/*
* Copyright (C) 2006 The Android Open Source Project
*
* 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 android.net;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import java.util.HashMap;
import java.util.Iterator;
/**
* A wrapper for a broadcast receiver that provides network connectivity
* state information, independent of network type (mobile, Wi-Fi, etc.).
* {@hide}
*/
public class NetworkConnectivityListener {
private static final String TAG = "NetworkConnectivityListener";
private static final boolean DBG = false;
private Context mContext;
private HashMap<Handler, Integer> mHandlers = new HashMap<Handler, Integer>();
private State mState;
private boolean mListening;
private String mReason;
private boolean mIsFailover;
/** Network connectivity information */
private NetworkInfo mNetworkInfo;
/**
* In case of a Disconnect, the connectivity manager may have
* already established, or may be attempting to establish, connectivity
* with another network. If so, {@code mOtherNetworkInfo} will be non-null.
*/
private NetworkInfo mOtherNetworkInfo;
private ConnectivityBroadcastReceiver mReceiver;
private class ConnectivityBroadcastReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (!action.equals(ConnectivityManager.CONNECTIVITY_ACTION) ||
mListening == false) {
Log.w(TAG, "onReceived() called with " + mState.toString() + " and " + intent);
return;
}
boolean noConnectivity =
intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
if (noConnectivity) {
mState = State.NOT_CONNECTED;
} else {
mState = State.CONNECTED;
}
mNetworkInfo = (NetworkInfo)
intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
mOtherNetworkInfo = (NetworkInfo)
intent.getParcelableExtra(ConnectivityManager.EXTRA_OTHER_NETWORK_INFO);
mReason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON);
mIsFailover =
intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false);
if (DBG) {
Log.d(TAG, "onReceive(): mNetworkInfo=" + mNetworkInfo + " mOtherNetworkInfo = "
+ (mOtherNetworkInfo == null ? "[none]" : mOtherNetworkInfo +
" noConn=" + noConnectivity) + " mState=" + mState.toString());
}
// Notifiy any handlers.
Iterator<Handler> it = mHandlers.keySet().iterator();
while (it.hasNext()) {
Handler target = it.next();
Message message = Message.obtain(target, mHandlers.get(target));
target.sendMessage(message);
}
}
};
public enum State {
UNKNOWN,
/** This state is returned if there is connectivity to any network **/
CONNECTED,
/**
* This state is returned if there is no connectivity to any network. This is set
* to true under two circumstances:
* <ul>
* <li>When connectivity is lost to one network, and there is no other available
* network to attempt to switch to.</li>
* <li>When connectivity is lost to one network, and the attempt to switch to
* another network fails.</li>
*/
NOT_CONNECTED
}
/**
* Create a new NetworkConnectivityListener.
*/
public NetworkConnectivityListener() {
mState = State.UNKNOWN;
mReceiver = new ConnectivityBroadcastReceiver();
}
/**
* This method starts listening for network connectivity state changes.
* @param context
*/
public synchronized void startListening(Context context) {
if (!mListening) {
mContext = context;
IntentFilter filter = new IntentFilter();
filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
context.registerReceiver(mReceiver, filter);
mListening = true;
}
}
/**
* This method stops this class from listening for network changes.
*/
public synchronized void stopListening() {
if (mListening) {
mContext.unregisterReceiver(mReceiver);
mContext = null;
mNetworkInfo = null;
mOtherNetworkInfo = null;
mIsFailover = false;
mReason = null;
mListening = false;
}
}
/**
* This methods registers a Handler to be called back onto with the specified what code when
* the network connectivity state changes.
*
* @param target The target handler.
* @param what The what code to be used when posting a message to the handler.
*/
public void registerHandler(Handler target, int what) {
mHandlers.put(target, what);
}
/**
* This methods unregisters the specified Handler.
* @param target
*/
public void unregisterHandler(Handler target) {
mHandlers.remove(target);
}
public State getState() {
return mState;
}
/**
* Return the NetworkInfo associated with the most recent connectivity event.
* @return {@code NetworkInfo} for the network that had the most recent connectivity event.
*/
public NetworkInfo getNetworkInfo() {
return mNetworkInfo;
}
/**
* If the most recent connectivity event was a DISCONNECT, return
* any information supplied in the broadcast about an alternate
* network that might be available. If this returns a non-null
* value, then another broadcast should follow shortly indicating
* whether connection to the other network succeeded.
*
* @return NetworkInfo
*/
public NetworkInfo getOtherNetworkInfo() {
return mOtherNetworkInfo;
}
/**
* Returns true if the most recent event was for an attempt to switch over to
* a new network following loss of connectivity on another network.
* @return {@code true} if this was a failover attempt, {@code false} otherwise.
*/
public boolean isFailover() {
return mIsFailover;
}
/**
* An optional reason for the connectivity state change may have been supplied.
* This returns it.
* @return the reason for the state change, if available, or {@code null}
* otherwise.
*/
public String getReason() {
return mReason;
}
}
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