feat : Add GameScreen and Core file interworking

INVADER-75

Author: YusunPark

src/engine/Core.java

@@ -141,9 +141,10 @@ public static void main(final String[] args) {
 							bonusLife, width, height, FPS);
 					LOGGER.info("Starting " + WIDTH + "x" + HEIGHT
 							+ " game screen at " + FPS + " fps.");
-					frame.setScreen(currentScreen);
+					returnCode = frame.setScreen(currentScreen);
+					
 					LOGGER.info("Closing game screen.");
-
+					if(returnCode != 1) break; 
 					gameState = ((GameScreen) currentScreen).getGameState();
 
 					gameState = new GameState(gameState.getLevel() + 1,
@@ -161,16 +162,18 @@ public static void main(final String[] args) {
 						+ gameState.getLivesRemaining() + " lives remaining, "
 						+ gameState.getBulletsShot() + " bullets shot and "
 						+ gameState.getShipsDestroyed() + " ships destroyed.");
-				currentScreen = new ScoreScreen(width, height, FPS, gameState);
-				returnCode = frame.setScreen(currentScreen);
-				LOGGER.info("Closing score screen.");
+				if(returnCode == 2) {
+					currentScreen = new ScoreScreen(width, height, FPS, gameState);
+					returnCode = frame.setScreen(currentScreen);
+					LOGGER.info("Closing score screen.");
+				}		
 				break;
 			case 3:
 				// High scores.
 				currentScreen = new HighScoreScreen(width, height, FPS);
 				LOGGER.info("Starting " + WIDTH + "x" + HEIGHT
 						+ " high score screen at " + FPS + " fps.");
-				returnCode = frame.setScreen(currentScreen);
+				returnCode = frame.setScreen(currentScreen);			
 				LOGGER.info("Closing high score screen.");
 				break;
 			case 4:
@@ -188,7 +191,7 @@ public static void main(final String[] args) {
 				LOGGER.info("Starting " + WIDTH + "x" + HEIGHT
 				+ " Audio screen at " + FPS + " fps.");
 				returnCode = frame.setScreen(currentScreen);
-				LOGGER.info("Closing Audio screen.");
+				LOGGER.info("Closing Audio screen.");				
 				break;
 			case 6:
 				// Video Setting? fps? something

src/screen/GameScreen.java

@@ -72,6 +72,8 @@ public class GameScreen extends Screen {
 	private boolean bonusLife;
 	/** Pause Screen */
 	private Screen pausescreen;
+
+	private Screen titlescreen;
 	/** Check if game is pause */
 	private boolean isPause;
 	/** Check ESC Cooldown */
@@ -146,7 +148,7 @@ public final int run() {
 
 		this.score += LIFE_SCORE * (this.lives - 1);
 		this.logger.info("Screen cleared with a score of " + this.score);
-		
+
 		return this.returnCode;
 	}
 
@@ -228,7 +230,17 @@ else if (this.enemyShipSpecialExplosionCooldown.checkFinished())
 
 		if (this.levelFinished && this.screenFinishedCooldown.checkFinished())
 			this.isRunning = false;
+		
+		if (this.returnCode == 1) {
+			this.isPause = false;
+
+			this.titlescreen = new screen.TitleScreen(this.width, this.height, this.fps);
+			returnCode = titlescreen.run();
 
+			this.levelFinished = true;
+			this.screenFinishedCooldown.reset();
+			this.isRunning = false;
+		}
 	}
 
 	/**