Provide sample to play custom ringtone when answer-on-bridge is enabled (#195)

* Provide sample to play custom ringtone when answer-on-bridge is enabled

Author: bobiechen-twilio

ObjcVoiceQuickstart.xcodeproj/project.pbxproj

@@ -14,6 +14,7 @@
 		2459FDD61D83664300917CA9 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 2459FDD51D83664300917CA9 /* Assets.xcassets */; };
 		2459FDD91D83664300917CA9 /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 2459FDD71D83664300917CA9 /* LaunchScreen.storyboard */; };
 		24BA34291D87431000B0B4F7 /* TwilioLogo.png in Resources */ = {isa = PBXBuildFile; fileRef = 24BA34281D87431000B0B4F7 /* TwilioLogo.png */; };
+		8F6BABF623973FE80030BE4F /* ringtone.wav in Resources */ = {isa = PBXBuildFile; fileRef = 8F6BABF523973FE80030BE4F /* ringtone.wav */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -29,6 +30,7 @@
 		2459FDDA1D83664300917CA9 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		24BA34241D87269500B0B4F7 /* ObjCVoiceQuickstart.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; path = ObjCVoiceQuickstart.entitlements; sourceTree = "<group>"; };
 		24BA34281D87431000B0B4F7 /* TwilioLogo.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = TwilioLogo.png; sourceTree = "<group>"; };
+		8F6BABF523973FE80030BE4F /* ringtone.wav */ = {isa = PBXFileReference; lastKnownFileType = audio.wav; path = ringtone.wav; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -48,6 +50,7 @@
 				2459FDC81D83664300917CA9 /* ObjCVoiceQuickstart */,
 				2459FDC71D83664300917CA9 /* Products */,
 				5FF12A4D246637936B670360 /* Frameworks */,
+				8F6BABF423973FE80030BE4F /* ringtone */,
 			);
 			sourceTree = "<group>";
 		};
@@ -92,6 +95,14 @@
 			name = Frameworks;
 			sourceTree = "<group>";
 		};
+		8F6BABF423973FE80030BE4F /* ringtone */ = {
+			isa = PBXGroup;
+			children = (
+				8F6BABF523973FE80030BE4F /* ringtone.wav */,
+			);
+			path = ringtone;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */

ObjcVoiceQuickstart/ViewController.m

@@ -18,7 +18,7 @@
 static NSString *const kIdentity = @"alice";
 static NSString *const kTwimlParamTo = @"to";
 
-@interface ViewController () <PKPushRegistryDelegate, TVONotificationDelegate, TVOCallDelegate, CXProviderDelegate, UITextFieldDelegate>
+@interface ViewController () <PKPushRegistryDelegate, TVONotificationDelegate, TVOCallDelegate, CXProviderDelegate, UITextFieldDelegate, AVAudioPlayerDelegate>
 
 @property (nonatomic, strong) NSString *deviceTokenString;
 
@@ -45,6 +45,9 @@ @interface ViewController () <PKPushRegistryDelegate, TVONotificationDelegate, T
 @property (weak, nonatomic) IBOutlet UISwitch *muteSwitch;
 @property (weak, nonatomic) IBOutlet UISwitch *speakerSwitch;
 
+@property (nonatomic, assign) BOOL playCustomRingback;
+@property (nonatomic, strong) AVAudioPlayer *ringtonePlayer;
+
 @end
 
 @implementation ViewController
@@ -71,6 +74,14 @@ - (void)viewDidLoad {
 
     self.activeCallInvites = [NSMutableDictionary dictionary];
     self.activeCalls = [NSMutableDictionary dictionary];
+    
+    /*
+     Custom ringback will be played when this flag is enabled.
+     When [answerOnBridge](https://www.twilio.com/docs/voice/twiml/dial#answeronbridge) is enabled in
+     the <Dial> TwiML verb, the caller will not hear the ringback while the call is ringing and awaiting
+     to be accepted on the callee's side. Configure this flag based on the TwiML application.
+     */
+    self.playCustomRingback = NO;
 }
 
 - (void)configureCallKit {
@@ -361,11 +372,25 @@ - (void)cancelledCallInviteReceived:(TVOCancelledCallInvite *)cancelledCallInvit
 - (void)callDidStartRinging:(TVOCall *)call {
     NSLog(@"callDidStartRinging:");
 
+    /*
+     When [answerOnBridge](https://www.twilio.com/docs/voice/twiml/dial#answeronbridge) is enabled in the
+     <Dial> TwiML verb, the caller will not hear the ringback while the call is ringing and awaiting to be
+     accepted on the callee's side. The application can use the `AVAudioPlayer` to play custom audio files
+     between the `[TVOCallDelegate callDidStartRinging:]` and the `[TVOCallDelegate callDidConnect:]` callbacks.
+     */
+    if (self.playCustomRingback) {
+        [self playRingback];
+    }
+    
     [self.placeCallButton setTitle:@"Ringing" forState:UIControlStateNormal];
 }
 
 - (void)callDidConnect:(TVOCall *)call {
     NSLog(@"callDidConnect:");
+    
+    if (self.playCustomRingback) {
+        [self stopRingback];
+    }
 
     self.callKitCompletionCallback(YES);
 
@@ -425,6 +450,10 @@ - (void)callDisconnected:(TVOCall *)call {
 
     self.userInitiatedDisconnect = NO;
 
+    if (self.playCustomRingback) {
+        [self stopRingback];
+    }
+    
     [self stopSpin];
     [self toggleUIState:YES showCallControl:NO];
     [self.placeCallButton setTitle:@"Call" forState:UIControlStateNormal];
@@ -686,4 +715,46 @@ - (void)performAnswerVoiceCallWithUUID:(NSUUID *)uuid
     }
 }
 
+#pragma mark - Ringtone
+
+- (void)playRingback {
+    NSString *ringtonePath = [[NSBundle mainBundle] pathForResource:@"ringtone" ofType:@"wav"];
+    if ([ringtonePath length] <= 0) {
+        NSLog(@"Can't find sound file");
+        return;
+    }
+    
+    NSError *error;
+    self.ringtonePlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL URLWithString:ringtonePath] error:&error];
+    if (error != nil) {
+        NSLog(@"Failed to initialize audio player: %@", error);
+    } else {
+        self.ringtonePlayer.delegate = self;
+        self.ringtonePlayer.numberOfLoops = -1;
+        
+        self.ringtonePlayer.volume = 1.0f;
+        [self.ringtonePlayer play];
+    }
+}
+
+- (void)stopRingback {
+    if (!self.ringtonePlayer.isPlaying) {
+        return;
+    }
+    
+    [self.ringtonePlayer stop];
+}
+
+- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag {
+    if (flag) {
+        NSLog(@"Audio player finished playing successfully");
+    } else {
+        NSLog(@"Audio player finished playing with some error");
+    }
+}
+
+- (void)audioPlayerDecodeErrorDidOccur:(AVAudioPlayer *)player error:(NSError *)error {
+    NSLog(@"Decode error occurred: %@", error);
+}
+
 @end