A combo box will fire an event if a DIFFERENT value is selected. I want to be also be able to listen to the SAME item being selected (that is, valueProperty has no change). There seems to be no way to do this.
I tried extending the ComboBox and finding a way to listen for the little popup menu being closed, but I don't even have access to that! What can I do?
Here is what I was trying:
class ResponsiveComboBox<E> extends ComboBox<E> {
public ResponsiveComboBox() {
super();
assert getContextMenu() != null; //Asssertion failed!
this.getContextMenu().setOnHiding((WindowEvent event) -> {
fireEvent(new ActionEvent());
});
}
}
comboBox.showingProperty().addListener((obs, wasShowing, isShowing) -> {
if (! isShowing) {
System.out.println("Combo box popup hidden");
}
});
This event handler might be triggered before the value is changed.
Related
like the title implies i've got a problem with my application. The application is supposed to run in fullscreen mode (no intention for switching back to window mode), so i designed a footer-bar holding some images (with a Label, in a VBox) so the user could navigate or exit the program.
So after starting the application all Buttons work just fine with touch. Even the Exit-button in my footer-bar responded correctly by opening my custom Dialog. But here starts my Problem. The Dialog is shown by showAndWait()-Method call, but does not respond to Touch-Events. In contrary mouse-events are still processed (i still can use a mouse to click the Buttons in my Dialog and the Dialog is responding correctly).
I hope someone got an idea what i'm doing wrong.
MyDialog.java:
public static boolean showExitDialog(Window owner, ResourceBundle resources) {
LOGGER.info("Showing exit dialog...");
final Dialog<ButtonType> dialog = new Dialog<ButtonType>();
dialog.getDialogPane().getStylesheets().add(MyDialog.getInstace().getCssPath());
dialog.setContentText(resources.getString("label.exitdialog.text"));
dialog.setHeaderText(resources.getString("label.exitdialog.header"));
dialog.initOwner(owner);
dialog.initStyle(StageStyle.TRANSPARENT);
dialog.initModality(Modality.APPLICATION_MODAL);
dialog.getDialogPane().getButtonTypes().add(new ButtonType(resources.getString("btn.Exitdialog.exit"), ButtonData.OK_DONE););
dialog.getDialogPane().getButtonTypes().add(new ButtonType(resources.getString("btn.Exitdialog.cancel"), ButtonData.FINISH));
Optional<ButtonType> result = dialog.showAndWait();
LOGGER.debug("Result: {}", result.get());
if(result.isPresent() && result.get().getButtonData() == ButtonData.OK_DONE) {
LOGGER.info("Closing exit dialog returning true...");
return true;
} else {
LOGGER.info("Closing exit dialog returning false...");
return false;
}
}
In MainApp.java:
private EventHandler<WindowEvent> confirmCloseEventHandler = event -> {
// close event handling logic.
// consume the event if you wish to cancel the close operation.
if(MyDialog.showExitDialog(primaryStage, rb)) {
event.consume();
System.exit(0);
}
};
...
primaryStage.setOnCloseRequest(confirmCloseEventHandler);
In FooterBar.java:
#FXML
private void exitProgramPressedTouch(TouchEvent event) {
event.consume();
controller.getWindow().fireEvent(new WindowEvent(controller.getWindow(), WindowEvent.WINDOW_CLOSE_REQUEST));
}
*Edit* Oh totally forgot: No Exception or anything else is thrown.
I don't know the reason for the described behavior - maybe a bug. However, you could try to listen for ActionEvent instead of TouchEvent. It handles both touch and mouse events:
#FXML
private void exitProgramPressedTouch(ActionEvent event) {
event.consume();
controller.getWindow().fireEvent(new WindowEvent(controller.getWindow(), WindowEvent.WINDOW_CLOSE_REQUEST));
}
Maybe you need also to change the attribute which binds the event listener (from onTouch to onAction) in your FXML file.
Finally, I think, you could avoid System.exit(0); if you consume the close event only when the cancel button has been clicked:
if(!MyDialog.showExitDialog(primaryStage)) {
event.consume();
}
I'm making a simple menu to delete items on a tree. However, after deleting the items, the tree does not receive a selection event, therefore, the code in the listener does not execute (the listener, in the full code, updates a part of the UI).
I have simplified the code below, leaving out details. It is something like this:
tree.addListener (SWT.Selection, new Listener(){
public void handleEvent(Event e) {
(....)
}
}
I also tried this:
tree.addSelectionListener (new SelectionListener(){
public void widgetDefaultSelected(SelectionEvent e){
(...)
}
public void widgetSelected(SelectionEvent e) {
(...)
}
}
On my menu action (delete selection), there is this:
TreeItem [] selected = tree.getSelection();
tree.deselectAll();
if (selected.length > 0)
{
for( TreeItem i : selected){
i.dispose();
}
}
After deleting the selection, my selection listener does not fire. It does fire if I deselect all itens using the ctrl+click combination.
What should I do? Is there a way to fire the SWT.Selection event to the tree after deleting the itens or should I isolate the code inside the listener to call it again? Shouldn't the tree.deselectAll() fire a Selection event?
You can send a selection event programmatically with:
Event event = new Event();
event.widget = tree;
event.display = tree.getDisplay();
event.type = SWT.Selection;
tree.notifyListeners(SWT.Selection, event);
Have same situation and found
this link mentioning, that programmatically setSelection may never send this event due to design, so always send it (if needed) programmatically after setting too
I have a JButton titled "select"
In the class that creates that JButton and other classes, I want to use an if condition with ActionPerformed method.
Something like(pseudo-code)
if(_selectListener.actionPerformed(ActionEvent)) { //i.e., if select Button is clicked,
//do something
}
Is this possible?
I want to call this method because I have to handle a situation in which a player should be able to choose something by clicking "select" button, or another "scroll" button, and I want to control it using something similar to a bunch of if statements like the one above.
If it is possible, what is the syntax for it? What is the argument ActionEvent?
Thank you!
The easiest and cleanest way is to add a dedicated, specific action listener to each button. That way, when the actionPerformed() method is called, you're sure that the associated button has been clicked, and don't need to test which button has been clicked:
selectButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// handle click on select button
}
});
scrollButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// handle click on scroll button
}
});
Another way is to use a common ActionListener, and use the getSource() method of ActionEvent to know which component triggered the event. Compare the result with each potential button to determine which is the one that has been clicked:
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == selectButton) {
// handle click on select button
}
else if (e.getSource() == scrollButton) {
// handle click on scroll button
}
}
What is the argument ActionEvent?
The answer is in the documentation. Read it.
no you cant call, if needs boolean expression/value, but this method returns void.
I have a JComboBox component in the panel and ItemListener attached to it. But it gets fired after every up/down keypress (when scrolling though opened popup list). I want to change the selected value after the user accepts selection by pressing for example Enter key.
This is not a case when using mouse. When I move mouse over the combobox's list the highlight follows mouse pointer, but selected item is not changed until I press the mouse button. I would like to have the same behavior for keyboard, i.e. moving highlight via up/down arrow does not change selected item, but pressing Enter does.
I believe you should be able to do:
comboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
after you have created your comboBox instance to get this functionality
In Java 8 they have fixed this behaviour, but only trigger if u set one UI property
UIManager.getLookAndFeelDefaults().put("ComboBox.noActionOnKeyNavigation", true);
the JComboBox.isTableCellEditor method works for arrow movement through the list, but does not work for type-ahead supported by the KeySelectionManager. i.e. you still get ActionEvents for every non-navigation key the user types, as the JComboBox interprets those characters for searching though the model to move to (or move close to) the user's intended selection.
this solution has a drawback in that it changes the action command for mouse clicks, which was a OK compromise for me because the the flow of the GUI forces the user to change the focus away from the combo box
I ended up making a special KeyListener, that relys on changing the combo box's default action command from comboBoxChanged to comboBoxMovement. Here's the line of code I need after my combo box is all initialized:
setExplicitSelectionManager(myComboBox);
... and here is the method and its contained class that do all the work:
private void setExplicitSelectionManager(JComboBox comboBox) {
class ExplicitSelectionManager implements KeyListener, FocusListener {
private JComboBox src;
private KeyListener superKeyListener;
ExplicitSelectionManager(JComboBox src) {
this.src = src;
// we like what the default key listener does, but not the action command
// it uses for ActionEvents it fires for plain text type-ahead characters
this.superKeyListener = src.getKeyListeners()[0]; // we only have one
src.removeKeyListener(superKeyListener); // will be replace right away, below
}
#Override
public void keyTyped(KeyEvent e) {
// basic combo box has no code in keyTyped
}
#Override
public void keyPressed(KeyEvent e) {
// in the default JComboBox implementation, the KeySelectionManager is
// called from keyPressed. I'm fine with the implementation of
// the default, but I don't want it firing ActionEvents that will cause
// model updates
src.setActionCommand("comboBoxMovement");
this.superKeyListener.keyPressed(e);
src.setActionCommand("comboBoxChanged");
if (e.getKeyCode() == 10) {
src.setSelectedIndex(src.getSelectedIndex());
}
}
#Override
public void keyReleased(KeyEvent e) {
// basic combo box has no code in keyReleased
}
#Override
public void focusGained(FocusEvent e) {
}
#Override
// this will also give us the event we want, if the user decides to Tab out of
// the combo box, instead of hitting Enter
public void focusLost(FocusEvent e) {
src.setSelectedIndex(src.getSelectedIndex());
}
}
ExplicitSelectionManager newSelectionManager = new ExplicitSelectionManager(comboBox);
comboBox.addKeyListener(newSelectionManager);
comboBox.addFocusListener(newSelectionManager);
}
... and here's the action performed method
private void comboBoxActionPerformed(java.awt.event.ActionEvent evt) {
JComboBox source = (JComboBox) evt.getSource();
// "comboBoxChanged" is the default,
// so any normal JComboBox can also use this action listener
if (evt.getActionCommand().equals("comboBoxChanged")) {
updateModel(source.getName(), (String) source.getSelectedItem());
}
}
Its the expected behavior with the ItemListener. whenever the displayed value changes the event is fired. For your requirement use an ActionListener.
Is there a way to distinguish between a JComboBox's index being changed programatically using setSelectedBoundValue and by clicking on the JComboBox?
This is ugly and truly a hack, but works!
The ActionEvent contains a field modifiers which in this case is the mouse button id. So using that may help you distinguish between setSelectedIndex or setSelectedValue and mouse clicks (by the way setSelectedBoundValue is not a method on JComboBox):
box.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getModifiers() != 0) {
// ~ mouse button pressed ;)
}
}
});
setSelectedBoundValue
Never heard of that method?
Is there a way to distinguish between a JComboBox's index being changed programatically
Not really. You can remove the listener:
comboBox.removeActionListener(...);
comboBox.setSelectedItem(...);
comboBox.addActionListener(...);
You can set your own class variable.
manualSelection = true;
comboBox.setSelectedIndex(...);
manualSelection = false;