[BAEL-3946] Javafx adding ActionListener to button (#11701)

* Add implementation for article.

* Add new line at the end of FXML layout file.

* Remove default prefWidth from button, convert eventHandler to lambda.

* Fix FXML file formatting.

javafx/src/main/java/com/baeldung/button/eventhandler/ButtonEventHandlerController.java

@@ -0,0 +1,64 @@
+package com.baeldung.button.eventhandler;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.fxml.FXML;
+import javafx.scene.control.Button;
+import javafx.scene.control.Label;
+import javafx.scene.effect.DropShadow;
+import javafx.scene.effect.Effect;
+import javafx.scene.input.MouseButton;
+import javafx.scene.input.MouseEvent;
+import javafx.scene.text.Font;
+
+public class ButtonEventHandlerController {
+
+    private static final Logger logger = LoggerFactory.getLogger(ButtonEventHandlerController.class);
+
+    @FXML
+    private Button button;
+
+    @FXML
+    private Label label;
+
+    @FXML
+    private void initialize() {
+        button.setText("Click me");
+
+        handleClickEvent();
+        handleHoverEffect();
+        reuseRightClickEventHandler();
+    }
+
+    private void handleClickEvent() {
+        button.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent event) {
+                logger.info("OnAction {}", event);
+            }
+        });
+
+        button.setOnAction(event -> logger.info("OnAction {}", event));
+        button.setOnAction(event -> logger.info("OnAction2 {}", event));
+    }
+
+    private void handleHoverEffect() {
+        Effect shadow = new DropShadow();
+        button.setOnMouseEntered(e -> button.setEffect(shadow));
+        button.setOnMouseExited(e -> button.setEffect(null));
+    }
+
+    private void reuseRightClickEventHandler() {
+        EventHandler<MouseEvent> rightClickHandler = event -> {
+            if (MouseButton.SECONDARY.equals(event.getButton())) {
+                button.setFont(new Font(button.getFont()
+                    .getSize() + 1));
+            }
+        };
+        button.setOnMousePressed(rightClickHandler);
+        label.setOnMousePressed(rightClickHandler);
+    }
+}

javafx/src/main/java/com/baeldung/button/eventhandler/Main.java

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+package com.baeldung.button.eventhandler;
+
+import javafx.application.Application;
+import javafx.fxml.FXMLLoader;
+import javafx.scene.Scene;
+import javafx.scene.layout.Pane;
+import javafx.stage.Stage;
+
+public class Main extends Application {
+
+    public static void main(String[] args) {
+        launch(args);
+    }
+
+    @Override
+    public void start(Stage primaryStage) throws Exception {
+        FXMLLoader loader = new FXMLLoader(getClass().getResource("/button_event-handler.fxml"));
+        Pane page = loader.load();
+
+        primaryStage.setTitle("Button event handler");
+        primaryStage.setScene(new Scene(page));
+        primaryStage.show();
+    }
+}

javafx/src/main/resources/button_event-handler.fxml

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+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.*?>
+<BorderPane xmlns:fx="http://javafx.com/fxml"
+    xmlns="http://javafx.com/javafx"
+    fx:controller="com.baeldung.button.eventhandler.ButtonEventHandlerController"
+    prefHeight="200.0" prefWidth="300.0">
+    <center>
+        <Button fx:id="button" HBox.hgrow="ALWAYS"/>
+    </center>
+    
+    <bottom>
+        <Label fx:id="label" text="Test label"/>
+    </bottom>
+</BorderPane>