Update README.md

Optimized Ticking and Rendering

README.md

@@ -2,7 +2,7 @@
 My advanced Hello World program is a version of the old game Snake.
 
 ## Features
-- normal playing experience of Snake
+- normal playing experience of Snake but hardware-accelerated
 - 5 different fruits that can be eaten to enlarge the Snake
 - theoretically Start- and Endscreen, currently mostly unused
 - theoretically visual display whether a result is good or bad, commented out for now as it does not appear to work as expected
@@ -23,4 +23,4 @@ My advanced Hello World program is a version of the old game Snake.
   - as the name suggests, defines the visual appearance before and after games 
   
 ## JAR of the final version
-If you follow <a href="https://github.com/delvh/Snake/releases">**this link**</a> and click on release "Snake - almost finished", you can download the runnable JAR of how the completed project should look like. Unfortunately due to poor Version-Control-skills, the original code got lost and had to be rewritten, however it should resemble the executed code closely
+If you follow <a href="https://github.com/delvh/Snake/releases">**this link**</a> and click on release "Snake - Rattlesnake version", you can download the runnable JAR of how the project currently looks like.

src/main/dev/lh/Food.java

@@ -0,0 +1,54 @@
+package dev.lh;
+
+import java.awt.Color;
+import java.awt.Graphics2D;
+import java.awt.Rectangle;
+
+/**
+ * Represents a food item.
+ * <p>
+ * Project: <strong>Snake</strong><br>
+ * File: <strong>Food.java</strong><br>
+ * Created: <strong>01.07.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Snake 1.2
+ */
+public final class Food implements Updateable {
+
+	private final Color color;
+	private final int lengthBonus;
+	private final Rectangle bounds;
+
+	/**
+	 * Constructs a food item.
+	 * 
+	 * @param color       the color of the food item
+	 * @param lengthBonus the length added to the snake when the food item is eaten
+	 * @param bounds      the bounds of the food item
+	 * @since Snake 1.2
+	 */
+	public Food(Color color, int lengthBonus, Rectangle bounds) {
+		this.color = color;
+		this.lengthBonus = lengthBonus;
+		this.bounds = bounds;
+	}
+
+	@Override
+	public void render(Graphics2D g) {
+		g.setColor(color);
+		g.fill(bounds);
+	}
+
+	/**
+	 * @return the length added to the snake when the food item is eaten
+	 * @since Snake 1.2
+	 */
+	public int getLengthBonus() { return lengthBonus; }
+
+	/**
+	 * @return the bounds of the food item
+	 * @since Snake 1.2
+	 */
+	public Rectangle getBounds() { return bounds; }
+}

src/main/dev/lh/FoodFactory.java

@@ -1,229 +1,69 @@
 package dev.lh;
 
-import java.awt.*;
+import static java.awt.Color.*;
 
-import dev.lh.ui.GameWindow;
+import java.awt.Color;
+import java.awt.Rectangle;
+import java.util.Random;
 
 /**
+ * Generates food items with predefined properties at random positions and calculates the next
+ * spawning time.
+ * <p>
  * Project: <strong>Snake</strong><br>
  * File: <strong>FoodFactory.java</strong><br>
  * Created: <strong>11 Mar 2020</strong><br>
  *
  * @author Leon Hofmeister
+ * @author Kai S. K. Engelbart
  * @since Snake 1.0
  */
-public class FoodFactory {
+public final class FoodFactory {
+
+	private int width, height;
+	private long nextSpawnTime;
+	private Random random = new Random();
+
+	private static final Color[] FOOD_COLORS = {
+		WHITE, YELLOW, ORANGE, RED, BLUE
+	};
+	private static final int[] FOOD_LENGTH_BONUSES = {
+		40, 15, 6, 2, 1
+	};
 
 	/**
-	 * This enum contains all possible variations of foods. The higher the ordinal
-	 * of an element, the less it is worth.<br>
-	 * <br>
-	 * Project: <strong>Snake</strong><br>
-	 * File: <strong>FoodFactory.java</strong><br>
-	 * Created: <strong>11 Mar 2020</strong><br>
-	 *
-	 * @author Leon Hofmeister
-	 * @since Snake 1.0
+	 * Initializes a food factory.
+	 * 
+	 * @param width  the width of the viewport
+	 * @param height the height of the viewport
+	 * @since Snake 1.2
 	 */
-	public static enum Food {
-		/**
-		 * Use if white food is wanted.
-		 */
-		white,
-
-		/**
-		 * Use if yellow food is wanted.
-		 */
-		yellow,
-
-		/**
-		 * Use if orange food is wanted.
-		 */
-		orange,
-
-		/**
-		 * Use if red food is wanted.
-		 */
-		red,
-
-		/**
-		 * Use if blue food is wanted.
-		 */
-		blue
-	}
-
-	private static FoodFactory foodFactory = new FoodFactory();
-
-	private long timeOfNextFood;
-
-	Point pFood = null;
-
-	private Food nextFood = Food.white;
-
-	private int rectangleSize = 6;
-
-	private FoodFactory() {}
-
-	/**
-	 * @return the (singleton) instance of FoodFactory
-	 * @since Snake 1.0
-	 */
-	public static FoodFactory getInstance() { return foodFactory; }
-
-	/**
-	 * @return a new {@link Food} object without its position
-	 * @since Snake 1.0
-	 */
-	public Food generateFood() {
-		int nextFoodIs = (int) Math.floor(Math.random() * 5);
-		switch (nextFoodIs) {
-
-			case 0:
-				nextFood = Food.white;
-				break;
-			case 1:
-				nextFood = Food.yellow;
-				break;
-			case 2:
-				nextFood = Food.orange;
-				break;
-			case 3:
-				nextFood = Food.red;
-				break;
-			case 4:
-				nextFood = Food.blue;
-				break;
-			default:
-				nextFood = generateFood();
-		}
-		rectangleSize = nextFood.ordinal() + 2;
-		setTimeToNextFoodMillis();
-		return nextFood;
+	public FoodFactory(int width, int height) {
+		this.width = width;
+		this.height = height;
 	}
 
 	/**
-	 * Generates the amount of time that needs to pass before the next food object
-	 * will be constructed.
-	 *
-	 * @since Snake 1.0
+	 * @return a new food item
+	 * @since Snake 1.2
 	 */
-	public void setTimeToNextFoodMillis() { timeOfNextFood = System.currentTimeMillis() + (int) Math.round(Math.random() * 15000 + 1000); }
-
-	/**
-	 * @return the type of the next food
-	 * @since Snake 1.0
-	 */
-	public Food getNextFood() { return nextFood; }
-
-	/**
-	 * @param nextFood the type the next food should have
-	 * @since Snake 1.0
-	 */
-	public void setNext(Food nextFood) { this.nextFood = nextFood; }
-
-	/**
-	 * @return the time at which a new food object will be automatically created
-	 * @since Snake 1.0
-	 */
-	public long getTimeOfNextFood() { return timeOfNextFood; }
-
-	/**
-	 * @param width  the width of the currently used {@link GameWindow}
-	 * @param height the height of the currently used {@link GameWindow}
-	 * @return the position of the new {@link Food} object
-	 * @since Snake 1.0
-	 */
-	public Point generateFoodLocation(int width, int height) {
-		pFood = new Point((int) Math.round(Math.random() * width), (int) Math.round(Math.random() * height));
-		if (pFood.x < 50 || pFood.x > width - 50 || pFood.y < 50 || pFood.y > height - 50) {
-			pFood.x	= (pFood.x < 50) ? 50 : (pFood.x > width - 50) ? width - 50 : pFood.x;
-			pFood.y	= (pFood.y < 50) ? 50 : (pFood.y > height - 50) ? height - 50 : pFood.y;
-		}
-		return pFood;
+	public synchronized Food spawn() {
+		nextSpawnTime = System.currentTimeMillis() + random.nextInt(15000) + 1000;
+		int seed = random.nextInt(5);
+		return new Food(
+			FOOD_COLORS[seed],
+			FOOD_LENGTH_BONUSES[seed],
+			new Rectangle(random.nextInt(width - 100) + 50,
+				random.nextInt(height - 100) + 50,
+				10 + seed * 5,
+				10 + seed * 5
+			)
+		);
 	}
 
 	/**
-	 * @return the size of the corresponding food (length = width)
-	 * @since Snake 1.0
+	 * @return the time after which a new food item should be spawned
+	 * @since Snake 1.2
 	 */
-	public int getRectangleSize() { return rectangleSize; }
-
-	/**
-	 * @return the location of the currently displayed food
-	 * @since Snake 1.0
-	 */
-	public Point getFoodLocation() { return pFood; }
-
-	/**
-	 * Sets the color of the given {@link Graphics} object according to the type of
-	 * food.
-	 *
-	 * @param g the graphics object to paint
-	 * @since Snake 1.0
-	 */
-	public void colorOfFood(Graphics g) {
-		switch (nextFood) {
-			case white:
-				g.setColor(Color.white);
-				break;
-			case yellow:
-				g.setColor(Color.yellow);
-				break;
-			case orange:
-				g.setColor(Color.orange);
-				break;
-			case red:
-				g.setColor(Color.red);
-				break;
-			case blue:
-				g.setColor(Color.blue);
-				break;
-		}// switch
-	}
-
-	/**
-	 * @param g the {@link Graphics} object used to paint the current food object
-	 * @since Snake 1.0
-	 */
-	public void paintFood(Graphics g) {
-		colorOfFood(g);
-		g.fillRect(pFood.x, pFood.y, 5 * rectangleSize, 5 * rectangleSize);
-	}
-
-	/**
-	 * @param snakeHead the the head of a {@link Snake} object
-	 * @return true if the current food intersects with the snakehead
-	 * @since Snake 1.0
-	 */
-	public boolean checkCollision(Rectangle snakeHead) {
-		int			s		= rectangleSize * 5;
-		Rectangle	food	= new Rectangle(pFood, new Dimension(s, s));
-		return food.intersects(snakeHead);
-	}
-
-	/**
-	 * @return the length that will be added to the snake
-	 * @since Snake 1.0
-	 */
-	public int getAdditionalLength() {
-		int snakeAdditionalLength = 0;
-		switch (nextFood) {
-			case white:
-				snakeAdditionalLength = 40;
-				break;
-			case yellow:
-				snakeAdditionalLength = 15;
-				break;
-			case orange:
-				snakeAdditionalLength = 6;
-				break;
-			case red:
-				snakeAdditionalLength = 2;
-				break;
-			case blue:
-				snakeAdditionalLength = 1;
-				break;
-		}
-		return snakeAdditionalLength;
-	}
+	public long getNextSpawnTime() { return nextSpawnTime; }
 }

src/main/dev/lh/Handler.java

@@ -0,0 +1,54 @@
+package dev.lh;
+
+import java.awt.Graphics2D;
+
+/**
+ * Manages the state of game objects.
+ * <p>
+ * Project: <strong>Snake</strong><br>
+ * File: <strong>Handler.java</strong><br>
+ * Created: <strong>01.07.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Snake 1.2
+ */
+public final class Handler implements Updateable {
+
+	private Snake snake = new Snake(7);
+	private FoodFactory foodFactory;
+
+	private volatile Food food;
+
+	/**
+	 * Constructs a handler.
+	 * 
+	 * @param snake       the snake
+	 * @param foodFactory the food factory
+	 * @since Snake 1.2
+	 */
+	public Handler(Snake snake, FoodFactory foodFactory) {
+		this.snake = snake;
+		this.foodFactory = foodFactory;
+		food = foodFactory.spawn();
+	}
+
+	@Override
+	public void tick() {
+		snake.tick();
+		food.tick();
+
+		// Check for food collision
+		if (snake.getHead().intersects(food.getBounds())) {
+			snake.addLength(food.getLengthBonus());
+			food = foodFactory.spawn();
+		}
+		if (System.currentTimeMillis() > foodFactory.getNextSpawnTime())
+			food = foodFactory.spawn();
+	}
+
+	@Override
+	public void render(Graphics2D g) {
+		snake.render(g);
+		food.render(g);
+	}
+}

src/main/dev/lh/Snake.java

@@ -1,14 +1,12 @@
 package dev.lh;
 
 import java.awt.Color;
-import java.awt.Graphics;
-import java.awt.Point;
+import java.awt.Graphics2D;
 import java.awt.Rectangle;
 import java.util.ArrayList;
 import java.util.List;
 
 import dev.lh.ui.Endscreen;
-import dev.lh.ui.GameWindow;
 
 /**
  * Project: <strong>Snake</strong><br>
@@ -30,34 +28,34 @@ public class Snake implements Updateable {
 	 * @author Leon Hofmeister
 	 * @since Snake 1.0
 	 */
-	public static enum Direction {
+	public enum Direction {
 		/**
 		 * Use if the snake should head left.
 		 */
-		Left,
+		LEFT,
 
 		/**
 		 * Use if the snake should head right.
 		 */
-		Right,
+		RIGHT,
 
 		/**
 		 * Use if the snake should head up.
 		 */
-		Up,
+		UP,
 
 		/**
 		 * Use if the snake should head down.
 		 */
-		Down;
+		DOWN;
 	}
 
-	private static FoodFactory	foodFactory	= FoodFactory.getInstance();
-	private static Endscreen	endscreen;
-	private Direction			Richtung;
-	private int					length;
-	private List<Point>			tiles		= new ArrayList<>();
-	private final int			snakeSize	= 10;
+	private static Endscreen		endscreen;
+	private Direction				direction	= Direction.RIGHT;
+	private int						length;
+	private final List<Rectangle>	tiles		= new ArrayList<>();
+
+	private static final int TILE_SIZE = 10;
 
 	/**
 	 * Constructs a new Snake with the given length in tiles.
@@ -66,61 +64,24 @@ public class Snake implements Updateable {
 	 * @since Snake 1.0
 	 */
 	public Snake(int length) {
-		this.length	= length;
-		Richtung	= Direction.Right;
-		// adding the initial tiles of the snake
+		this.length = length;
+
+		// Add initial tiles
 		for (int i = 0; i < length; i++)
-			tiles.add(new Point(320 - snakeSize * i, 240));
-	}
-
-	@Override
-	public void nextFrame() {
-		int velX = 0, velY = 0;
-		switch (Richtung) {
-			case Up:
-				velY = -snakeSize;
-				break;
-			case Down:
-				velY = snakeSize;
-				break;
-			case Left:
-				velX = -snakeSize;
-				break;
-			case Right:
-				velX = snakeSize;
-				break;
-		}
-		Point next = (Point) tiles.get(0).clone(), cur;
-		tiles.get(0).x	+= velX;
-		tiles.get(0).y	+= velY;
-
-		for (int i = 1; i < length; i++) {
-			cur = tiles.get(i);
-			tiles.set(i, (Point) next.clone());
-			next = cur;
-		}
-
-		// case if snake is outside of the screen or touches itself
-		if (checkSelfCollision()) gameOver();
-		// TODO: the game bounds checking below appears to work on Windows, however throws a NullPointerException on Linux/UNIX systems
-		// if (!Main.getGame().getBounds().contains(tiles.get(0))) gameOver();
-
-		// case if snake eats food
-		if (foodFactory.checkCollision(new Rectangle(tiles.get(0).x, tiles.get(0).y, snakeSize, snakeSize))) {
-			addLength(foodFactory.getAdditionalLength());
-			GameWindow game = Main.getGame();
-			game.newFood();
-		}
+			tiles.add(new Rectangle(320 - TILE_SIZE * i, 240, TILE_SIZE, TILE_SIZE));
 	}
 
 	/**
+	 * Increases the given length to the current snake object.
 	 *
-	 * @since Snake 1.1
+	 * @param additional the number of tiles to add
+	 * @since Snake 1.0
 	 */
-	private void gameOver() {
-		endscreen = new Endscreen(length);
-		endscreen.setVisible(true);
-		Main.getGame().close();
+	public void addLength(int additional) {
+		final Rectangle last = tiles.get(tiles.size() - 1);
+		for (int i = 0; i < additional; i++)
+			tiles.add(last);
+		length += additional;
 	}
 
 	/**
@@ -128,44 +89,77 @@ public class Snake implements Updateable {
 	 * @since Snake 1.1
 	 */
 	private boolean checkSelfCollision() {
-		Point		headIndex	= tiles.get(0);
-		Rectangle	head		= new Rectangle(headIndex.x, headIndex.y, snakeSize, snakeSize);
-		for (int index = 1; index < tiles.size(); index++) {
-			Point bodyIndex = tiles.get(index);
-			if (head.contains(new Rectangle(bodyIndex.x, bodyIndex.y, snakeSize, snakeSize))) return true;
-		}
-		return false;
+		return tiles.stream().skip(1).anyMatch(tiles.get(0)::contains);
+	}
+
+	/**
+	 * @since Snake 1.1
+	 */
+	private void gameOver() {
+		Main.getGame().close();
+		endscreen = new Endscreen(length);
+		endscreen.setVisible(true);
 	}
 
 	@Override
-	public void render(Graphics g) {
+	public void tick() {
+		int velX = 0, velY = 0;
+		switch (direction) {
+			case UP:
+				velY = -TILE_SIZE;
+				break;
+			case DOWN:
+				velY = TILE_SIZE;
+				break;
+			case LEFT:
+				velX = -TILE_SIZE;
+				break;
+			case RIGHT:
+				velX = TILE_SIZE;
+				break;
+		}
+		// Add a new tile at the front
+		tiles.add(
+			0,
+			new Rectangle(tiles.get(0).x + velX, tiles.get(0).y + velY, TILE_SIZE, TILE_SIZE)
+		);
+		// Remove the last tile
+		tiles.remove(tiles.size() - 1);
+		// Case if snake is outside of the screen or touches itself
+		if (checkSelfCollision()) {
+			gameOver();
+			System.out.println("Snake collided with itself.");
+			return;
+		}
+		// TODO: Test on Linux
+		if (!Main.getGame().getBounds().contains(getHead())) {
+			gameOver();
+			System.out.println("Snake went out of bounds.");
+			return;
+		}
+	}
+
+	@Override
+	public void render(Graphics2D g) {
 		g.setColor(Color.green);
-		for (int i = 0; i < length; i++)
-			g.fillRect(tiles.get(i).x, tiles.get(i).y, snakeSize, snakeSize);
+		tiles.forEach(g::fill);
 	}
 
 	/**
 	 * @return the current {@link Direction} of the snake
-	 * @since Snake 1.0
+	 * @since Snake 1.2
 	 */
-	public Direction getRichtung() { return Richtung; }
+	public Direction getDirection() { return direction; }
 
 	/**
-	 * @param richtung the new {@link Direction} of the snake
+	 * @param direction the new {@link Direction} of the snake
 	 * @since Snake 1.0
 	 */
-	public void setRichtung(Direction richtung) { Richtung = richtung; }
+	public void setDirection(Direction direction) { this.direction = direction; }
 
 	/**
-	 * Adds the given length to the current snake object
-	 *
-	 * @param additional the number of tiles to add
-	 * @since Snake 1.0
+	 * @return a rectangle representing the head of the snake
+	 * @since Snake 1.2
 	 */
-	public void addLength(int additional) {
-		Point last = tiles.get(tiles.size() - 1);
-		for (int i = 0; i < additional; i++)
-			tiles.add(last);
-		length += additional;
-	}
+	public Rectangle getHead() { return tiles.get(0); }
 }

src/main/dev/lh/Updateable.java

@@ -1,10 +1,10 @@
 package dev.lh;
 
-import java.awt.Graphics;
+import java.awt.Graphics2D;
 
 /**
- * This interface contains everything that needs to updated regularly.<br>
- * <br>
+ * This interface contains everything that needs to be updated regularly.
+ * <p>
  * Project: <strong>Snake</strong><br>
  * File: <strong>Updateable.java</strong><br>
  * Created: <strong>11 Mar 2020</strong><br>
@@ -18,15 +18,15 @@ public interface Updateable {
 	 * Here should the actions be implemented that are supposed to happen when a new
 	 * frame gets created.
 	 *
-	 * @since Snake 1.0
+	 * @since Snake 1.2
 	 */
-	void nextFrame();
+	default void tick() {}
 
 	/**
 	 * Renders the object.
 	 *
-	 * @param g the {@link Graphics} object that is used to render this object
+	 * @param g the graphics object that is used to render this object
 	 * @since Snake 1.0
 	 */
-	void render(Graphics g);
+	default void render(Graphics2D g) {}
 }

src/main/dev/lh/Viewport.java

@@ -0,0 +1,94 @@
+package dev.lh;
+
+import java.awt.Canvas;
+import java.awt.Color;
+import java.awt.Graphics2D;
+import java.util.Timer;
+import java.util.TimerTask;
+
+/**
+ * Implements a hardware-accelerated rendering loop.
+ * <p>
+ * Project: <strong>Snake</strong><br>
+ * File: <strong>Viewport.java</strong><br>
+ * Created: <strong>01.07.2020</strong><br>
+ *
+ * @author Kai S. K. Engelbart
+ * @since Snake 1.2
+ */
+public class Viewport extends Canvas {
+
+	private static final long serialVersionUID = 1L;
+
+	// Enable OpenGL hardware acceleration
+	static {
+		System.setProperty("sun.java2d.trace", "timestamp,log,count");
+		System.setProperty("sun.java2d.transaccel", "True");
+		System.setProperty("sun.java2d.opengl", "True");
+	}
+
+	private Updateable gameRoot;
+	private Timer timer = new Timer();
+	private TimerTask renderTask;
+
+	/**
+	 * @param gameRoot the game object responsible for updating the rest
+	 * @since Snake 1.2
+	 */
+	public Viewport(Updateable gameRoot) {
+		this.gameRoot = gameRoot;
+		setIgnoreRepaint(true);
+	}
+
+	/**
+	 * Starts the render task.
+	 *
+	 * @since Snake 1.2
+	 */
+	public void start() {
+		if (renderTask != null) renderTask.cancel();
+		else createBufferStrategy(2);
+
+		renderTask = new TimerTask() {
+
+			// private long lastTime = System.currentTimeMillis();
+
+			@Override
+			public void run() {
+				// final long time = System.currentTimeMillis();
+				// final double dt = (time - lastTime) * 1E-3;
+				// lastTime = time;
+				// TODO: Delta time adjustment
+				gameRoot.tick();
+				render();
+			}
+		};
+
+		timer.schedule(renderTask, 0, 100);
+	}
+
+	/**
+	 * Stops the render task.
+	 *
+	 * @since Snake 1.2
+	 */
+	public void stop() { renderTask.cancel(); }
+
+	private void render() {
+		final Graphics2D g = (Graphics2D) getBufferStrategy().getDrawGraphics();
+
+		// Clear the screen
+		g.setColor(Color.BLACK);
+		g.fillRect(0, 0, getWidth(), getHeight());
+
+		// Perform the actual rendering
+		gameRoot.render(g);
+
+		// Flip buffers
+		g.dispose();
+		getBufferStrategy().show();
+
+		// Synchronize with display refresh rate
+		getToolkit().sync();
+	}
+}

src/main/dev/lh/ui/Endscreen.java

@@ -1,6 +1,7 @@
 package dev.lh.ui;
 
-import java.awt.*;
+import java.awt.BorderLayout;
+import java.awt.Font;
 import java.awt.event.KeyEvent;
 
 import javax.swing.*;
@@ -20,9 +21,9 @@ public class Endscreen extends JDialog {
 
 	private static final long serialVersionUID = -4457484397259161063L;
 
-	private final JPanel		contentPanel	= new JPanel();
-	private int					score			= 0;
-	private static final int	goodOrBadResult	= 200;
+	// private static final int goodOrBadResult = 200;
+	private final JPanel	contentPanel	= new JPanel();
+	private final int		score;
 
 	/**
 	 * Create the dialog.
@@ -31,49 +32,28 @@ public class Endscreen extends JDialog {
 	 */
 	public Endscreen(int score) {
 		this.score = score;
-		try {
-			// readInHighscoresPoints();
-			// readInHighscoresPlayers();
+		setTitle("Endscreen");
+		setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
+		setBounds(100, 100, 700, 700);
+		getContentPane().setLayout(new BorderLayout());
+		contentPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
+		contentPanel.setLayout(new BorderLayout(0, 0));
+		getContentPane().add(contentPanel, BorderLayout.CENTER);
 
-			setTitle("Endscreen");
-			setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
-			setBounds(100, 100, 700, 700);
-			getContentPane().setLayout(new BorderLayout());
-			contentPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
-			getContentPane().add(contentPanel, BorderLayout.CENTER);
-			addWindowListener(new java.awt.event.WindowAdapter() {
-
-				@Override
-				public void windowClosing(java.awt.event.WindowEvent windowEvent) {
-					Thread.getAllStackTraces().forEach((thread, stackTraceElement) -> thread.interrupt());
-					System.exit(0);
-				}
-			});
-		} catch (Exception e) {
-			e.printStackTrace();
-		}
-
-		JButton btnNewButton = new JButton("Play again");
+		final JButton btnNewButton = new JButton("Play again");
 		btnNewButton.setMnemonic(KeyEvent.VK_ENTER);
 		btnNewButton.addActionListener(e -> { Main.startGame(); dispose(); });
-		contentPanel.setLayout(new BorderLayout(0, 0));
-		// btnNewButton.setIcon(new
-		// ImageIcon(ClassLoader.getSystemResource("/com/sun/javafx/webkit/prism/resources/mediaPlayDisabled.png")));
-		btnNewButton.setIconTextGap(5);
 		btnNewButton.setFont(new Font("Times New Roman", Font.PLAIN, 15));
 		contentPanel.add(btnNewButton, BorderLayout.SOUTH);
 
-		JLabel lblDeinPunktestand = new JLabel("Dein Punktestand:	     " + String.valueOf(score));
+		final JLabel lblDeinPunktestand = new JLabel("Dein Punktestand:	     " + String.valueOf(score));
 		lblDeinPunktestand.setFont(new Font("Times New Roman", Font.PLAIN, 25));
 		contentPanel.add(lblDeinPunktestand, BorderLayout.NORTH);
 
-//TODO: the display ofthe result image could work, but not guaranteed		
-//		Image resultImage = Toolkit.getDefaultToolkit()
-//			.getImage(this.getClass()
-//				.getResource((score < goodOrBadResult) ? "/Snake/src/main/resources/Try_Again.jpg" : "/Snake/src/main/resources/1211548-200.png"));
-//		resultImage.flush();
-
-		setVisible(true);
+		// final Image resultImage = Toolkit.getDefaultToolkit()
+		// .getImage(this.getClass().getResource(score < goodOrBadResult ?
+		// "/Try_Again.jpg" : "/1211548-200.png"));
+		// resultImage.flush();
 	}
 
 	/**
@@ -81,10 +61,4 @@ public class Endscreen extends JDialog {
 	 * @since Snake 1.0
 	 */
 	public int getScore() { return score; }
-
-	/**
-	 * @param score the new highscore
-	 * @since Snake 1.0
-	 */
-	public void setScore(int score) { this.score = score; }
 }

src/main/dev/lh/ui/GameWindow.java

@@ -1,15 +1,14 @@
 package dev.lh.ui;
 
-import java.awt.*;
+import java.awt.Dimension;
+import java.awt.Rectangle;
+import java.awt.Toolkit;
 import java.awt.event.KeyAdapter;
 import java.awt.event.KeyEvent;
 
 import javax.swing.JFrame;
-import javax.swing.JPanel;
-import javax.swing.Timer;
 
-import dev.lh.FoodFactory;
-import dev.lh.Snake;
+import dev.lh.*;
 import dev.lh.Snake.Direction;
 
 /**
@@ -22,21 +21,20 @@ import dev.lh.Snake.Direction;
  */
 public class GameWindow extends JFrame {
 
-	private static final long	serialVersionUID	= 1L;
-	private Snake				s					= new Snake(7);
-	private FoodFactory			foodFactory			= FoodFactory.getInstance();
+	private static final long serialVersionUID = 1L;
+
+	private Viewport viewport;
 
 	/**
 	 * @param title the title of the frame
 	 * @since Snake 1.0
 	 */
 	public GameWindow(String title) {
+		// Initialize window
 		super(title);
-		newFood();
 		Dimension size = Toolkit.getDefaultToolkit().getScreenSize();
 		setBounds(new Rectangle(size));
 		setLocation(0, 0);
-		setLocationRelativeTo(null);
 		setMinimumSize(size);
 		setPreferredSize(size);
 		setMaximumSize(size);
@@ -44,19 +42,14 @@ public class GameWindow extends JFrame {
 		setResizable(false);
 		setDefaultCloseOperation(EXIT_ON_CLOSE);
 
-		add(new JPanel() {
+		// Initialize game objects
+		Snake snake = new Snake(7);
+		FoodFactory foodFactory = new FoodFactory(getWidth(), getHeight());
+		Handler handler = new Handler(snake, foodFactory);
 
-			private static final long serialVersionUID = 1L;
-
-			@Override
-			protected void paintComponent(Graphics g) {
-				super.paintComponent(g);
-				g.setColor(Color.black);
-				g.fillRect(0, 0, super.getWidth(), super.getHeight());
-				s.render(g);
-				foodFactory.paintFood(g);
-			}
-		});
+		// Initialize viewport
+		viewport = new Viewport(handler);
+		add(viewport);
 
 		addKeyListener(new KeyAdapter() {
 
@@ -66,46 +59,40 @@ public class GameWindow extends JFrame {
 				switch (e.getKeyCode()) {
 					case KeyEvent.VK_W:
 					case KeyEvent.VK_UP:
-						if (!s.getRichtung().equals(Direction.Down)) s.setRichtung(Direction.Up);
+						if (!snake.getDirection().equals(Direction.DOWN))
+							snake.setDirection(Direction.UP);
 						break;
 					case KeyEvent.VK_A:
 					case KeyEvent.VK_LEFT:
-						if (!s.getRichtung().equals(Direction.Right)) s.setRichtung(Direction.Left);
+						if (!snake.getDirection().equals(Direction.RIGHT))
+							snake.setDirection(Direction.LEFT);
 						break;
 					case KeyEvent.VK_S:
 					case KeyEvent.VK_DOWN:
-						if (!s.getRichtung().equals(Direction.Up)) s.setRichtung(Direction.Down);
+						if (!snake.getDirection().equals(Direction.UP))
+							snake.setDirection(Direction.DOWN);
 						break;
 					case KeyEvent.VK_D:
 					case KeyEvent.VK_RIGHT:
-						if (!s.getRichtung().equals(Direction.Left)) s.setRichtung(Direction.Right);
+						if (!snake.getDirection().equals(Direction.LEFT))
+							snake.setDirection(Direction.RIGHT);
 						break;
 				}
 			}
 		});
 
-		Timer timer = new Timer(50,
-				evt -> { s.nextFrame(); if (System.currentTimeMillis() >= foodFactory.getTimeOfNextFood()) newFood(); repaint(); });
-		timer.start();
-
 		setVisible(true);
+		viewport.start();
 	}
 
 	/**
-	 * Generates new food
+	 * Disposes this frame.
 	 *
 	 * @since Snake 1.1
 	 */
-	public void newFood() {
-		foodFactory.generateFood();
-		foodFactory.generateFoodLocation(getWidth(), getHeight());
-		repaint();
+	public void close() {
+		viewport.stop();
+		setVisible(false);
+		dispose();
 	}
-
-	/**
-	 * Disposes this frame
-	 *
-	 * @since Snake 1.1
-	 */
-	public void close() { dispose(); }
 }

src/main/dev/lh/ui/StartScreen.java

@@ -19,11 +19,10 @@ import dev.lh.Main;
  */
 public class StartScreen extends JFrame {
 
-	private static final long	serialVersionUID	= 6055940532003735543L;
-	private JPanel				contentPane;
+	private static final long serialVersionUID = 6055940532003735543L;
 
 	/**
-	 * closes the application.
+	 * Closes the application.
 	 */
 	public static void close() { System.exit(0); }
 
@@ -33,48 +32,32 @@ public class StartScreen extends JFrame {
 	 * @param args the program arguments
 	 * @since Snake 1.0
 	 */
-	public static void main(String[] args) {
-		EventQueue.invokeLater(() -> {
-			try {
-				StartScreen frame = new StartScreen();
-				frame.setVisible(true);
-			} catch (Exception e) {
-				e.printStackTrace();
-			}
-		});
-	}
+	public static void main(String[] args) { EventQueue.invokeLater(StartScreen::new); }
 
 	/**
 	 * Create the frame.
 	 */
 	public StartScreen() {
-		try {
-			// readInHighscores();
-			setTitle("Snake - Startscreen");
-			setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
-			setBounds(500, 200, 550, 550);
-			contentPane = new JPanel();
-			contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
-			setContentPane(contentPane);
+		setTitle("Snake - Startscreen");
+		setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
+		setBounds(500, 200, 550, 550);
 
-			JButton buPlay = new JButton("Start Game");
-			buPlay.setBounds(158, 197, 190, 131);
-			buPlay.setIcon(new ImageIcon(StartScreen.class.getResource("/com/sun/javafx/webkit/prism/resources/mediaPlayDisabled.png")));
-			buPlay.setMnemonic(KeyEvent.VK_ENTER);
-			buPlay.setFont(new Font("Times New Roman", Font.PLAIN, 16));
+		final JPanel contentPane = new JPanel();
+		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
+		setContentPane(contentPane);
 
-			buPlay.addActionListener(a -> {
-
-				Main.startGame();
-				setVisible(false);
-				dispose();
-				System.gc();
-			});
-			contentPane.setLayout(null);
-
-		} catch (Exception e) {
-
-			e.printStackTrace();
-		}
+		final JButton buPlay = new JButton("Start Game");
+		buPlay.setBounds(158, 197, 190, 131);
+		buPlay.setMnemonic(KeyEvent.VK_ENTER);
+		buPlay.setFont(new Font("Times New Roman", Font.PLAIN, 16));
+		buPlay.addActionListener(a -> {
+			Main.startGame();
+			setVisible(false);
+			dispose();
+			System.gc();
+		});
+		contentPane.add(buPlay);
+		contentPane.setLayout(null);
+		setVisible(true);
 	}
 }