migrate to null safety

.github/workflows/dart.yml

@@ -26,4 +26,3 @@ jobs:
           channel: 'stable'
       - run: flutter packages get
       - run: flutter format lib/ test/ --set-exit-if-changed
-      - run: flutter pub run import_sorter:main --no-comments --exit-if-changed

analysis_options.yaml

@@ -1,4 +1,4 @@
-include: package:pedantic/analysis_options.yaml
+include: package:lints/recommended.yaml
 
 linter:
   rules:
@@ -45,7 +45,6 @@ analyzer:
     slash_for_doc_comments: ignore
     library_prefixes: ignore
     unused_field: ignore
-    top_level_function_literal_block: ignore
     avoid_init_to_null: ignore
     prefer_is_empty: ignore
     unused_element: ignore
@@ -59,6 +58,8 @@ analyzer:
     unused_import: ignore
     must_be_immutable: ignore
     todo: ignore
+    non_constant_identifier_names: ignore
+    unnecessary_null_comparison: ignore
 
   exclude:
     - lib/src/grammar_parser.dart

example/analysis_options.yaml

@@ -1,6 +1,29 @@
-include: package:pedantic/analysis_options.yaml
+# This file configures the analyzer, which statically analyzes Dart code to
+# check for errors, warnings, and lints.
+#
+# The issues identified by the analyzer are surfaced in the UI of Dart-enabled
+# IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be
+# invoked from the command line by running `flutter analyze`.
 
-analyzer:
- strong-mode:
-    implicit-casts: false
-    implicit-dynamic: false
+# The following line activates a set of recommended lints for Flutter apps,
+# packages, and plugins designed to encourage good coding practices.
+include: package:flutter_lints/flutter.yaml
+
+linter:
+  # The lint rules applied to this project can be customized in the
+  # section below to disable rules from the `package:flutter_lints/flutter.yaml`
+  # included above or to enable additional rules. A list of all available lints
+  # and their documentation is published at
+  # https://dart-lang.github.io/linter/lints/index.html.
+  #
+  # Instead of disabling a lint rule for the entire project in the
+  # section below, it can also be suppressed for a single line of code
+  # or a specific dart file by using the `// ignore: name_of_lint` and
+  # `// ignore_for_file: name_of_lint` syntax on the line or in the file
+  # producing the lint.
+  rules:
+    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
+    # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
+
+# Additional information about this file can be found at
+# https://dart.dev/guides/language/analysis-options

example/lib/main.dart

@@ -1,13 +1,13 @@
 import 'package:flutter/foundation.dart'
     show debugDefaultTargetPlatformOverride;
-
 import 'package:flutter/material.dart';
-import 'package:sip_ua/sip_ua.dart';
 import 'package:flutter_webrtc/flutter_webrtc.dart';
-import 'src/register.dart';
-import 'src/dialpad.dart';
-import 'src/callscreen.dart';
+import 'package:sip_ua/sip_ua.dart';
+
 import 'src/about.dart';
+import 'src/callscreen.dart';
+import 'src/dialpad.dart';
+import 'src/register.dart';
 
 void main() {
   if (WebRTC.platformIsDesktop) {
@@ -17,23 +17,23 @@ void main() {
 }
 
 typedef PageContentBuilder = Widget Function(
-    [SIPUAHelper helper, Object arguments]);
+    [SIPUAHelper? helper, Object? arguments]);
 
 // ignore: must_be_immutable
 class MyApp extends StatelessWidget {
   final SIPUAHelper _helper = SIPUAHelper();
   Map<String, PageContentBuilder> routes = {
-    '/': ([SIPUAHelper helper, Object arguments]) => DialPadWidget(helper),
-    '/register': ([SIPUAHelper helper, Object arguments]) =>
+    '/': ([SIPUAHelper? helper, Object? arguments]) => DialPadWidget(helper),
+    '/register': ([SIPUAHelper? helper, Object? arguments]) =>
         RegisterWidget(helper),
-    '/callscreen': ([SIPUAHelper helper, Object arguments]) =>
-        CallScreenWidget(helper, arguments as Call),
-    '/about': ([SIPUAHelper helper, Object arguments]) => AboutWidget(),
+    '/callscreen': ([SIPUAHelper? helper, Object? arguments]) =>
+        CallScreenWidget(helper, arguments as Call?),
+    '/about': ([SIPUAHelper? helper, Object? arguments]) => AboutWidget(),
   };
 
-  Route<dynamic> _onGenerateRoute(RouteSettings settings) {
-    final String name = settings.name;
-    final PageContentBuilder pageContentBuilder = routes[name];
+  Route<dynamic>? _onGenerateRoute(RouteSettings settings) {
+    final String? name = settings.name;
+    final PageContentBuilder? pageContentBuilder = routes[name!];
     if (pageContentBuilder != null) {
       if (settings.arguments != null) {
         final Route route = MaterialPageRoute<Widget>(

example/lib/src/callscreen.dart

@@ -3,61 +3,61 @@ import 'dart:async';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_webrtc/flutter_webrtc.dart';
+import 'package:sip_ua/sip_ua.dart';
 
 import 'widgets/action_button.dart';
-import 'package:sip_ua/sip_ua.dart';
 
 class CallScreenWidget extends StatefulWidget {
-  final SIPUAHelper _helper;
-  final Call _call;
-  CallScreenWidget(this._helper, this._call, {Key key}) : super(key: key);
+  final SIPUAHelper? _helper;
+  final Call? _call;
+  CallScreenWidget(this._helper, this._call, {Key? key}) : super(key: key);
   @override
   _MyCallScreenWidget createState() => _MyCallScreenWidget();
 }
 
 class _MyCallScreenWidget extends State<CallScreenWidget>
     implements SipUaHelperListener {
-  RTCVideoRenderer _localRenderer = RTCVideoRenderer();
-  RTCVideoRenderer _remoteRenderer = RTCVideoRenderer();
-  double _localVideoHeight;
-  double _localVideoWidth;
-  EdgeInsetsGeometry _localVideoMargin;
-  MediaStream _localStream;
-  MediaStream _remoteStream;
+  RTCVideoRenderer? _localRenderer = RTCVideoRenderer();
+  RTCVideoRenderer? _remoteRenderer = RTCVideoRenderer();
+  double? _localVideoHeight;
+  double? _localVideoWidth;
+  EdgeInsetsGeometry? _localVideoMargin;
+  MediaStream? _localStream;
+  MediaStream? _remoteStream;
 
   bool _showNumPad = false;
   String _timeLabel = '00:00';
-  Timer _timer;
+  late Timer _timer;
   bool _audioMuted = false;
   bool _videoMuted = false;
   bool _speakerOn = false;
   bool _hold = false;
-  String _holdOriginator;
+  String? _holdOriginator;
   CallStateEnum _state = CallStateEnum.NONE;
-  SIPUAHelper get helper => widget._helper;
+  SIPUAHelper? get helper => widget._helper;
 
   bool get voiceonly =>
-      (_localStream == null || _localStream.getVideoTracks().isEmpty) &&
-      (_remoteStream == null || _remoteStream.getVideoTracks().isEmpty);
+      (_localStream == null || _localStream!.getVideoTracks().isEmpty) &&
+      (_remoteStream == null || _remoteStream!.getVideoTracks().isEmpty);
 
-  String get remote_identity => call.remote_identity;
+  String? get remote_identity => call!.remote_identity;
 
-  String get direction => call.direction;
+  String get direction => call!.direction;
 
-  Call get call => widget._call;
+  Call? get call => widget._call;
 
   @override
   initState() {
     super.initState();
     _initRenderers();
-    helper.addSipUaHelperListener(this);
+    helper!.addSipUaHelperListener(this);
     _startTimer();
   }
 
   @override
   deactivate() {
     super.deactivate();
-    helper.removeSipUaHelperListener(this);
+    helper!.removeSipUaHelperListener(this);
     _disposeRenderers();
   }
 
@@ -78,20 +78,20 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
 
   void _initRenderers() async {
     if (_localRenderer != null) {
-      await _localRenderer.initialize();
+      await _localRenderer!.initialize();
     }
     if (_remoteRenderer != null) {
-      await _remoteRenderer.initialize();
+      await _remoteRenderer!.initialize();
     }
   }
 
   void _disposeRenderers() {
     if (_localRenderer != null) {
-      _localRenderer.dispose();
+      _localRenderer!.dispose();
       _localRenderer = null;
     }
     if (_remoteRenderer != null) {
-      _remoteRenderer.dispose();
+      _remoteRenderer!.dispose();
       _remoteRenderer = null;
     }
   }
@@ -107,15 +107,15 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
     }
 
     if (callState.state == CallStateEnum.MUTED) {
-      if (callState.audio) _audioMuted = true;
-      if (callState.video) _videoMuted = true;
+      if (callState.audio!) _audioMuted = true;
+      if (callState.video!) _videoMuted = true;
       this.setState(() {});
       return;
     }
 
     if (callState.state == CallStateEnum.UNMUTED) {
-      if (callState.audio) _audioMuted = false;
-      if (callState.video) _videoMuted = false;
+      if (callState.audio!) _audioMuted = false;
+      if (callState.video!) _videoMuted = false;
       this.setState(() {});
       return;
     }
@@ -154,10 +154,10 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
   void registrationStateChanged(RegistrationState state) {}
 
   void _cleanUp() {
-    _localStream?.getTracks()?.forEach((track) {
+    _localStream?.getTracks().forEach((track) {
       track.stop();
     });
-    _localStream.dispose();
+    _localStream!.dispose();
     _localStream = null;
   }
 
@@ -170,19 +170,19 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
   }
 
   void _handelStreams(CallState event) async {
-    MediaStream stream = event.stream;
+    MediaStream? stream = event.stream;
     if (event.originator == 'local') {
       if (_localRenderer != null) {
-        _localRenderer.srcObject = stream;
+        _localRenderer!.srcObject = stream;
       }
       if (!kIsWeb && !WebRTC.platformIsDesktop) {
-        event.stream?.getAudioTracks()?.first?.enableSpeakerphone(false);
+        event.stream?.getAudioTracks().first.enableSpeakerphone(false);
       }
       _localStream = stream;
     }
     if (event.originator == 'remote') {
       if (_remoteRenderer != null) {
-        _remoteRenderer.srcObject = stream;
+        _remoteRenderer!.srcObject = stream;
       }
       _remoteStream = stream;
     }
@@ -205,12 +205,12 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
   }
 
   void _handleHangup() {
-    call.hangup();
+    call!.hangup();
     _timer.cancel();
   }
 
   void _handleAccept() async {
-    bool remote_has_video = call.remote_has_video;
+    bool remote_has_video = call!.remote_has_video;
     final mediaConstraints = <String, dynamic>{
       'audio': true,
       'video': remote_has_video
@@ -229,41 +229,41 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
       mediaStream = await navigator.mediaDevices.getUserMedia(mediaConstraints);
     }
 
-    call.answer(helper.buildCallOptions(!remote_has_video),
+    call!.answer(helper!.buildCallOptions(!remote_has_video),
         mediaStream: mediaStream);
   }
 
   void _switchCamera() {
     if (_localStream != null) {
-      _localStream.getVideoTracks()[0].switchCamera();
+      Helper.switchCamera(_localStream!.getVideoTracks()[0]);
     }
   }
 
   void _muteAudio() {
     if (_audioMuted) {
-      call.unmute(true, false);
+      call!.unmute(true, false);
     } else {
-      call.mute(true, false);
+      call!.mute(true, false);
     }
   }
 
   void _muteVideo() {
     if (_videoMuted) {
-      call.unmute(false, true);
+      call!.unmute(false, true);
     } else {
-      call.mute(false, true);
+      call!.mute(false, true);
     }
   }
 
   void _handleHold() {
     if (_hold) {
-      call.unhold();
+      call!.unhold();
     } else {
-      call.hold();
+      call!.hold();
     }
   }
 
-  String _tansfer_target;
+  late String _tansfer_target;
   void _handleTransfer() {
     showDialog<Null>(
       context: context,
@@ -286,7 +286,7 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
             TextButton(
               child: Text('Ok'),
               onPressed: () {
-                call.refer(_tansfer_target);
+                call!.refer(_tansfer_target);
                 Navigator.of(context).pop();
               },
             ),
@@ -304,7 +304,7 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
 
   void _handleDtmf(String tone) {
     print('Dtmf tone => $tone');
-    call.sendDTMF(tone);
+    call!.sendDTMF(tone);
   }
 
   void _handleKeyPad() {
@@ -317,7 +317,7 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
     if (_localStream != null) {
       _speakerOn = !_speakerOn;
       if (!kIsWeb) {
-        _localStream.getAudioTracks()[0].enableSpeakerphone(_speakerOn);
+        _localStream!.getAudioTracks()[0].enableSpeakerphone(_speakerOn);
       }
     }
   }
@@ -502,14 +502,14 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
 
     if (!voiceonly && _remoteStream != null) {
       stackWidgets.add(Center(
-        child: RTCVideoView(_remoteRenderer),
+        child: RTCVideoView(_remoteRenderer!),
       ));
     }
 
     if (!voiceonly && _localStream != null) {
       stackWidgets.add(Container(
         child: AnimatedContainer(
-          child: RTCVideoView(_localRenderer),
+          child: RTCVideoView(_localRenderer!),
           height: _localVideoHeight,
           width: _localVideoWidth,
           alignment: Alignment.topRight,
@@ -536,7 +536,7 @@ class _MyCallScreenWidget extends State<CallScreenWidget>
                     child: Text(
                       (voiceonly ? 'VOICE CALL' : 'VIDEO CALL') +
                           (_hold
-                              ? ' PAUSED BY ${this._holdOriginator.toUpperCase()}'
+                              ? ' PAUSED BY ${this._holdOriginator!.toUpperCase()}'
                               : ''),
                       style: TextStyle(fontSize: 24, color: Colors.black54),
                     ))),