Create network change notifier.

talk/app/webrtc/java/android/org/webrtc/NetworkMonitorAutoDetect.java

Index: talk/app/webrtc/java/android/org/webrtc/NetworkMonitorAutoDetect.java
diff --git a/talk/app/webrtc/java/android/org/webrtc/NetworkMonitorAutoDetect.java b/talk/app/webrtc/java/android/org/webrtc/NetworkMonitorAutoDetect.java
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+/*
+ * libjingle
+ * Copyright 2015 Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.webrtc;
+
+import static android.net.NetworkCapabilities.NET_CAPABILITY_INTERNET;
+
+import android.Manifest.permission;
+import android.annotation.SuppressLint;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.pm.PackageManager;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkCapabilities;
+import android.net.NetworkInfo;
+import android.net.wifi.WifiInfo;
+import android.net.wifi.WifiManager;
+import android.os.Build;
+import android.telephony.TelephonyManager;
+import android.util.Log;
+
+/**
+ * Borrowed from Chromium's
+ * src/net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java
+ *
+ * Used by the NetworkMonitor to listen to platform changes in connectivity.
+ * Note that use of this class requires that the app have the platform
+ * ACCESS_NETWORK_STATE permission.
+ */
+public class NetworkMonitorAutoDetect extends BroadcastReceiver {
+  static enum ConnectionType {
+    CONNECTION_UNKNOWN,
+    CONNECTION_ETHERNET,
+    CONNECTION_WIFI,
+    CONNECTION_4G,
+    CONNECTION_3G,
+    CONNECTION_2G,
+    CONNECTION_BLUETOOTH,
+    CONNECTION_NONE
+  }
+
+  static class NetworkState {
+    private final boolean connected;
+    // Defined from ConnectivityManager.TYPE_XXX for non-mobile; for mobile, it is
+    // further divided into 2G, 3G, or 4G from the subtype.
+    private final int type;
+    // Defined from NetworkInfo.subtype, which is one of the TelephonyManager.NETWORK_TYPE_XXXs.
+    // Will be useful to find the maximum bandwidth.
+    private final int subtype;
+
+    public NetworkState(boolean connected, int type, int subtype) {
+      this.connected = connected;
+      this.type = type;
+      this.subtype = subtype;
+    }
+
+    public boolean isConnected() {
+      return connected;
+    }
+
+    public int getNetworkType() {
+      return type;
+    }
+
+    public int getNetworkSubType() {
+      return subtype;
+    }
+  }
+
+  /** Queries the ConnectivityManager for information about the current connection. */
+  static class ConnectivityManagerDelegate {
+    private final ConnectivityManager connectivityManager;
+
+    ConnectivityManagerDelegate(Context context) {
+      connectivityManager =
+          (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+    }
+
+    // For testing.
+    ConnectivityManagerDelegate() {
+      // All the methods below should be overridden.
+      connectivityManager = null;
+    }
+
+    /**
+     * Returns connection type and status information about the current
+     * default network.
+     */
+    NetworkState getNetworkState() {
+      return getNetworkState(connectivityManager.getActiveNetworkInfo());
+    }
+
+    /**
+     * Returns connection type and status information about |network|.
+     * Only callable on Lollipop and newer releases.
+     */
+    @SuppressLint("NewApi")
+    NetworkState getNetworkState(Network network) {
+      return getNetworkState(connectivityManager.getNetworkInfo(network));
+    }
+
+    /**
+     * Returns connection type and status information gleaned from networkInfo.
+     */
+    NetworkState getNetworkState(NetworkInfo networkInfo) {
+      if (networkInfo == null || !networkInfo.isConnected()) {
+        return new NetworkState(false, -1, -1);
+      }
+      return new NetworkState(true, networkInfo.getType(), networkInfo.getSubtype());
+    }
+
+    /**
+     * Returns all connected networks.
+     * Only callable on Lollipop and newer releases.
+     */
+    @SuppressLint("NewApi")
+    Network[] getAllNetworks() {
+      return connectivityManager.getAllNetworks();
+    }
+
+    /**
+     * Returns the NetID of the current default network. Returns
+     * INVALID_NET_ID if no current default network connected.
+     * Only callable on Lollipop and newer releases.
+     */
+    @SuppressLint("NewApi")
+    int getDefaultNetId() {
+      // Android Lollipop had no API to get the default network; only an
+      // API to return the NetworkInfo for the default network. To
+      // determine the default network one can find the network with
+      // type matching that of the default network.
+      final NetworkInfo defaultNetworkInfo = connectivityManager.getActiveNetworkInfo();
+      if (defaultNetworkInfo == null) {
+        return INVALID_NET_ID;
+      }
+      final Network[] networks = getAllNetworks();
+      int defaultNetId = INVALID_NET_ID;
+      for (Network network : networks) {
+        if (!hasInternetCapability(network)) {
+          continue;
+        }
+        final NetworkInfo networkInfo = connectivityManager.getNetworkInfo(network);
+        if (networkInfo != null && networkInfo.getType() == defaultNetworkInfo.getType()) {
+          // There should not be multiple connected networks of the
+          // same type. At least as of Android Marshmallow this is
+          // not supported. If this becomes supported this assertion
+          // may trigger. At that point we could consider using
+          // ConnectivityManager.getDefaultNetwork() though this
+          // may give confusing results with VPNs and is only
+          // available with Android Marshmallow.
+          assert defaultNetId == INVALID_NET_ID;
+          defaultNetId = networkToNetId(network);
+        }
+      }
+      return defaultNetId;
+    }
+
+    /**
+     * Returns true if {@code network} can provide Internet access. Can be used to
+     * ignore specialized networks (e.g. IMS, FOTA).
+     */
+    @SuppressLint("NewApi")
+    boolean hasInternetCapability(Network network) {
+      final NetworkCapabilities capabilities =
+          connectivityManager.getNetworkCapabilities(network);
+      return capabilities != null && capabilities.hasCapability(NET_CAPABILITY_INTERNET);
+    }
+  }
+
+  /** Queries the WifiManager for SSID of the current Wifi connection. */
+  static class WifiManagerDelegate {
+    private final Context context;
+    private final WifiManager wifiManager;
+    private final boolean hasWifiPermission;
+
+    WifiManagerDelegate(Context context) {
+      this.context = context;
+
+      hasWifiPermission = context.getPackageManager().checkPermission(
+          permission.ACCESS_WIFI_STATE, context.getPackageName())
+          == PackageManager.PERMISSION_GRANTED;
+      wifiManager = hasWifiPermission
+          ? (WifiManager) context.getSystemService(Context.WIFI_SERVICE) : null;
+    }
+
+    // For testing.
+    WifiManagerDelegate() {
+      // All the methods below should be overridden.
+      context = null;
+      wifiManager = null;
+      hasWifiPermission = false;
+    }
+
+    String getWifiSSID() {
+      final Intent intent = context.registerReceiver(null,
+          new IntentFilter(WifiManager.NETWORK_STATE_CHANGED_ACTION));
+      if (intent != null) {
+        final WifiInfo wifiInfo = intent.getParcelableExtra(WifiManager.EXTRA_WIFI_INFO);
+        if (wifiInfo != null) {
+          final String ssid = wifiInfo.getSSID();
+          if (ssid != null) {
+            return ssid;
+          }
+        }
+      }
+      return "";
+    }
+
+    boolean getHasWifiPermission() {
+      return hasWifiPermission;
+    }
+  }
+
+  static final int INVALID_NET_ID = -1;
+  private static final String TAG = "NetworkMonitorAutoDetect";
+  private static final int UNKNOWN_LINK_SPEED = -1;
+  private final IntentFilter intentFilter;
+
+  // Observer for the connection type change.
+  private final Observer observer;
+
+  private final Context context;
+  // connectivityManagerDelegates and wifiManagerDelegate are only non-final for testing.
+  private ConnectivityManagerDelegate connectivityManagerDelegate;
+  private WifiManagerDelegate wifiManagerDelegate;
+  private boolean isRegistered;
+  private ConnectionType connectionType;
+  private String wifiSSID;
+
+  /**
+   * Observer interface by which observer is notified of network changes.
+   */
+  public static interface Observer {
+    /**
+     * Called when default network changes.
+     */
+    public void onConnectionTypeChanged(ConnectionType newConnectionType);
+  }
+
+  /**
+   * Constructs a NetworkMonitorAutoDetect. Should only be called on UI thread.
+   */
+  public NetworkMonitorAutoDetect(Observer observer, Context context) {
+    this.observer = observer;
+    this.context = context;
+    connectivityManagerDelegate = new ConnectivityManagerDelegate(context);
+    wifiManagerDelegate = new WifiManagerDelegate(context);
+
+    final NetworkState networkState = connectivityManagerDelegate.getNetworkState();
+    connectionType = getCurrentConnectionType(networkState);
+    wifiSSID = getCurrentWifiSSID(networkState);
+    intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
+    registerReceiver();
+  }
+
+  /**
+   * Allows overriding the ConnectivityManagerDelegate for tests.
+   */
+  void setConnectivityManagerDelegateForTests(ConnectivityManagerDelegate delegate) {
+    connectivityManagerDelegate = delegate;
+  }
+
+  /**
+   * Allows overriding the WifiManagerDelegate for tests.
+   */
+  void setWifiManagerDelegateForTests(WifiManagerDelegate delegate) {
+    wifiManagerDelegate = delegate;
+  }
+
+  /**
+   * Returns whether the object has registered to receive network connectivity intents.
+   * Visible for testing.
+   */
+  boolean isReceiverRegisteredForTesting() {
+    return isRegistered;
+  }
+
+  public void destroy() {
+    unregisterReceiver();
+  }
+
+  /**
+   * Registers a BroadcastReceiver in the given context.
+   */
+  private void registerReceiver() {
+    if (!isRegistered) {
+      isRegistered = true;
+      context.registerReceiver(this, intentFilter);
+    }
+  }
+
+  /**
+   * Unregisters the BroadcastReceiver in the given context.
+   */
+  private void unregisterReceiver() {
+    if (isRegistered) {
+      isRegistered = false;
+      context.unregisterReceiver(this);
+    }
+  }
+
+  public NetworkState getCurrentNetworkState() {
+    return connectivityManagerDelegate.getNetworkState();
+  }
+
+  /**
+   * Returns NetID of device's current default connected network used for
+   * communication.
+   * Only implemented on Lollipop and newer releases, returns INVALID_NET_ID
+   * when not implemented.
+   */
+  public int getDefaultNetId() {
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+      return INVALID_NET_ID;
+    }
+    return connectivityManagerDelegate.getDefaultNetId();
+  }
+
+  public ConnectionType getCurrentConnectionType(NetworkState networkState) {
+    if (!networkState.isConnected()) {
+      return ConnectionType.CONNECTION_NONE;
+    }
+
+    switch (networkState.getNetworkType()) {
+      case ConnectivityManager.TYPE_ETHERNET:
+        return ConnectionType.CONNECTION_ETHERNET;
+      case ConnectivityManager.TYPE_WIFI:
+        return ConnectionType.CONNECTION_WIFI;
+      case ConnectivityManager.TYPE_WIMAX:
+        return ConnectionType.CONNECTION_4G;
+      case ConnectivityManager.TYPE_BLUETOOTH:
+        return ConnectionType.CONNECTION_BLUETOOTH;
+      case ConnectivityManager.TYPE_MOBILE:
+        // Use information from TelephonyManager to classify the connection.
+        switch (networkState.getNetworkSubType()) {
+          case TelephonyManager.NETWORK_TYPE_GPRS:
+          case TelephonyManager.NETWORK_TYPE_EDGE:
+          case TelephonyManager.NETWORK_TYPE_CDMA:
+          case TelephonyManager.NETWORK_TYPE_1xRTT:
+          case TelephonyManager.NETWORK_TYPE_IDEN:
+            return ConnectionType.CONNECTION_2G;
+          case TelephonyManager.NETWORK_TYPE_UMTS:
+          case TelephonyManager.NETWORK_TYPE_EVDO_0:
+          case TelephonyManager.NETWORK_TYPE_EVDO_A:
+          case TelephonyManager.NETWORK_TYPE_HSDPA:
+          case TelephonyManager.NETWORK_TYPE_HSUPA:
+          case TelephonyManager.NETWORK_TYPE_HSPA:
+          case TelephonyManager.NETWORK_TYPE_EVDO_B:
+          case TelephonyManager.NETWORK_TYPE_EHRPD:
+          case TelephonyManager.NETWORK_TYPE_HSPAP:
+            return ConnectionType.CONNECTION_3G;
+          case TelephonyManager.NETWORK_TYPE_LTE:
+            return ConnectionType.CONNECTION_4G;
+          default:
+            return ConnectionType.CONNECTION_UNKNOWN;
+        }
+      default:
+        return ConnectionType.CONNECTION_UNKNOWN;
+    }
+  }
+
+  private String getCurrentWifiSSID(NetworkState networkState) {
+    if (getCurrentConnectionType(networkState) != ConnectionType.CONNECTION_WIFI) return "";
+    return wifiManagerDelegate.getWifiSSID();
+  }
+
+  // BroadcastReceiver
+  @Override
+  public void onReceive(Context context, Intent intent) {
+    final NetworkState networkState = getCurrentNetworkState();
+    if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())) {
+      connectionTypeChanged(networkState);
+    }
+  }
+
+  private void connectionTypeChanged(NetworkState networkState) {
+    ConnectionType newConnectionType = getCurrentConnectionType(networkState);
+    String newWifiSSID = getCurrentWifiSSID(networkState);
+    if (newConnectionType == connectionType && newWifiSSID.equals(wifiSSID)) return;
+
+    connectionType = newConnectionType;
+    wifiSSID = newWifiSSID;
+    Log.d(TAG, "Network connectivity changed, type is: " + connectionType);
+    observer.onConnectionTypeChanged(newConnectionType);
+  }
+
+  /**
+   * Extracts NetID of network. Only available on Lollipop and newer releases.
+   */
+  @SuppressLint("NewApi")
+  private static int networkToNetId(Network network) {
+    // NOTE(pauljensen): This depends on Android framework implementation details.
+    // Fortunately this functionality is unlikely to ever change.
+    // TODO(honghaiz): When we update to Android M SDK, use Network.getNetworkHandle().
+    return Integer.parseInt(network.toString());
+  }
+}