Add a mDNS auto-discovery service

AndroidManifest.xml

@@ -11,6 +11,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
     
     <uses-feature android:name="android.hardware.touchscreen" android:required="false" />
 
@@ -39,6 +40,9 @@
                 android:name="android.support.PARENT_ACTIVITY"
                 android:value="com.limelight.Connection" />
         </activity>
+        <service
+            android:name="com.limelight.discovery.DiscoveryService"
+            android:label="mDNS PC Auto-Discovery Service" />
     </application>
 
 </manifest>

src/com/limelight/discovery/DiscoveryService.java

@@ -0,0 +1,114 @@
+package com.limelight.discovery;
+
+import java.io.IOException;
+import java.util.List;
+
+import com.limelight.nvstream.mdns.MdnsComputer;
+import com.limelight.nvstream.mdns.MdnsDiscoveryAgent;
+import com.limelight.nvstream.mdns.MdnsDiscoveryListener;
+
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.net.wifi.WifiManager;
+import android.net.wifi.WifiManager.MulticastLock;
+import android.os.Binder;
+import android.os.IBinder;
+
+public class DiscoveryService extends Service {
+	
+	private MdnsDiscoveryAgent discoveryAgent;
+	private MdnsDiscoveryListener boundListener;
+	private MulticastLock multicastLock;
+	
+	public class DiscoveryBinder extends Binder {
+		public void setListener(MdnsDiscoveryListener listener) {
+			boundListener = listener;
+		}
+		
+		public void startDiscovery(int queryIntervalMs) {
+			multicastLock.acquire();
+			discoveryAgent.startDiscovery(queryIntervalMs);
+		}
+		
+		public void stopDiscovery() {
+			discoveryAgent.stopDiscovery();
+			multicastLock.release();
+		}
+		
+		public List<MdnsComputer> getComputerSet() {
+			return discoveryAgent.getComputerSet();
+		}
+	}
+	
+	@Override
+	public void onCreate() {
+		WifiManager wifiMgr = (WifiManager) getSystemService(Context.WIFI_SERVICE);
+		multicastLock = wifiMgr.createMulticastLock("Limelight mDNS");
+		multicastLock.setReferenceCounted(false);
+		
+		// This pattern is nasty. We have to do it
+		// because we can't do network on the main thread
+		// even if it's non-blocking
+		Thread initThread = new Thread() {
+			@Override
+			public void run() {
+				try {
+					discoveryAgent = MdnsDiscoveryAgent.createDiscoveryAgent(new MdnsDiscoveryListener() {
+						@Override
+						public void notifyComputerAdded(MdnsComputer computer) {
+							if (boundListener != null) {
+								boundListener.notifyComputerAdded(computer);
+							}
+						}
+
+						@Override
+						public void notifyComputerRemoved(MdnsComputer computer) {
+							if (boundListener != null) {
+								boundListener.notifyComputerRemoved(computer);
+							}
+						}
+
+						@Override
+						public void notifyDiscoveryFailure(Exception e) {
+							if (boundListener != null) {
+								boundListener.notifyDiscoveryFailure(e);
+							}
+						}
+					});
+				} catch (IOException e) {
+					discoveryAgent = null;
+				}
+			}
+		};
+		initThread.start();
+		try {
+			initThread.join();
+		} catch (InterruptedException e) {
+			discoveryAgent = null;
+		}
+	}
+	
+	private DiscoveryBinder binder = new DiscoveryBinder();
+	
+	@Override
+	public IBinder onBind(Intent intent) {
+		// We should only be bindable if discovery can happen
+		if (discoveryAgent != null) {
+			return binder;
+		}
+		
+		return null;
+	}
+	
+	@Override
+	public boolean onUnbind(Intent intent) {
+		// Stop any discovery session
+		discoveryAgent.stopDiscovery();
+		multicastLock.release();
+		
+		// Unbind the listener
+		boundListener = null;
+		return false;
+	}
+}