Merge pull request #3 from brarcher/staging

Better recovery from connection disconnects

README.md

@@ -15,10 +15,8 @@ The current version of _Protect Baby Monitor_ is rudimentary at best. It is capa
 of successfully advertising itself on the network, allows clients to connect,
 and streams audio. Room for improvement includes:
 
-1. Decent UI
+1. Robust usage of the AudioTrack API
-2. Hook into audio controls to adjust volume
+2. Handle dropped packets gracefully
-3. Robust usage of the AudioTrack API
-4. Handle dropped packets gracefully
 
 At the time this project was started there was no obvious open source solution for a
 baby monitor for Android. There are both free and paid options available for Android,
@@ -36,3 +34,5 @@ proposed changed.
 
 App icon originals from [WPZOOM](http://www.wpzoom.com/wpzoom/new-freebie-wpzoom-developer-icon-set-154-free-icons)
 and formatted using [Android Asset Studio](https://romannurik.github.io/AndroidAssetStudio/index.html).
+
+Audio file originals from [freesound](https://freesound.org).

src/protect/babymonitor/DiscoverActivity.java

@@ -27,7 +27,6 @@ import android.view.View;
 import android.widget.Button;
 import android.widget.TableLayout;
 import android.widget.TableRow;
-import android.widget.TextView;
 
 public class DiscoverActivity extends Activity
 {
@@ -99,13 +98,13 @@ public class DiscoverActivity extends Activity
                         public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode)
                         {
                             // Called when the resolve fails.  Use the error code to debug.
-                            Log.e(TAG, "Resolve failed" + errorCode);
+                            Log.e(TAG, "Resolve failed: error " + errorCode + " for service: " + serviceInfo);
                         }
 
                         @Override
                         public void onServiceResolved(final NsdServiceInfo serviceInfo)
                         {
-                            Log.e(TAG, "Resolve Succeeded. " + serviceInfo);
+                            Log.i(TAG, "Resolve Succeeded: " + serviceInfo);
 
                             DiscoverActivity.this.runOnUiThread(new Runnable()
                             {
@@ -159,7 +158,7 @@ public class DiscoverActivity extends Activity
             {
                 // When the network service is no longer available.
                 // Internal bookkeeping code goes here.
-                Log.e(TAG, "service lost" + service);
+                Log.e(TAG, "Service lost: " + service);
             }
 
             @Override

src/protect/babymonitor/ListenActivity.java

@@ -28,6 +28,7 @@ import android.app.Activity;
 import android.media.AudioFormat;
 import android.media.AudioManager;
 import android.media.AudioTrack;
+import android.media.MediaPlayer;
 import android.os.Bundle;
 import android.util.Log;
 import android.widget.TextView;
@@ -139,6 +140,14 @@ public class ListenActivity extends Activity
                     Log.e(TAG, "Failed to stream audio", e);
                 }
 
+                if(Thread.currentThread().isInterrupted() == false)
+                {
+                    // If this thread has not been interrupted, likely something
+                    // bad happened with the connection to the child device. Play
+                    // an alert to notify the user that the connection has been
+                    // interrupted.
+                    playAlert();
+
                     ListenActivity.this.runOnUiThread(new Runnable()
                     {
                         @Override
@@ -152,6 +161,7 @@ public class ListenActivity extends Activity
                         }
                     });
                 }
+            }
         });
 
         _listenThread.start();
@@ -165,4 +175,26 @@ public class ListenActivity extends Activity
 
         super.onDestroy();
     }
+
+    private void playAlert()
+    {
+        final MediaPlayer mp = MediaPlayer.create(this, R.raw.upward_beep_chromatic_fifths);
+        if(mp != null)
+        {
+            Log.i(TAG, "Playing alert");
+            mp.setOnCompletionListener(new MediaPlayer.OnCompletionListener()
+            {
+                @Override
+                public void onCompletion(MediaPlayer mp)
+                {
+                    mp.release();
+                }
+            });
+            mp.start();
+        }
+        else
+        {
+            Log.e(TAG, "Failed to play alert");
+        }
+    }
 }

src/protect/babymonitor/MonitorActivity.java

@@ -42,7 +42,6 @@ public class MonitorActivity extends Activity
 
     NsdManager.RegistrationListener _registrationListener;
 
-    ServerSocket _serverSocket;
     Thread _serviceThread;
 
     private void serviceConnection(Socket socket) throws IOException
@@ -67,6 +66,9 @@ public class MonitorActivity extends Activity
                 audioEncoding, bufferSize);
 
         byte[] buffer = new byte[bufferSize*2];
+
+        try
+        {
             audioRecord.startRecording();
 
             OutputStream out = socket.getOutputStream();
@@ -79,10 +81,12 @@ public class MonitorActivity extends Activity
                 int read = audioRecord.read(buffer, 0, bufferSize);
                 out.write(buffer, 0, read);
             }
-
+        }
-        socket.close();
+        finally
+        {
             audioRecord.stop();
         }
+    }
 
     @Override
     protected void onCreate(Bundle savedInstanceState)
@@ -94,71 +98,78 @@ public class MonitorActivity extends Activity
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_monitor);
 
-        try
-        {
-            // Initialize a server socket on the next available port.
-            _serverSocket = new ServerSocket(0);
-
-            // Store the chosen port.
-            int localPort = _serverSocket.getLocalPort();
-
-            registerService(localPort);
-
         _serviceThread = new Thread(new Runnable()
         {
             @Override
             public void run()
             {
+                while(Thread.currentThread().isInterrupted() == false)
+                {
+                    ServerSocket serverSocket = null;
+
+                    try
+                    {
+                        // Initialize a server socket on the next available port.
+                        serverSocket = new ServerSocket(0);
+
+                        // Store the chosen port.
+                        int localPort = serverSocket.getLocalPort();
+
+                        // Register the service so that parent devices can
+                        // locate the child device
+                        registerService(localPort);
+
+                        // Wait for a parent to find us and connect
+                        Socket socket = serverSocket.accept();
+                        Log.i(TAG, "Connection from parent device received");
+
+                        // We now have a client connection.
+                        // Unregister so no other clients will
+                        // attempt to connect
+                        serverSocket.close();
+                        serverSocket = null;
+                        unregisterService();
+
                         try
                         {
-                        Socket socket = _serverSocket.accept();
                             serviceConnection(socket);
                         }
+                        finally
+                        {
+                            socket.close();
+                        }
+                    }
                     catch(IOException e)
                     {
-                        Log.e(TAG, "Failed when serving connection", e);
+                        Log.e(TAG, "Connection failed", e);
                     }
 
+                    // If an exception was thrown before the connection
+                    // could be closed, clean it up
+                    if(serverSocket != null)
+                    {
                         try
                         {
-                        _serverSocket.close();
+                            serverSocket.close();
                         }
                         catch (IOException e)
                         {
-
+                            Log.e(TAG, "Failed to close stray connection", e);
+                        }
+                        serverSocket = null;
                     }
-
-                    MonitorActivity.this.runOnUiThread(new Runnable()
-                    {
-                        @Override
-                        public void run()
-                        {
-                            final TextView statusText = (TextView) findViewById(R.id.textStatus);
-                            statusText.setText(R.string.stopped);
                 }
-                    });
             }
         });
         _serviceThread.start();
     }
-        catch (IOException e)
-        {
-            Log.e(TAG, "Failed to create server socket", e);
-        }
-    }
 
     @Override
     protected void onDestroy()
     {
         Log.i(TAG, "Baby monitor stop");
 
-        if(_registrationListener != null)
+        unregisterService();
-        {
-            Log.i(TAG, "Unregistering monitoring service");
-
-            _nsdManager.unregisterService(_registrationListener);
-            _registrationListener = null;
-        }
 
         if(_serviceThread != null)
         {
@@ -190,7 +201,7 @@ public class MonitorActivity extends Activity
         return super.onOptionsItemSelected(item);
     }
 
-    public void registerService(int port)
+    private void registerService(int port)
     {
         NsdServiceInfo serviceInfo  = new NsdServiceInfo();
         serviceInfo.setServiceName("ProtectBabyMonitor");
@@ -249,4 +260,19 @@ public class MonitorActivity extends Activity
         _nsdManager.registerService(
                 serviceInfo, NsdManager.PROTOCOL_DNS_SD, _registrationListener);
     }
+
+    /**
+     * Uhregistered the service and assigns the listener
+     * to null.
+     */
+    private void unregisterService()
+    {
+        if(_registrationListener != null)
+        {
+            Log.i(TAG, "Unregistering monitoring service");
+
+            _nsdManager.unregisterService(_registrationListener);
+            _registrationListener = null;
+        }
+    }
 }