Add help screen

src/engine/Core.java

@@ -8,11 +8,7 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import screen.GameScreen;
-import screen.HighScoreScreen;
-import screen.ScoreScreen;
-import screen.Screen;
-import screen.TitleScreen;
+import screen.*;
 
 /**
  * Implements core game logic.
@@ -172,6 +168,22 @@ public static void main(final String[] args) {
 				returnCode = frame.setScreen(currentScreen);
 				LOGGER.info("Closing high score screen.");
 				break;
+			case 4:
+				// Help.
+				currentScreen = new HelpScreen(width, height, FPS);
+				LOGGER.info("Starting " + WIDTH + "x" + HEIGHT
+						+ " help screen at " + FPS + " fps.");
+				returnCode = frame.setScreen(currentScreen);
+				LOGGER.info("Closing help screen.");
+				break;
+			case 5:
+				// Settings.
+				currentScreen = new SettingsScreen(width, height, FPS);
+				LOGGER.info("Starting " + WIDTH + "x" + HEIGHT
+						+ " settings screen at " + FPS + " fps.");
+				returnCode = frame.setScreen(currentScreen);
+				LOGGER.info("Closing settings screen.");
+				break;
 			default:
 				break;
 			}

src/engine/DrawManager.java

@@ -283,15 +283,18 @@ public void drawHorizontalLine(final Screen screen, final int positionY) {
 	 */
 	public void drawTitle(final Screen screen) {
 		String titleString = "Invaders";
-		String instructionsString =
-				"select with w+s / arrows, confirm with space";
+		String[] instructionsStrings = {"Select with w+s / arrows", "Confirm with space"};
+		int i = 0;
 
 		backBufferGraphics.setColor(Color.GRAY);
-		drawCenteredRegularString(screen, instructionsString,
-				screen.getHeight() / 2);
+		for (String instructionString : instructionsStrings) {
+			drawCenteredRegularString(screen, instructionString,
+					screen.getHeight() * 4 / 15 + fontRegularMetrics.getHeight() * 2 * i);
+			i++;
+		}
 
 		backBufferGraphics.setColor(Color.GREEN);
-		drawCenteredBigString(screen, titleString, screen.getHeight() / 3);
+		drawCenteredBigString(screen, titleString, screen.getHeight() / 6);
 	}
 
 	/**
@@ -305,26 +308,40 @@ public void drawTitle(final Screen screen) {
 	public void drawMenu(final Screen screen, final int option) {
 		String playString = "Play";
 		String highScoresString = "High scores";
-		String exitString = "exit";
+		String helpString = "Help";
+		String settingsString = "Settings";
+		String exitString = "Exit";
 
 		if (option == 2)
 			backBufferGraphics.setColor(Color.GREEN);
 		else
 			backBufferGraphics.setColor(Color.WHITE);
 		drawCenteredRegularString(screen, playString,
-				screen.getHeight() / 3 * 2);
+				screen.getHeight() * 11 / 20);
 		if (option == 3)
 			backBufferGraphics.setColor(Color.GREEN);
 		else
 			backBufferGraphics.setColor(Color.WHITE);
-		drawCenteredRegularString(screen, highScoresString, screen.getHeight()
-				/ 3 * 2 + fontRegularMetrics.getHeight() * 2);
+		drawCenteredRegularString(screen, highScoresString,
+				screen.getHeight() * 11 / 20 + fontRegularMetrics.getHeight() * 2);
+		if (option == 4)
+			backBufferGraphics.setColor(Color.GREEN);
+		else
+			backBufferGraphics.setColor(Color.WHITE);
+		drawCenteredRegularString(screen, helpString,
+				screen.getHeight() * 11 / 20 + fontRegularMetrics.getHeight() * 4);
+		if (option == 5)
+			backBufferGraphics.setColor(Color.GREEN);
+		else
+			backBufferGraphics.setColor(Color.WHITE);
+		drawCenteredRegularString(screen, settingsString,
+				screen.getHeight() * 11 / 20 + fontRegularMetrics.getHeight() * 6);
 		if (option == 0)
 			backBufferGraphics.setColor(Color.GREEN);
 		else
 			backBufferGraphics.setColor(Color.WHITE);
-		drawCenteredRegularString(screen, exitString, screen.getHeight() / 3
-				* 2 + fontRegularMetrics.getHeight() * 4);
+		drawCenteredRegularString(screen, exitString,
+				screen.getHeight() * 11 / 20 + fontRegularMetrics.getHeight() * 8);
 	}
 
 	/**
@@ -487,6 +504,67 @@ public void drawHighScores(final Screen screen,
 		}
 	}
 
+	/**
+	 * Draws help screen
+	 *
+	 * @param screen
+	 *            Screen to draw on.
+	 */
+	public void drawHelp(final Screen screen) {
+		String helpString = "Help";
+		String instructionsString = "Press Space to return";
+		String[] rule1 = {"Press the arrow keys", "(or the A or D keys)", "to move your ship"};
+		String[] rule2 = {"Press space to shoot", "missiles at the enemy ships"};
+		String[] rule3 = {"Avoid the missiles shot", "by the enemy ships"};
+		String[] rule4 = {"The color of an enemy ship", "depends on their remaining", "health points"};
+		String[][] rules = {rule1, rule2, rule3, rule4};
+		int i = 0;
+		int j = 0;
+
+		backBufferGraphics.setColor(Color.GREEN);
+		drawCenteredBigString(screen, helpString, screen.getHeight() / 8);
+
+		backBufferGraphics.setColor(Color.GRAY);
+		drawCenteredRegularString(screen, instructionsString,
+				screen.getHeight() / 5);
+
+		backBufferGraphics.setColor(Color.WHITE);
+		for (String[] rule : rules) {
+			for (String ruleString : rule) {
+				drawCenteredRegularString(screen, ruleString,
+						screen.getHeight() * 3 / 10
+								+ fontRegularMetrics.getHeight() * i
+								+ fontRegularMetrics.getHeight() * 2 * j);
+				i++;
+			}
+			j++;
+		}
+	}
+
+	/**
+	 * Draws settings screen
+	 *
+	 * @param screen
+	 *            Screen to draw on.
+	 */
+	public void drawSettings(final Screen screen) {
+		String settingsString = "Settings";
+		String[] instructionsStrings = {"Press Space to return", "Use the arrow keys to", "enable/disable settings"};
+		int i = 0;
+
+		backBufferGraphics.setColor(Color.GREEN);
+		drawCenteredBigString(screen, settingsString, screen.getHeight() / 8);
+
+		backBufferGraphics.setColor(Color.GRAY);
+		for (String instructionsString : instructionsStrings) {
+			drawCenteredRegularString(screen, instructionsString,
+					(int) (screen.getHeight() / 5 + Math.round(fontRegularMetrics.getHeight() * 1.5 * i)));
+			i++;
+		}
+
+		backBufferGraphics.setColor(Color.WHITE);
+	}
+
 	/**
 	 * Draws a centered string on regular font.
 	 * 

src/screen/HelpScreen.java

@@ -0,0 +1,64 @@
+package screen;
+
+import java.awt.event.KeyEvent;
+import java.io.IOException;
+import java.util.List;
+
+import engine.Core;
+import engine.Score;
+
+/**
+ * Implements the help screen, it shows the player instructions on how to play the game.
+ */
+
+public class HelpScreen extends Screen {
+    /**
+     * Constructor, establishes the properties of the screen.
+     *
+     * @param width
+     *            Screen width.
+     * @param height
+     *            Screen height.
+     * @param fps
+     *            Frames per second, frame rate at which the game is run.
+     */
+    public HelpScreen(final int width, final int height, final int fps) {
+        super(width, height, fps);
+
+        this.returnCode = 1;
+    }
+
+    /**
+     * Starts the action.
+     *
+     * @return Next screen code.
+     */
+    public final int run() {
+        super.run();
+
+        return this.returnCode;
+    }
+
+    /**
+     * Updates the elements on screen and checks for events.
+     */
+    protected final void update() {
+        super.update();
+
+        draw();
+        if (inputManager.isKeyDown(KeyEvent.VK_SPACE)
+                && this.inputDelay.checkFinished())
+            this.isRunning = false;
+    }
+
+    /**
+     * Draws the elements associated with the screen.
+     */
+    private void draw() {
+        drawManager.initDrawing(this);
+
+        drawManager.drawHelp(this);
+
+        drawManager.completeDrawing(this);
+    }
+}

src/screen/SettingsScreen.java

@@ -0,0 +1,64 @@
+package screen;
+
+import java.awt.event.KeyEvent;
+import java.io.IOException;
+import java.util.List;
+
+import engine.Core;
+import engine.Score;
+
+/**
+ * Implements the help screen, it shows the player instructions on how to play the game.
+ */
+
+public class SettingsScreen extends Screen {
+    /**
+     * Constructor, establishes the properties of the screen.
+     *
+     * @param width
+     *            Screen width.
+     * @param height
+     *            Screen height.
+     * @param fps
+     *            Frames per second, frame rate at which the game is run.
+     */
+    public SettingsScreen(final int width, final int height, final int fps) {
+        super(width, height, fps);
+
+        this.returnCode = 1;
+    }
+
+    /**
+     * Starts the action.
+     *
+     * @return Next screen code.
+     */
+    public final int run() {
+        super.run();
+
+        return this.returnCode;
+    }
+
+    /**
+     * Updates the elements on screen and checks for events.
+     */
+    protected final void update() {
+        super.update();
+
+        draw();
+        if (inputManager.isKeyDown(KeyEvent.VK_SPACE)
+                && this.inputDelay.checkFinished())
+            this.isRunning = false;
+    }
+
+    /**
+     * Draws the elements associated with the screen.
+     */
+    private void draw() {
+        drawManager.initDrawing(this);
+
+        drawManager.drawSettings(this);
+
+        drawManager.completeDrawing(this);
+    }
+}

src/screen/TitleScreen.java

@@ -77,7 +77,7 @@ protected final void update() {
 	 * Shifts the focus to the next menu item.
 	 */
 	private void nextMenuItem() {
-		if (this.returnCode == 3)
+		if (this.returnCode == 5)
 			this.returnCode = 0;
 		else if (this.returnCode == 0)
 			this.returnCode = 2;
@@ -90,7 +90,7 @@ else if (this.returnCode == 0)
 	 */
 	private void previousMenuItem() {
 		if (this.returnCode == 0)
-			this.returnCode = 3;
+			this.returnCode = 5;
 		else if (this.returnCode == 2)
 			this.returnCode = 0;
 		else