Pass around the candidate removals events in IOS clients

webrtc/examples/objc/AppRTCDemo/ARDSignalingMessage.m

 /*
  *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #import "ARDSignalingMessage.h"
 
 #import "WebRTC/RTCLogging.h"
 
 #import "ARDUtilities.h"
 #import "RTCIceCandidate+JSON.h"
 #import "RTCSessionDescription+JSON.h"
 
-static NSString const *kARDSignalingMessageTypeKey = @"type";
+static NSString * const kARDSignalingMessageTypeKey = @"type";
+static NSString * const kARDTypeValueRemoveCandidates = @"remove-candidates";
 
 @implementation ARDSignalingMessage
 
 @synthesize type = _type;
 
 - (instancetype)initWithType:(ARDSignalingMessageType)type {
   if (self = [super init]) {
     _type = type;
   }
   return self;
@@ skipping 10 matching lines @@
     RTCLogError(@"Error parsing signaling message JSON.");
     return nil;
   }
 
   NSString *typeString = values[kARDSignalingMessageTypeKey];
   ARDSignalingMessage *message = nil;
   if ([typeString isEqualToString:@"candidate"]) {
     RTCIceCandidate *candidate =
         [RTCIceCandidate candidateFromJSONDictionary:values];
     message = [[ARDICECandidateMessage alloc] initWithCandidate:candidate];
+  } else if ([typeString isEqualToString:kARDTypeValueRemoveCandidates]) {
+    RTCLogInfo(@"Received remove-candidates message");
+    NSArray<RTCIceCandidate *> *candidates =
+        [RTCIceCandidate candidatesFromJSONDictionary:values];
+    message = [[ARDICECandidateRemovalMessage alloc]
+                  initWithRemovedCandidates:candidates];
   } else if ([typeString isEqualToString:@"offer"] ||
              [typeString isEqualToString:@"answer"]) {
     RTCSessionDescription *description =
         [RTCSessionDescription descriptionFromJSONDictionary:values];
     message =
         [[ARDSessionDescriptionMessage alloc] initWithDescription:description];
   } else if ([typeString isEqualToString:@"bye"]) {
     message = [[ARDByeMessage alloc] init];
   } else {
     RTCLogError(@"Unexpected type: %@", typeString);
@@ skipping 17 matching lines @@
   }
   return self;
 }
 
 - (NSData *)JSONData {
   return [_candidate JSONData];
 }
 
 @end
 
+@implementation ARDICECandidateRemovalMessage
+
+@synthesize candidates = _candidates;
+
+- (instancetype)initWithRemovedCandidates:(
+    NSArray<RTCIceCandidate *> *)candidates {
+  NSParameterAssert(candidates.count);
+  if (self = [super initWithType:kARDSignalingMessageTypeCandidateRemoval]) {
+    _candidates = candidates;
+  }
+  return self;
+}
+
+- (NSData *)JSONData {
+  return
+      [RTCIceCandidate JSONDataForIceCandidates:_candidates
+                                       withType:kARDTypeValueRemoveCandidates];
+}
+
+@end
+
 @implementation ARDSessionDescriptionMessage
 
 @synthesize sessionDescription = _sessionDescription;
 
 - (instancetype)initWithDescription:(RTCSessionDescription *)description {
   ARDSignalingMessageType messageType = kARDSignalingMessageTypeOffer;
   RTCSdpType sdpType = description.type;
   switch (sdpType) {
     case RTCSdpTypeOffer:
       messageType = kARDSignalingMessageTypeOffer;
@@ skipping 27 matching lines @@
 - (NSData *)JSONData {
   NSDictionary *message = @{
     @"type": @"bye"
   };
   return [NSJSONSerialization dataWithJSONObject:message
                                          options:NSJSONWritingPrettyPrinted
                                            error:NULL];
 }
 
 @end