Added Null safety v2

.gitignore

@@ -70,3 +70,4 @@ build/
 !**/ios/**/default.pbxuser
 !**/ios/**/default.perspectivev3
 !/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages
+/.vs

lib/models/pad_button_item.dart

@@ -11,15 +11,15 @@ class PadButtonItem {
 
   /// [buttonText] optional parameter, the text to be displayed inside the
   /// button. Omitted if [buttonImage] is set. Default value is empty string.
-  final String buttonText;
+  final String? buttonText;
 
   /// [buttonImage] optional parameter, image which will be displayed inside
   /// the button.
-  final Image buttonImage;
+  final Image? buttonImage;
 
   /// [buttonIcon] optional parameter, image which will be displayed inside
   /// the button.
-  final Icon buttonIcon;
+  final Icon? buttonIcon;
 
   /// [backgroundColor] color of button in default state.
   final Color backgroundColor;
@@ -34,12 +34,12 @@ class PadButtonItem {
   final List<Gestures> supportedGestures;
 
   const PadButtonItem({
-    @required this.index,
+    required this.index,
     this.buttonText,
     this.buttonImage,
     this.buttonIcon,
     this.backgroundColor = Colors.white54,
     this.pressedColor = Colors.lightBlueAccent,
     this.supportedGestures = const [Gestures.TAP],
-  }) : assert(index != null);
+  });
 }

lib/views/circle_view.dart

@@ -2,28 +2,25 @@ import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 
 class CircleView extends StatelessWidget {
-  final double size;
+  final double? size;
 
-  final Color color;
+  final Color? color;
 
-  final List<BoxShadow> boxShadow;
+  final List<BoxShadow>? boxShadow;
 
-  final Border border;
+  final Border? border;
 
-  final double opacity;
+  final Image? buttonImage;
 
-  final Image buttonImage;
+  final Icon? buttonIcon;
 
-  final Icon buttonIcon;
-
-  final String buttonText;
+  final String? buttonText;
 
   CircleView({
     this.size,
     this.color = Colors.transparent,
     this.boxShadow,
     this.border,
-    this.opacity,
     this.buttonImage,
     this.buttonIcon,
     this.buttonText,
@@ -34,19 +31,19 @@ class CircleView extends StatelessWidget {
     return Container(
       width: size,
       height: size,
-      child: Center(
-        child: buttonIcon != null
-            ? buttonIcon
-            : (buttonImage != null)
-                ? buttonImage
-                : (buttonText != null) ? Text(buttonText) : null,
-      ),
       decoration: BoxDecoration(
         color: color,
         shape: BoxShape.circle,
         border: border,
         boxShadow: boxShadow,
       ),
+      child: Center(
+        child: buttonIcon != null
+            ? buttonIcon!
+            : (buttonImage != null)
+                ? buttonImage!
+                : (buttonText != null) ? Text(buttonText!) : null,
+      ),
     );
   }
 
@@ -87,11 +84,10 @@ class CircleView extends StatelessWidget {
 
   factory CircleView.padBackgroundCircle(
           double size, Color backgroundColour, borderColor, Color shadowColor,
-          {double opacity}) =>
+          {double? opacity}) =>
       CircleView(
         size: size,
         color: backgroundColour,
-        opacity: opacity,
         border: Border.all(
           color: borderColor,
           width: 4.0,
@@ -108,10 +104,10 @@ class CircleView extends StatelessWidget {
 
   factory CircleView.padButtonCircle(
     double size,
-    Color color,
-    Image image,
-    Icon icon,
-    String text,
+    Color? color,
+    Image? image,
+    Icon? icon,
+    String? text,
   ) =>
       CircleView(
         size: size,

lib/views/joystick_view.dart

@@ -13,7 +13,7 @@ class JoystickView extends StatelessWidget {
   ///
   /// Defaults to half of the width in the portrait
   /// or half of the height in the landscape mode
-  final double size;
+  final double? size;
 
   /// Color of the icons
   ///
@@ -35,12 +35,12 @@ class JoystickView extends StatelessWidget {
   /// The opacity applies to the whole joystick including icons
   ///
   /// Defaults to [null] which means there will be no [Opacity] widget used
-  final double opacity;
+  final double? opacity;
 
   /// Callback to be called when user pans the joystick
   ///
   /// Defaults to [null]
-  final JoystickDirectionCallback onDirectionChanged;
+  final JoystickDirectionCallback? onDirectionChanged;
 
   /// Indicates how often the [onDirectionChanged] should be called.
   ///
@@ -50,36 +50,34 @@ class JoystickView extends StatelessWidget {
   ///
   /// The exception is the [onDirectionChanged] callback being called
   /// on the [onPanStart] and [onPanEnd] callbacks. It will be called immediately.
-  final Duration interval;
+  final Duration? interval;
 
   /// Shows top/right/bottom/left arrows on top of Joystick
   ///
   /// Defaults to [true]
   final bool showArrows;
 
-  JoystickView(
-      {this.size,
-      this.iconsColor = Colors.white54,
-      this.backgroundColor = Colors.blueGrey,
-      this.innerCircleColor = Colors.blueGrey,
-      this.opacity,
-      this.onDirectionChanged,
-      this.interval,
-      this.showArrows = true});
+  JoystickView({
+    this.size,
+    this.iconsColor = Colors.white54,
+    this.backgroundColor = Colors.blueGrey,
+    this.innerCircleColor = Colors.blueGrey,
+    this.opacity,
+    this.onDirectionChanged,
+    this.interval,
+    this.showArrows = true});
 
   @override
   Widget build(BuildContext context) {
-    double actualSize = size != null
-        ? size
-        : _math.min(MediaQuery.of(context).size.width,
-                MediaQuery.of(context).size.height) *
-            0.5;
-    double innerCircleSize = actualSize / 2;
-    Offset lastPosition = Offset(innerCircleSize, innerCircleSize);
-    Offset joystickInnerPosition = _calculatePositionOfInnerCircle(
-        lastPosition, innerCircleSize, actualSize, Offset(0, 0));
-
-    DateTime _callbackTimestamp;
+    final actualSize = size != null
+      ? size!
+      : _math.min(MediaQuery.of(context).size.width, MediaQuery.of(context).size.height) * 0.5;
+    final innerCircleSize = actualSize / 2;
+    var lastPosition = Offset(innerCircleSize, innerCircleSize);
+    var joystickInnerPosition = _calculatePositionOfInnerCircle(
+      lastPosition, innerCircleSize, actualSize, Offset(0, 0));
+
+    DateTime? _callbackTimestamp;
 
     return Center(
       child: StatefulBuilder(
@@ -91,12 +89,12 @@ class JoystickView extends StatelessWidget {
                 backgroundColor,
               ),
               Positioned(
+                top: joystickInnerPosition.dy,
+                left: joystickInnerPosition.dx,
                 child: CircleView.joystickInnerCircle(
                   actualSize / 2,
                   innerCircleColor,
                 ),
-                top: joystickInnerPosition.dy,
-                left: joystickInnerPosition.dx,
               ),
               if (showArrows) ...createArrows(),
             ],
@@ -111,7 +109,7 @@ class JoystickView extends StatelessWidget {
             onPanEnd: (details) {
               _callbackTimestamp = null;
               if (onDirectionChanged != null) {
-                onDirectionChanged(0, 0);
+                onDirectionChanged!(0, 0);
               }
               joystickInnerPosition = _calculatePositionOfInnerCircle(
                   Offset(innerCircleSize, innerCircleSize),
@@ -133,7 +131,7 @@ class JoystickView extends StatelessWidget {
               setState(() => lastPosition = details.localPosition);
             },
             child: (opacity != null)
-                ? Opacity(opacity: opacity, child: joystick)
+                ? Opacity(opacity: opacity!, child: joystick)
                 : joystick,
           );
         },
@@ -144,67 +142,71 @@ class JoystickView extends StatelessWidget {
   List<Widget> createArrows() {
     return [
       Positioned(
+        top: 7.0,
+        left: 0.0,
+        right: 0.0,
         child: Icon(
           Icons.arrow_upward,
           color: iconsColor,
+          size: 15,
         ),
-        top: 16.0,
-        left: 0.0,
-        right: 0.0,
       ),
       Positioned(
+        top: 0.0,
+        bottom: 0.0,
+        left: 7.0,
         child: Icon(
           Icons.arrow_back,
           color: iconsColor,
+          size: 15,
         ),
-        top: 0.0,
-        bottom: 0.0,
-        left: 16.0,
       ),
       Positioned(
+        top: 0.0,
+        bottom: 0.0,
+        right: 7.0,
         child: Icon(
           Icons.arrow_forward,
           color: iconsColor,
+          size: 15,
         ),
-        top: 0.0,
-        bottom: 0.0,
-        right: 16.0,
       ),
       Positioned(
+        bottom: 7.0,
+        left: 0.0,
+        right: 0.0,
         child: Icon(
           Icons.arrow_downward,
           color: iconsColor,
+          size: 15,
         ),
-        bottom: 16.0,
-        left: 0.0,
-        right: 0.0,
       ),
     ];
   }
 
-  DateTime _processGesture(double size, double ignoreSize, Offset offset,
-      DateTime callbackTimestamp) {
-    double middle = size / 2.0;
+  DateTime? _processGesture(double size, double ignoreSize, Offset offset,
+      DateTime? callbackTimestamp) {
+    final middle = size / 2.0;
 
-    double angle = _math.atan2(offset.dy - middle, offset.dx - middle);
-    double degrees = angle * 180 / _math.pi + 90;
+    final angle = _math.atan2(offset.dy - middle, offset.dx - middle);
+    var degrees = angle * 180 / _math.pi + 90;
     if (offset.dx < middle && offset.dy < middle) {
       degrees = 360 + degrees;
     }
 
-    double dx = _math.max(0, _math.min(offset.dx, size));
-    double dy = _math.max(0, _math.min(offset.dy, size));
+    final dx = _math.max(0, _math.min(offset.dx, size));
+    final dy = _math.max(0, _math.min(offset.dy, size));
 
-    double distance =
+    final distance =
         _math.sqrt(_math.pow(middle - dx, 2) + _math.pow(middle - dy, 2));
 
-    double normalizedDistance = _math.min(distance / (size / 2), 1.0);
+    final normalizedDistance = _math.min(distance / (size / 2), 1.0);
 
-    DateTime _callbackTimestamp = callbackTimestamp;
+    var _callbackTimestamp = callbackTimestamp;
     if (onDirectionChanged != null &&
         _canCallOnDirectionChanged(callbackTimestamp)) {
       _callbackTimestamp = DateTime.now();
-      onDirectionChanged(degrees, normalizedDistance);
+      onDirectionChanged!(degrees, normalizedDistance);
     }
 
     return _callbackTimestamp;
@@ -214,11 +216,11 @@ class JoystickView extends StatelessWidget {
   ///
   /// Returns true if enough time has passed since last time it was called
   /// or when there is no [interval] set.
-  bool _canCallOnDirectionChanged(DateTime callbackTimestamp) {
+  bool _canCallOnDirectionChanged(DateTime? callbackTimestamp) {
     if (interval != null && callbackTimestamp != null) {
-      int intervalMilliseconds = interval.inMilliseconds;
-      int timestampMilliseconds = callbackTimestamp.millisecondsSinceEpoch;
-      int currentTimeMilliseconds = DateTime.now().millisecondsSinceEpoch;
+      final intervalMilliseconds = interval!.inMilliseconds;
+      final timestampMilliseconds = callbackTimestamp.millisecondsSinceEpoch;
+      final currentTimeMilliseconds = DateTime.now().millisecondsSinceEpoch;
 
       if (currentTimeMilliseconds - timestampMilliseconds <=
           intervalMilliseconds) {
@@ -231,16 +233,16 @@ class JoystickView extends StatelessWidget {
 
   Offset _calculatePositionOfInnerCircle(
       Offset lastPosition, double innerCircleSize, double size, Offset offset) {
-    double middle = size / 2.0;
+    final middle = size / 2.0;
 
-    double angle = _math.atan2(offset.dy - middle, offset.dx - middle);
-    double degrees = angle * 180 / _math.pi;
+    final angle = _math.atan2(offset.dy - middle, offset.dx - middle);
+    var degrees = angle * 180 / _math.pi;
     if (offset.dx < middle && offset.dy < middle) {
       degrees = 360 + degrees;
     }
-    bool isStartPosition = lastPosition.dx == innerCircleSize &&
+    final isStartPosition = lastPosition.dx == innerCircleSize &&
         lastPosition.dy == innerCircleSize;
-    double lastAngleRadians =
+    final lastAngleRadians =
         (isStartPosition) ? 0 : (degrees) * (_math.pi / 180.0);
 
     var rBig = size / 2;