implemented InputHandler.java, modified Main.java

src/main/java/de/hdm_stuttgart/battlearena/Main/Main.java

 package de.hdm_stuttgart.battlearena.Main;
 
+import de.hdm_stuttgart.battlearena.Model.Inputs.InputHandler;
 import javafx.application.Application;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Parent;
@@ -15,6 +16,8 @@ public class Main extends Application {
 
     private static final Logger log = LogManager.getLogger(Main.class);
 
+    InputHandler inputHandler = InputHandler.getInstance();
+
     public static void main(String[] args) {
         launch(args);
     }
@@ -25,6 +28,9 @@ public class Main extends Application {
 
         Scene scene = new Scene(root);
 
+        scene.setOnKeyPressed(inputHandler::handleKeyPress);
+        scene.setOnKeyReleased(inputHandler::handleKeyRelease);
+
         stage.setTitle("BattleArena");
         stage.setScene(scene);
 

src/main/java/de/hdm_stuttgart/battlearena/Model/Inputs/InputHandler.java

 package de.hdm_stuttgart.battlearena.Model.Inputs;
 
+import javafx.scene.input.KeyCode;
+import javafx.scene.input.KeyEvent;
+
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.LogManager;
 
@@ -7,4 +10,66 @@ public class InputHandler {
 
     private static final Logger log = LogManager.getLogger(InputHandler.class);
 
-}
+    private static final InputHandler inputHandler = new InputHandler();
+
+    private InputHandler(){}
+
+    public static InputHandler getInstance() {
+        return inputHandler;
+    }
+
+    private boolean moveUp, moveDown, moveLeft, moveRight;
+
+    public void handleKeyPress(KeyEvent event) {
+        KeyCode code = event.getCode();
+
+        switch (code) {
+            case W:
+                moveUp = true;
+                break;
+            case S:
+                moveDown = true;
+                break;
+            case A:
+                moveLeft = true;
+                break;
+            case D:
+                moveRight = true;
+                break;
+        }
+    }
+
+    public void handleKeyRelease(KeyEvent event) {
+        KeyCode code = event.getCode();
+
+        switch (code) {
+            case W:
+                moveUp = false;
+                break;
+            case S:
+                moveDown = false;
+            case A:
+                moveLeft = false;
+                break;
+            case D:
+                moveRight = false;
+                break;
+        }
+    }
+
+    public boolean isMoveUp() {
+        return moveUp;
+    }
+
+    public boolean isMoveDown() {
+        return moveDown;
+    }
+
+    public boolean isMoveLeft() {
+        return moveLeft;
+    }
+
+    public boolean isMoveRight() {
+        return moveRight;
+    }
+}
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