Develop Reference

How to open another JFrame with selected RadioButton according to data in JTable?

I am trying to send data to JFrame named UpdateCar using a button. Data should say which radio button should be selected.
btnUpdateCar.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
UpdateCar updatePage = new UpdateCar();
updatePage.setVisible(true);
int selectedRow = table.getSelectedRow();
updatePage.buttonGroup.setSelected(getSelectedButton(model,selectedRow).getModel(),true);
// when I use above line it doesn't work. But instead if I use the thing it will return, it works for that value.
}
});
I wrote a method like this for this purpose:
public JRadioButton getSelectedButton(DefaultTableModel model, int selectedRow) {
String selectedButton = (String) model.getValueAt(selectedRow,3);
UpdateCar updatePage = new UpdateCar();
if(selectedButton.equals("Automatic")) {
return updatePage.rdbtnAutomatic;
}else {
return updatePage.rdbtnManuel;
}
}

Well, apparently both method and btnUpdateCar's action perfrom method should have same reference for target JFrame. I was using two different calls for that JFrame. Now I have global variable for that Jframe and problem solved.

JPopupMenu on JTable -> Get the cell the menu was created on

I have a situation where I have a popup menu created when a JTable is right clicked on. Standard way of creating the popup menu:
aJTable.setComponentPopupMenu(rightClickMenu);
Now afterwards in the action that gets registered, I am unable to find out which cell was right clicked on to get that popup menu to appear.
rightClickMenuItem.addActionListener(new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
// Work out what cell was right clicked to generate the menu
}
});
Any ideas on how you do this?

Astonishing fact: with a componentPopupMenu installed, a mouseListener never sees the mouseEvent that is the popupTrigger (reason is that showing the componentPopup is handled globally by a AWTEventListener installed by BasicLookAndFeel, and that listener consumes the event).
The only place which sees the mousePosition of that trigger is the getPopupLocation(MouseEvent), so the only reliable way to get hold of it (for doing location dependent config/actions) is #Mad's suggestion to override that method and store the value somewhere for later use.
The snippet below uses a clientProperty as storage location:
final JTable table = new JTable(new AncientSwingTeam()) {
#Override
public Point getPopupLocation(MouseEvent event) {
setPopupTriggerLocation(event);
return super.getPopupLocation(event);
}
protected void setPopupTriggerLocation(MouseEvent event) {
putClientProperty("popupTriggerLocation",
event != null ? event.getPoint() : null);
}
};
JPopupMenu popup = new JPopupMenu();
Action action = new AbstractAction("show trigger location") {
#Override
public void actionPerformed(ActionEvent e) {
JPopupMenu parent = (JPopupMenu) SwingUtilities.getAncestorOfClass(
JPopupMenu.class, (Component) e.getSource());
JTable invoker = (JTable) parent.getInvoker();
Point p = (Point) invoker.getClientProperty("popupTriggerLocation");
String output = p != null ? "row/col: "
+ invoker.rowAtPoint(p) + "/" + invoker.columnAtPoint(p) : null;
System.out.println(output);
}
};
popup.add(action);
popup.add("dummy2");
table.setComponentPopupMenu(popup);

#MadProgrammer's suggestion of getPopupLocation looked promising, but I couldn't work out how to get the information across between the table and the actionEvent...
I got around this by making sure that the row was selected when you rightclicked on it -> since the popup menu prevents the selection of the row, you can add in a mouse listener that makes sure the row gets selected no matter what click (left or right) is pressed.
aTable.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
int r = aTable.rowAtPoint(e.getPoint());
if (r >= 0 && r < clt.getRowCount()) {
aTable.setRowSelectionInterval(r, r);
} else {
aTable.clearSelection();
}
}
});
This means that in the rightClickMenuItem's action listener, you can grab the table's selected cell / row
rightClickMenuItem.addActionListener(new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
aTable.get details about the selected one....
}
});
Too easy! Thanks everyone for the help.

JTable has methods
int row = rowAtPoint(p);
int col = columnAtPoint(p);
So pass the MouseEvent's point and use the values
Add a MouseListener and store the last right click point somewhere.

Java Swing: Focus issue

I'm making a level editor for my game. I have a property panel where I can modify the selected object its properties. I also have a Save button to write the level xml.
A field-edit is submitted(*) when the editor component lost the focus or Enter is pressed. This is working great, but the only problem is that when I have this sequence of actions:
Edit a field
Press the save button
Because, what happens is this:
I edit the field
I press the save button
The level is saved
The field lost the focus
The edit is submitted
As you can see, this is the wrong order. Of course I want the field to lose its focus, which causes the submit and then save the level.
Is there a trick, hack or workaround to make the field first lose the focus and then perform the action listener of the save button?
Thanks in advance.
(* submit = the edit to the field is also made in the object property)
EDIT: For the field I'm using a FocusAdapter with focusLost:
FocusAdapter focusAdapter = new FocusAdapter()
{
#Override
public void focusLost(FocusEvent e)
{
compProperties.setProperty(i, getColor());
record(); // For undo-redo mechanism
}
};
And for the button a simple ActionListener with actionPerformed`.
btnSave.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
// Save the level
}
});

Hmm ... can't reproduce: in the snippet below the lost is always notified before the actionPerfomed, independent on whether I click the button or use the mnemonic:
final JTextField field = new JTextField("some text to change");
FocusAdapter focus = new FocusAdapter() {
#Override
public void focusLost(FocusEvent e) {
LOG.info("lost: " + field.getText());
}
};
field.addFocusListener(focus);
Action save = new AbstractAction("save") {
#Override
public void actionPerformed(ActionEvent e) {
LOG.info("save: " + field.getText());
}
};
save.putValue(Action.MNEMONIC_KEY, KeyEvent.VK_S);
JButton button = new JButton(save);
JComponent box = Box.createHorizontalBox();
box.add(field);
box.add(button);
On the other hand, focus is a tricky property to rely on, the ordering might be system-dependent (mine is win vista). Check how the snippet behave on yours.
If you see the same sequence as I do, the problem is somewhere else
if you get the save before the lost, try to wrap the the save action into invokeLater (which puts it at the end of the EventQueue, so it's executed after all pending events)
Action save = new AbstractAction("save") {
#Override
public void actionPerformed(ActionEvent e) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
LOG.info("save: " + field.getText());
}
});
}
};

Normally, wrapping your save code into an SwingUtilities.invokeLater() should do the trick. As you already mentioned, this doesn't work? Try this:
private boolean editFocus = false;
FocusAdapter focusAdapter = new FocusAdapter()
{
#Override
public void focusGained(FocusEvent e){
editFocus = true;
}
#Override
public void focusLost(FocusEvent e){
compProperties.setProperty(i, getColor());
record(); // For undo-redo mechanism
editFocus = false;
if (saveRequested){
save();
}
}
};
and for your button:
private boolean saveRequested = false;
btnSave.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
if (editFocus){
saveRequested = true;
return;
} else {
save();
}
}
});
and then your save method:
private void save(){
// do your saving work
saveRequested = false;
}
This only works when your focusLost gets called after your button's action. If suddenly the order is correct, this code will get save() called twice.
But again, wrapping your save() code in your original approach should work, because the save code will execute after processing all events. That is after processing your button click and your focusLost events. Because your focusLost code executes immediately (it's not wrapped in an invokeLater()), the focusLost code should be executed always before your save code. This does not mean that the event order will be correct! But the code associated to the events will executed in the right order.

How to avoid firing actionlistener event of JComboBox when an item is get added into it dynamically in java?

I need your suggestions and guidence on following task.
I have a frame which has two JComboBoxes supposed they are named combo1 and combo2, a JTable and other components.
At initial stage when frame is visible with above component. The combo1 combobox is filled with some values but no value is selected at initial stage, the combo2 combobox is disabled and the table is empty.
I have added an actionListener on combo1 as well as combo2. There are two types of values in combo1 suppose those values are type1 and type2.
Condition 1:
When we selects value type1 from Combo1 the actionListener method is called of combo1 which invokes a method which combo2 remains disabled and adds some rows to table related to selected value type1 from combo1.
Condition 2:
when we selects value type2 from combo1 the actionListener method is called of combo1 which invokes a method who makes combo2 filled with some values related to type2 and gets enabled but no value is selected from combo2 and table also should remain empty until we selects any value from combo2.
table at every addition of value to combo2 the action listener method of combo2 is gets fired. In actionListener method of combo2 which gets combo2 selected value but here there is no selected value of combo2 which leads to a NullPointerException.
So what should I do that the action listner method of combo2 will not be get executed after addition of an values to combo2.

You could remove the action listener before you add the new elements, and add it back once you're done . Swing is single threaded so there is no need to worry about other threads needing to fire the listener.
Your listener could probably also check if something is selected and take appropriate action if not. Better than getting a NPE.

What i do instead of adding and removing action listeners i have a boolean variable in my action listeners that is true if it has to allow the action through or false if it has to block it.
I then set it to false when i do some changes that will fire off the action listener
JComboBox test = new JComboBox();
test.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
if(testActionListenerActive)
{
//runn your stuff here
}
}
});
//then when i want to update something where i want to ignore all action evetns:
testActionListenerActive = false;
//do stuff here like add
SwingUtilities.invokeLater(() -> testActionListenerActive = false);
//and now it is back enabled again
//The reason behind the invoke later is so that if any event was popped onto the awt queue
//it will not be processed and only events that where inserted after the enable
//event will get processed.

try this:
indicatorComboBox = new JComboBox() {
/**
* Do not fire if set by program.
*/
protected void fireActionEvent() {
// if the mouse made the selection -> the comboBox has focus
if(this.hasFocus())
super.fireActionEvent();
}
};

although its late, a better alternative would be to disabled the combobox to be modified prior to being modified. by doing so, you prevent firing events of the modified combobox, when for example, you use methods likes removeAllItems() or addItem()
String orderByOptions[] = {"smallest","highest","longest"};
JComboBox<String> jcomboBox_orderByOption1 = new JComboBox<String(orderByOptions);
JComboBox<String> jcomboBox_orderByOption2 = new JComboBox<String(orderByOptions);
JComboBox<String> jcomboBox_orderByOption3 = new JComboBox<String(orderByOptions);
jcomboBox_orderByOption1.addItemListener(new ItemListener()
{
public void itemStateChanged(ItemEvent itemEvent)
{
int eventID = itemEvent.getStateChange();
if (eventID == ItemEvent.SELECTED)
{
Object selectedItem = jcomboBox_orderByOption1.getSelectedItem();
jcomboBox_orderByOption2.setEnabled(false);
jcomboBox_orderByOption2.removeAllItems();
for (String item: string_orderByOptions)
{
if (!item.equals(selectedItem))
{
jcomboBox_orderByOption2.addItem(item);
}
}
jcomboBox_orderByOption2.setEnabled(true);
}
}
});
jcomboBox_orderByOption2.addItemListener(new ItemListener()
{
public void itemStateChanged(ItemEvent itemEvent)
{
int eventID = itemEvent.getStateChange();
if (eventID == ItemEvent.SELECTED)
{
Object selectedItem1 = jcomboBox_orderByOption1.getSelectedItem();
Object selectedItem2 = jcomboBox_orderByOption2.getSelectedItem();
jcomboBox_orderByOption3.setEnabled(false);
jcomboBox_orderByOption3.removeAllItems();
for (String item: string_orderByOptions)
{
if (!item.equals(selectedItem1) && !item.equals(selectedItem2))
{
jcomboBox_orderByOption3.addItem(item);
}
}
jcomboBox_orderByOption3.setEnabled(true);
}
}
});

The cleaner way is to use lambda expressions like this:
do(comboBox, () -> comboBox.setSelectedItem("Item Name"));
For the above to work, you need the following method defined somewhere:
public static void do(final JComboBox<String> component, final Runnable f) {
final ActionListener[] actionListeners = component.getActionListeners();
for (final ActionListener listener : actionListeners)
component.removeActionListener(listener);
try {
f.run();
} finally {
for (final ActionListener listener : actionListeners)
component.addActionListener(listener);
}
}

This works:
/** Implements a Combo Box with special setters to set selected item or
* index without firing action listener. */
public class MyComboBox extends JComboBox {
/** Constructs a ComboBox for the given array of items. */
public MyComboBox(String[] items) {
super(items);
}
/** Flag indicating that item was set by program. */
private boolean isSetByProgram;
/** Do not fire if set by program. */
protected void fireActionEvent() {
if (isSetByProgram)
return;
super.fireActionEvent();
}
/** Sets selected Object item without firing Action Event. */
public void setSelection(Object item) {
isSetByProgram = true;
setSelectedItem(item);
isSetByProgram = false;
}
/** Sets selected index without firing Action Event. */
public void setSelection(int index) {
isSetByProgram = true;
setSelectedIndex(index);
isSetByProgram = false;
}
}
Note: You can't just override setSelectedItem(...) or setSelectedIndex(...) because these are also used internally when items are actually selected by user keyboard or mouse actions, when you do not want to inhibit firing the listeners.

To determine whether or not to perform various methods in actionListener interface methods (actionPerformed() blocks of code) use setActionCommand() on source components (combo1 or combo2).
For your example, before adding elements to combo2, call setActionCommand("doNothing") and guard your comboBoxActionPerformed() method.
Here's a compilable example that uses this principle to have one combo set another combo's selected index while also displaying a String in a JTextField. By using setActionCommand() and guarding the comboActionPerformed() block of code, the JTextField will cycle through each word in the wordBank. If the comboActionPerformed() method was not guarded or if the actionCommand String was not changed, 2 actionEvents will trigger and the textField will skip words.
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
/** #author PianoKiddo */
public class CoolCombos extends JPanel {
JComboBox<String> candyCombo;
JComboBox<String> flavorCombo;
JTextField field;
String[] wordBank;
int i = 0;
CoolCombos() {
super();
initComponents();
addComponentsToPanel();
}
private void initComponents() {
initCombos();
initTextField();
}
private void initCombos() {
ActionListener comboListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
comboActionPerformed(e);
}
};
String[] candyList = {"Sourpatch", "Skittles"};
String[] flavorList = {"Watermelon", "Original"};
candyCombo = new JComboBox<>(candyList);
candyCombo.addActionListener(comboListener);
flavorCombo = new JComboBox<>(flavorList);
flavorCombo.addActionListener(comboListener);
}
private void initTextField() {
wordBank = new String[]{"Which", "Do", "You", "Like", "Better?"};
field = new JTextField("xxxxx");
field.setEditable(false);
field.setText(wordBank[i]);
}
private void addComponentsToPanel() {
this.setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
this.add(candyCombo);
this.add(flavorCombo);
this.add(field);
}
public void comboActionPerformed(ActionEvent e) {
String command = e.getActionCommand();
if (!command.equals("doNothing")) {
JComboBox combo = (JComboBox) e.getSource();
if (combo.equals(candyCombo)) {
setOtherComboIndex(candyCombo, flavorCombo); }
else {
setOtherComboIndex(flavorCombo, candyCombo); }
displayText(); //replace here for toDo() code
}
}
private void setOtherComboIndex(JComboBox combo, JComboBox otherCombo) {
String command = otherCombo.getActionCommand();
otherCombo.setActionCommand("doNothing"); //comment this line to skip words.
otherCombo.setSelectedIndex(combo.getSelectedIndex());
otherCombo.setActionCommand(command);
}
private void displayText() {
i++;
String word;
if (i > 4) { i = 0; }
word = wordBank[i];
field.setText(word);
this.repaint();
}
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("CoolCombos");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
JComponent newContentPane = new CoolCombos();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setMinimumSize(frame.getSize());
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}

I kind of went the stupid simple route with this issue for my program since I am new to programming.
I changed the action listeners to have a counter if statement:
if(stopActionlistenersFromFiringOnLoad != 0){//action performed ;}
Then at the end of the java program creation, I added 1 to the counter:
topActionlistenersFromFiringOnLoad += 1;

To avoid that addItem method fire events is better to use an DefaultComboBoxModel in the JComboBox to add data. Also, if you invoke a model.addElement(), an event is fired, so, you can add all the elements to the model and later use JComboBox.setModel(model). In this way, if you add elements to the model, events are not fired because you have not link the JComboBox with the model. Then, I show you an example.
private void rellenarArrendatarioComboBox(ArrayList<Arrendatario> arrendatarios) {
DefaultComboBoxModel model = new DefaultComboBoxModel();
model.addElement(new Arrendatario(" -- Seleccione un arrendatario --"));
for (Arrendatario arrendatario : arrendatarios) {
model.addElement(arrendatario);
}
ArrendatarioComboBox.setModel(model);
}
First, we create the model, add all elements to the model (events are not fired because you have not link the JComboBox with the model), we link the model with the JComboBox using ArrendatarioComboBox.setModel(model). After linking, events are fired.

How to keep the popup menu of a JComboBox open on populating it?

I have a JComboBox on my Panel. One of the popup menu items is 'More' and when I click that I fetch more menu items and add them to the existing list. After this, I wish to keep the popup menu open so that the user realizes that more items have been fetched however, the popup closes. The event handler code I am using is as follows
public void actionPerformed(ActionEvent e)
{
if (e.getSource() == myCombo) {
JComboBox selectedBox = (JComboBox) e.getSource();
String item = (String) selectedBox.getSelectedItem();
if (item.toLowerCase().equals("more")) {
fetchItems(selectedBox);
}
selectedBox.showPopup();
selectedBox.setPopupVisible(true);
}
}
private void fetchItems(JComboBox box)
{
box.removeAllItems();
/* code to fetch items and store them in the Set<String> items */
for (String s : items) {
box.addItem(s);
}
}
I do not understand why the showPopup() and setPopupVisible() methods are not functioning as expected.

add the following line in the fetchItems method
SwingUtilities.invokeLater(new Runnable(){
public void run()
{
box.showPopup();
}
}
If u call selectedBox.showPopup(); inside invokelater also it will work.

overwrite the JCombobox setPopupVisible metod
public void setPopupVisible(boolean v) {
if(v)
super.setPopupVisible(v);
}

jComboBox1 = new javax.swing.JComboBox(){
#Override
public void setPopupVisible(boolean v) {
super.setPopupVisible(true); //To change body of generated methods, choose Tools | Templates.
}
};

I found some simple solution to always keep popup open. It may be useful with some custom JComboBox'es, like the one I have in my project, but is a little hacky.
public class MyComboBox extends JComboBox
{
boolean keep_open_flag = false; //when that flag ==true, popup will stay open
public MyComboBox(){
keep_open_flag = true; //set that flag where you need
setRenderer(new MyComboBoxRenderer()); //our spesial render
}
class MyComboBoxRenderer extends BasicComboBoxRenderer {
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean cellHasFocus) {
if (index == -1){ //if popup hidden
if (keep_open_flag) showPopup(); //show it again
}
}
}
}