iOS implementation

android/src/main/java/com/ryanheise/just_audio/AudioPlayer.java

@@ -34,7 +34,7 @@ public class AudioPlayer implements MethodCallHandler, MediaPlayer.OnCompletionL
 		}
 	};
 
-	private final long id;
+	private final String id;
 	private final MediaPlayer player;
 	private PlaybackState state;
 	private PlaybackState stateBeforeSeek;
@@ -42,7 +42,7 @@ public class AudioPlayer implements MethodCallHandler, MediaPlayer.OnCompletionL
 	private int updatePosition;
 	private Integer seekPos;
 
-	public AudioPlayer(final Registrar registrar, final long id) {
+	public AudioPlayer(final Registrar registrar, final String id) {
 		this.registrar = registrar;
 		this.id = id;
 		methodChannel = new MethodChannel(registrar.messenger(), "com.ryanheise.just_audio.methods." + id);

android/src/main/java/com/ryanheise/just_audio/JustAudioPlugin.java

@@ -24,7 +24,7 @@ public class JustAudioPlugin implements MethodCallHandler {
   public void onMethodCall(MethodCall call, Result result) {
 		switch (call.method) {
 		case "init":
-			long id = (Long)call.arguments;
+			String id = (String)call.arguments;
 			new AudioPlayer(registrar, id);
 			result.success(null);
 			break;

example/ios/Flutter/Debug.xcconfig

@@ -1 +1,2 @@
+#include "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Generated.xcconfig"

example/ios/Flutter/Release.xcconfig

@@ -1 +1,2 @@
+#include "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Generated.xcconfig"

example/ios/Podfile

@@ -0,0 +1,72 @@
+# Uncomment this line to define a global platform for your project
+# platform :ios, '9.0'
+
+# CocoaPods analytics sends network stats synchronously affecting flutter build latency.
+ENV['COCOAPODS_DISABLE_STATS'] = 'true'
+
+project 'Runner', {
+  'Debug' => :debug,
+  'Profile' => :release,
+  'Release' => :release,
+}
+
+def parse_KV_file(file, separator='=')
+  file_abs_path = File.expand_path(file)
+  if !File.exists? file_abs_path
+    return [];
+  end
+  pods_ary = []
+  skip_line_start_symbols = ["#", "/"]
+  File.foreach(file_abs_path) { |line|
+      next if skip_line_start_symbols.any? { |symbol| line =~ /^\s*#{symbol}/ }
+      plugin = line.split(pattern=separator)
+      if plugin.length == 2
+        podname = plugin[0].strip()
+        path = plugin[1].strip()
+        podpath = File.expand_path("#{path}", file_abs_path)
+        pods_ary.push({:name => podname, :path => podpath});
+      else
+        puts "Invalid plugin specification: #{line}"
+      end
+  }
+  return pods_ary
+end
+
+target 'Runner' do
+  # Prepare symlinks folder. We use symlinks to avoid having Podfile.lock
+  # referring to absolute paths on developers' machines.
+  system('rm -rf .symlinks')
+  system('mkdir -p .symlinks/plugins')
+
+  # Flutter Pods
+  generated_xcode_build_settings = parse_KV_file('./Flutter/Generated.xcconfig')
+  if generated_xcode_build_settings.empty?
+    puts "Generated.xcconfig must exist. If you're running pod install manually, make sure flutter pub get is executed first."
+  end
+  generated_xcode_build_settings.map { |p|
+    if p[:name] == 'FLUTTER_FRAMEWORK_DIR'
+      symlink = File.join('.symlinks', 'flutter')
+      File.symlink(File.dirname(p[:path]), symlink)
+      pod 'Flutter', :path => File.join(symlink, File.basename(p[:path]))
+    end
+  }
+
+  # Plugin Pods
+  plugin_pods = parse_KV_file('../.flutter-plugins')
+  plugin_pods.map { |p|
+    symlink = File.join('.symlinks', 'plugins', p[:name])
+    File.symlink(p[:path], symlink)
+    pod p[:name], :path => File.join(symlink, 'ios')
+  }
+end
+
+# Prevent Cocoapods from embedding a second Flutter framework and causing an error with the new Xcode build system.
+install! 'cocoapods', :disable_input_output_paths => true
+
+post_install do |installer|
+  installer.pods_project.targets.each do |target|
+    target.build_configurations.each do |config|
+      config.build_settings['ENABLE_BITCODE'] = 'NO'
+    end
+  end
+end

example/ios/Podfile.lock

@@ -0,0 +1,28 @@
+PODS:
+  - Flutter (1.0.0)
+  - just_audio (0.0.1):
+    - Flutter
+  - path_provider (0.0.1):
+    - Flutter
+
+DEPENDENCIES:
+  - Flutter (from `.symlinks/flutter/ios`)
+  - just_audio (from `.symlinks/plugins/just_audio/ios`)
+  - path_provider (from `.symlinks/plugins/path_provider/ios`)
+
+EXTERNAL SOURCES:
+  Flutter:
+    :path: ".symlinks/flutter/ios"
+  just_audio:
+    :path: ".symlinks/plugins/just_audio/ios"
+  path_provider:
+    :path: ".symlinks/plugins/path_provider/ios"
+
+SPEC CHECKSUMS:
+  Flutter: 0e3d915762c693b495b44d77113d4970485de6ec
+  just_audio: c695d6e7e37f9e96672dd84039d7530e7fd5c205
+  path_provider: fb74bd0465e96b594bb3b5088ee4a4e7bb1f2a9d
+
+PODFILE CHECKSUM: 7fb83752f59ead6285236625b82473f90b1cb932
+
+COCOAPODS: 1.7.5

example/ios/Runner.xcodeproj/project.pbxproj

@@ -19,6 +19,7 @@
 		97C146FC1CF9000F007C117D /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FA1CF9000F007C117D /* Main.storyboard */; };
 		97C146FE1CF9000F007C117D /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FD1CF9000F007C117D /* Assets.xcassets */; };
 		97C147011CF9000F007C117D /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FF1CF9000F007C117D /* LaunchScreen.storyboard */; };
+		D06FA586B72D3A4E8145F7B3 /* libPods-Runner.a in Frameworks */ = {isa = PBXBuildFile; fileRef = C5F18129E1310C9DA1B65F44 /* libPods-Runner.a */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXCopyFilesBuildPhase section */
@@ -39,11 +40,13 @@
 /* Begin PBXFileReference section */
 		1498D2321E8E86230040F4C2 /* GeneratedPluginRegistrant.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GeneratedPluginRegistrant.h; sourceTree = "<group>"; };
 		1498D2331E8E89220040F4C2 /* GeneratedPluginRegistrant.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GeneratedPluginRegistrant.m; sourceTree = "<group>"; };
+		2920064AACAD73E894573C6E /* Pods-Runner.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Runner.release.xcconfig"; path = "Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"; sourceTree = "<group>"; };
 		3B3967151E833CAA004F5970 /* AppFrameworkInfo.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.xml; name = AppFrameworkInfo.plist; path = Flutter/AppFrameworkInfo.plist; sourceTree = "<group>"; };
 		3B80C3931E831B6300D905FE /* App.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = App.framework; path = Flutter/App.framework; sourceTree = "<group>"; };
 		7AFA3C8E1D35360C0083082E /* Release.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; name = Release.xcconfig; path = Flutter/Release.xcconfig; sourceTree = "<group>"; };
 		7AFFD8ED1D35381100E5BB4D /* AppDelegate.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = AppDelegate.h; sourceTree = "<group>"; };
 		7AFFD8EE1D35381100E5BB4D /* AppDelegate.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = AppDelegate.m; sourceTree = "<group>"; };
+		936C8FBACDB1725D477088CC /* Pods-Runner.profile.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Runner.profile.xcconfig"; path = "Target Support Files/Pods-Runner/Pods-Runner.profile.xcconfig"; sourceTree = "<group>"; };
 		9740EEB21CF90195004384FC /* Debug.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; name = Debug.xcconfig; path = Flutter/Debug.xcconfig; sourceTree = "<group>"; };
 		9740EEB31CF90195004384FC /* Generated.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; name = Generated.xcconfig; path = Flutter/Generated.xcconfig; sourceTree = "<group>"; };
 		9740EEBA1CF902C7004384FC /* Flutter.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Flutter.framework; path = Flutter/Flutter.framework; sourceTree = "<group>"; };
@@ -53,6 +56,8 @@
 		97C146FD1CF9000F007C117D /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		97C147001CF9000F007C117D /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/LaunchScreen.storyboard; sourceTree = "<group>"; };
 		97C147021CF9000F007C117D /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		C5F18129E1310C9DA1B65F44 /* libPods-Runner.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-Runner.a"; sourceTree = BUILT_PRODUCTS_DIR; };
+		EEEB488F061389F2C0725BDD /* Pods-Runner.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Runner.debug.xcconfig"; path = "Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -62,12 +67,21 @@
 			files = (
 				9705A1C61CF904A100538489 /* Flutter.framework in Frameworks */,
 				3B80C3941E831B6300D905FE /* App.framework in Frameworks */,
+				D06FA586B72D3A4E8145F7B3 /* libPods-Runner.a in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		1E7998A536E2BAD21DDFF12E /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				C5F18129E1310C9DA1B65F44 /* libPods-Runner.a */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
 		9740EEB11CF90186004384FC /* Flutter */ = {
 			isa = PBXGroup;
 			children = (
@@ -87,7 +101,8 @@
 				9740EEB11CF90186004384FC /* Flutter */,
 				97C146F01CF9000F007C117D /* Runner */,
 				97C146EF1CF9000F007C117D /* Products */,
-				CF3B75C9A7D2FA2A4C99F110 /* Frameworks */,
+				A27F1C3EF07264C52FFA0B86 /* Pods */,
+				1E7998A536E2BAD21DDFF12E /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -123,6 +138,17 @@
 			name = "Supporting Files";
 			sourceTree = "<group>";
 		};
+		A27F1C3EF07264C52FFA0B86 /* Pods */ = {
+			isa = PBXGroup;
+			children = (
+				EEEB488F061389F2C0725BDD /* Pods-Runner.debug.xcconfig */,
+				2920064AACAD73E894573C6E /* Pods-Runner.release.xcconfig */,
+				936C8FBACDB1725D477088CC /* Pods-Runner.profile.xcconfig */,
+			);
+			name = Pods;
+			path = Pods;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -130,12 +156,14 @@
 			isa = PBXNativeTarget;
 			buildConfigurationList = 97C147051CF9000F007C117D /* Build configuration list for PBXNativeTarget "Runner" */;
 			buildPhases = (
+				3D5B4DF09BB47DFA6E4B8495 /* [CP] Check Pods Manifest.lock */,
 				9740EEB61CF901F6004384FC /* Run Script */,
 				97C146EA1CF9000F007C117D /* Sources */,
 				97C146EB1CF9000F007C117D /* Frameworks */,
 				97C146EC1CF9000F007C117D /* Resources */,
 				9705A1C41CF9048500538489 /* Embed Frameworks */,
 				3B06AD1E1E4923F5004D2608 /* Thin Binary */,
+				A38593E728AFE0DAE382B1D1 /* [CP] Embed Pods Frameworks */,
 			);
 			buildRules = (
 			);
@@ -208,6 +236,28 @@
 			shellPath = /bin/sh;
 			shellScript = "/bin/sh \"$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh\" thin";
 		};
+		3D5B4DF09BB47DFA6E4B8495 /* [CP] Check Pods Manifest.lock */ = {
+			isa = PBXShellScriptBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			inputFileListPaths = (
+			);
+			inputPaths = (
+				"${PODS_PODFILE_DIR_PATH}/Podfile.lock",
+				"${PODS_ROOT}/Manifest.lock",
+			);
+			name = "[CP] Check Pods Manifest.lock";
+			outputFileListPaths = (
+			);
+			outputPaths = (
+				"$(DERIVED_FILE_DIR)/Pods-Runner-checkManifestLockResult.txt",
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+			shellPath = /bin/sh;
+			shellScript = "diff \"${PODS_PODFILE_DIR_PATH}/Podfile.lock\" \"${PODS_ROOT}/Manifest.lock\" > /dev/null\nif [ $? != 0 ] ; then\n    # print error to STDERR\n    echo \"error: The sandbox is not in sync with the Podfile.lock. Run 'pod install' or update your CocoaPods installation.\" >&2\n    exit 1\nfi\n# This output is used by Xcode 'outputs' to avoid re-running this script phase.\necho \"SUCCESS\" > \"${SCRIPT_OUTPUT_FILE_0}\"\n";
+			showEnvVarsInLog = 0;
+		};
 		9740EEB61CF901F6004384FC /* Run Script */ = {
 			isa = PBXShellScriptBuildPhase;
 			buildActionMask = 2147483647;
@@ -222,6 +272,21 @@
 			shellPath = /bin/sh;
 			shellScript = "/bin/sh \"$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh\" build";
 		};
+		A38593E728AFE0DAE382B1D1 /* [CP] Embed Pods Frameworks */ = {
+			isa = PBXShellScriptBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			inputPaths = (
+			);
+			name = "[CP] Embed Pods Frameworks";
+			outputPaths = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+			shellPath = /bin/sh;
+			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-Runner/Pods-Runner-frameworks.sh\"\n";
+			showEnvVarsInLog = 0;
+		};
 /* End PBXShellScriptBuildPhase section */
 
 /* Begin PBXSourcesBuildPhase section */

example/ios/Runner.xcworkspace/contents.xcworkspacedata

@@ -4,4 +4,7 @@
    <FileRef
       location = "group:Runner.xcodeproj">
    </FileRef>
+   <FileRef
+      location = "group:Pods/Pods.xcodeproj">
+   </FileRef>
 </Workspace>

example/pubspec.lock

@@ -1,6 +1,20 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  archive:
+    dependency: transitive
+    description:
+      name: archive
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.10"
+  args:
+    dependency: transitive
+    description:
+      name: args
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.5.2"
   async:
     dependency: transitive
     description:
@@ -8,13 +22,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.3.0"
-  just_audio:
-    dependency: "direct dev"
-    description:
-      path: ".."
-      relative: true
-    source: path
-    version: "0.0.1"
   boolean_selector:
     dependency: transitive
     description:
@@ -36,6 +43,20 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.14.11"
+  convert:
+    dependency: transitive
+    description:
+      name: convert
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.1"
+  crypto:
+    dependency: transitive
+    description:
+      name: crypto
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.3"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -53,6 +74,20 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  image:
+    dependency: transitive
+    description:
+      name: image
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.4"
+  just_audio:
+    dependency: "direct dev"
+    description:
+      path: ".."
+      relative: true
+    source: path
+    version: "0.0.1"
   matcher:
     dependency: transitive
     description:
@@ -88,6 +123,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.8.0+1"
+  petitparser:
+    dependency: transitive
+    description:
+      name: petitparser
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.4.0"
   platform:
     dependency: transitive
     description:
@@ -170,6 +212,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.0.8"
+  xml:
+    dependency: transitive
+    description:
+      name: xml
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.5.0"
 sdks:
-  dart: ">=2.2.2 <3.0.0"
+  dart: ">=2.4.0 <3.0.0"
   flutter: ">=1.9.1+hotfix.5 <2.0.0"

ios/Classes/AudioPlayer.h

@@ -0,0 +1,16 @@
+#import <Flutter/Flutter.h>
+
+@interface AudioPlayer : NSObject<FlutterStreamHandler>
+
+- (instancetype)initWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar playerId:(NSString*)idParam;
+
+@end
+
+enum PlaybackState {
+	none,
+	stopped,
+	paused,
+	playing,
+	buffering,
+	connecting
+};

ios/Classes/AudioPlayer.m

@@ -0,0 +1,286 @@
+#import "AudioPlayer.h"
+#import <AVFoundation/AVFoundation.h>
+
+// TODO: Check for and report invalid state transitions.
+@implementation AudioPlayer {
+	NSObject<FlutterPluginRegistrar>* _registrar;
+	FlutterMethodChannel* _methodChannel;
+	FlutterEventChannel* _eventChannel;
+	FlutterEventSink _eventSink;
+	NSString* _playerId;
+	AVPlayer* _player;
+	enum PlaybackState _state;
+	enum PlaybackState _stateBeforeSeek;
+	long long _updateTime;
+	int _updatePosition;
+	int _seekPos;
+	FlutterResult _connectionResult;
+	id _endObserver;
+	id _timeObserver;
+}
+
+- (instancetype)initWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar playerId:(NSString*)idParam {
+	self = [super init];
+	NSAssert(self, @"super init cannot be nil");
+	_registrar = registrar;
+	_playerId = idParam;
+	_methodChannel = [FlutterMethodChannel
+		methodChannelWithName:[NSMutableString stringWithFormat:@"com.ryanheise.just_audio.methods.%@", _playerId]
+		      binaryMessenger:[registrar messenger]];
+	_eventChannel = [FlutterEventChannel
+		eventChannelWithName:[NSMutableString stringWithFormat:@"com.ryanheise.just_audio.events.%@", _playerId]
+		     binaryMessenger:[registrar messenger]];
+	[_eventChannel setStreamHandler:self];
+	_state = none;
+	_stateBeforeSeek = none;
+	_player = nil;
+	_seekPos = -1;
+	_endObserver = 0;
+	_timeObserver = 0;
+	__weak __typeof__(self) weakSelf = self;
+	[_methodChannel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
+		  [weakSelf handleMethodCall:call result:result];
+	}];
+	return self;
+}
+
+- (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
+	NSArray* args = (NSArray*)call.arguments;
+	if ([@"setUrl" isEqualToString:call.method]) {
+		[self setUrl:args[0] result:result];
+	} else if ([@"play" isEqualToString:call.method]) {
+		[self play:args[0]];
+		result(nil);
+	} else if ([@"pause" isEqualToString:call.method]) {
+		[self pause];
+		result(nil);
+	} else if ([@"stop" isEqualToString:call.method]) {
+		[self stop];
+		result(nil);
+	} else if ([@"setVolume" isEqualToString:call.method]) {
+		[self setVolume:(float)[args[0] doubleValue]];
+		result(nil);
+	} else if ([@"seek" isEqualToString:call.method]) {
+		[self seek:[args[0] intValue] result:result];
+		result(nil);
+	} else if ([@"dispose" isEqualToString:call.method]) {
+		[self dispose];
+		result(nil);
+	} else {
+		result(FlutterMethodNotImplemented);
+	}
+	// TODO
+	/* } catch (Exception e) { */
+	/* 	e.printStackTrace(); */
+	/* 	result.error("Error", null, null); */
+	/* } */
+}
+
+- (FlutterError*)onListenWithArguments:(id)arguments eventSink:(FlutterEventSink)eventSink {
+	_eventSink = eventSink;
+	return nil;
+}
+
+- (FlutterError*)onCancelWithArguments:(id)arguments {
+	_eventSink = nil;
+	return nil;
+}
+
+- (void)checkForDiscontinuity {
+	if (!_eventSink) return;
+	if (_state != playing && _state != buffering) return;
+	long long now = (long long)([[NSDate date] timeIntervalSince1970] * 1000.0);
+	int position = [self getCurrentPosition];
+	long long timeSinceLastUpdate = now - _updateTime;
+	long long expectedPosition = _updatePosition + timeSinceLastUpdate;
+	long long drift = position - expectedPosition;
+	// Update if we've drifted or just started observing
+	if (_updateTime == 0L) {
+		[self broadcastPlayerState];
+	} else if (drift < -100) {
+		NSLog(@"time discontinuity detected: %lld", drift);
+		[self setPlaybackState:buffering];
+	} else if (_state == buffering) {
+		[self setPlaybackState:playing];
+	}
+}
+
+- (void)broadcastPlayerState {
+	long long now = (long long)([[NSDate date] timeIntervalSince1970] * 1000.0);
+	_updatePosition = [self getCurrentPosition];
+	_updateTime = now;
+	_eventSink(@[
+		// state
+		@(_state),
+		// updatePosition
+		@(_updatePosition),
+		// updateTime
+		@(_updateTime),
+	]);
+}
+
+- (int)getCurrentPosition {
+	if (_state == none || _state == connecting) {
+		return 0;
+	} else if (_seekPos != -1) {
+		return _seekPos;
+	} else {
+		return (int)(1000 * CMTimeGetSeconds([_player currentTime]));
+	}
+}
+
+- (void)setPlaybackState:(enum PlaybackState)state {
+	//enum PlaybackState oldState = _state;
+	_state = state;
+	// TODO: Investigate when we need to start and stop
+	// observing item position.
+	/* if (oldState != playing && state == playing) { */
+	/* 	[self startObservingPosition]; */
+	/* } */
+	[self broadcastPlayerState];
+}
+
+- (void)setUrl:(NSString*)url result:(FlutterResult)result {
+	// TODO: error if already connecting
+	_connectionResult = result;
+	[self setPlaybackState:connecting];
+	if (_player) {
+		[[_player currentItem] removeObserver:self forKeyPath:@"status"];
+		[[NSNotificationCenter defaultCenter] removeObserver:_endObserver];
+		_endObserver = 0;
+	}
+	AVPlayerItem* playerItem = [[AVPlayerItem alloc] initWithURL:[NSURL URLWithString:url]];
+	[playerItem addObserver:self
+		     forKeyPath:@"status"
+			options:NSKeyValueObservingOptionNew
+			context:nil];
+	// TODO: Add observer for _endObserver.
+	_endObserver = [[NSNotificationCenter defaultCenter]
+		addObserverForName:AVPlayerItemDidPlayToEndTimeNotification
+			    object:playerItem
+			     queue:nil
+			usingBlock:^(NSNotification* note) {
+				NSLog(@"Reached play end time");
+				[self setPlaybackState:stopped];
+			}
+	];
+	if (_player) {
+		[_player replaceCurrentItemWithPlayerItem:playerItem];
+	} else {
+		_player = [[AVPlayer alloc] initWithPlayerItem:playerItem];
+	}
+	if (_timeObserver) {
+		[_player removeTimeObserver:_timeObserver];
+		_timeObserver = 0;
+	}
+	// TODO: learn about the different ways to define weakSelf.
+	//__weak __typeof__(self) weakSelf = self;
+	//typeof(self) __weak weakSelf = self;
+	__unsafe_unretained typeof(self) weakSelf = self;
+	_timeObserver = [_player addPeriodicTimeObserverForInterval:CMTimeMake(200, 1000)
+		queue:nil
+		usingBlock:^(CMTime time) {
+			[weakSelf checkForDiscontinuity];
+		}
+	];
+	// We send result after the playerItem is ready in observeValueForKeyPath.
+}
+
+- (void)observeValueForKeyPath:(NSString *)keyPath
+		ofObject:(id)object
+		change:(NSDictionary<NSString *,id> *)change
+		context:(void *)context {
+
+	if ([keyPath isEqualToString:@"status"]) {
+		AVPlayerItemStatus status = AVPlayerItemStatusUnknown;
+		NSNumber *statusNumber = change[NSKeyValueChangeNewKey];
+		if ([statusNumber isKindOfClass:[NSNumber class]]) {
+			status = statusNumber.integerValue;
+		}
+		switch (status) {
+			case AVPlayerItemStatusReadyToPlay:
+				[self setPlaybackState:stopped];
+				_connectionResult(@((int)(1000 * CMTimeGetSeconds([[_player currentItem] duration]))));
+				break;
+			case AVPlayerItemStatusFailed:
+				NSLog(@"AVPlayerItemStatusFailed");
+				_connectionResult(nil);
+				break;
+			case AVPlayerItemStatusUnknown:
+				break;
+		}
+	}
+}
+
+- (void)play:(NSNumber*)untilPosition {
+	// TODO: dynamically adjust the lag.
+	//int lag = 6;
+	int start = [self getCurrentPosition];
+	if (untilPosition != [NSNull null] && [untilPosition intValue] <= start) {
+		return;
+	}
+	[_player play];
+	[self setPlaybackState:playing];
+	// TODO: convert this Android code to iOS
+	/* if (endDetector != null) { */
+	/* 	handler.removeCallbacks(endDetector); */
+	/* } */
+	/* if (untilPosition != null) { */
+	/* 	final int duration = Math.max(0, untilPosition - start - lag); */
+	/* 	handler.postDelayed(new Runnable() { */
+	/* 		@Override */
+	/* 		public void run() { */
+	/* 			final int position = getCurrentPosition(); */
+	/* 			if (position > untilPosition - 20) { */
+	/* 				pause(); */
+	/* 			} else { */
+	/* 				final int duration = Math.max(0, untilPosition - position - lag); */
+	/* 				handler.postDelayed(this, duration); */
+	/* 			} */
+	/* 		} */
+	/* 	}, duration); */
+	/* } */
+}
+
+- (void)pause {
+	[_player pause];
+	[self setPlaybackState:paused];
+}
+
+- (void)stop {
+	[_player pause];
+	[[_player currentItem] seekToTime:CMTimeMake(0, 1000)];
+	[self setPlaybackState:stopped];
+}
+
+- (void)setVolume:(float)volume {
+	[_player setVolume:volume];
+}
+
+- (void)seek:(int)position result:(FlutterResult)result {
+	_stateBeforeSeek = _state;
+	_seekPos = position;
+	NSLog(@"seek. enter buffering");
+	[self setPlaybackState:buffering];
+	[_player seekToTime:CMTimeMake(position, 1000)
+	  completionHandler:^(BOOL finished) {
+		  NSLog(@"seek completed");
+		  [self onSeekCompletion:result];
+	  }];
+}
+
+- (void)onSeekCompletion:(FlutterResult)result {
+	_seekPos = -1;
+	[self setPlaybackState:_stateBeforeSeek];
+	_stateBeforeSeek = none;
+	result(nil);
+}
+
+- (void)dispose {
+	if (_state != none) {
+		[self stop];
+		[self setPlaybackState:none];
+	}
+}
+
+@end

ios/Classes/JustAudioPlugin.m

@@ -1,17 +1,31 @@
 #import "JustAudioPlugin.h"
+#import "AudioPlayer.h"
+#import "AudioPlayer.h"
+
+@implementation JustAudioPlugin {
+  NSObject<FlutterPluginRegistrar>* _registrar;
+}
 
-@implementation JustAudioPlugin
 + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
   FlutterMethodChannel* channel = [FlutterMethodChannel
-      methodChannelWithName:@"just_audio"
+    methodChannelWithName:@"com.ryanheise.just_audio.methods"
-            binaryMessenger:[registrar messenger]];
+          binaryMessenger:[registrar messenger]];
-  JustAudioPlugin* instance = [[JustAudioPlugin alloc] init];
+  JustAudioPlugin* instance = [[JustAudioPlugin alloc] initWithRegistrar:registrar];
   [registrar addMethodCallDelegate:instance channel:channel];
 }
 
+- (instancetype)initWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
+  self = [super init];
+  NSAssert(self, @"super init cannot be nil");
+  _registrar = registrar;
+  return self;
+}
+
 - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
-  if ([@"getPlatformVersion" isEqualToString:call.method]) {
+  if ([@"init" isEqualToString:call.method]) {
-    result([@"iOS " stringByAppendingString:[[UIDevice currentDevice] systemVersion]]);
+    NSString* playerId = call.arguments;
+    AudioPlayer* player = [[AudioPlayer alloc] initWithRegistrar:_registrar playerId:playerId];
+    result(nil);
   } else {
     result(FlutterMethodNotImplemented);
   }

lib/just_audio.dart

@@ -48,7 +48,7 @@ class AudioPlayer {
       MethodChannel('com.ryanheise.just_audio.methods');
 
   static Future<MethodChannel> _createChannel(int id) async {
-    await _mainChannel.invokeMethod('init', id);
+    await _mainChannel.invokeMethod('init', '$id');
     return MethodChannel('com.ryanheise.just_audio.methods.$id');
   }