Merge pull request #44 from TouchInstinct/wifi_observe

Wifi state observable added

src/main/java/ru/touchin/templates/DeviceUtils.java

@@ -19,12 +19,17 @@
 
 package ru.touchin.templates;
 
+import android.content.BroadcastReceiver;
 import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
 import android.content.SharedPreferences;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
+import android.net.wifi.WifiManager;
 import android.provider.Settings;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 
@@ -32,6 +37,8 @@ import java.io.UnsupportedEncodingException;
 import java.util.UUID;
 
 import ru.touchin.roboswag.core.log.Lc;
+import rx.Observable;
+import rx.Subscriber;
 
 /**
  * Utility class that is providing common methods related to android device.
@@ -148,6 +155,28 @@ public final class DeviceUtils {
         return getNetworkType(context) != NetworkType.NONE;
     }
 
+
+    /**
+     * Returns observable to observe is device connected to Wi-Fi network.
+     *
+     * @param context Context to register BroadcastReceiver to check network state;
+     * @return Observable of Wi-Fi connection status.
+     */
+    @NonNull
+    public static Observable<Boolean> observeIsConnectedToWifi(@NonNull final Context context) {
+        return Observable.switchOnNext(Observable.fromCallable(() -> {
+            final WifiStateReceiver wifiStateReceiver = new WifiStateReceiver();
+            return Observable
+                    .<Boolean>create(subscriber -> {
+                        subscriber.onNext(DeviceUtils.getNetworkType(context) == DeviceUtils.NetworkType.WI_FI);
+                        wifiStateReceiver.setSubscriber(subscriber);
+                        context.registerReceiver(wifiStateReceiver, WifiStateReceiver.INTENT_FILTER);
+                    })
+                    .doOnUnsubscribe(() -> context.unregisterReceiver(wifiStateReceiver))
+                    .distinctUntilChanged();
+        }));
+    }
+
     private DeviceUtils() {
     }
 
@@ -193,4 +222,25 @@ public final class DeviceUtils {
 
     }
 
+    private static class WifiStateReceiver extends BroadcastReceiver {
+
+        private static final IntentFilter INTENT_FILTER = new IntentFilter(WifiManager.NETWORK_STATE_CHANGED_ACTION);
+
+        @Nullable
+        private Subscriber<? super Boolean> subscriber;
+
+        public void setSubscriber(@Nullable final Subscriber<? super Boolean> subscriber) {
+            this.subscriber = subscriber;
+        }
+
+        @Override
+        public void onReceive(@NonNull final Context context, @NonNull final Intent intent) {
+            final NetworkInfo networkInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
+            if (subscriber != null) {
+                subscriber.onNext(networkInfo != null && networkInfo.isConnected());
+            }
+        }
+
+    }
+
 }