[sensors] Update to NNBD stable (flutter#3589)

Includes migrating example to null-safety.

packages/sensors/CHANGELOG.md

@@ -1,8 +1,4 @@
-## 2.0.0-nullsafety
-
-* * Update version to (semi-belatedly) meet 1.0-consistency promise.
-
-## 0.5.0-nullsafety
+## 2.0.0
 
 * Migrate to null safety.
 

packages/sensors/example/lib/main.dart

@@ -28,7 +28,7 @@ class MyApp extends StatelessWidget {
 }
 
 class MyHomePage extends StatefulWidget {
-  MyHomePage({Key key, this.title}) : super(key: key);
+  MyHomePage({Key? key, required this.title}) : super(key: key);
 
   final String title;
 
@@ -41,21 +41,21 @@ class _MyHomePageState extends State<MyHomePage> {
   static const int _snakeColumns = 20;
   static const double _snakeCellSize = 10.0;
 
-  List<double> _accelerometerValues;
-  List<double> _userAccelerometerValues;
-  List<double> _gyroscopeValues;
+  List<double>? _accelerometerValues;
+  List<double>? _userAccelerometerValues;
+  List<double>? _gyroscopeValues;
   List<StreamSubscription<dynamic>> _streamSubscriptions =
       <StreamSubscription<dynamic>>[];
 
   @override
   Widget build(BuildContext context) {
-    final List<String> accelerometer =
-        _accelerometerValues?.map((double v) => v.toStringAsFixed(1))?.toList();
-    final List<String> gyroscope =
-        _gyroscopeValues?.map((double v) => v.toStringAsFixed(1))?.toList();
-    final List<String> userAccelerometer = _userAccelerometerValues
+    final List<String>? accelerometer =
+        _accelerometerValues?.map((double v) => v.toStringAsFixed(1)).toList();
+    final List<String>? gyroscope =
+        _gyroscopeValues?.map((double v) => v.toStringAsFixed(1)).toList();
+    final List<String>? userAccelerometer = _userAccelerometerValues
         ?.map((double v) => v.toStringAsFixed(1))
-        ?.toList();
+        .toList();
 
     return Scaffold(
       appBar: AppBar(

packages/sensors/example/lib/snake.dart

@@ -56,15 +56,14 @@ class SnakeBoardPainter extends CustomPainter {
 }
 
 class SnakeState extends State<Snake> {
-  SnakeState(int rows, int columns, this.cellSize) {
-    state = GameState(rows, columns);
-  }
+  SnakeState(int rows, int columns, this.cellSize)
+      : state = GameState(rows, columns);
 
   double cellSize;
   GameState state;
-  AccelerometerEvent acceleration;
-  StreamSubscription<AccelerometerEvent> _streamSubscription;
-  Timer _timer;
+  AccelerometerEvent? acceleration;
+  late StreamSubscription<AccelerometerEvent> _streamSubscription;
+  late Timer _timer;
 
   @override
   Widget build(BuildContext context) {
@@ -96,21 +95,21 @@ class SnakeState extends State<Snake> {
   }
 
   void _step() {
-    final math.Point<int> newDirection = acceleration == null
+    final AccelerometerEvent? currentAcceleration = acceleration;
+    final math.Point<int>? newDirection = currentAcceleration == null
         ? null
-        : acceleration.x.abs() < 1.0 && acceleration.y.abs() < 1.0
+        : currentAcceleration.x.abs() < 1.0 && currentAcceleration.y.abs() < 1.0
             ? null
-            : (acceleration.x.abs() < acceleration.y.abs())
-                ? math.Point<int>(0, acceleration.y.sign.toInt())
-                : math.Point<int>(-acceleration.x.sign.toInt(), 0);
+            : (currentAcceleration.x.abs() < currentAcceleration.y.abs())
+                ? math.Point<int>(0, currentAcceleration.y.sign.toInt())
+                : math.Point<int>(-currentAcceleration.x.sign.toInt(), 0);
     state.step(newDirection);
   }
 }
 
 class GameState {
-  GameState(this.rows, this.columns) {
-    snakeLength = math.min(rows, columns) - 5;
-  }
+  GameState(this.rows, this.columns)
+      : snakeLength = math.min(rows, columns) - 5;
 
   int rows;
   int columns;
@@ -119,7 +118,7 @@ class GameState {
   List<math.Point<int>> body = <math.Point<int>>[const math.Point<int>(0, 0)];
   math.Point<int> direction = const math.Point<int>(1, 0);
 
-  void step(math.Point<int> newDirection) {
+  void step(math.Point<int>? newDirection) {
     math.Point<int> next = body.last + direction;
     next = math.Point<int>(next.x % columns, next.y % rows);
 

packages/sensors/example/pubspec.yaml

@@ -17,12 +17,11 @@ dev_dependencies:
     sdk: flutter
   integration_test:
     path: ../../integration_test
-  pedantic: ^1.8.0
+  pedantic: ^1.10.0
 
 flutter:
   uses-material-design: true
 
 environment:
-  sdk: ">=2.0.0-dev.28.0 <3.0.0"
-  flutter: ">=1.9.1+hotfix.2"
-
+  sdk: ">=2.12.0-259.9.beta <3.0.0"
+  flutter: ">=1.20.0"

packages/sensors/example/test_driver/test/integration_test.dart

@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+// @dart = 2.9
+
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';

packages/sensors/pubspec.yaml

@@ -2,7 +2,7 @@ name: sensors
 description: Flutter plugin for accessing the Android and iOS accelerometer and
   gyroscope sensors.
 homepage: https://github.com/flutter/plugins/tree/master/packages/sensors
-version: 2.0.0-nullsafety
+version: 2.0.0
 
 flutter:
   plugin:
@@ -18,14 +18,14 @@ dependencies:
     sdk: flutter
 
 dev_dependencies:
-  test: ^1.16.0-nullsafety
+  test: ^1.16.0
   flutter_test:
     sdk: flutter
   integration_test:
     path: ../integration_test
   mockito: ^5.0.0-nullsafety.0
-  pedantic: ^1.10.0-nullsafety
+  pedantic: ^1.10.0
 
 environment:
-  sdk: ">=2.12.0-0 <3.0.0"
+  sdk: ">=2.12.0-259.9.beta <3.0.0"
   flutter: ">=1.12.13+hotfix.5"