Merged Engine into the Core! Woooo open source

src/resources/control/IntentManager.java

@@ -0,0 +1,130 @@
+package resources.control;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.TimeUnit;
+
+
+/**
+ * Don't you dare make this public.
+ */
+class IntentManager {
+	
+	private static final IntentManager instance = new IntentManager();
+	private final Runnable broadcastRunnable;
+	private ExecutorService broadcastThreads;
+	private Map <String, List<IntentReceiver>> intentRegistrations;
+	private Queue <Intent> intentQueue;
+	private boolean initialized = false;
+	private boolean terminated = false;
+	
+	public IntentManager() {
+		initialize();
+		broadcastRunnable = new Runnable() {
+			public void run() {
+				Intent i = intentQueue.poll();
+				if (i != null)
+					broadcast(i);
+			}
+		};
+	}
+	
+	public void initialize() {
+		if (!initialized) {
+			broadcastThreads = Executors.newCachedThreadPool();
+			intentRegistrations = new HashMap<String, List<IntentReceiver>>();
+			intentQueue = new ConcurrentLinkedQueue<Intent>();
+			initialized = true;
+			terminated = false;
+		}
+	}
+	
+	public void terminate() {
+		if (!terminated) {
+			broadcastThreads.shutdownNow();
+			try {
+				broadcastThreads.awaitTermination(5, TimeUnit.SECONDS);
+			} catch (InterruptedException e) {
+				e.printStackTrace();
+			}
+			initialized = false;
+			terminated = true;
+		}
+	}
+	
+	public void broadcastIntent(Intent i) {
+		if (i == null)
+			throw new NullPointerException("Intent cannot be null!");
+		intentQueue.add(i);
+		try { broadcastThreads.submit(broadcastRunnable); }
+		catch (RejectedExecutionException e) { } // This error is thrown when the server is being shut down
+	}
+	
+	public void registerForIntent(String intentType, IntentReceiver r) {
+		if (r == null)
+			throw new NullPointerException("Cannot register a null value for an intent");
+		synchronized (intentRegistrations) {
+			List <IntentReceiver> intents = intentRegistrations.get(intentType);
+			if (intents == null) {
+				intents = new ArrayList<IntentReceiver>();
+				intentRegistrations.put(intentType, intents);
+			}
+			synchronized (intents) {
+				intents.add(r);
+			}
+		}
+	}
+	
+	public void unregisterForIntent(String intentType, IntentReceiver r) {
+		if (r == null)
+			return;
+		synchronized (intentRegistrations) {
+			if (!intentRegistrations.containsKey(intentType))
+				return;
+			List<IntentReceiver> receivers = intentRegistrations.get(intentType);
+			for (IntentReceiver recv : receivers) {
+				if (r == recv || r.equals(recv)) {
+					r = recv;
+					break;
+				}
+			}
+			receivers.remove(r);
+		}
+	}
+	
+	private void broadcast(Intent i) {
+		List <IntentReceiver> receivers;
+		synchronized (intentRegistrations) {
+			receivers = intentRegistrations.get(i.getType());
+		}
+		if (receivers == null)
+			return;
+		synchronized (receivers) {
+			for (IntentReceiver r : receivers) {
+				broadcast(r, i);
+			}
+		}
+		i.markAsComplete();
+	}
+	
+	private void broadcast(IntentReceiver r, Intent i) {
+		try {
+			r.onIntentReceived(i);
+		} catch (Exception e) {
+			System.err.println("Fatal Exception while processing intent: " + i);
+			e.printStackTrace();
+		}
+	}
+	
+	public static IntentManager getInstance() {
+		return instance;
+	}
+	
+}