talk/app/webrtc/java/android/org/webrtc/NetworkMonitorAutoDetect.java - platform/external/webrtc - Git at Google

 /*
  * 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());
   }
 }
	/*
	* 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());
	}
	}