examples/ios/AppRTCDemo/APPRTCAppDelegate.m - external/webrtc/stable/talk - Git at Google

 /*
  * libjingle
  * Copyright 2013, Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
  *     this list of conditions and the following disclaimer in the documentation
  *     and/or other materials provided with the distribution.
  *  3. The name of the author may not be used to endorse or promote products
  *     derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #import "APPRTCAppDelegate.h"

 #import "APPRTCViewController.h"
 #import "RTCICECandidate.h"
 #import "RTCICEServer.h"
 #import "RTCMediaConstraints.h"
 #import "RTCMediaStream.h"
 #import "RTCPair.h"
 #import "RTCPeerConnection.h"
 #import "RTCPeerConnectionDelegate.h"
 #import "RTCPeerConnectionFactory.h"
 #import "RTCSessionDescription.h"

 @interface PCObserver : NSObject<RTCPeerConnectionDelegate>

 - (id)initWithDelegate:(id<APPRTCSendMessage>)delegate;

 @end

 @implementation PCObserver {
   id<APPRTCSendMessage> _delegate;
 }

 - (id)initWithDelegate:(id<APPRTCSendMessage>)delegate {
   if (self = [super init]) {
     _delegate = delegate;
   }
   return self;
 }

 - (void)peerConnectionOnError:(RTCPeerConnection *)peerConnection {
   NSLog(@"PCO onError.");
   NSAssert(NO, @"PeerConnection failed.");
 }

 - (void)peerConnection:(RTCPeerConnection *)peerConnection
     signalingStateChanged:(RTCSignalingState)stateChanged {
   NSLog(@"PCO onSignalingStateChange: %d", stateChanged);
 }

 - (void)peerConnection:(RTCPeerConnection *)peerConnection
              addedStream:(RTCMediaStream *)stream {
   NSLog(@"PCO onAddStream.");
   dispatch_async(dispatch_get_main_queue(), ^(void) {
     NSAssert([stream.audioTracks count] >= 1,
              @"Expected at least 1 audio stream");
     //NSAssert([stream.videoTracks count] >= 1,
     //         @"Expected at least 1 video stream");
     // TODO(hughv): Add video support
   });
 }

 - (void)peerConnection:(RTCPeerConnection *)peerConnection
          removedStream:(RTCMediaStream *)stream {
   NSLog(@"PCO onRemoveStream.");
   // TODO(hughv): Remove video track.
 }

 - (void)
     peerConnectionOnRenegotiationNeeded:(RTCPeerConnection *)peerConnection {
   NSLog(@"PCO onRenegotiationNeeded.");
   // TODO(hughv): Handle this.
 }

 - (void)peerConnection:(RTCPeerConnection *)peerConnection
        gotICECandidate:(RTCICECandidate *)candidate {
   NSLog(@"PCO onICECandidate.\n  Mid[%@] Index[%d] Sdp[%@]",
         candidate.sdpMid,
         candidate.sdpMLineIndex,
         candidate.sdp);
   NSDictionary *json =
       @{ @"type" : @"candidate",
          @"label" : [NSNumber numberWithInt:candidate.sdpMLineIndex],
          @"id" : candidate.sdpMid,
          @"candidate" : candidate.sdp };
   NSError *error;
   NSData *data =
       [NSJSONSerialization dataWithJSONObject:json options:0 error:&error];
   if (!error) {
     [_delegate sendData:data];
   } else {
     NSAssert(NO, @"Unable to serialize JSON object with error: %@",
              error.localizedDescription);
   }
 }

 - (void)peerConnection:(RTCPeerConnection *)peerConnection
     iceGatheringChanged:(RTCICEGatheringState)newState {
   NSLog(@"PCO onIceGatheringChange. %d", newState);
 }

 - (void)peerConnection:(RTCPeerConnection *)peerConnection
     iceConnectionChanged:(RTCICEConnectionState)newState {
   NSLog(@"PCO onIceConnectionChange. %d", newState);
   if (newState == RTCICEConnectionConnected)
     [self displayLogMessage:@"ICE Connection Connected."];
   NSAssert(newState != RTCICEConnectionFailed, @"ICE Connection failed!");
 }

 - (void)displayLogMessage:(NSString *)message {
   [_delegate displayLogMessage:message];
 }

 @end

 @interface APPRTCAppDelegate ()

 @property(nonatomic, strong) APPRTCAppClient *client;
 @property(nonatomic, strong) PCObserver *pcObserver;
 @property(nonatomic, strong) RTCPeerConnection *peerConnection;
 @property(nonatomic, strong) RTCPeerConnectionFactory *peerConnectionFactory;
 @property(nonatomic, strong) NSMutableArray *queuedRemoteCandidates;

 @end

 @implementation APPRTCAppDelegate

 @synthesize window = _window;
 @synthesize viewController = _viewController;
 @synthesize client = _client;
 @synthesize pcObserver = _pcObserver;
 @synthesize peerConnection = _peerConnection;
 @synthesize peerConnectionFactory = _peerConnectionFactory;
 @synthesize queuedRemoteCandidates = _queuedRemoteCandidates;

 #pragma mark - UIApplicationDelegate methods

 - (BOOL)application:(UIApplication *)application
     didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
   [RTCPeerConnectionFactory initializeSSL];
   self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
   self.viewController =
       [[APPRTCViewController alloc] initWithNibName:@"APPRTCViewController"
                                              bundle:nil];
   self.window.rootViewController = self.viewController;
   [self.window makeKeyAndVisible];
   return YES;
 }

 - (void)applicationWillResignActive:(UIApplication *)application {
   [self displayLogMessage:@"Application lost focus, connection broken."];
   [self disconnect];
   [self.viewController resetUI];
 }

 - (void)applicationDidEnterBackground:(UIApplication *)application {
 }

 - (void)applicationWillEnterForeground:(UIApplication *)application {
 }

 - (void)applicationDidBecomeActive:(UIApplication *)application {
 }

 - (void)applicationWillTerminate:(UIApplication *)application {
 }

 - (BOOL)application:(UIApplication *)application
               openURL:(NSURL *)url
     sourceApplication:(NSString *)sourceApplication
            annotation:(id)annotation {
   if (self.client) {
     return NO;
   }
   self.client = [[APPRTCAppClient alloc] init];
   self.client.ICEServerDelegate = self;
   self.client.messageHandler = self;
   [self.client connectToRoom:url];
   return YES;
 }

 - (void)displayLogMessage:(NSString *)message {
   NSLog(@"%@", message);
   [self.viewController displayText:message];
 }

 #pragma mark - RTCSendMessage method

 - (void)sendData:(NSData *)data {
   [self.client sendData:data];
 }

 #pragma mark - ICEServerDelegate method

 - (void)onICEServers:(NSArray *)servers {
   self.queuedRemoteCandidates = [NSMutableArray array];
   self.peerConnectionFactory = [[RTCPeerConnectionFactory alloc] init];
   RTCMediaConstraints *constraints = [[RTCMediaConstraints alloc] init];
   self.pcObserver = [[PCObserver alloc] initWithDelegate:self];
   self.peerConnection =
       [self.peerConnectionFactory peerConnectionWithICEServers:servers
                                                    constraints:constraints
                                                       delegate:self.pcObserver];
   RTCMediaStream *lms =
       [self.peerConnectionFactory mediaStreamWithLabel:@"ARDAMS"];
   // TODO(hughv): Add video.
   [lms addAudioTrack:[self.peerConnectionFactory audioTrackWithID:@"ARDAMSa0"]];
   [self.peerConnection addStream:lms constraints:constraints];
   [self displayLogMessage:@"onICEServers - add local stream."];
 }

 #pragma mark - GAEMessageHandler methods

 - (void)onOpen {
   [self displayLogMessage:@"GAE onOpen - create offer."];
   RTCPair *audio =
       [[RTCPair alloc] initWithKey:@"OfferToReceiveAudio" value:@"true"];
   // TODO(hughv): Add video.
   //  RTCPair *video = [[RTCPair alloc] initWithKey:@"OfferToReceiveVideo"
   //                                          value:@"true"];
   NSArray *mandatory = @[ audio /*, video*/ ];
   RTCMediaConstraints *constraints =
       [[RTCMediaConstraints alloc] initWithMandatoryConstraints:mandatory
                                             optionalConstraints:nil];
   [self.peerConnection createOfferWithDelegate:self constraints:constraints];
   [self displayLogMessage:@"PC - createOffer."];
 }

 - (void)onMessage:(NSString *)data {
   NSString *message = [self unHTMLifyString:data];
   NSError *error;
   NSDictionary *objects = [NSJSONSerialization
       JSONObjectWithData:[message dataUsingEncoding:NSUTF8StringEncoding]
                  options:0
                    error:&error];
   NSAssert(!error,
            @"%@",
            [NSString stringWithFormat:@"Error: %@", error.description]);
   NSAssert([objects count] > 0, @"Invalid JSON object");
   NSString *value = [objects objectForKey:@"type"];
   [self displayLogMessage:
           [NSString stringWithFormat:@"GAE onMessage type - %@", value]];
   if ([value compare:@"candidate"] == NSOrderedSame) {
     NSString *mid = [objects objectForKey:@"id"];
     NSNumber *sdpLineIndex = [objects objectForKey:@"label"];
     NSString *sdp = [objects objectForKey:@"candidate"];
     RTCICECandidate *candidate =
         [[RTCICECandidate alloc] initWithMid:mid
                                        index:sdpLineIndex.intValue
                                          sdp:sdp];
     if (self.queuedRemoteCandidates) {
       [self.queuedRemoteCandidates addObject:candidate];
     } else {
       [self.peerConnection addICECandidate:candidate];
     }
   } else if (([value compare:@"offer"] == NSOrderedSame) ||
              ([value compare:@"answer"] == NSOrderedSame)) {
     NSString *sdpString = [objects objectForKey:@"sdp"];
     RTCSessionDescription *sdp = [[RTCSessionDescription alloc]
         initWithType:value sdp:[APPRTCAppDelegate preferISAC:sdpString]];
     [self.peerConnection setRemoteDescriptionWithDelegate:self
                                        sessionDescription:sdp];
     [self displayLogMessage:@"PC - setRemoteDescription."];
   } else if ([value compare:@"bye"] == NSOrderedSame) {
     [self disconnect];
   } else {
     NSAssert(NO, @"Invalid message: %@", data);
   }
 }

 - (void)onClose {
   [self displayLogMessage:@"GAE onClose."];
   [self disconnect];
 }

 - (void)onError:(int)code withDescription:(NSString *)description {
   [self displayLogMessage:
           [NSString stringWithFormat:@"GAE onError:  %@", description]];
   [self disconnect];
 }

 #pragma mark - RTCSessionDescriptonDelegate methods

 // Match |pattern| to |string| and return the first group of the first
 // match, or nil if no match was found.
 + (NSString *)firstMatch:(NSRegularExpression *)pattern
               withString:(NSString *)string {
   NSTextCheckingResult* result =
     [pattern firstMatchInString:string
                         options:0
                           range:NSMakeRange(0, [string length])];
   if (!result)
     return nil;
   return [string substringWithRange:[result rangeAtIndex:1]];
 }

 // Mangle |origSDP| to prefer the ISAC/16k audio codec.
 + (NSString *)preferISAC:(NSString *)origSDP {
   int mLineIndex = -1;
   NSString* isac16kRtpMap = nil;
   NSArray* lines = [origSDP componentsSeparatedByString:@"\n"];
   NSRegularExpression* isac16kRegex = [NSRegularExpression
       regularExpressionWithPattern:@"^a=rtpmap:(\\d+) ISAC/16000[\r]?$"
                            options:0
                              error:nil];
   for (int i = 0;
        (i < [lines count]) && (mLineIndex == -1 || isac16kRtpMap == nil);
        ++i) {
     NSString* line = [lines objectAtIndex:i];
     if ([line hasPrefix:@"m=audio "]) {
       mLineIndex = i;
       continue;
     }
     isac16kRtpMap = [self firstMatch:isac16kRegex withString:line];
   }
   if (mLineIndex == -1) {
     NSLog(@"No m=audio line, so can't prefer iSAC");
     return origSDP;
   }
   if (isac16kRtpMap == nil) {
     NSLog(@"No ISAC/16000 line, so can't prefer iSAC");
     return origSDP;
   }
   NSArray* origMLineParts =
       [[lines objectAtIndex:mLineIndex] componentsSeparatedByString:@" "];
   NSMutableArray* newMLine =
       [NSMutableArray arrayWithCapacity:[origMLineParts count]];
   int origPartIndex = 0;
   // Format is: m=<media> <port> <proto> <fmt> ...
   [newMLine addObject:[origMLineParts objectAtIndex:origPartIndex++]];
   [newMLine addObject:[origMLineParts objectAtIndex:origPartIndex++]];
   [newMLine addObject:[origMLineParts objectAtIndex:origPartIndex++]];
   [newMLine addObject:isac16kRtpMap];
   for (; origPartIndex < [origMLineParts count]; ++origPartIndex) {
     if ([isac16kRtpMap compare:[origMLineParts objectAtIndex:origPartIndex]]
         != NSOrderedSame) {
       [newMLine addObject:[origMLineParts objectAtIndex:origPartIndex]];
     }
   }
   NSMutableArray* newLines = [NSMutableArray arrayWithCapacity:[lines count]];
   [newLines addObjectsFromArray:lines];
   [newLines replaceObjectAtIndex:mLineIndex
                       withObject:[newMLine componentsJoinedByString:@" "]];
   return [newLines componentsJoinedByString:@"\n"];
 }

 - (void)peerConnection:(RTCPeerConnection *)peerConnection
     didCreateSessionDescription:(RTCSessionDescription *)origSdp
                           error:(NSError *)error {
   if (error) {
     [self displayLogMessage:@"SDP onFailure."];
     NSAssert(NO, error.description);
     return;
   }

   [self displayLogMessage:@"SDP onSuccess(SDP) - set local description."];
   RTCSessionDescription* sdp =
       [[RTCSessionDescription alloc]
           initWithType:origSdp.type
                    sdp:[APPRTCAppDelegate preferISAC:origSdp.description]];
   [self.peerConnection setLocalDescriptionWithDelegate:self
                                     sessionDescription:sdp];
   [self displayLogMessage:@"PC setLocalDescription."];
   dispatch_async(dispatch_get_main_queue(), ^(void) {
     NSDictionary *json = @{ @"type" : sdp.type, @"sdp" : sdp.description };
     NSError *error;
     NSData *data =
         [NSJSONSerialization dataWithJSONObject:json options:0 error:&error];
     NSAssert(!error,
              @"%@",
              [NSString stringWithFormat:@"Error: %@", error.description]);
     [self sendData:data];
   });
 }

 - (void)peerConnection:(RTCPeerConnection *)peerConnection
     didSetSessionDescriptionWithError:(NSError *)error {
   if (error) {
     [self displayLogMessage:@"SDP onFailure."];
     NSAssert(NO, error.description);
     return;
   }

   [self displayLogMessage:@"SDP onSuccess() - possibly drain candidates"];
   dispatch_async(dispatch_get_main_queue(), ^(void) {
     // TODO(hughv): Handle non-initiator case.  http://s10/46622051
     if (self.peerConnection.remoteDescription) {
       [self displayLogMessage:@"SDP onSuccess - drain candidates"];
       [self drainRemoteCandidates];
     }
   });
 }

 #pragma mark - internal methods

 - (void)disconnect {
   [self.client
       sendData:[@"{\"type\": \"bye\"}" dataUsingEncoding:NSUTF8StringEncoding]];
   self.peerConnection = nil;
   self.peerConnectionFactory = nil;
   self.pcObserver = nil;
   self.client.ICEServerDelegate = nil;
   self.client.messageHandler = nil;
   self.client = nil;
   [RTCPeerConnectionFactory deinitializeSSL];
 }

 - (void)drainRemoteCandidates {
   for (RTCICECandidate *candidate in self.queuedRemoteCandidates) {
     [self.peerConnection addICECandidate:candidate];
   }
   self.queuedRemoteCandidates = nil;
 }

 - (NSString *)unHTMLifyString:(NSString *)base {
   // TODO(hughv): Investigate why percent escapes are being added.  Removing
   // them isn't necessary on Android.
   // convert HTML escaped characters to UTF8.
   NSString *removePercent =
       [base stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
   // remove leading and trailing ".
   NSRange range;
   range.length = [removePercent length] - 2;
   range.location = 1;
   NSString *removeQuotes = [removePercent substringWithRange:range];
   // convert \" to ".
   NSString *removeEscapedQuotes =
       [removeQuotes stringByReplacingOccurrencesOfString:@"\\\""
                                               withString:@"\""];
   // convert \\ to \.
   NSString *removeBackslash =
       [removeEscapedQuotes stringByReplacingOccurrencesOfString:@"\\\\"
                                                      withString:@"\\"];
   return removeBackslash;
 }

 @end
	/*
	* libjingle
	* Copyright 2013, Google Inc.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* 1. Redistributions of source code must retain the above copyright notice,
	* this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials provided with the distribution.
	* 3. The name of the author may not be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
	* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
	* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
	* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#import "APPRTCAppDelegate.h"

	#import "APPRTCViewController.h"
	#import "RTCICECandidate.h"
	#import "RTCICEServer.h"
	#import "RTCMediaConstraints.h"
	#import "RTCMediaStream.h"
	#import "RTCPair.h"
	#import "RTCPeerConnection.h"
	#import "RTCPeerConnectionDelegate.h"
	#import "RTCPeerConnectionFactory.h"
	#import "RTCSessionDescription.h"

	@interface PCObserver : NSObject<RTCPeerConnectionDelegate>

	- (id)initWithDelegate:(id<APPRTCSendMessage>)delegate;

	@end

	@implementation PCObserver {
	id<APPRTCSendMessage> _delegate;
	}

	- (id)initWithDelegate:(id<APPRTCSendMessage>)delegate {
	if (self = [super init]) {
	_delegate = delegate;
	}
	return self;
	}

	- (void)peerConnectionOnError:(RTCPeerConnection *)peerConnection {
	NSLog(@"PCO onError.");
	NSAssert(NO, @"PeerConnection failed.");
	}

	- (void)peerConnection:(RTCPeerConnection *)peerConnection
	signalingStateChanged:(RTCSignalingState)stateChanged {
	NSLog(@"PCO onSignalingStateChange: %d", stateChanged);
	}

	- (void)peerConnection:(RTCPeerConnection *)peerConnection
	addedStream:(RTCMediaStream *)stream {
	NSLog(@"PCO onAddStream.");
	dispatch_async(dispatch_get_main_queue(), ^(void) {
	NSAssert([stream.audioTracks count] >= 1,
	@"Expected at least 1 audio stream");
	//NSAssert([stream.videoTracks count] >= 1,
	// @"Expected at least 1 video stream");
	// TODO(hughv): Add video support
	});
	}

	- (void)peerConnection:(RTCPeerConnection *)peerConnection
	removedStream:(RTCMediaStream *)stream {
	NSLog(@"PCO onRemoveStream.");
	// TODO(hughv): Remove video track.
	}

	- (void)
	peerConnectionOnRenegotiationNeeded:(RTCPeerConnection *)peerConnection {
	NSLog(@"PCO onRenegotiationNeeded.");
	// TODO(hughv): Handle this.
	}

	- (void)peerConnection:(RTCPeerConnection *)peerConnection
	gotICECandidate:(RTCICECandidate *)candidate {
	NSLog(@"PCO onICECandidate.\n Mid[%@] Index[%d] Sdp[%@]",
	candidate.sdpMid,
	candidate.sdpMLineIndex,
	candidate.sdp);
	NSDictionary *json =
	@{ @"type" : @"candidate",
	@"label" : [NSNumber numberWithInt:candidate.sdpMLineIndex],
	@"id" : candidate.sdpMid,
	@"candidate" : candidate.sdp };
	NSError *error;
	NSData *data =
	[NSJSONSerialization dataWithJSONObject:json options:0 error:&error];
	if (!error) {
	[_delegate sendData:data];
	} else {
	NSAssert(NO, @"Unable to serialize JSON object with error: %@",
	error.localizedDescription);
	}
	}

	- (void)peerConnection:(RTCPeerConnection *)peerConnection
	iceGatheringChanged:(RTCICEGatheringState)newState {
	NSLog(@"PCO onIceGatheringChange. %d", newState);
	}

	- (void)peerConnection:(RTCPeerConnection *)peerConnection
	iceConnectionChanged:(RTCICEConnectionState)newState {
	NSLog(@"PCO onIceConnectionChange. %d", newState);
	if (newState == RTCICEConnectionConnected)
	[self displayLogMessage:@"ICE Connection Connected."];
	NSAssert(newState != RTCICEConnectionFailed, @"ICE Connection failed!");
	}

	- (void)displayLogMessage:(NSString *)message {
	[_delegate displayLogMessage:message];
	}

	@end

	@interface APPRTCAppDelegate ()

	@property(nonatomic, strong) APPRTCAppClient *client;
	@property(nonatomic, strong) PCObserver *pcObserver;
	@property(nonatomic, strong) RTCPeerConnection *peerConnection;
	@property(nonatomic, strong) RTCPeerConnectionFactory *peerConnectionFactory;
	@property(nonatomic, strong) NSMutableArray *queuedRemoteCandidates;

	@end

	@implementation APPRTCAppDelegate

	@synthesize window = _window;
	@synthesize viewController = _viewController;
	@synthesize client = _client;
	@synthesize pcObserver = _pcObserver;
	@synthesize peerConnection = _peerConnection;
	@synthesize peerConnectionFactory = _peerConnectionFactory;
	@synthesize queuedRemoteCandidates = _queuedRemoteCandidates;

	#pragma mark - UIApplicationDelegate methods

	- (BOOL)application:(UIApplication *)application
	didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
	[RTCPeerConnectionFactory initializeSSL];
	self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
	self.viewController =
	[[APPRTCViewController alloc] initWithNibName:@"APPRTCViewController"
	bundle:nil];
	self.window.rootViewController = self.viewController;
	[self.window makeKeyAndVisible];
	return YES;
	}

	- (void)applicationWillResignActive:(UIApplication *)application {
	[self displayLogMessage:@"Application lost focus, connection broken."];
	[self disconnect];
	[self.viewController resetUI];
	}

	- (void)applicationDidEnterBackground:(UIApplication *)application {
	}

	- (void)applicationWillEnterForeground:(UIApplication *)application {
	}

	- (void)applicationDidBecomeActive:(UIApplication *)application {
	}

	- (void)applicationWillTerminate:(UIApplication *)application {
	}

	- (BOOL)application:(UIApplication *)application
	openURL:(NSURL *)url
	sourceApplication:(NSString *)sourceApplication
	annotation:(id)annotation {
	if (self.client) {
	return NO;
	}
	self.client = [[APPRTCAppClient alloc] init];
	self.client.ICEServerDelegate = self;
	self.client.messageHandler = self;
	[self.client connectToRoom:url];
	return YES;
	}

	- (void)displayLogMessage:(NSString *)message {
	NSLog(@"%@", message);
	[self.viewController displayText:message];
	}

	#pragma mark - RTCSendMessage method

	- (void)sendData:(NSData *)data {
	[self.client sendData:data];
	}

	#pragma mark - ICEServerDelegate method

	- (void)onICEServers:(NSArray *)servers {
	self.queuedRemoteCandidates = [NSMutableArray array];
	self.peerConnectionFactory = [[RTCPeerConnectionFactory alloc] init];
	RTCMediaConstraints *constraints = [[RTCMediaConstraints alloc] init];
	self.pcObserver = [[PCObserver alloc] initWithDelegate:self];
	self.peerConnection =
	[self.peerConnectionFactory peerConnectionWithICEServers:servers
	constraints:constraints
	delegate:self.pcObserver];
	RTCMediaStream *lms =
	[self.peerConnectionFactory mediaStreamWithLabel:@"ARDAMS"];
	// TODO(hughv): Add video.
	[lms addAudioTrack:[self.peerConnectionFactory audioTrackWithID:@"ARDAMSa0"]];
	[self.peerConnection addStream:lms constraints:constraints];
	[self displayLogMessage:@"onICEServers - add local stream."];
	}

	#pragma mark - GAEMessageHandler methods

	- (void)onOpen {
	[self displayLogMessage:@"GAE onOpen - create offer."];
	RTCPair *audio =
	[[RTCPair alloc] initWithKey:@"OfferToReceiveAudio" value:@"true"];
	// TODO(hughv): Add video.
	// RTCPair *video = [[RTCPair alloc] initWithKey:@"OfferToReceiveVideo"
	// value:@"true"];
	NSArray mandatory = @[ audio /, video*/ ];
	RTCMediaConstraints *constraints =
	[[RTCMediaConstraints alloc] initWithMandatoryConstraints:mandatory
	optionalConstraints:nil];
	[self.peerConnection createOfferWithDelegate:self constraints:constraints];
	[self displayLogMessage:@"PC - createOffer."];
	}

	- (void)onMessage:(NSString *)data {
	NSString *message = [self unHTMLifyString:data];
	NSError *error;
	NSDictionary *objects = [NSJSONSerialization
	JSONObjectWithData:[message dataUsingEncoding:NSUTF8StringEncoding]
	options:0
	error:&error];
	NSAssert(!error,
	@"%@",
	[NSString stringWithFormat:@"Error: %@", error.description]);
	NSAssert([objects count] > 0, @"Invalid JSON object");
	NSString *value = [objects objectForKey:@"type"];
	[self displayLogMessage:
	[NSString stringWithFormat:@"GAE onMessage type - %@", value]];
	if ([value compare:@"candidate"] == NSOrderedSame) {
	NSString *mid = [objects objectForKey:@"id"];
	NSNumber *sdpLineIndex = [objects objectForKey:@"label"];
	NSString *sdp = [objects objectForKey:@"candidate"];
	RTCICECandidate *candidate =
	[[RTCICECandidate alloc] initWithMid:mid
	index:sdpLineIndex.intValue
	sdp:sdp];
	if (self.queuedRemoteCandidates) {
	[self.queuedRemoteCandidates addObject:candidate];
	} else {
	[self.peerConnection addICECandidate:candidate];
	}
	} else if (([value compare:@"offer"] == NSOrderedSame) \|\|
	([value compare:@"answer"] == NSOrderedSame)) {
	NSString *sdpString = [objects objectForKey:@"sdp"];
	RTCSessionDescription *sdp = [[RTCSessionDescription alloc]
	initWithType:value sdp:[APPRTCAppDelegate preferISAC:sdpString]];
	[self.peerConnection setRemoteDescriptionWithDelegate:self
	sessionDescription:sdp];
	[self displayLogMessage:@"PC - setRemoteDescription."];
	} else if ([value compare:@"bye"] == NSOrderedSame) {
	[self disconnect];
	} else {
	NSAssert(NO, @"Invalid message: %@", data);
	}
	}

	- (void)onClose {
	[self displayLogMessage:@"GAE onClose."];
	[self disconnect];
	}

	- (void)onError:(int)code withDescription:(NSString *)description {
	[self displayLogMessage:
	[NSString stringWithFormat:@"GAE onError: %@", description]];
	[self disconnect];
	}

	#pragma mark - RTCSessionDescriptonDelegate methods

	// Match \|pattern\| to \|string\| and return the first group of the first
	// match, or nil if no match was found.
	+ (NSString )firstMatch:(NSRegularExpression )pattern
	withString:(NSString *)string {
	NSTextCheckingResult* result =
	[pattern firstMatchInString:string
	options:0
	range:NSMakeRange(0, [string length])];
	if (!result)
	return nil;
	return [string substringWithRange:[result rangeAtIndex:1]];
	}

	// Mangle \|origSDP\| to prefer the ISAC/16k audio codec.
	+ (NSString )preferISAC:(NSString )origSDP {
	int mLineIndex = -1;
	NSString* isac16kRtpMap = nil;
	NSArray* lines = [origSDP componentsSeparatedByString:@"\n"];
	NSRegularExpression* isac16kRegex = [NSRegularExpression
	regularExpressionWithPattern:@"^a=rtpmap:(\\d+) ISAC/16000[\r]?$"
	options:0
	error:nil];
	for (int i = 0;
	(i < [lines count]) && (mLineIndex == -1 \|\| isac16kRtpMap == nil);
	++i) {
	NSString* line = [lines objectAtIndex:i];
	if ([line hasPrefix:@"m=audio "]) {
	mLineIndex = i;
	continue;
	}
	isac16kRtpMap = [self firstMatch:isac16kRegex withString:line];
	}
	if (mLineIndex == -1) {
	NSLog(@"No m=audio line, so can't prefer iSAC");
	return origSDP;
	}
	if (isac16kRtpMap == nil) {
	NSLog(@"No ISAC/16000 line, so can't prefer iSAC");
	return origSDP;
	}
	NSArray* origMLineParts =
	[[lines objectAtIndex:mLineIndex] componentsSeparatedByString:@" "];
	NSMutableArray* newMLine =
	[NSMutableArray arrayWithCapacity:[origMLineParts count]];
	int origPartIndex = 0;
	// Format is: m=<media> <port> <proto> <fmt> ...
	[newMLine addObject:[origMLineParts objectAtIndex:origPartIndex++]];
	[newMLine addObject:[origMLineParts objectAtIndex:origPartIndex++]];
	[newMLine addObject:[origMLineParts objectAtIndex:origPartIndex++]];
	[newMLine addObject:isac16kRtpMap];
	for (; origPartIndex < [origMLineParts count]; ++origPartIndex) {
	if ([isac16kRtpMap compare:[origMLineParts objectAtIndex:origPartIndex]]
	!= NSOrderedSame) {
	[newMLine addObject:[origMLineParts objectAtIndex:origPartIndex]];
	}
	}
	NSMutableArray* newLines = [NSMutableArray arrayWithCapacity:[lines count]];
	[newLines addObjectsFromArray:lines];
	[newLines replaceObjectAtIndex:mLineIndex
	withObject:[newMLine componentsJoinedByString:@" "]];
	return [newLines componentsJoinedByString:@"\n"];
	}

	- (void)peerConnection:(RTCPeerConnection *)peerConnection
	didCreateSessionDescription:(RTCSessionDescription *)origSdp
	error:(NSError *)error {
	if (error) {
	[self displayLogMessage:@"SDP onFailure."];
	NSAssert(NO, error.description);
	return;
	}

	[self displayLogMessage:@"SDP onSuccess(SDP) - set local description."];
	RTCSessionDescription* sdp =
	[[RTCSessionDescription alloc]
	initWithType:origSdp.type
	sdp:[APPRTCAppDelegate preferISAC:origSdp.description]];
	[self.peerConnection setLocalDescriptionWithDelegate:self
	sessionDescription:sdp];
	[self displayLogMessage:@"PC setLocalDescription."];
	dispatch_async(dispatch_get_main_queue(), ^(void) {
	NSDictionary *json = @{ @"type" : sdp.type, @"sdp" : sdp.description };
	NSError *error;
	NSData *data =
	[NSJSONSerialization dataWithJSONObject:json options:0 error:&error];
	NSAssert(!error,
	@"%@",
	[NSString stringWithFormat:@"Error: %@", error.description]);
	[self sendData:data];
	});
	}

	- (void)peerConnection:(RTCPeerConnection *)peerConnection
	didSetSessionDescriptionWithError:(NSError *)error {
	if (error) {
	[self displayLogMessage:@"SDP onFailure."];
	NSAssert(NO, error.description);
	return;
	}

	[self displayLogMessage:@"SDP onSuccess() - possibly drain candidates"];
	dispatch_async(dispatch_get_main_queue(), ^(void) {
	// TODO(hughv): Handle non-initiator case. http://s10/46622051
	if (self.peerConnection.remoteDescription) {
	[self displayLogMessage:@"SDP onSuccess - drain candidates"];
	[self drainRemoteCandidates];
	}
	});
	}

	#pragma mark - internal methods

	- (void)disconnect {
	[self.client
	sendData:[@"{\"type\": \"bye\"}" dataUsingEncoding:NSUTF8StringEncoding]];
	self.peerConnection = nil;
	self.peerConnectionFactory = nil;
	self.pcObserver = nil;
	self.client.ICEServerDelegate = nil;
	self.client.messageHandler = nil;
	self.client = nil;
	[RTCPeerConnectionFactory deinitializeSSL];
	}

	- (void)drainRemoteCandidates {
	for (RTCICECandidate *candidate in self.queuedRemoteCandidates) {
	[self.peerConnection addICECandidate:candidate];
	}
	self.queuedRemoteCandidates = nil;
	}

	- (NSString )unHTMLifyString:(NSString )base {
	// TODO(hughv): Investigate why percent escapes are being added. Removing
	// them isn't necessary on Android.
	// convert HTML escaped characters to UTF8.
	NSString *removePercent =
	[base stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
	// remove leading and trailing ".
	NSRange range;
	range.length = [removePercent length] - 2;
	range.location = 1;
	NSString *removeQuotes = [removePercent substringWithRange:range];
	// convert \" to ".
	NSString *removeEscapedQuotes =
	[removeQuotes stringByReplacingOccurrencesOfString:@"\\\""
	withString:@"\""];
	// convert \\ to \.
	NSString *removeBackslash =
	[removeEscapedQuotes stringByReplacingOccurrencesOfString:@"\\\\"
	withString:@"\\"];
	return removeBackslash;
	}

	@end