Wait for network when websocket connection failed

app/src/main/java/com/github/gotify/service/WebSocketConnection.java

@@ -1,5 +1,7 @@
 package com.github.gotify.service;
 
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
 import android.os.Handler;
 import com.github.gotify.SSLSettings;
 import com.github.gotify.Utils;
@@ -16,6 +18,7 @@ import okhttp3.WebSocket;
 import okhttp3.WebSocketListener;
 
 public class WebSocketConnection {
+    private final ConnectivityManager connectivityManager;
     private OkHttpClient client;
 
     private final Handler handler = new Handler();
@@ -31,8 +34,14 @@ public class WebSocketConnection {
     private OnFailureCallback onFailure;
     private Runnable onReconnected;
     private boolean isClosed;
+    private Runnable onDisconnect;
 
-    WebSocketConnection(String baseUrl, SSLSettings settings, String token) {
+    WebSocketConnection(
+            String baseUrl,
+            SSLSettings settings,
+            String token,
+            ConnectivityManager connectivityManager) {
+        this.connectivityManager = connectivityManager;
         OkHttpClient.Builder builder =
                 new OkHttpClient.Builder()
                         .readTimeout(0, TimeUnit.MILLISECONDS)
@@ -66,6 +75,11 @@ public class WebSocketConnection {
         return this;
     }
 
+    synchronized WebSocketConnection onDisconnect(Runnable onDisconnect) {
+        this.onDisconnect = onDisconnect;
+        return this;
+    }
+
     synchronized WebSocketConnection onFailure(OnFailureCallback onFailure) {
         this.onFailure = onFailure;
         return this;
@@ -153,6 +167,13 @@ public class WebSocketConnection {
                     return;
                 }
 
+                NetworkInfo network = connectivityManager.getActiveNetworkInfo();
+                if (network == null || !network.isConnected()) {
+                    Log.i("WebSocket: Network not connected");
+                    onDisconnect.run();
+                    return;
+                }
+
                 int minutes = Math.min(errorCount * 2 + 1, 20);
 
                 Log.i("WebSocket: trying to restart in " + minutes + " minute(s)");