JavaFX alert dialog ignores the focused button - javafx

Question

Why does the JavaFX alert dialog fires the Platform.exit(); when I press the Enter key even though the focused button in the alert dialog is Cancel?
soaStage.setOnCloseRequest(new EventHandler<WindowEvent>()
{
#Override
public void handle(WindowEvent event)
{
Alert alert = new Alert(Alert.AlertType.CONFIRMATION);
alert.setTitle("Confirm");
alert.setHeaderText("Are you sure you want to exit?");
alert.setContentText("Press OK to exit, or Cancel to stay.");
alert.initOwner(soaStage);
Optional<ButtonType> result = alert.showAndWait();
if (result.get() == ButtonType.OK)
{
Platform.exit();
}
else
{
event.consume();
}
}
});

Answer 1

Default buttons are fired on enter
The OK button is fired when you press enter because it is a default button.
A default Button is the button that receives a keyboard VK_ENTER press, if no other node in the scene consumes it.
In the default JavaFX 8 Modena stylesheet, the default button is indicated by being a blue color rather than than the gray color of a standard button.
How to remove default button behaviour
You can remove this behavior from the alert dialog by not making the OK button a default button:
Button okButton = (Button) alert.getDialogPane().lookupButton(ButtonType.OK);
okButton.setDefaultButton(false);
I advise you not to do this, but instead to always leave a default button in alert dialogs.
On OS X, standard alert type dialogs have a default button which is triggered by enter even if another button is focused, so the standard behavior in JavaFX is consistent with that. Note: to allow this behavior in default dialogs in OS X it is necessary to enable full keyboard access.
If you do change the OK button to not be a default button, I suggest you change its text to something else (e.g. Exit for your case):
okButton.setText("Exit");
How to make enter fire focused buttons
Now, if you also want to make it so that the focused button fires when you press enter, then you can do this:
EventHandler<KeyEvent> fireOnEnter = event -> {
if (KeyCode.ENTER.equals(event.getCode())
&& event.getTarget() instanceof Button) {
((Button) event.getTarget()).fire();
}
};
DialogPane dialogPane = alert.getDialogPane();
dialogPane.getButtonTypes().stream()
.map(dialogPane::lookupButton)
.forEach(button ->
button.addEventHandler(
KeyEvent.KEY_PRESSED,
fireOnEnter
)
);
Note: In any case, focused buttons are always fired when you press space.

Answer 2

We can add ENTER binding to the whole buttons by creating a class that need to be instantiated once when the application starts.
public class EnableButtonEnterKey extends ButtonBehavior<Button> {
public EnableButtonEnterKey() {
super(new Button());
BUTTON_BINDINGS.add(new KeyBinding(ENTER, KEY_PRESSED, "Press"));
BUTTON_BINDINGS.add(new KeyBinding(ENTER, KEY_RELEASED, "Release"));
}
}
When starting the application, call
new EnableButtonEnterKey();
That's it.