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Create modal dialog from scratch

I'm trying to create my own implementation for an overlay dialog that opens up when the user clicks a button. The code you see below works perfectly fine but is not that pretty. I'm searching for an implementation where I don't have to create a Thread for each dialog I create. Is there any way to acchieve this?
I've been browsing through various Java source files like JOptionPane and JDialog to figure out what they do in order to block the thread until the user closes the dialog, but I didn't manage to understand it. Additionally I tried various code snippets including the EventQueue like for example EventQueue.invokeLater or EventQueue.invokeAndWait.
// MainViewController.java
#FXML
private void handleServerButton(ActionEvent evt){
Thread t = new Thread(() -> {
if (serverD.showDialog(overlay) == Dialog.OK_OPTION){
System.out.println("OK");
} else {
System.out.println("ABORT");
}
});
t.start();
}
// Dialog.java
public int showDialog(Pane parent) {
latch = new CountDownLatch(1);
this.result.set(NONE);
approveButton.setDefaultButton(true);
abortButton.setCancelButton(true);
container.setVisible(true);
parent.setVisible(true);
try {
latch.await();
} catch (InterruptedException ex){ }
approveButton.setDefaultButton(false);
abortButton.setCancelButton(false);
container.setVisible(false);
parent.setVisible(false);
return result.get();
}
#Override
public void changed(ObservableValue<? extends Integer> observable, Integer oldValue, Integer newValue) {
if (newValue != NONE)
latch.countDown();
}
This is what it looks like (please note: the overlay dialog is not a window itself but rather a pane within the main window):
Final Result

Look at the Alert and Dialog documentation. Both provide functionality similar to what you want, and both can be customised if they don't quite match your use case.
Quick example:
Alert alert = new Alert(Alert.AlertType.ERROR);
alert.setTitle("title");
alert.setContent("content");
...
// More customisation available, read the docs
alert.show();. // Or showAndWait()

I solved the problem by deriving a Dialog class from Stage and implementing the logic there. The only thing that is left, is to extract the values from the controls of the view controller. But I already noticed that the dialog is passed as a Window through the ActionEvent - so that should be a minor issue.
public class Dialog extends Stage {
public static int OK_OPTION = 0;
public static int ABORT_OPTION = -1;
private int result;
public Dialog(Scene parent, String url) throws IOException{
super(StageStyle.TRANSPARENT);
Parent root = FXMLLoader.load(getClass().getResource(url));
Scene scene = new Scene(root);
if (System.getProperty("os.name").equals("Mac OS X")){
root.setStyle("-fx-background-radius: 0 0 3px 3px;");
}
scene.setFill(Color.TRANSPARENT);
setScene(scene);
initOwner(parent.getWindow());
double titlebar = parent.getWindow().getHeight() - parent.getHeight();
setX(parent.getWindow().getX());
setY(parent.getWindow().getY() + titlebar + 50);
}
public int showDialog(){
showAndWait();
return result;
}
}

JavaFX KeyEvents during Drag & Drop operation

I need to know whether a certain key is down while performing a drag & drop operation.
So I tried to use setOnKeyPressed / setOnKeyReleased of a Scene with a combination of HashMap, but I have a problem with this approach:
Imagine a scenario that one drags & drops a TableView item to somewhere while holding Control down. Now if I display a dialog at the end of the drop, while still holding Control down, the setOnKeyReleased is never called with this approach... as the Dialog is the one receiving the key released event.
How could I fix this?

Hope I understand your question here is a possible solution(work with any key):
public class Main extends Application {
SimpleBooleanProperty isKeyPress = new SimpleBooleanProperty(false);
#Override
public void start(Stage primaryStage) throws Exception{
Parent window = new VBox();
((VBox) window).getChildren().add(new Label("example of small window:"));
primaryStage.setTitle("example");
Scene scene=new Scene(window);
primaryStage.setScene(scene);
primaryStage.show();
scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
#Override
public void handle(KeyEvent event) {
System.out.println("Press");
isKeyPress.set(true);
Alert alert = new Alert(Alert.AlertType.INFORMATION);
alert.setTitle("Information Dialog");
alert.setHeaderText(null);
alert.setContentText("I have a great message for you!");
Scene alertScene = alert.getDialogPane().getScene();
alertScene.setOnKeyReleased(new EventHandler<KeyEvent>() {
#Override
public void handle(KeyEvent event) {
System.out.println("Released on dialog");
isKeyPress.set(false);
}
});
alert.showAndWait();
}
});
scene.setOnKeyReleased(new EventHandler<KeyEvent>() {
#Override
public void handle(KeyEvent event) {
System.out.println("Released");
isKeyPress.set(false);
}
});
}
public static void main(String[] args) {
launch(args);
}
}
output exmple:
Press
Released on dialog

From your comment the goal is to change the behavior of the drag and drop depending on whether or not Ctrl is down. When it is do a copy operation, otherwise do a move operation. You do not need to deal with KeyEvents to implement this behavior. Instead, you would determine whether to copy or move in the onDragDetected handler. The onDragDetected handler uses a MouseEvent which has methods for querying the status of modifier keys—such as isControlDown(). Using this, we can specify what transfer modes are allowed based on the modifier keys.
Node node = ...;
node.setOnDragDetected(event -> {
Dragboard board;
if (event.isControlDown()) {
board = node.startDragAndDrop(TransferMode.COPY);
} else {
board = node.startDragAndDrop(TransferMode.MOVE);
}
// add contents to Dragboard
});
Note it may be more cross-platform to use isShortcutDown().

Javafx listen for Control changes in a Panel

I want to add a change listener for every control in a panel. I want it to be robust, so whenever I change fxml file, I wouldn't have to alter the code that listens for changes in controls.
I have figured a way to add a listener for a specific type of control.
panel.getChildren()
.stream()
.filter(node -> node instanceof TextField).forEach(node ->
((TextField) node).textProperty()
.addListener((observable, oldValue, newValue) -> {
//execute some code
}));
However I would need to a add similar code to every type of control I intend to use in a panel for this to work.
panel.getChildren()
.stream()
.filter(node -> node instanceof TextField).forEach(node ->
((TextField) node).textProperty()
.addListener((observable, oldValue, newValue) -> {
//execute some code
}));
panel.getChildren()
.stream()
.filter(node -> node instanceof TextArea).forEach(node ->
((TextArea) node).textProperty()
.addListener((observable, oldValue, newValue) -> {
//execute some code
}));
//and so on...
panel.getChildren()
.stream()
.filter(node -> node instanceof ComboBox).forEach(node ->
((ComboBox<?>) node).valueProperty()
.addListener((observable, oldValue, newValue) -> {
//execute some code
}));
What I want to do is.
I've a document editor that has a panel with controls, so whenever user changes one of that controls preset value, panel with save and cancel buttons would be enabled. Also if user tried to exit a program, without canceling or saving a document, a warning would pop up asking him if he wants to discard changes and exit or cancel.
However I intend to do a lot of changes to document structure, so I will need to add and remove controls from panel constantly. So I need the best way to add this type of listener for every control in a panel in one go.

you should write (extend) your own controls and use them in your application. In them you can implement all specific tracking logic as #James_D mentioned. Such an extended TextField should look like this:
public class TrackableTextField extends javafx.scene.control.TextField {
private StringProperty originalText = new ReadOnlyStringWrapper(this, "originalText");
public final String getOriginalText() { return originalText.get(); }
public final void setOriginalText(String value) {
originalText.set(value);
setText(value);
}
public final StringProperty originalTextProperty() { return originalText; }
private final ReadOnlyBooleanWrapper dirty = new ReadOnlyBooleanWrapper(this, "dirty", false);
public final boolean isDirty() { return dirty.get(); }
public final ReadOnlyBooleanProperty dirtyProperty() { return dirty.getReadOnlyProperty(); }
public TrackableTextField() {
init();
}
public TrackableTextField(String text) {
init();
setOriginalText(text);
}
private void init() {
textProperty().addListener( e -> {
dirty.set(!Objects.equals(getOriginalText(), getText()));
} );
}
public void rollback() {
setText(getOriginalText());
}
public void commit() {
setOriginalText(getText());
}
}
and a usage example may be like
public class Test extends Application {
private TrackableTextField tf_name = new TrackableTextField();
private TrackableTextField tf_sname = new TrackableTextField();
private Button save = new Button("Save");
private Button discard = new Button("Discard");
#Override
public void start(Stage primaryStage) {
GridPane root = new GridPane();
root.add(new Label("Name: "), 0, 0);
root.add(tf_name, 1, 0);
root.add(new Label("Surname: "), 0, 1);
root.add(tf_sname, 1, 1);
root.add(save, 0, 2);
root.add(discard, 1, 2);
Scene scene = new Scene(root, 300, 250);
primaryStage.setScene(scene);
primaryStage.show();
initialize();
}
private void initialize() {
save.setDisable(true);
discard.setDisable(true);
save.disableProperty().bind(tf_name.dirtyProperty().or(tf_sname.dirtyProperty()).not());
discard.disableProperty().bind(tf_name.dirtyProperty().or(tf_sname.dirtyProperty()).not());
tf_name.setOriginalText("guleryuz");
tf_sname.setOriginalText("guleryuz");
save.setOnAction( e -> {
tf_name.commit();
tf_sname.commit();
} );
discard.setOnAction( e -> {
tf_name.rollback();
tf_sname.rollback();
} );
}
public static void main(String[] args) {
launch(args);
}
}

javafx: How to bind the Enter key to a button and fire off an event when it is clicked?

Basically, I have a okayButton that sits in a stage and when it is clicked , it performs a list of tasks. Now I want to bind the Enter key to this button such that when it is clicked OR the ENTER key is pressed, it performs a list of tasks.
okayButton.setOnAction(e -> {
.........
}
});
How can I do that ? I have read the following post already. However, it did not help me to achieve what I want to do.

First, set a hanlder on your button :
okayButton.setOnAction(e -> {
......
});
If the button has the focus, pressing Enter will automatically call this handler. Otherwise, you can do this in your start method :
#Override
public void start(Stage primaryStage) {
// ...
Node root = ...;
setGlobalEventHandler(root);
Scene scene = new Scene(root, 0, 0);
primaryStage.setScene(scene);
primaryStage.show();
}
private void setGlobalEventHandler(Node root) {
root.addEventHandler(KeyEvent.KEY_PRESSED, ev -> {
if (ev.getCode() == KeyCode.ENTER) {
okayButton.fire();
ev.consume();
}
});
}
If you have only one button of this kind, you can use the following method instead.
okayButton.setDefaultButton(true);

You can dynamically change the default button property of the currently focused button by using binding
btn.defaultButtonProperty().bind(btn.focusedProperty());

I've had the same problem like mynameisJEFF. (I'm using Windows and as I read here: http://mail.openjdk.java.net/pipermail/openjfx-dev/2016-June/019234.html it is the SPACE_BAR and not ENTER, which fires a Button in JavaFX) I didn't want to add a listener to every Button, so I registered a Listener to the root node and asked the scene, which node is focused to fire that one. Here is my code (it is xtend, but I think it very easy to understand):
override start(Stage primaryStage) throws Exception {
val root = FXTable.createRoot
val mainScene = new Scene(root)
root.addEventHandler(KeyEvent.KEY_RELEASED, [event|
if(event.code === KeyCode.ENTER){
switch(focusedNode : mainScene.focusOwnerProperty.get){
Button:{
focusedNode.fire
event.consume
}
default:{
}
}
}
])
primaryStage.scene = mainScene
primaryStage.show
primaryStage.maximized = true
}

There is a much more simple a standard way to do that using setOnKeyPressed
okayButton.setOnKeyPressed(event -> {
if (event.getCode().equals(KeyCode.ENTER)) {
okayButton.fire();
}
}
);
And don't forget that you should define SetOnAction too, other way it's work but it's doing nothing.
okayButton.setOnAction(event -> {
// Do what ever you want to your button do. Like :
System.Out.Print("Okay Button Fired (Clicked or Pressed");
}
);

This should work:
okayButton.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
if(evt.getKeyCode() == KeyEvent.VK_ENTER){
System.out.print("Your function call or code can go here");
}
}
});

How to make an event for left & right click at the same time?

I know how to deal with left or right click separately, dragging, double-clicking, but I can't figure out how to do something if the user clicks left and right mouse buttons at the same time without interfering/causing other events to fire.
#Override
public void handle(Event event) {
if (event.getSource() instanceof Tile) {
Tile tile = (Tile) event.getSource();
if (event.getEventType().equals(MouseEvent.MOUSE_CLICKED)) {
if (((MouseEvent) event).getButton().equals(MouseButton.SECONDARY))
tile.toggleFlag();
else if (((MouseEvent) event).getClickCount() == 2)
mineField.massClick(tile);
}
if (event.getEventType().equals(MouseEvent.DRAG_DETECTED))
if (!((MouseEvent) event).getButton().equals(MouseButton.SECONDARY))
tile.startFullDrag();
if (event.getEventType().equals(MouseDragEvent.MOUSE_DRAG_ENTERED))
tile.arm();
if (event.getEventType().equals(MouseDragEvent.MOUSE_DRAG_EXITED))
tile.disarm();
if (event.getEventType().equals(MouseDragEvent.MOUSE_DRAG_RELEASED))
mineField.clickedTile(tile);
if (event.getEventType().equals(ActionEvent.ANY))
mineField.clickedTile(tile);
}
}
Also, if you see a problem with my code feel free to point it out, always looking to improve.

The simple version is this:
public class Main extends Application {
#Override
public void start(Stage primaryStage) {
try {
StackPane root = new StackPane();
root.addEventFilter(MouseEvent.MOUSE_PRESSED, e -> {
if( e.isPrimaryButtonDown() && e.isSecondaryButtonDown()) {
System.out.println( "Both down");
} else if( e.isPrimaryButtonDown()) {
System.out.println( "Primary down");
} else if( e.isSecondaryButtonDown()) {
System.out.println( "Secondary down");
}
});
Scene scene = new Scene(root,400,400);
primaryStage.setScene(scene);
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
If you prefer your own event happening when both buttons are pressed, you could try it this way:
public class Main extends Application {
BooleanProperty primaryMouseButtonDown = new SimpleBooleanProperty();
BooleanProperty secondaryMouseButtonDown = new SimpleBooleanProperty();
#Override
public void start(Stage primaryStage) {
try {
StackPane root = new StackPane();
root.addEventFilter(MouseEvent.MOUSE_PRESSED, e -> {
primaryMouseButtonDown.setValue( e.isPrimaryButtonDown());
secondaryMouseButtonDown.setValue( e.isSecondaryButtonDown());
});
root.addEventFilter(MouseEvent.MOUSE_RELEASED, e -> {
primaryMouseButtonDown.setValue( e.isPrimaryButtonDown());
secondaryMouseButtonDown.setValue( e.isSecondaryButtonDown());
});
BooleanBinding binding = Bindings.and(primaryMouseButtonDown, secondaryMouseButtonDown);
binding.addListener( new ChangeListener<Boolean>() {
#Override
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
System.out.println( "Mouse Button Event: " + oldValue + " -> " + newValue);
}
});
Scene scene = new Scene(root,400,400);
primaryStage.setScene(scene);
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
There are 2 boolean properties, one for the primary button down and one for the secondary button down. Both properties are connected via a BooleanBinding. Whenever one of the properties change via the mouse event, an event is fired. So what's left to do is for you to check if newValue is true and fire your handling code.

Do something more along the lines of, watch for mouse presses, and set a boolean to true when a mousePressed event is called for left/right mouse button. Then later in the event look to see if both booleans for left and right are true. If they are, act on it as if both were pressed at the same time.
boolean mouse_1, mouse_2 = false;
public void mousePressed(MouseEvent e){
//The numbers are just made up I don't remember the actual codes for the buttons but it's simple enough to figure out.
if(e.getButton()==1){
mouse_1 = true;
}
if(e.getButton()==2){
mouse_2 = true;
}
if(mouse_1&&mouse_2){
//Your code here
}
}
public void mouseReleased(MouseEvent e){
if(e.getButton() == 1){
mouse_1 = false;
}
if(e.getButton() == 2){
mouse_2 = false;
}
}
Assume this is some sort of handler class... But this is the short for how to implement it.

I'm probably late to answer this question, but I'm going to post my solution in order to demonstrate how to handle single-button clicks separately from both buttons being clicked at the same time
Existing answers already explained how to detect both mouse buttons being clicked at the same time. But mouse events (click, press, and release) are still triggered by individual buttons and previous posters didn't address how to avoid these events from interfering with each other.
My solution is to track both buttons being pressed on mouse press and detect mouse clicks of any kind on mouse release:
//flag to track both buttons being pressed
private boolean wereBothButtonsPressed = false;
private void onMousePressed(MouseEvent e) {
//single button press sets flag to false
wereBothButtonsPressed = e.isPrimaryButtonDown() && e.isSecondaryButtonDown();
}
private void onMouseReleased(MouseEvent e) {
if (e.isPrimaryButtonDown() || e.isSecondaryButtonDown()) {
//do nothing if user is still holding the button
return;
}
if (wereBothButtonsPressed) {
System.out.prinln("Both buttons");
} else if (e.getButton() == MouseButton.PRIMARY) {
System.out.prinln("Only primary");
} else if (e.getButton() == MouseButton.SECONDARY) {
System.out.prinln("Only secondary");
}
}
You can set these handlers for specific events on specific controls or fit them into your method:
private boolean wereBothButtonsPressed = false;
#Override
public void handle(Event event) {
...
if (event.getEventType().equals(MouseEvent.MOUSE_PRESSED)) {
MouseEvent me = (MouseEvent) event;
wereBothButtonsPressed = me.isPrimaryButtonDown() && me.isSecondaryButtonDown();
} else if (event.getEventType().equals(MouseEvent.MOUSE_RELEASED)) {
MouseEvent me = (MouseEvent) event;
if (!me.isPrimaryButtonDown() && !me.isSecondaryButtonDown()) {
if(wereBothButtonsPressed) {
mineField.massClick(tile);
} else if(me.getButton() == MouseButton.PRIMARY) {
mineField.clickedTile(tile);
} else if(me.getButton() == MouseButton.SECONDARY) {
tile.toggleFlag();
}
}
...