How to add a javafx shortcut key combinations for buttons - javafx

Question

My UI has a adding button and I want to assign a keyboard shortcut combination for that. I have failed to use the setAcceleartor for this purpose.
What is the easiest way to set up keyboard shortcuts in javafx applications?
button declaration in the UI:
<Button fx:id="addButton" alignment="CENTER" minWidth="-Infinity" mnemonicParsing="false" onAction="#addAction" prefHeight="31.0" prefWidth="130.0" text="Add" HBox.hgrow="ALWAYS" />
Controller button binding:
#FXML
private Button addButton;
The method that wants to setOnAction for the shortcut for the button:
public void addAction(ActionEvent event) throws SQLException, ClassNotFoundException {
if (validateInput()) {
String productName = productField.getText();
double unitPrice = Double.parseDouble(priceField.getText());
int quantity = Integer.parseInt(quantityField.getText());
double total = unitPrice * quantity;
ITEMLIST.add(new Item(productName, unitPrice, quantity, total));
calculation();
resetAdd();
productTableView.getSelectionModel().clearSelection();
ObservableList<Product> productsData = ProductDAO.searchProducts();
populateProducts(productsData);
searchField.setText("");
}
}
initialize() method:
#FXML
private void initialize() throws SQLException, ClassNotFoundException, IOException {
setSaveAccelerator(addButton);
}
The code I tried with setAccelerator:
private void setSaveAccelerator(final Button button) {
Scene scene = button.getScene();
if (scene == null) {
throw new IllegalArgumentException("setSaveAccelerator must be called when a button is attached to a scene");
}
scene.getAccelerators().put(
new KeyCodeCombination(KeyCode.S, KeyCombination.SHORTCUT_DOWN),
new Runnable() {
#FXML public void run() {
button.fire();
}
}
);
}

Answer 1

In your setSaveAccelerator method, instead of directly calling addAction(ActionEvent event), just instruct the button to fire its event to its listeners such as: button.fire(). For example:
private void setSaveAccelerator(Button button) {
if(button==null) {
System.out.println("Button is null! "); // check that the button was injected properly through your fxml
}
Scene scene = button.getScene();
if (scene == null) {
throw new IllegalArgumentException("setSaveAccelerator must be called when a button is attached to a scene");
}
scene.getAccelerators().put(
new KeyCodeCombination(KeyCode.S, KeyCombination.SHORTCUT_DOWN),
new Runnable() {
#FXML public void run() {
button.fire();
}
}
);
}
EDIT
To also avoid the IllegalArgumentException you must attach the accelerator after the button is attached to a scene. I managed to achieve this by creating a public method in the controller to attach the accelerator after the scene has been set. Then, in the class where the scene is loaded the controller's method can be called which sets up this functionality. See the example below:
In the controller class (in my case MainController):
public void setup() {
setSaveAccelerator(button);
}
In your main class when loading the fxml file:
FXMLLoader loader = new FXMLLoader(MainController.class.getResource("mainFXML.fxml"));
AnchorPane page = (AnchorPane) loader.load();
MainController controller = loader.getController();
Scene scene = new Scene(page);
controller.setup(); // calls the setup method attaching the accelerators
FULL EXAMPLE
Main class:
public class Main extends Application{
public static Stage primaryStage;
#Override
public void start(Stage primaryStage) throws Exception {
Main.primaryStage=primaryStage;
FXMLLoader loader = new FXMLLoader(MainController.class.getResource("mainFXML.fxml"));
AnchorPane page = (AnchorPane) loader.load();
MainController controller = loader.getController();
Scene scene = new Scene(page);
primaryStage.setTitle("Shortcut example");
primaryStage.setScene(scene);
controller.setup();
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Maincontroller:
public class MainController {
#FXML
private ResourceBundle resources;
#FXML
private URL location;
#FXML
private Button button;
#FXML
private AnchorPane rootPane;
#FXML
private TextArea textarea;
#FXML
void action(ActionEvent event) {
textarea.setText("Action fired!!");
}
#FXML
void initialize() {
assert button != null : "fx:id=\"button\" was not injected: check your FXML file 'MainFXML.fxml'.";
assert rootPane != null : "fx:id=\"rootPane\" was not injected: check your FXML file 'MainFXML.fxml'.";
assert textarea != null : "fx:id=\"textarea\" was not injected: check your FXML file 'MainFXML.fxml'.";
}
public void setup() {
setSaveAccelerator(button);
}
private void setSaveAccelerator(Button button) {
if(button==null) {
System.out.println("Button null!!");
}
Scene scene = button.getScene();
if (scene == null) {
throw new IllegalArgumentException("setSaveAccelerator must be called when a button is attached to a scene");
}
scene.getAccelerators().put(
new KeyCodeCombination(KeyCode.S, KeyCombination.SHORTCUT_DOWN),
new Runnable() {
#FXML public void run() {
button.fire();
}
}
);
}
}
MainFXML.fxml
<AnchorPane fx:id="rootPane" prefHeight="408.0" prefWidth="330.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.MainController">
<children>
<Button fx:id="button" layoutX="139.0" layoutY="350.0" mnemonicParsing="false" onAction="#action" text="Button" />
<TextArea fx:id="textarea" layoutX="73.0" layoutY="38.0" prefHeight="200.0" prefWidth="200.0" />
</children>
</AnchorPane>