Fixed bad architecture decision: set read timeout on tcp socket, so that it gets closed automatically after a set period of time. This way there's no need to invoke disconnect() when each activity pauses, so we don't have to maintain this control.

app/src/main/java/com/syncedsynapse/kore2/jsonrpc/HostConnection.java

@@ -15,7 +15,7 @@
  */
 package com.syncedsynapse.kore2.jsonrpc;
 
-import android.os.*;
+import android.os.Handler;
 import android.os.Process;
 import android.util.Base64;
 
@@ -24,7 +24,8 @@ import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.syncedsynapse.kore2.host.HostInfo;
-import com.syncedsynapse.kore2.jsonrpc.notification.*;
+import com.syncedsynapse.kore2.jsonrpc.notification.Input;
+import com.syncedsynapse.kore2.jsonrpc.notification.Player;
 import com.syncedsynapse.kore2.jsonrpc.notification.System;
 import com.syncedsynapse.kore2.utils.LogUtils;
 
@@ -37,7 +38,6 @@ import java.net.HttpURLConnection;
 import java.net.InetSocketAddress;
 import java.net.ProtocolException;
 import java.net.Socket;
-import java.net.SocketException;
 import java.net.URL;
 import java.util.HashMap;
 import java.util.concurrent.ExecutorService;
@@ -134,31 +134,33 @@ public class HostConnection {
 
     private ExecutorService executorService;
 
-    private final int connectionTimeout;
+    private final int connectTimeout;
 
-    private static final int DEFAULT_TIMEOUT = 10000; // ms
+    private static final int DEFAULT_CONNECT_TIMEOUT = 5000; // ms
+
+    private static final int TCP_READ_TIMEOUT = 30000; // ms
 
     /**
      * Creates a new host connection
      * @param hostInfo Host info object
      */
     public HostConnection(final HostInfo hostInfo) {
-        this(hostInfo, DEFAULT_TIMEOUT);
+        this(hostInfo, DEFAULT_CONNECT_TIMEOUT);
 	}
 
     /**
      * Creates a new host connection
      * @param hostInfo Host info object
-     * @param connectionTimeout Connection timeout in ms
+     * @param connectTimeout Connection timeout in ms
      */
-    public HostConnection(final HostInfo hostInfo, int connectionTimeout) {
+    public HostConnection(final HostInfo hostInfo, int connectTimeout) {
         this.hostInfo = hostInfo;
         // Start with the default host protocol
         this.protocol = hostInfo.getProtocol();
         // Create a single threaded executor
         this.executorService = Executors.newSingleThreadExecutor();
         // Set timeout
-        this.connectionTimeout = connectionTimeout;
+        this.connectTimeout = connectTimeout;
     }
 
     /**
@@ -356,8 +358,8 @@ public class HostConnection {
 //			LogUtils.LOGD(TAG, "Opening HTTP connection.");
 			HttpURLConnection connection = (HttpURLConnection) new URL(hostInfo.getJsonRpcHttpEndpoint()).openConnection();
 			connection.setRequestMethod("POST");
-			connection.setConnectTimeout(connectionTimeout);
-			//connection.setReadTimeout(connectionTimeout);
+			connection.setConnectTimeout(connectTimeout);
+			//connection.setReadTimeout(connectTimeout);
 			connection.setRequestProperty("Content-Type", "application/json");
 			connection.setDoOutput(true);
 
@@ -482,10 +484,6 @@ public class HostConnection {
 	 */
 	private <T> void executeThroughTcp(final ApiMethod<T> method, final ApiCallback<T> callback,
 									   final Handler handler) {
-
-		// TODO: We're going to create a background listener thread.
-		// Also create a thread that periodically checks if the connection should be shutdown
-		// based on not having activity. Use android timer or Thread.sleep
         String methodId = String.valueOf(method.getId());
 		try {
 			// Save this method/callback for later response
@@ -534,13 +532,11 @@ public class HostConnection {
 
 			Socket socket = new Socket();
 			final InetSocketAddress address = new InetSocketAddress(hostInfo.getAddress(), hostInfo.getTcpPort());
-			socket.setSoTimeout(0); // No read timeout. Read should block
-			socket.connect(address, connectionTimeout);
+            // We're setting a read timeout on the socket, so no need to explicitly close it
+			socket.setSoTimeout(TCP_READ_TIMEOUT);
+			socket.connect(address, connectTimeout);
 
 			return socket;
-		} catch (SocketException e) {
-			LogUtils.LOGW(TAG, "Failed to open TCP connection to host: " + hostInfo.getAddress());
-			throw new ApiException(ApiException.IO_EXCEPTION_WHILE_CONNECTING, e);
 		} catch (IOException e) {
 			LogUtils.LOGW(TAG, "Failed to open TCP connection to host: " + hostInfo.getAddress());
 			throw new ApiException(ApiException.IO_EXCEPTION_WHILE_CONNECTING, e);

app/src/main/java/com/syncedsynapse/kore2/ui/AddonsActivity.java

@@ -35,7 +35,7 @@ import com.syncedsynapse.kore2.utils.Utils;
  * Controls the presentation of Addons information (list, details)
  * All the information is presented by specific fragments
  */
-public class AddonsActivity extends HostConnectionActivity
+public class AddonsActivity extends BaseActivity
         implements AddonListFragment.OnAddonSelectedListener {
     private static final String TAG = LogUtils.makeLogTag(AddonsActivity.class);
 

app/src/main/java/com/syncedsynapse/kore2/ui/HostConnectionActivity.java

@@ -1,47 +0,0 @@
-/*
- * Copyright 2015 Synced Synapse. All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.syncedsynapse.kore2.ui;
-
-import android.os.Bundle;
-
-import com.syncedsynapse.kore2.host.HostManager;
-import com.syncedsynapse.kore2.jsonrpc.HostConnection;
-
-/**
- * This activity manages the closing of the {@link HostConnection} singleton provided by
- * {@link HostManager}.
- * All activities that plan to use the {@link HostConnection}, or their fragments do,
- * should inherit from this class to make sure the connection is closed onPause/
- */
-public class HostConnectionActivity extends BaseActivity {
-
-	@Override
-	protected void onCreate(Bundle savedInstanceState) {
-		super.onCreate(savedInstanceState);
-	}
-
-    @Override
-    public void onPause() {
-        super.onPause();
-
-        // Disconnect from the connections used in the fragments
-        HostConnection connection = HostManager.getInstance(this).getConnection();
-        if (connection != null) {
-            connection.disconnect();
-        }
-
-    }
-}

app/src/main/java/com/syncedsynapse/kore2/ui/MoviesActivity.java

@@ -35,7 +35,7 @@ import com.syncedsynapse.kore2.utils.Utils;
  * Controls the presentation of Movies information (list, details)
  * All the information is presented by specific fragments
  */
-public class MoviesActivity extends HostConnectionActivity
+public class MoviesActivity extends BaseActivity
         implements MovieListFragment.OnMovieSelectedListener {
     private static final String TAG = LogUtils.makeLogTag(MoviesActivity.class);
 

app/src/main/java/com/syncedsynapse/kore2/ui/MusicActivity.java

@@ -34,7 +34,7 @@ import com.syncedsynapse.kore2.utils.Utils;
  * Controls the presentation of Music information (list, details)
  * All the information is presented by specific fragments
  */
-public class MusicActivity extends HostConnectionActivity
+public class MusicActivity extends BaseActivity
         implements ArtistListFragment.OnArtistSelectedListener,
         AlbumListFragment.OnAlbumSelectedListener,
         AudioGenresListFragment.OnAudioGenreSelectedListener,

app/src/main/java/com/syncedsynapse/kore2/ui/RemoteActivity.java

@@ -51,7 +51,7 @@ import butterknife.ButterKnife;
 import butterknife.InjectView;
 
 
-public class RemoteActivity extends HostConnectionActivity
+public class RemoteActivity extends BaseActivity
         implements HostConnectionObserver.PlayerEventsObserver,
         NowPlayingFragment.NowPlayingListener,
         SendTextDialogFragment.SendTextDialogListener {

app/src/main/java/com/syncedsynapse/kore2/ui/TVShowsActivity.java

@@ -35,7 +35,7 @@ import com.syncedsynapse.kore2.utils.Utils;
  * Controls the presentation of TV Shows information (list, details)
  * All the information is presented by specific fragments
  */
-public class TVShowsActivity extends HostConnectionActivity
+public class TVShowsActivity extends BaseActivity
         implements TVShowListFragment.OnTVShowSelectedListener,
         TVShowEpisodeListFragment.OnEpisodeSelectedListener {
     private static final String TAG = LogUtils.makeLogTag(TVShowsActivity.class);