--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/src/main/java/com/five_ten_sg/connectbot/service/ConnectivityReceiver.java	Thu Dec 03 11:23:55 2015 -0800
@@ -0,0 +1,150 @@
+/**
+ *
+ */
+package com.five_ten_sg.connectbot.service;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
+import android.net.NetworkInfo.State;
+import android.net.wifi.WifiManager;
+import android.net.wifi.WifiManager.WifiLock;
+import android.util.Log;
+
+/**
+ * @author kroot
+ *
+ */
+public class ConnectivityReceiver extends BroadcastReceiver {
+    private static final String TAG = "ConnectBot.ConnectivityManager";
+
+    private boolean mIsConnected = false;
+
+    final private TerminalManager mTerminalManager;
+
+    final private WifiLock mWifiLock;
+
+    private int mNetworkRef = 0;
+
+    private boolean mLockingWifi;
+
+    private Object[] mLock = new Object[0];
+
+    public ConnectivityReceiver(TerminalManager manager, boolean lockingWifi) {
+        mTerminalManager = manager;
+        final ConnectivityManager cm =
+            (ConnectivityManager) manager.getSystemService(Context.CONNECTIVITY_SERVICE);
+        final WifiManager wm = (WifiManager) manager.getSystemService(Context.WIFI_SERVICE);
+        mWifiLock = wm.createWifiLock(TAG);
+        final NetworkInfo info = cm.getActiveNetworkInfo();
+
+        if (info != null) {
+            mIsConnected = (info.getState() == State.CONNECTED);
+        }
+
+        mLockingWifi = lockingWifi;
+        final IntentFilter filter = new IntentFilter();
+        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
+        manager.registerReceiver(this, filter);
+    }
+
+    /* (non-Javadoc)
+     * @see android.content.BroadcastReceiver#onReceive(android.content.Context, android.content.Intent)
+     */
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        final String action = intent.getAction();
+
+        if (!action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
+            Log.w(TAG, "onReceived() called: " + intent);
+            return;
+        }
+
+        boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
+        boolean isFailover = intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false);
+        Log.d(TAG, "onReceived() called; noConnectivity? " + noConnectivity + "; isFailover? " + isFailover);
+
+        if (noConnectivity && !isFailover && mIsConnected) {
+            mIsConnected = false;
+            mTerminalManager.onConnectivityLost();
+        }
+        else if (!mIsConnected) {
+            NetworkInfo info = (NetworkInfo) intent.getExtras()
+                               .get(ConnectivityManager.EXTRA_NETWORK_INFO);
+
+            if (mIsConnected = (info.getState() == State.CONNECTED)) {
+                mTerminalManager.onConnectivityRestored();
+            }
+        }
+    }
+
+    /**
+     *
+     */
+    public void cleanup() {
+        if (mWifiLock.isHeld())
+            mWifiLock.release();
+
+        mTerminalManager.unregisterReceiver(this);
+    }
+
+    /**
+     * Increase the number of things using the network. Acquire a Wi-Fi lock
+     * if necessary.
+     */
+    public void incRef() {
+        synchronized (mLock) {
+            mNetworkRef  += 1;
+            acquireWifiLockIfNecessaryLocked();
+        }
+    }
+
+    /**
+     * Decrease the number of things using the network. Release the Wi-Fi lock
+     * if necessary.
+     */
+    public void decRef() {
+        synchronized (mLock) {
+            mNetworkRef -= 1;
+            releaseWifiLockIfNecessaryLocked();
+        }
+    }
+
+    /**
+     * @param mLockingWifi
+     */
+    public void setWantWifiLock(boolean lockingWifi) {
+        synchronized (mLock) {
+            mLockingWifi = lockingWifi;
+
+            if (mLockingWifi) {
+                acquireWifiLockIfNecessaryLocked();
+            }
+            else {
+                releaseWifiLockIfNecessaryLocked();
+            }
+        }
+    }
+
+    private void acquireWifiLockIfNecessaryLocked() {
+        if (mLockingWifi && mNetworkRef > 0 && !mWifiLock.isHeld()) {
+            mWifiLock.acquire();
+        }
+    }
+
+    private void releaseWifiLockIfNecessaryLocked() {
+        if (mNetworkRef == 0 && mWifiLock.isHeld()) {
+            mWifiLock.release();
+        }
+    }
+
+    /**
+     * @return whether we're connected to a network
+     */
+    public boolean isConnected() {
+        return mIsConnected;
+    }
+}