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I need to add listeners to the checkboxes and changes in selection is shown in the textArea

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class JDorm implements ItemListener{
public static void main(String[] args){
JCheckBox privateroom = new JCheckBox("Private Room",false);
JCheckBox interweb = new JCheckBox("Internet Connection",false);
JCheckBox cable = new JCheckBox("Cable TV connection",false);
JCheckBox fridg = new JCheckBox("Refridgerator",false);
JCheckBox microwave = new JCheckBox("Microwave",false);
JCheckBox soon = new JCheckBox(",and so on",false);
JLabel greet = new JLabel("Please choose ammenities");
String sel = "Your selected options";
JTextArea textBox = new JTextArea(sel,0,1);
cable.addItemListener();
JFrame dormFrame = new JFrame("Dorm Options");// creates frame with title
final int WIDTH = 250;
final int HEIGHT = 500;
dormFrame.setSize(WIDTH, HEIGHT);// sets the size of frame in pixels
dormFrame.setVisible(true);// note: default visibility is false
dormFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
dormFrame.setLayout(new FlowLayout());
dormFrame.add(greet);
dormFrame.add(microwave);
dormFrame.add(fridg);
dormFrame.add(cable);
dormFrame.add(interweb);
dormFrame.add(privateroom);
dormFrame.add(soon);
dormFrame.add(textBox);
}
public void itemStateChanged(ItemEvent event){
Object source = event.getSource();
int select = event.getStateChange();
}
}
This is what I have so far, I know I need listeners, and a message to appear in the box when selection is checked and unchecked.
Do I need if statements for the changes?

Create a generic listener that can be added to all the check boxes. Something like:
ItemListener listener = new ItemListener()
{
public void itemStateChanged(ItemEvent event)
{
JCheckBox checkBox = (JCheckBox)event.getSource();
textBox.setText( checkBox.getText() );
}
};
Then you add the listener to each check box:
privateRoom.addItemListener( listener );
interweb.addItemListener( listener );

I have tried for one Checkbox and you can do others similarly
final JCheckBox privateroom = new JCheckBox("Private Room",false);
Now add item listener to checkbox privateroom and also the actions which you would like to happen i.e.
privateroom.addItemListener(new ItemListener()
{
public void itemStateChanged(ItemEvent event)
{
if (event.getItemSelectable() == privateroom)
textBox.setText("Private Room");
}
});
The reason i have declared Checkbox privaterroom as final is because privaterroom is local and is being accessed from an inner class.
One more thing I don't know the way you have written your program is good or bad because I am also learning swing and am a newbie. But the way i write my program has the following structure
class MyClass extends JFrame implements LISTENER_NAME
{
// Components declared here
// constructor starts
public MyClass()
{
//Componenets instantiated
// add listeners to appropriate components
// setVisible(), setDefaultCloseOperation(),setSize() etc called
}
// listener interface methods here like
public void itemStateChanged(ItemEvent ie)
{
................
}
// main method
public static void main(String[] args)
{
new MyClass();
}
} // class over
This way I have never encountered the final keyword etc problems. I hope some expert will guide us.

How to check whether a radiobutton is selected in a buttongroup?

I have a buttongroup of 5 radio buttons and I need to check if at least one of them is selected or not.
Is this right?
buttonGroup1.isSelected(ButtonModel);
But what is ButtonmModel here?

buttonGroup1.getSelection()==null

Additionally, and more to the point of your question, you can determine if there is a selection among the radio buttons of a button group using the getSelected() method of the ButtonGroup class since it returns null if nothing is selected.
private boolean isSelection(ButtonGroup buttonGroup) {
return (buttonGroup.getSelected() != null);
}
I hope this helps someone!!!

You can't do much by way of the ButtonModel when it comes to finding a selected radio button. But a ButtonGroup does have the method getElements() that returns an Enumeration of AbstractButtons. These AbstractButtons can be cast to JRadioButtons during iteration through the Enumeration...
The following method will return the selected JRadioButton of the ButtonGroup passed into it, or return null if none is selected...
private JRadioButton getSelectedRadioButton(ButtonGroup buttonGroup) {
Enumeration<AbstractButton> abstractButtons = buttonGroup.getElements();
JRadioButton radioButton = null;
while (abstractButtons.hasMoreElements()) {
radioButton = (JRadioButton) abstractButtons.nextElement();
if (radioButton.isSelected()) {
break;
}
}
return radioButton;
}
Once you have the selected JRadioButton, it's elementary to access its properties. Suppose you want the text property of whatever button is selected...
String selectedRadioButtonText = getSelectedRadioButton(buttonGroup).getText();
I hope this helps someone!!!

Since you only have 5 radio buttons you could manually check all of them
(assume the radio buttons are named radio1, ... , radio5):
boolean isRadio1, isRadio2, isRadio3, isRadio4, isRadio5 = false;
if (radio1.isSelected() == true) isRadio1 = true;
if (radio2.isSelected() == true) isRadio2 = true;
if (radio3.isSelected() == true) isRadio3 = true;
if (radio4.isSelected() == true) isRadio4 = true;
if (radio5.isSelected() == true) isRadio5 = true;
Not the most elegant solution, but it will do the trick.

package radiobuttongroup;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.swing.ButtonGroup;
import javax.swing.ButtonModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JRadioButton;
public class RadioButtonGroup {
public static void main(String[] args) {
new RadioButtonGroup();
}
private RadioButtonGroup() {
Container contentPane = frame.getContentPane();
contentPane.setLayout(new GridLayout(0, 1));
for (int i = 1; i <= 5; i++) {
JRadioButton radio = new JRadioButton(Integer.toString(i));
ButtonModel buttonModel = radio.getModel();
modelToRadioButton.put(buttonModel, radio);
buttonGroup.add(radio);
contentPane.add(radio);
}
JButton buttonTestSelection = new JButton("Selection Test");
JButton buttonClearSelection = new JButton("Clear Selection");
contentPane.add(buttonTestSelection);
contentPane.add(buttonClearSelection);
buttonTestSelection.addActionListener(new ActionListener() {
#Override public void actionPerformed(ActionEvent arg0) {
ButtonModel buttonModel = buttonGroup.getSelection();
if (buttonModel == null) {
System.out.println("No radio button is selected");
}
else {
if (modelToRadioButton.containsKey(buttonModel)) {
JRadioButton b = modelToRadioButton.get(buttonModel);
System.out.println("You selected button " + b.getText());
}
else {
System.err.println("Weird, unrecognised button model!");
}
}
}
});
buttonClearSelection.addActionListener(new ActionListener() {
#Override public void actionPerformed(ActionEvent e) {
buttonGroup.clearSelection();
}
});
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private JFrame frame = new JFrame("RadioButtonGroup");
private Map<ButtonModel, JRadioButton> modelToRadioButton =
new LinkedHashMap<ButtonModel, JRadioButton>();
private ButtonGroup buttonGroup = new ButtonGroup();
}

case sensitive jcombobox

My problem is a bit tricky. I am using an Editable JComboBox. It may contain case sensitive items. For example, it may have Item1 and item1. So, these two items should be treated as different in my case.
But the problem is, these two items is treated as same. No matter which Items I have selected, it always select the first one (Item1). I've searched in Google, but didn't find any solution. That's why, I am here.
Code:
//loading of Items
jdcbmItemType = new javax.swing.DefaultComboBoxModel(ItemTypeHandler.getItemTypeComboData(MainFrame.companyId));
private void jcbItemTypeMouseReleased(MouseEvent evt)
{
if (jcbItemType.getSelectedIndex() != -1)
{
loadItemTypeDetails(((ItemObject) jcbItemType.getSelectedItem()).getId());
}
else
{
resetFields();
}
}
public static Vector<ItemObject> getItemTypeComboDataV(BigInteger companyId, BigInteger categoryId, boolean addFirstElement, TriState deleted) throws ExceptionWrapper, EJBException
{
try
{
return (Vector<ItemObject>)lookupItemTypeFacade().getItemTypeComboData(companyId, categoryId, addFirstElement, deleted);
} catch (ExceptionWrapper exceptionWrapper)
{
throw exceptionWrapper;
} catch (EJBException ejbEx)
{
throw ejbEx;
} catch (Exception ex)
{
throw new ExceptionWrapper(ex.getMessage());
}
}
ItemObject is a customClass where one field is BigInteger and another is String.
getItemTypeComboData is functioning properly. So, you can assume to get a list of ItemObject from here and it will nicely convert it to Vector<ItemObject>
jcbItemType.getSelectedIndex() always return the same index for Item1 and item1. But it returns different index for item2.
I know, it would be better if I can use itemStateChanged event. But in my case, I can't use it. But my question is, MouseReleased and FocusLost works fine for different name string but not same string with different case. I am really stumbled.
Another way to ask the question:
Does MouseReleased or FocusLost event check for case-sensitive items?
How to resolve this problem?
Thanks.

Here is my SSCCE and this works fine , If this is not what youre looking for, then post your SSCCE for better sooner help!
import javax.swing.*;
import java.awt.event.*;
public class ComboBoxTest {
JComboBox combo;
JTextField txt;
public static void main(String[] args) {
new ComboBoxTest();
}
public ComboBoxTest() {
String items[] = {"Item1", "item1"};
JFrame frame = new JFrame("JComboBox Case-sensitivity Test");
JPanel panel = new JPanel();
combo = new JComboBox(items);
combo.setEditable(true);
txt = new JTextField(10);
panel.add(combo);
panel.add(txt);
frame.add(panel);
combo.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent ie) {
String str = (String) combo.getSelectedItem();
txt.setText(str);
}
});
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 100);
frame.setVisible(true);
}
}

I think you are doing like this :-
String[] items = {"item1", "item2"};
JComboBox cb = new JComboBox(items);
cb.setEditable(true);
Now you have to access the JCombobox elements which you have insert into this as in array form like this:-
MyItemListener actionListener = new MyItemListener();
cb.addItemListener(actionListener);
class MyItemListener implements ItemListener {
// This method is called only if a new item has been selected.
public void itemStateChanged(ItemEvent evt) {
JComboBox cb = (JComboBox)evt.getSource();
// Get the affected item
Object item = evt.getItem();
if (evt.getStateChange() == ItemEvent.SELECTED) {
// Item was just selected
} else if (evt.getStateChange() == ItemEvent.DESELECTED) {
// Item is no longer selected
}
}
}
After adding the itemListener you can do your different tasks with individual JCombobox Item

Try this, it works fine...
use ActionListener() to capture the click... then use getSelectedItem() to capture the item clicked on the JComboBox
try this,
check in your console for the output
myComboBox.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent ie) {
String str = (String) myComboBox.getSelectedItem();
System.out.println(str);
}

How can i make an event to a JComboBox which triggers AFTER selection?

I want to make an event which will be triggered after i make the selection to the JComboBox.
the problem I'm now facing is that when i added an ActionListener, it was triggered when the user clicked on the box but BEFORE he actually chose the new item, thus the action listener was activated all the time on the previous value which was selected in the box. what i want to do is simply changing the title of an JTextArea according to the selection.
I tried doing something like this:
jBox.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e) {
String alt = GetAlgoAreaTitleByChoice();
panel.remove(jArea);
currentBest = setArea("",alt);
currentBest.setBounds(50, 350, 1000, 290);
panel.add(jArea);
}
});
and the method inside:
private String GetArgsAreaTitleByChoice(){
String chi = jBox.getSelectedItem().toString();
if(chi.equals(generalChoice)){
return "Hello";
}
else if(chi.equals(algoChoice)){
return "World";
}
else if(chi.equals(argsChoice)){
return "Hello";
}
return null;
}
I've tried using the SELECTED events now like this:
public void itemStateChanged(ItemEvent e) {
JComboBox cb = (JComboBox)e.getSource();
// Get the affected item
String item = cb.getSelectedItem().toString();
if (e.getStateChange() == ItemEvent.SELECTED) {
panel.remove(jBox);
textArea = setArea("", item);
panel.add(jBox);
}
but it seems to remove the area from the panel without adding it back... why is this happening?

Here is a simple demonstration with a sample code :
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Tester {
public Tester(){
JComboBox box = new JComboBox();
box.addItem("One");
box.addItem("Two");
box.addItem("Three");
box.addItemListener(new ItemListener(){
public void itemStateChanged(ItemEvent e){
if(e.getStateChange()==ItemEvent.SELECTED){
e.getItem(); //Do what ever you want :))
}
}
});
JFrame frame = new JFrame();
frame.getContentPane().add(box);
frame.pack();
frame.setVisible(true);
}
public static void main(String [] args) {
Tester tester = new Tester();
}
}

For listening of events from JComboBox is better implements ItemListener, returns two events SELECTED/DESELECTED
EDIT
if you remove/add JComponent(s) on Runtime and in already visible container, then you have to call (as least code lines)
revalidate();
repaint();

Java Swing, JComboBox drop down list change listener before clicking

I have a JComboBox which has a list of midi files, I wonder if the following is doable :
when I click on the JComboBox, a drop down list opens up, when I move the mouse on to a midi file, it plays a 10 second sample sound, so I know what the file contains before I click and select that file, so if I have 50 midi files, I can open the list and move the mouse up and down the list without clicking on it, but still play the 10 second samples from the file the mouse points to, then after I decide which one, click on it, and that one will be the selected one in the JComboBox.
How to get notified for the mouse position change/pointing events from the JComboBox ?

How to get notified for the mouse position change/pointing events
from the JComboBox ?
by implements ItemListener, that fired twice (SELECTED and DESELECTED)
or
add there CustomRenderer
or ...
three possible Events for JComboBox for example
import java.awt.Component;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.plaf.basic.BasicComboBoxRenderer;
public class ComboBoxHoverOver {
private JComboBox combo = new JComboBox();
public ComboBoxHoverOver() {
combo.setPrototypeDisplayValue("XXXXXXXXXXXXXXXXXXXXXX");
combo.setRenderer(new ComboToolTipRenderer(combo));
combo.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent e) {
System.out.println(combo.getSelectedItem().toString());
}
});
combo.addItem("");
combo.addItem("Long text 4");
combo.addItem("Long text 3");
combo.addItem("Long text 2");
combo.addItem("Long text 1");
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(combo);
f.pack();
f.setVisible(true);
}
private class ComboToolTipRenderer extends BasicComboBoxRenderer {
private static final long serialVersionUID = 1L;
private JComboBox combo;
private JList comboList;
ComboToolTipRenderer(JComboBox combo) {
this.combo = combo;
}
#Override
public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
if (comboList == null) {
comboList = list;
KeyAdapter listener = new KeyAdapter() {
#Override
public void keyReleased(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_DOWN || e.getKeyCode() == KeyEvent.VK_UP) {
int x = 5;
int y = comboList.indexToLocation(comboList.getSelectedIndex()).y;
System.out.println(comboList.getSelectedIndex());
}
}
};
combo.addKeyListener(listener);
combo.getEditor().getEditorComponent().addKeyListener(listener);
}
if (isSelected) {
System.out.println(value.toString());
}
return this;
}
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
ComboBoxHoverOver comboBoxHoverOver = new ComboBoxHoverOver();
}
});
}
}

FocusListener might be a good idea. Here is some good information about how to implement one.
http://download.oracle.com/javase/tutorial/uiswing/events/focuslistener.html