How to set KeyEvent to KeyCode.BACK_SAPCE in JavaFx? - javafx

Question

I'm trying to set KeyEvent KeyCode to KeyCode.BACK_SAPCE if entered value is not a digit.
But I'm not able to achieve it
public void textFieldKeyReleased(KeyEvent e) {
if (!e.getCode().isDigitKey()) {
textField.setText(""); //manually set text
e.getCode() = KeyCode.BACK_SPACE; //required: variable found: value
}
}
I want to remove a character if it is not a digit.
I've assigned KeyCode.BACK_SAPCE to KeyEvent e but doesn't work.
Hot to use KeyCode (s)?
I manually set textField.setText(""); but want to make use of KeyCode

Answer 1

So you want to prevent any non-digit chars from being added to the TextField? There is actually a much better way of doing this: use a TextFormatter that prevents any changes that result in text that isn't desired. This works much better with copy&paste ect.. You can even implement logic for fixing a change, e.g. removing any non-digit chars from in case of copy&paste.
#Override
public void start(Stage primaryStage) throws Exception {
TextField digitsOnly = new TextField();
TextFormatter formatter = new TextFormatter((UnaryOperator<TextFormatter.Change>) change -> {
if (change.getControlNewText().matches("\\d*")) {
return change; // allow change without modifying it
} else {
return null; // don't allow change
}
});
digitsOnly.setTextFormatter(formatter);
Scene scene = new Scene(new VBox(digitsOnly));
primaryStage.setScene(scene);
primaryStage.show();
}