We Keep Coding

Make a conditional in a JDialog

I'm trying to put a conditional in a JDialog which detect if the two buttons in it are disabled. I need that also to close the dialog when it reach this condition so I found 2 problems. Example code:
public static String windowvisitAlert(JButton but, JButton but2, String message1, String message2) throws Exception, Exception {
String n = "";
Object[] options = {but, but2};
Object a = message1;
JOptionPane pane = new JOptionPane(a, JOptionPane.QUESTION_MESSAGE, JOptionPane.YES_NO_OPTION, null, options, options[0]);
JDialog dialog = pane.createDialog(message2);
dialog.setContentPane(pane);
dialog.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
dialog.setSize(new Dimension(450, 10));
dialog.pack();
dialog.setVisible(true);
return n;
}
This is the method which creates a JDialog from a JPanel options. We have 2 buttons and 2 "messages" which only determinates the name of the dialog window.
I tried to put :
if (but.isEnabled()==false && but2.isEnabled()==false) {
dialog.setVisible(false);
}else{
dialog.setVisible(true);}
Also this method will return the value n so I don't know how will a condition work inside it.
Where i implement this method:
public void actionPerformed(ActionEvent e) {
final JButton but = new JButton("VISITA");
final JButton but2 = new JButton("RESPONSABLE");
try {
ActionListener actionListener2 = new ActionListener() {
public void actionPerformed(ActionEvent actionEvent) {
//action performed
}
};
ActionListener actionListener = new ActionListener() {
public void actionPerformed(ActionEvent actionEvent) {
//action performed
}
};
but.addActionListener(actionListener2);
but2.addActionListener(actionListener);
Alerts.windowvisitAlert(but, but2, Gui.getProperties().getProperty("text"), Gui.getProperties().getProperty("text"));
}catch (Exception ex) {
sc.functionSavingInLog(Utils.getClassInfo(Thread.currentThread().getStackTrace()[1]), ex.toString());
System.out.println(Utils.getClassInfo(Thread.currentThread().getStackTrace()[1]) + ex);
}
}
This is actually not working so my question is:
-How can I make this condition work and make the JDialog close when it hits it?
If not, how can I change the method or just do a jpanel?

Java Swing: how to stop unwanted shift-tab keystroke action

When I have a JTextField in a JPanel and it has focus, pressing "tab" doesn't do anything... but pressing "shift-tab" causes focus to be lost (FocusEvent.getOppositeComponent() is null).
If there are other focusable components on the JPanel (or rather under the "focus cycle root") this doesn't happen: instead, they get the focus on shift-tab.
In the SSCCE below I demonstrate this... each time you press Return in the search box you add a row to the JTable, which causes it to become focusable. You can also uncomment the line which makes the JRadioButtons unfocusable.
I looked at the InputMaps as well to see whether shift-tab is somehow involved there ... not at all.
I also tried experimenting with FocusTraversalPolicy to see whether I could understand the problem. No joy.
My goal: to stop "shift-tab" causing a loss of focus (focus disappears) when there is a single focusable component in the focus cycle root's ambit.
later
a workaround is to add the line
if( oppComp == null ){ impl.searchBox.requestFocus(); }
at the end of the focusLost method of the search box's FocusListener ... but for me this is only a workaround... 1) it doesn't solve the problem through understanding of the focus traversal mechanism; 2) there might be circs when you would need the focus to be lost from the search box...
import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import java.lang.reflect.InvocationTargetException;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
class BackTabProb {
JFrame mainFrame;
JTextField searchBox;
JTable resultsTable;
public static void print(String msg) {
System.out.println(msg);
}
public static void main(String[] a_args) throws InvocationTargetException, InterruptedException {
final BackTabProb impl = new BackTabProb();
class Show implements Runnable {
public void run() {
impl.mainFrame = new JFrame("Back Tab problem");
impl.mainFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent) {
impl.mainFrame.dispose();
}
});
impl.resultsTable = new JTable();
impl.resultsTable.setFocusable(false);
Vector<Object> dataVector = new Vector<Object>();
Vector<Object> colIdentifiers = new Vector<Object>(Arrays.asList(new String[] { "ONE", "TWO" }));
((DefaultTableModel) impl.resultsTable.getModel()).setDataVector(dataVector, colIdentifiers);
JScrollPane jsp = new JScrollPane(impl.resultsTable);
JPanel northPanel = new JPanel();
northPanel.setLayout(new BoxLayout(northPanel, BoxLayout.X_AXIS));
impl.searchBox = new JTextField("Enter search text", 10);
JLabel label = new JLabel("Search:");
label.setLabelFor(impl.searchBox);
northPanel.add(label);
northPanel.add(impl.searchBox);
ButtonGroup buttonGroup = new ButtonGroup();
ArrayList<JRadioButton> indexButtons = new ArrayList<JRadioButton>();
for (int i = 0; i < 2; i++) {
JRadioButton indexButton = new JRadioButton(i == 0 ? "Stemmer" : "Simple");
// commenting this out means back-tabbing from search box does not result
// in focus going "nowhere"
indexButton.setFocusable(false);
buttonGroup.add(indexButton);
northPanel.add(indexButton);
}
impl.mainFrame.getContentPane().setLayout(new BorderLayout());
impl.mainFrame.getContentPane().add(northPanel, BorderLayout.NORTH);
impl.mainFrame.getContentPane().add(jsp, BorderLayout.CENTER);
impl.mainFrame.pack();
impl.mainFrame.setVisible(true);
print("=== visible");
}
}
EventQueue.invokeAndWait(new Show());
class AddMore implements Runnable {
public void run() {
impl.mainFrame.setFocusTraversalPolicyProvider(true);
class SearchBoxFocusListener implements FocusListener {
public void focusGained(FocusEvent focusEvent) {
print("=== search box got focus");
impl.searchBox.selectAll();
}
public void focusLost(FocusEvent focusEvent) {
Component oppComp = focusEvent.getOppositeComponent();
print(String.format("=== search box lost focus to %s",
oppComp == null ? "nowhere" : oppComp.getClass()));
}
}
impl.searchBox.addFocusListener(new SearchBoxFocusListener());
class SearchBoxActionListener implements ActionListener {
public void actionPerformed( ActionEvent actionEvent ){
if( actionEvent.getSource() != null ){
((DefaultTableModel)impl.resultsTable.getModel()).insertRow( 0, new Object[]{ "blip", "blap" });
// as soon as the table has at least one row it is set to "focusable"
// commenting this out means back-tabbing from search box results
// in focus going "nowhere"
impl.resultsTable.setFocusable( true );
}
}
}
impl.searchBox.addActionListener( new SearchBoxActionListener() );
ActionMap am = impl.searchBox.getActionMap();
print("=== ActionMap");
for (Object key : am.allKeys()) {
print(String.format(" === action key %s", key));
}
for (int i = 0; i < 3; i++) {
print(String.format("=== InputMap type %d", i));
InputMap im = impl.searchBox.getInputMap(i);
KeyStroke[] allKeys = im.allKeys();
if (allKeys != null) {
for (KeyStroke ks : allKeys) {
print(String.format(" === keystroke %s object %s", ks, im.get(ks)));
}
}
}
// various experiments with FocusTraversalPolicy... NB LayoutTraversalPolicy
// is what the framework uses here by default
class MainFrameFocusTraversalPolicy extends LayoutTraversalPolicy {
public Component getComponentAfter(Container arg0, Component arg1) {
Component comp = super.getComponentAfter(arg0, arg1);
print(String.format("=== comp after %s", comp == null ? "Null" : comp.getClass()));
return comp;
}
public Component getComponentBefore(Container arg0, Component arg1) {
Component comp = super.getComponentBefore(arg0, arg1);
print(String.format("=== comp before %s", comp == null ? "Null" : comp.getClass()));
return comp;
}
public Component getDefaultComponent(Container arg0) {
Component comp = super.getDefaultComponent(arg0);
print(String.format("=== default comp %s", comp == null ? "Null" : comp.getClass()));
return comp;
}
public Component getFirstComponent(Container arg0) {
Component comp = super.getFirstComponent(arg0);
print(String.format("=== first comp %s", comp == null ? "Null" : comp.getClass()));
return comp;
// return impl.searchBox;
}
public Component getLastComponent(Container arg0) {
Component comp = super.getLastComponent(arg0);
print(String.format("=== last comp %s", comp == null ? "Null" : comp.getClass()));
return comp;
}
protected boolean accept(Component comp) {
boolean accept = super.accept(comp);
print(String.format("=== accept %s? %s", comp == null ? "Null" : comp.getClass(), accept));
return accept;
}
}
impl.mainFrame.setFocusTraversalPolicy(new MainFrameFocusTraversalPolicy());
}
}
EventQueue.invokeAndWait(new AddMore());
}
}

Maybe you can use Container#setFocusTraversalKeys(...) method:
Set<AWTKeyStroke> backwardKeys = Collections.emptySet();
//alone JTextField(pointed out by #mKorbel): impl.mainFrame.setFocusTraversalKeys(
impl.searchBox.setFocusTraversalKeys(
KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, backwardKeys);

this still comes under the workaround heading for me... but it's a bit more useful than the workaround I gave under "later"
if( oppComp == null ){
final Component srcComp = (Component)focusEvent.getSource();
FocusTraversalPolicy ftp = impl.mainFrame.getFocusTraversalPolicy();
Component lastComp = ftp.getLastComponent( impl.mainFrame );
Component beforeComp = ftp.getComponentBefore( impl.mainFrame, srcComp );
if( lastComp == beforeComp ){
EventQueue.invokeLater( new Runnable(){
public void run() {
if( impl.mainFrame.isFocused()){
srcComp.requestFocus();
};
}});
}
}
Indeed, this is the situation faced by a single focusable component: on Shift-Tab the focus traversal policy then finds that the "before" comp is the same as the "last" comp. Under these circs component focus (as opposed to window focus) appears to vanish. The odd thing is that on Tab (traverse forwards), when the "after" comp is the same as the "first" comp, it doesn't. Is this a bug?
Anyway, having ascertained this you then have to check the focus of the window asynchronously... so that focus can be allowed to go to another window. Results in a slight flicker (boo!) on Shift-Tab.

InputVerifier don't display each component icon(lable)

I have a form that set a input verifier to it.
I want when a user type a correct value for a text field and want to go to other text field, a check icon should be display besides of text field.
But now in my code, when user type a correct value on first text field an go to other, Two icons displayed together!
public class UserDialog extends JDialog {
JButton cancelBtn, okBtn;
JTextField fNameTf, lNameTf;
JRadioButton maleRb, femaleRb;
ButtonGroup group;
JLabel fNameLbl, fNamePicLbl, lNameLbl, lNamePicLbl, genderLbl, tempBtn, temp3;
public UserDialog() {
add(createForm(), BorderLayout.CENTER);
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
setLocation(400, 100);
pack();
setVisible(true);
}
public JPanel createForm() {
JPanel panel = new JPanel();
ImageIcon image = new ImageIcon("Check.png");
okBtn = new JButton("Ok");
cancelBtn = new JButton("Cancel");
tempBtn = new JLabel();
fNameLbl = new JLabel("First Name");
fNamePicLbl = new JLabel(image);
fNamePicLbl.setVisible(false);
lNameLbl = new JLabel("Last Name");
lNamePicLbl = new JLabel(image);
lNamePicLbl.setVisible(false);
genderLbl = new JLabel("Gender");
maleRb = new JRadioButton("Male");
femaleRb = new JRadioButton("Female");
temp3 = new JLabel();
group = new ButtonGroup();
group.add(maleRb);
group.add(femaleRb);
fNameTf = new JTextField(10);
fNameTf.setName("FnTF");
fNameTf.setInputVerifier(new MyVerifier(new JComponent[]{maleRb, femaleRb, okBtn}));
lNameTf = new JTextField(10);
lNameTf.setName("LnTF");
lNameTf.setInputVerifier(new MyVerifier(new JComponent[]{maleRb, femaleRb, okBtn}));
panel.add(fNameLbl);
panel.add(fNameTf);
panel.add(fNamePicLbl);
panel.add(lNameLbl);
panel.add(lNameTf);
panel.add(lNamePicLbl);
panel.add(genderLbl);
JPanel radioPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
radioPanel.add(maleRb);
radioPanel.add(femaleRb);
panel.add(radioPanel);
panel.add(temp3);
panel.add(okBtn);
panel.add(cancelBtn);
panel.add(tempBtn);
panel.setLayout(new SpringLayout());
SpringUtilities.makeCompactGrid(panel, 4, 3, 50, 10, 80, 60);
return panel;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new UserDialog();
}
});
}
public class MyVerifier extends InputVerifier {
private JComponent[] component;
public MyVerifier(JComponent[] components) {
component = components;
}
#Override
public boolean verify(JComponent input) {
String name = input.getName();
if (name.equals("FnTF")) {
String text = ((JTextField) input).getText().trim();
if (text.matches(".*\\d.*") || text.length() == 0) {
//disable dependent components
for (JComponent r : component) {
r.setEnabled(false);
}
return false;
}
} else if (name.equals("LnTF")) {
String text = ((JTextField) input).getText();
if (text.matches(".*\\d.*") || text.length() == 0) {
//disable dependent components
for (JComponent r : component) {
r.setEnabled(false);
}
return false;
}
}
//enable dependent components
for (JComponent r : component) {
r.setEnabled(true);
}
fNamePicLbl.setVisible(true);
lNamePicLbl.setVisible(true);
return true;
}
}
}
}
Updated
public class MyVerifier extends InputVerifier {
private JComponent[] component;
public MyVerifier(JComponent[] components) {
component = components;
}
#Override
public boolean verify(JComponent input) {
String name = input.getName();
if (name.equals("FnTF")) {
String text = ((JTextField) input).getText().trim();
if (text.matches(".*\\d.*") || text.length() == 0) {
return false;
}
} else if (name.equals("LnTF")) {
String text = ((JTextField) input).getText();
if (text.matches(".*\\d.*") || text.length() == 0) {
return false;
}
}
return true;
}
#Override
public boolean shouldYieldFocus(JComponent input) {
boolean isValidDate = verify(input);
if (isValidDate) {
for (JComponent r : component) {
r.setEnabled(true);
}
} else {
for (JComponent r : component) {
r.setEnabled(false);
}
}
return isValidDate;
}

But now in my code, when user type a correct value on first text field
an go to other, Two icons displayed together!
Because you did so: (Read the comments)
public boolean verify(JComponent input) {
String name = input.getName();
if (name.equals("FnTF")) {
// your code
}
} else if (name.equals("LnTF")) {
// your code
}
//enable dependent components
for (JComponent r : component) {
r.setEnabled(true);
}
/* And Now we are here */
fNamePicLbl.setVisible(true);
lNamePicLbl.setVisible(true);
// making visible two of them at once as soon as verify is called
// on any one of the components, verifier is registered
return true;
}
setVisible should be controlled by the if-else condition too. For your better understanding you need to do something like this:
if (text.matches(".*\\d.*") || text.length() == 0) {
// your code
}
else
{
fNamePicLbl.setVisible(true);
}
Second Issue:
fNameTf.setInputVerifier(new MyVerifier(new JComponent[]{maleRb, femaleRb, okBtn}));
lNameTf = new JTextField(10);
lNameTf.setName("LnTF");
lNameTf.setInputVerifier(new MyVerifier(new JComponent[]{maleRb, femaleRb, okBtn}));
The MyVerfier has the common code to verify both input field. But you are creating two instances of it with same instances of components. Create one and set it as the input verifier of the two field.
You might want to create two different InputVerifier class for the two Text Field. FnTFVerifier and LnTFVerifier. Then put your verification code that relates them e.g., enabling the radio buttons and showing the label with check.png. most of the if-else checking will go-away.
But I think, this should not really be the preferable way. As the two text field has the common functionality, one InputVerifier class and instance is sufficient. you would have to just encapsulate the input text field and related cehckLabel to one component, then register the InputVerifier instances to this component.
Third issue: you are misusing verify function:
The verify function is meant to be used for nothing but verify data: whether data is valid or not with user required condition. It should do nothing more. InputVerifier has another function boolean ShouldYieldFocus(Jcomponent): Before focus is transfered to another Swing component that requests it, the input verifier's shouldYieldFocus method is called, which decides whither the component under verification should lose focus or not. Focus is transferred only if this method returns true. You should however write the required state change of components inside this function.
public boolean shouldYieldFocus(JComponent input) {
boolean isDataValid = verify(input);
if(isDataValid); //do stuff
return isDataValid; // if verify is true(valid) return true;
}

JOptionPane Passing Custom Buttons

I'm trying to get the value returned by custom buttons passed to JOptionPane. However the buttons I pass don't return a value at all. Only when the exit button is pressed is a value of -1 returned. I need this because I am changing the properties of the buttons enabled or disabled. I assume I need the buttons to return some information to the JOptionPane in some way. Any idea?
JButton button1= new JButton("Button 1");
JButton button2= new JButton("Button 2");
button1.setEnabled(false);
int value = JOptionPane.showOptionDialog(null, "Heres a test message", "Test", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, null, new Object[]{button1, button2}, button1);
JOptionPane.showMessageDialog(null, "You entered " + value);
Nb This is related to my previous question - JOptionPane Grey Out One Button
I tried setting the value of the buttons like you said but they never return OK or CANCEL.
Whenever checking the value of the buttons, they never return the value I set them too.
JButton button1= new JButton("Button1");
JButton button2= new JButton("Button2");
button1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane pane = getOptionPane((JComponent)e.getSource());
// set the value of the option pane
pane.setValue(JOptionPane.OK_OPTION);
}
});
button2.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane pane = getOptionPane((JComponent)e.getSource());
// set the value of the option pane
pane.setValue(JOptionPane.CANCEL_OPTION);
}
});
if (JOptionPane.showOptionDialog(null, "Pick a button", "Pick", JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE, null, new Object[]{button1, button2}, button1) == JOptionPane.OK_OPTION) {
JOptionPane.showMessageDialog(null, "Button1");
}
else{
JOptionPane.showMessageDialog(null, "Button2");
}
See above, always I get the button2 popup no matter what.

In the example I linked to you previous question, the buttons use the JOptionPane#setValue method to set the return value. This allows you to continue using the API as normal, while providing you with the customisation your after.
final JButton okay = new JButton("Ok");
okay.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane pane = getOptionPane((JComponent)e.getSource());
// set the value of the option pane
pane.setValue(JOptionPane.OK_OPTION);
}
});
Take a closer look at Disable ok button on JOptionPane.dialog until user gives an input
Updated
I've gone back through the code and correct the actionPerformed methods to enable it to return a valid value...
final JButton okay = new JButton("Ok");
okay.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane pane = getOptionPane((JComponent)e.getSource());
pane.setValue(okay);
}
});
okay.setEnabled(false);
final JButton cancel = new JButton("Cancel");
cancel.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane pane = getOptionPane((JComponent)e.getSource());
pane.setValue(cancel);
}
});
The value returned by the index of the value in the options array (last parameter)
So, for example...
int value = JOptionPane.showOptionDialog(
null,
field,
"Get",
JOptionPane.YES_NO_OPTION,
JOptionPane.QUESTION_MESSAGE,
null,
new Object[]{okay, cancel},
okay);
If the user clicks the okay button, the return value will be 0, or if they select the cancel button, it will be 1

If you need this complex behavior, consider creating your own JDialog and then displaying it in a modal fashion.
If you have to use a JOptionPane, you can do this by extracting its JDialog and recursively iterating through its components til you find the one you want to disable and disable it:
import java.awt.Component;
import java.awt.Container;
import javax.swing.*;
public class Foo2 {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
doRun();
}
});
}
public static void doRun() {
String[] options = {"Button 1", "Button 2", "Button 3"};
JOptionPane myOptionPane = new JOptionPane("Heres a test message",
JOptionPane.QUESTION_MESSAGE, JOptionPane.YES_NO_OPTION,
null, options, options[2]);
JDialog myDialog = myOptionPane.createDialog(null, "My Test");
myDialog.setModal(true);
inactivateOption(myDialog, options[1]);
myDialog.setVisible(true);
Object result = myOptionPane.getValue();
// Note: result might be null if the option is cancelled
System.out.println("result: " + result);
System.exit(0); // to stop Swing event thread
}
private static void inactivateOption(Container container, String text) {
Component[] comps = container.getComponents();
for (Component comp : comps) {
if (comp instanceof AbstractButton) {
AbstractButton btn = (AbstractButton) comp;
if (btn.getActionCommand().equals(text)) {
btn.setEnabled(false);
return;
}
} else if (comp instanceof Container) {
inactivateOption((Container) comp, text);
}
}
}
}
However for myself, I'd just create a JDialog.

You don't have to define your buttons explicitly.
int result = JOptionPane.showOptionDialog(this, "Are you sure you want to...?", "Title", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, null, new String[] { "Yes", "No" }, JOptionPane.NO_OPTION);
if (result == JOptionPane.YES_OPTION) {
...
}

Java Swing Combobox removeAllItems calling ItemStateChanged also?

My code is quite simple actually. I saw a simple and similar code was from this article.
At first, I have 1 combobox. I have a listener on it called itemStateChanged(). My purpose to add into this listener is that; "to execute some code when user click (select) an item from its dropbox".
Cmb_ItemCategory = new javax.swing.JComboBox();
Cmb_ItemCategory.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Loading..." }));
Cmb_ItemCategory.addItemListener(new java.awt.event.ItemListener() {
public void itemStateChanged(java.awt.event.ItemEvent evt) {
Cmb_ItemCategoryItemStateChanged(evt);
}
});
private void Cmb_ItemCategoryItemStateChanged(java.awt.event.ItemEvent evt) {
if(evt.getStateChange() == java.awt.event.ItemEvent.SELECTED){
System.err.println("Sombody click or change my model content");
}
}
Behind the code, I grab some data, and then calling a method of removeAllItems() .
And then I set a new Model (from new data) into it.
-- at another line of code ---
Cmb_ItemCategory.removeAllItems();
Cmb_ItemCategory.setModel(newModel);
I juz realized that my itemStateChanged() is called when i do the removeAllItem() method. called once.
So, How to make it only called once user Click (select) only AND not when removeAllItems() called?
it similar to this article. But it's not removingItems case. CMIIW.

Here check this code out, this works flawlessly, might be you doing something wrong where you calling removeAllItems() :
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ComboState
{
private void createAndDisplayGUI()
{
JFrame frame = new JFrame("Combo State Testing : ");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
final JComboBox cbox = new JComboBox();
cbox.addItem("One");
cbox.addItem("Two");
cbox.addItem("Three");
cbox.addItem("Four");
cbox.addItemListener(new ItemListener()
{
public void itemStateChanged(ItemEvent ie)
{
if (ie.getStateChange() == ItemEvent.SELECTED)
{
System.out.println("Item Selected is : " + ie.getItem());
}
/*else
{
System.out.println("I am called for other reasons.");
}*/
}
});
/*
* Click me to remove JComboBox's items.
*/
JButton removeButton = new JButton("REMOVE");
removeButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
cbox.removeAllItems();
}
});
frame.add(cbox, BorderLayout.CENTER);
frame.add(removeButton, BorderLayout.PAGE_END);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new ComboState().createAndDisplayGUI();
}
});
}
}

As nIcE cOw already illustrated in his example, it should certainly work when you use a DefaultComboBoxModel (which is the case in his sample code, although it happens behind the screens).
I could explain the behavior you encounter for the non-DefaultComboBoxModel case, although your code snippet suggests you use one. Looking at the source code for JComboBox#removeAllItems there is a different code path since the removeAllElements method is not part of the MutableComboBoxModel interface
public void removeAllItems() {
checkMutableComboBoxModel();
MutableComboBoxModel<E> model = (MutableComboBoxModel<E>)dataModel;
int size = model.getSize();
if ( model instanceof DefaultComboBoxModel ) {
((DefaultComboBoxModel)model).removeAllElements();
}
else {
for ( int i = 0; i < size; ++i ) {
E element = model.getElementAt( 0 );
model.removeElement( element );
}
}
selectedItemReminder = null;
if (isEditable()) {
editor.setItem(null);
}
}
So with a non-DefaultComboBoxModel you are going to remove the items one by one. This means that at a certain point in time, you will remove the selected element. A possible implementation of your model might change the selected element at that point. If you look for example at the implementation in DefaultComboBoxModel (although this code will not be triggered) you can clearly see it changes the selection.
public void removeElementAt(int index) {
if ( getElementAt( index ) == selectedObject ) {
if ( index == 0 ) {
setSelectedItem( getSize() == 1 ? null : getElementAt( index + 1 ) );
}
else {
setSelectedItem( getElementAt( index - 1 ) );
}
}
objects.removeElementAt(index);
fireIntervalRemoved(this, index, index);
}
Perhaps your model does something similar, which explains the event. Just for making this post complete, the code behind the DefaultComboBoxModel#removeAllElements where you can clearly see it sets the selection to null and does not select another object. Only weird thing in that code is that it does not fire a DESELECTED event first, although you know the selection has changed if you listen for the intervalRemoved event ... but that is not really relevant to your problem
public void removeAllElements() {
if ( objects.size() > 0 ) {
int firstIndex = 0;
int lastIndex = objects.size() - 1;
objects.removeAllElements();
selectedObject = null;
fireIntervalRemoved(this, firstIndex, lastIndex);
} else {
selectedObject = null;
}
}
So to conclude: I say the solution for your problem is located in your model, and not in the code you posted

One quick way to do is to have a bool set to true before you call removeAllItem() and back false after. Execute the code in your itemStateChanged() only if the bool variable is false.
Ideally you could override the removeAllItem() function.

not clear from whole discusion,
you have to remove all Listener(s) from JComboBox before removing all Items, after Items are removed you can add Listener(s) back,
still not sure if you want to add & remove Items dynamically, or you can set whatever value for another JComponent(s),
(against complicating simple things) did you see there remove,
.
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class ComboBoxTwo extends JFrame implements ActionListener, ItemListener {
private static final long serialVersionUID = 1L;
private JComboBox mainComboBox;
private JComboBox subComboBox;
private Hashtable<Object, Object> subItems = new Hashtable<Object, Object>();
public ComboBoxTwo() {
String[] items = {"Select Item", "Color", "Shape", "Fruit"};
mainComboBox = new JComboBox(items);
mainComboBox.addActionListener(this);
mainComboBox.addItemListener(this);
//prevent action events from being fired when the up/down arrow keys are used
//mainComboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
getContentPane().add(mainComboBox, BorderLayout.WEST);
subComboBox = new JComboBox();// Create sub combo box with multiple models
subComboBox.setPrototypeDisplayValue("XXXXXXXXXX"); // JDK1.4
subComboBox.addItemListener(this);
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);
// mainComboBox.setSelectedIndex(1);
}
#Override
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));
}
}
#Override
public void itemStateChanged(ItemEvent e) {
if (e.getStateChange() == ItemEvent.SELECTED) {
if (e.getSource() == mainComboBox) {
if (mainComboBox.getSelectedIndex() != 0) {
FirstDialog firstDialog = new FirstDialog(ComboBoxTwo.this,
mainComboBox.getSelectedItem().toString(), "Please wait, Searching for ..... ");
}
}
}
}
private class FirstDialog extends JDialog {
private static final long serialVersionUID = 1L;
FirstDialog(final Frame parent, String winTitle, String msgString) {
super(parent, winTitle);
setModalityType(Dialog.ModalityType.APPLICATION_MODAL);
JLabel myLabel = new JLabel(msgString);
JButton bNext = new JButton("Stop Processes");
add(myLabel, BorderLayout.CENTER);
add(bNext, BorderLayout.SOUTH);
bNext.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
setVisible(false);
}
});
javax.swing.Timer t = new javax.swing.Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
setVisible(false);
}
});
t.setRepeats(false);
t.start();
setLocationRelativeTo(parent);
setSize(new Dimension(400, 100));
setVisible(true);
}
}
public static void main(String[] args) {
JFrame frame = new ComboBoxTwo();
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}

The method removeAllItems does not call ItemStateChanged, but it call actionPerformed, you can check it by running this simple code:
public class Tuto {
public static void main(String[] args) {
//create the main frame
JFrame frame = new JFrame();
frame.setResizable(false);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setLayout(null);
frame.setLocation(new Point(10, 10));
frame.setPreferredSize(new Dimension(400, 300));
JComboBox<String> combo = new JComboBox();
combo.addItem("item 1");
combo.addItem("item 2");
combo.addItem("item 3");
combo.setBounds(50, 30, 300, 20);
combo.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
System.out.println(" action Performed ");
}
});
frame.add(combo);
JButton button = new JButton("Remove");
button.setBounds(50, 100, 100, 30);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
combo.removeAllItems();
}
});
frame.add(button);
frame.pack();
frame.setVisible(true);
}
}