by converting that entry to the empty string
for (int i = 0; i < keys.length; i++) {
Object key = keys[i];
if (key instanceof String) {
continue;
} else {
keys[i] = "";
}
}
Arrays.sort(keys);
for (int i = 0; i < keys.length; i++) { // Create a new row in the model for every Action found
Object key = keys[i];
if (key != "") {
Object[] row = {key, "", "", ""};
model.addRow(row);
}
}
// Now check each InputMap to see if a KeyStroke is bound the the Action
updateModelForInputMap(model, 1, component.getInputMap(JComponent.WHEN_FOCUSED));
updateModelForInputMap(model, 2, component.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW));
updateModelForInputMap(model, 3, component.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT));
}
/*
* The model is potentially update for each of the 3 different InputMaps
*/
private void updateModelForInputMap(TableModel model, int column, InputMap inputMap) {
if (inputMap == null) {
return;
}
KeyStroke[] keys = inputMap.allKeys();
if (keys == null) {
return;
}
// The InputMap is keyed by KeyStroke, however we want to be able to
// access the action names that are bound to a KeyStroke so we will create
// a Hashtble that is keyed by action name.
// Note that multiple KeyStrokes can be bound to the same action name.
Hashtable<Object, String> actions = new Hashtable<Object, String>(keys.length);
for (int i = 0; i < keys.length; i++) {
KeyStroke key = keys[i];
Object actionName = inputMap.get(key);
Object value = actions.get(actionName);
if (value == null) {
actions.put(actionName, key.toString().replace("pressed ", ""));
} else {
actions.put(actionName, value + ", " + key.toString().replace("pressed ", ""));
}
}
for (int i = 0; i < model.getRowCount(); i++) {
// Now we can update the model for those actions that have KeyStrokes mapped to them
String o = actions.get(model.getValueAt(i, 0));
if (o != null) {
model.setValueAt(o.toString(), i, column);
}
}
}
/*
* Change the LAF and recreate the UIManagerDefaults so that the properties
* of the new LAF are correctly displayed.
*/
private class ChangeLookAndFeelAction extends AbstractAction {
private static final long serialVersionUID = 1L;
private String laf;
protected ChangeLookAndFeelAction(String laf, String name) {
this.laf = laf;
putValue(Action.NAME, name);
putValue(Action.SHORT_DESCRIPTION, getValue(Action.NAME));
}
#Override
public void actionPerformed(ActionEvent e) {
try {
JMenuItem mi = (JMenuItem) e.getSource();
JPopupMenu popup = (JPopupMenu) mi.getParent();
JRootPane rootPane = SwingUtilities.getRootPane(popup.getInvoker());
Component c = rootPane.getContentPane().getComponent(0);
rootPane.getContentPane().remove(c);
UIManager.setLookAndFeel(laf);
KeyBindings bindings = new KeyBindings();
rootPane.getContentPane().add(bindings.getContentPane());
SwingUtilities.updateComponentTreeUI(rootPane);
rootPane.requestFocusInWindow();
} catch (Exception ex) {
System.out.println("Failed loading L&F: " + laf);
System.out.println(ex);
}
}
}
private class ExitAction extends AbstractAction {
private static final long serialVersionUID = 1L;
public ExitAction() {
putValue(Action.NAME, "Exit");
putValue(Action.SHORT_DESCRIPTION, getValue(Action.NAME));
putValue(Action.MNEMONIC_KEY, new Integer(KeyEvent.VK_X));
}
#Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
private class DummyFileSystemView extends FileSystemView {
#Override
public File createNewFolder(File containingDir) {
return null;
}
#Override
public File getDefaultDirectory() {
return null;
}
#Override
public File getHomeDirectory() {
return null;
}
}
private static void createAndShowGUI() {
KeyBindings application = new KeyBindings();
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("Key Bindings");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setJMenuBar(application.getMenuBar());
frame.getContentPane().add(application.getContentPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
//UIManager.put("swing.boldMetal", Boolean.FALSE);
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGUI();
}
});
}
}

If you want to run "global events" on your application regardless of where you your current focus is, you'll need to work with the KeyboardFocusManager :
KeyboardFocusManager kfm = KeyboardFocusManager.getCurrentKeyboardFocusManager();
kfm.addKeyEventDispatcher(new KeyEventDispatcher() {
#Override
public boolean dispatchKeyEvent(KeyEvent e) {
// do your stuff here
return done;
}
});
Hope this helps.

Auto suggested combobox in JFrame

I use the following code for retrieve the data into combobox. How to change Jcombobox into Auto suggested combobox . It means when I press A the words which are start with A that will show in the items field in combobox.
public void combo(){
try{
GCS.GContnStr();
TmpFlxTSt= GCS.GCotnStr.createStatement();
String select = "Select StudName from studentmaster";
TmpFlxTRs = TmpFlxTSt.executeQuery(select);
while(TmpFlxTRs.next())
{
String TmpOb1=TmpFlxTRs.getString("StudName");
TmpOb1.toString();
cbx.addItem(TmpOb1);
cbx.setMaximumRowCount(1);
}

Try to use Combobox component from package org.jdesktop.swingx.autocomplete, maven repository here

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.plaf.basic.*;
class Test
{
private JComboBox_ cb = null;
public Test() {
JFrame fr=new JFrame("TEST ComboBox");
JPanel p = new JPanel();
p.setLayout( new BorderLayout() );
String[] ss = new String[]
{ "112","1123","1124","1134",
"first",
"second",
"third",
"third 1 before",
"third 2",
"third 1 after",
"third quarter",
"fourth",
"fourth and more",
"fourth and more and more"
};
fr.getContentPane().add(p);
cb = new JComboBox_(ss);
p.add("South",cb);
p.add("Center",new JButton("test combo box"));
fr.pack();
fr.show();
}
public static void main( String[] args ) {
Test test=new Test();
}
}
class JComboBox_ extends JComboBox {
public int caretPos=0;
public JTextField tf=null;
public JComboBox_(final Object items[]) {
super(items);
this.setEditor(new BasicComboBoxEditor());
this.setEditable(true);
}
public void setSelectedIndex(int ind) {
super.setSelectedIndex(ind);
tf.setText(getItemAt(ind).toString());
tf.setSelectionEnd(caretPos+tf.getText().length());
tf.moveCaretPosition(caretPos);
// tf.setSelectionStart(caretPos);
}
public void setEditor(ComboBoxEditor anEditor) {
super.setEditor(anEditor);
if (anEditor.getEditorComponent() instanceof JTextField) {
tf=(JTextField)anEditor.getEditorComponent();
tf.addKeyListener(new KeyAdapter()
{
public void keyReleased( KeyEvent ev )
{
char key=ev.getKeyChar();
if (! (Character.isLetterOrDigit(key)||Character.isSpaceChar(key) )) return;
String s = tf.getText();
caretPos=tf.getCaretPosition();
String text="";
try {
text=tf.getText(0,caretPos);
}
catch (Exception ex) {
ex.printStackTrace();
}
int n=getItemCount();
for (int i=0; i<n; i++) {
int ind=((String)getItemAt(i)).indexOf(text);
if (ind==0) {
setSelectedIndex(i);
return;
}
}
}
} );
}
}
}

java JComboBox issue

I was trying to have two Jcomboxes, where second Jcombox should changes its values according to the change in the first one.
I tried but could not succeed,Any help is appreciated. Thanks
This is what I have tried so Far:
public class SharedDataBetweenComboBoxSample {
static private String selectedString(ItemSelectable is) {
Object selected[] = is.getSelectedObjects();
return ((selected.length == 0) ? "null" : (String)selected[0]);
}
public static void main(String args[]) {
final String labels[] = { "A", "B", "C" };
final String labelsA[] = { "A", "AA", "AAA" };
final String labelsB[] = { "B", "BB", "BBB" };
final String labelsC[] = { "C", "CC", "CCC" };
final JFrame frame = new JFrame("Shared Data");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
JComboBox comboBox1 = new JComboBox();
comboBox1.addItem(labels);
comboBox1.setSelectedItem(null);
final JComboBox comboBox2 = new JComboBox();
// comboBox2.setEditable(true);
panel.add(comboBox1);
panel.add(comboBox2);
frame.add(panel,BorderLayout.NORTH);
ItemListener itemListener = new ItemListener() {
public void itemStateChanged(ItemEvent itemEvent) {
int state = itemEvent.getStateChange();
System.out.println((state == ItemEvent.SELECTED) ? "Selected" : "Deselected");
System.out.println("Item: " + itemEvent.getItem());
ItemSelectable is = itemEvent.getItemSelectable();
System.out.println(", Selected: " + selectedString(is));
if (selectedString(is) == "B") {
comboBox2.addItem(labelsB);
// frame.add(comboBox1, BorderLayout.CENTER);
} else if (selectedString(is) == "A") {
comboBox2.addItem(labelsA);
// frame.add(comboBox1, BorderLayout.CENTER);
} else if (selectedString(is) == "C") {
comboBox2.addItem(labelsC);
// frame.add(comboBox1, BorderLayout.CENTER);
} else {
comboBox2.setSelectedItem(null);
// frame.add(comboBox1, BorderLayout.CENTER);
}
}
};
comboBox1.addItemListener(itemListener);
frame.setSize(300,200);
frame.setVisible(true);
}
}

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class ComboBoxTwo extends JFrame implements ActionListener
{
private JComboBox mainComboBox;
private JComboBox subComboBox;
private Hashtable subItems = new Hashtable();
public ComboBoxTwo()
{
String[] items = { "Select Item", "Color", "Shape", "Fruit" };
mainComboBox = new JComboBox( items );
mainComboBox.addActionListener( this );
getContentPane().add( mainComboBox, BorderLayout.WEST );
// Create sub combo box with multiple models
subComboBox = new JComboBox();
subComboBox.setPrototypeDisplayValue("XXXXXXXXXX"); // JDK1.4
getContentPane().add( subComboBox, BorderLayout.EAST );
String[] subItems1 = { "Select Color", "Red", "Blue", "Green" };
subItems.put(items[1], subItems1);
String[] subItems2 = { "Select Shape", "Circle", "Square", "Triangle" };
subItems.put(items[2], subItems2);
String[] subItems3 = { "Select Fruit", "Apple", "Orange", "Banana" };
subItems.put(items[3], subItems3);
}
public void actionPerformed(ActionEvent e)
{
String item = (String)mainComboBox.getSelectedItem();
Object o = subItems.get( item );
if (o == null)
{
subComboBox.setModel( new DefaultComboBoxModel() );
}
else
{
subComboBox.setModel( new DefaultComboBoxModel( (String[])o ) );
}
}
public static void main(String[] args)
{
JFrame frame = new ComboBoxTwo();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setLocationRelativeTo( null );
frame.setVisible( true );
}
}

not really sure what your problem is as you don't say. Maybe the issue is
comboBox2.addItem(labelsB);
this is adding an array as a single item in the list, perfectly acceptable assuming it is right, however i'm guessing you want to iterate through the array and add each one as separate items. You may want to remove items on deselection.
I assume you are trying from multiple selections on the first list (based on your selectedString operation), if not your code is miles out? If you are you do not want an if/else construct, just multiple ifs
Also, don't use (selectedString(is)=="A"), you might get lucky, but you should use `"A".equals(selectedString(is))