Add single response handler.

* Some calls might end being called twice from the native side. Even if we already cover this from the native side, add safe
check to avoid more than one call to the same flutter response

Author: Jeasmine

android/src/main/java/com/onesignal/flutter/OneSignalPlugin.java

@@ -17,13 +17,13 @@
 import com.onesignal.OSSubscriptionStateChanges;
 import com.onesignal.OneSignal;
 import com.onesignal.OneSignal.EmailUpdateError;
-import com.onesignal.OneSignal.EmailUpdateHandler;
 
 import org.json.JSONException;
 import org.json.JSONObject;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import io.flutter.plugin.common.MethodCall;
 import io.flutter.plugin.common.MethodChannel;
@@ -231,28 +231,7 @@ private void getDeviceState(Result reply) {
 
   private void postNotification(MethodCall call, final Result reply) {
     JSONObject json = new JSONObject((Map<String, Object>) call.arguments);
-    OneSignal.postNotification(json, new OneSignal.PostNotificationResponseHandler() {
-      @Override
-      public void onSuccess(JSONObject response) {
-        try {
-          replySuccess(reply, OneSignalSerializer.convertJSONObjectToHashMap(response));
-        } catch (JSONException e) {
-          replyError(reply, "OneSignal", "Encountered an error attempting to deserialize server response: " + e.getMessage(), null);
-        }
-      }
-
-      @Override
-      public void onFailure(final JSONObject response) {
-        try {
-          replyError(reply, "OneSignal",
-                  "Encountered an error attempting to post notification: " + response.toString(),
-                  OneSignalSerializer.convertJSONObjectToHashMap(response));
-        } catch (JSONException e) {
-          OneSignal.onesignalLog(OneSignal.LOG_LEVEL.ERROR,
-                  "Encountered an error attempting to deserialize server response: " + e.getMessage());
-        }
-      }
-    });
+    OneSignal.postNotification(json, new OSFlutterResultHandler(flutterRegistrar, channel, reply, "postNotification"));
   }
 
   private void promptLocation(Result reply) {
@@ -269,80 +248,22 @@ private void setEmail(MethodCall call, final Result reply) {
     String email = call.argument("email");
     String emailAuthHashToken = call.argument("emailAuthHashToken");
 
-    OneSignal.setEmail(email, emailAuthHashToken, new EmailUpdateHandler() {
-      @Override
-      public void onSuccess() {
-        replySuccess(reply, null);
-      }
-
-      @Override
-      public void onFailure(EmailUpdateError error) {
-        replyError(reply, "OneSignal",
-                "Encountered an error setting email: " + error.getMessage(),
-                null);
-      }
-    });
+    OneSignal.setEmail(email, emailAuthHashToken, new OSFlutterEmailHandle(flutterRegistrar, channel, reply, "setEmail"));
   }
 
   private void logoutEmail(final Result reply) {
-    OneSignal.logoutEmail(new EmailUpdateHandler() {
-      @Override
-      public void onSuccess() {
-        replySuccess(reply, null);
-      }
-
-      @Override
-      public void onFailure(EmailUpdateError error) {
-        replyError(reply, "OneSignal",
-                "Encountered an error loggoing out of email: " + error.getMessage(),
-                null);
-      }
-    });
+    OneSignal.logoutEmail(new OSFlutterEmailHandle(flutterRegistrar, channel, reply, "logoutEmail"));
   }
 
   private void setSMSNumber(MethodCall call, final Result reply) {
     String smsNumber = call.argument("smsNumber");
     String smsAuthHashToken = call.argument("smsAuthHashToken");
 
-    OneSignal.setSMSNumber(smsNumber, smsAuthHashToken, new OneSignal.OSSMSUpdateHandler() {
-      @Override
-      public void onSuccess(JSONObject result) {
-        try {
-          replySuccess(reply, OneSignalSerializer.convertJSONObjectToHashMap(result));
-        } catch (JSONException e) {
-          OneSignal.onesignalLog(OneSignal.LOG_LEVEL.ERROR,
-                  "Encountered an error attempting to deserialize server response for setSMSNumber: " + e.getMessage());
-        }
-      }
-
-      @Override
-      public void onFailure(OneSignal.OSSMSUpdateError error) {
-        replyError(reply, "OneSignal",
-                "Encountered an error setting SMS Number: " + error.getMessage(),
-                null);
-      }
-    });
+    OneSignal.setSMSNumber(smsNumber, smsAuthHashToken, new OSFlutterResultHandler(flutterRegistrar, channel, reply, "setSMSNumber"));
   }
 
   private void logoutSMSNumber(final Result reply) {
-    OneSignal.logoutSMSNumber(new OneSignal.OSSMSUpdateHandler() {
-      @Override
-      public void onSuccess(JSONObject result) {
-        try {
-          replySuccess(reply, OneSignalSerializer.convertJSONObjectToHashMap(result));
-        } catch (JSONException e) {
-          OneSignal.onesignalLog(OneSignal.LOG_LEVEL.ERROR,
-                  "Encountered an error attempting to deserialize server response for logoutSMSNumber: " + e.getMessage());
-        }
-      }
-
-      @Override
-      public void onFailure(OneSignal.OSSMSUpdateError error) {
-        replyError(reply, "OneSignal",
-                "Encountered an error logging out SMS number: " + error.getMessage(),
-                null);
-      }
-    });
+    OneSignal.logoutSMSNumber(new OSFlutterResultHandler(flutterRegistrar, channel, reply, "logoutSMSNumber"));
   }
 
   private void setLanguage(MethodCall call, final Result result) {
@@ -361,45 +282,11 @@ private void setExternalUserId(MethodCall call, final Result result) {
     if (authHashToken != null && authHashToken.length() == 0)
       authHashToken = null;
 
-    OneSignal.setExternalUserId(externalUserId, authHashToken, new OneSignal.OSExternalUserIdUpdateCompletionHandler() {
-      @Override
-      public void onSuccess(JSONObject results) {
-        try {
-          replySuccess(result, OneSignalSerializer.convertJSONObjectToHashMap(results));
-        } catch (JSONException e) {
-          OneSignal.onesignalLog(OneSignal.LOG_LEVEL.ERROR,
-                  "Encountered an error attempting to deserialize server response for setExternalUserId: " + e.getMessage());
-        }
-      }
-
-      @Override
-      public void onFailure(OneSignal.ExternalIdError error) {
-        replyError(result, "OneSignal",
-                "Encountered an error setting external id: " + error.getMessage(),
-                null);
-      }
-    });
+    OneSignal.setExternalUserId(externalUserId, authHashToken, new OSFlutterResultHandler(flutterRegistrar, channel, result, "setExternalUserId"));
   }
 
   private void removeExternalUserId(final Result result) {
-    OneSignal.removeExternalUserId(new OneSignal.OSExternalUserIdUpdateCompletionHandler() {
-      @Override
-      public void onSuccess(JSONObject results) {
-        try {
-          replySuccess(result, OneSignalSerializer.convertJSONObjectToHashMap(results));
-        } catch (JSONException e) {
-          OneSignal.onesignalLog(OneSignal.LOG_LEVEL.ERROR,
-                  "Encountered an error attempting to deserialize server response for removeExternalUserId: " + e.getMessage());
-        }
-      }
-
-      @Override
-      public void onFailure(OneSignal.ExternalIdError error) {
-        replyError(result, "OneSignal",
-                "Encountered an error removing external id: " + error.getMessage(),
-                null);
-      }
-    });
+    OneSignal.removeExternalUserId(new OSFlutterResultHandler(flutterRegistrar, channel, result, "removeExternalUserId"));
   }
 
   private void initNotificationOpenedHandlerParams() {
@@ -509,4 +396,90 @@ public void notificationWillShowInForeground(OSNotificationReceivedEvent notific
     }
   }
 
+  static class OSFlutterEmailHandle extends FlutterRegistrarResponder
+          implements OneSignal.EmailUpdateHandler {
+    private final Result result;
+    private final String methodName;
+    private final AtomicBoolean replySubmitted = new AtomicBoolean(false);
+
+    OSFlutterEmailHandle(PluginRegistry.Registrar flutterRegistrar, MethodChannel channel, Result res, String methodName) {
+        this.flutterRegistrar = flutterRegistrar;
+        this.channel = channel;
+        this.result = res;
+        this.methodName = methodName;
+    }
+
+    @Override
+    public void onSuccess() {
+      if (this.replySubmitted.getAndSet(true))
+          return;
+
+      replySuccess(result, null);
+    }
+
+    @Override
+    public void onFailure(EmailUpdateError error) {
+      if (this.replySubmitted.getAndSet(true))
+          return;
+
+      replyError(result, "OneSignal",
+              "Encountered an error when " + methodName + ": " + error.getMessage(),
+              null);
+    }
+  }
+
+  static class OSFlutterResultHandler extends FlutterRegistrarResponder
+            implements OneSignal.OSExternalUserIdUpdateCompletionHandler, OneSignal.OSSMSUpdateHandler, OneSignal.PostNotificationResponseHandler {
+    private final Result result;
+    private final String methodName;
+    private final AtomicBoolean replySubmitted = new AtomicBoolean(false);
+
+    OSFlutterResultHandler(PluginRegistry.Registrar flutterRegistrar, MethodChannel channel, Result res, String methodName) {
+        this.flutterRegistrar = flutterRegistrar;
+        this.channel = channel;
+        this.result = res;
+        this.methodName = methodName;
+    }
+
+    @Override
+    public void onSuccess(JSONObject results) {
+      if (this.replySubmitted.getAndSet(true))
+          return;
+
+      try {
+          replySuccess(result, OneSignalSerializer.convertJSONObjectToHashMap(results));
+      } catch (JSONException e) {
+          replyError(result, "OneSignal", "Encountered an error attempting to deserialize server response for " + methodName + ": " + e.getMessage(), null);
+      }
+    }
+
+    @Override
+    public void onFailure(OneSignal.OSSMSUpdateError error) {
+      if (this.replySubmitted.getAndSet(true))
+          return;
+
+      replyError(result, "OneSignal", "Encountered an error when " + methodName + " (" + error.getType() + "): " + error.getMessage(), null);
+    }
+
+    @Override
+    public void onFailure(OneSignal.ExternalIdError error) {
+      if (this.replySubmitted.getAndSet(true))
+          return;
+
+      replyError(result, "OneSignal", "Encountered an error when " + methodName + " (" + error.getType() + "): " + error.getMessage(), null);
+    }
+
+    @Override
+    public void onFailure(JSONObject response) {
+      if (this.replySubmitted.getAndSet(true))
+          return;
+
+      try {
+          replyError(result, "OneSignal", "Encountered an error attempting to " + methodName + " " + response.toString(), OneSignalSerializer.convertJSONObjectToHashMap(response));
+      } catch (JSONException jsonException) {
+          replyError(result, "OneSignal", "Encountered an error attempting to deserialize server response " + methodName + " " + jsonException.getMessage(), null);
+      }
+    }
+  }
+
 }