How do I create KeyEvents in Java FXML? - javafx

Question

I created this small project to test key events. But when I press keys, it isn't behaving as I want. Actually I need key events for my Calculator project. I created a Calculator project and aside from mouse clicks, I want to add a feature where numbers or operators can be typed from a keyboard. Can anyone check this and help make it more functional?
public class FXMLDocumentController implements Initializable{
#FXML
private Label label;
#FXML
private Button backSpace;
#FXML
private Button spaceBar;
#FXML
private Button enter;
#FXML
void typedBS(KeyEvent event) {
if (event.getCode() == KeyCode.BACK_SPACE) {
label.setText(event.getText() + " typed.");
}
}
#FXML
void typedE(KeyEvent event) {
if (event.getCode()==KeyCode.ENTER) {
label.setText(event.getText() + " typed");
}
}
#FXML
void typedSB(KeyEvent event) {
if (event.getCode()==KeyCode.SPACE) {
label.setText(event.getText()+" typed");
}
}
#FXML
void PressBackSpace(KeyEvent event) {
if (event.getCode() == KeyCode.BACK_SPACE) {
label.setText("You pressed Back Space key!");
}
}
#FXML
void clickBackSpace(ActionEvent event) {
label.setText("You clicked Back Space key!");
}
#FXML
void clickEnter(ActionEvent event) {
label.setText("You clicked Enter key!");
}
#FXML
void clickSpaceBar(ActionEvent event) {
label.setText("You clicked SpaceBar key!");
}
#FXML
void pressEnter(KeyEvent event) {
if (event.getCode() == KeyCode.ENTER) {
label.setText("You pressed Enter key!");
}
}
#FXML
void pressSpaceBar(KeyEvent event) {
if (event.getCode() == KeyCode.SPACE) {
label.setText("You pressed SpaceBar key!");
}
}
#Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
}
}

Answer 1

If you look at this FXML file you can see my root node(The AnchorPane) has an onKeyPressed and onKeyReleased.
<AnchorPane id="AnchorPane" onKeyPressed="#handleOnKeyPressed" onKeyReleased="#handleOnKeyReleased" prefHeight="650.0" prefWidth="855.0" xmlns="http://javafx.com/javafx/8.0.111" xmlns:fx="http://javafx.com/fxml/1" fx:controller="atmfx.FXMLDocumentController">
<children>
<BorderPane layoutX="263.0" layoutY="94.0" prefHeight="200.0" prefWidth="200.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<left>
<AnchorPane fx:id="apLeftDisplay" prefHeight="200.0" prefWidth="200.0" BorderPane.alignment="CENTER">
<children>
In The Controller my method that handles these two KeyEvents are
#FXML
private void handleOnKeyReleased(KeyEvent event)
{
System.out.println();
Button tempButton = buttons.get(event.getText());
System.out.println("Released key text: " + event.getText());
System.out.println("Released key code: " + event.getCode());
if (tempButton != null) {
tempButton.disarm();
tempButton.setStyle("");
}
else if (event.getCode().equals(KeyCode.ENTER)) {
tempButton = buttons.get("enter");
tempButton.disarm();
tempButton.setStyle("");
}
else if (event.getCode().equals(KeyCode.BACK_SPACE)) {
tempButton = buttons.get("backspace");
tempButton.disarm();
tempButton.setStyle("");
}
else if (event.getCode().equals(KeyCode.SPACE)) {
tempButton = buttons.get("space");
tempButton.disarm();
tempButton.setStyle("");
}
}
#FXML
private void handleOnKeyPressed(KeyEvent event)
{
Button tempButton = buttons.get(event.getText());
System.out.println("Pressed key text: " + event.getText());
System.out.println("Pressed key code: " + event.getCode());
if (tempButton != null) {
tempButton.arm();
tempButton.setStyle("-fx-background-color: blue");
}
else if (event.getCode().equals(KeyCode.ENTER)) {
tempButton = buttons.get("enter");
tempButton.arm();
tempButton.setStyle("-fx-background-color: blue");
}
else if (event.getCode().equals(KeyCode.BACK_SPACE)) {
tempButton = buttons.get("backspace");
tempButton.arm();
tempButton.setStyle("-fx-background-color: blue");
}
else if (event.getCode().equals(KeyCode.SPACE)) {
tempButton = buttons.get("space");
tempButton.arm();
tempButton.setStyle("-fx-background-color: blue");
}
}
In this code I added all of my buttons to a HasMap. That way in my keyevent handlers I was able to retrieve the button depending on the keyboard key I pressed.
Map<String, Button> buttons = new HashMap<>();
TheButtonsParentNode.getChildren().stream().filter((tempNode)
-> (tempNode instanceof Button)).map((
tempNode) -> (Button) tempNode).forEachOrdered((tempButton) -> {
buttons.put(tempButton.getText().toLowerCase(), tempButton);//adding button text and the button to hashmap
});

Answer 2

Define the event and the handling in the same thing.
try something like this:
if u are using a borderpane as an example
borderPane.setOnKeyPressed(this::handleKeyPress);
private void handleKeyPress(KeyEvent event) {
if (event.getCode() == KeyCode.BACK_SPACE) {
label.setText(event.getText() + " typed.");
}
if (event.getCode() == KeyCode.SPACE) {
label.setText("You pressed SpaceBar key!");
}
//TODO
}
Hope it helps