feat: null safety and list []

lib/models/pad_button_item.dart

@@ -7,25 +7,25 @@ import 'gestures.dart';
 /// Model of one padd button.
 class PadButtonItem {
   /// [index] required parameter, the key to recognize button instance.
-  final int index;
+  final int? index;
 
   /// [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;
+  final Color? backgroundColor;
 
   /// [pressedColor] color of button when it is pressed.
-  final Color pressedColor;
+  final Color? pressedColor;
 
   /// [supportedGestures] optional parameter, list of gestures for button which
   /// will call the callback [PadButtonsView.padButtonPressedCallback].

lib/views/circle_view.dart

@@ -2,21 +2,21 @@ 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 double? opacity;
 
-  final Image buttonImage;
+  final Image? buttonImage;
 
-  final Icon buttonIcon;
+  final Icon? buttonIcon;
 
-  final String buttonText;
+  final String? buttonText;
 
   CircleView({
     this.size,
@@ -34,19 +34,22 @@ 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(
+        // ignore: prefer_if_null_operators
+        child: buttonIcon != null
+            ? buttonIcon
+            : (buttonImage != null)
+                ? buttonImage
+                : (buttonText != null)
+                    ? Text(buttonText!)
+                    : null,
+      ),
     );
   }
 
@@ -85,9 +88,9 @@ class CircleView extends StatelessWidget {
         ],
       );
 
-  factory CircleView.padBackgroundCircle(
-          double size, Color backgroundColour, borderColor, Color shadowColor,
-          {double opacity}) =>
+  factory CircleView.padBackgroundCircle(double? size, Color? backgroundColour,
+          borderColor, Color? shadowColor,
+          {double? opacity}) =>
       CircleView(
         size: size,
         color: backgroundColour,
@@ -99,7 +102,7 @@ class CircleView extends StatelessWidget {
         ),
         boxShadow: <BoxShadow>[
           BoxShadow(
-            color: shadowColor,
+            color: shadowColor!,
             spreadRadius: 8.0,
             blurRadius: 8.0,
           )

lib/views/joystick_view.dart

@@ -13,34 +13,34 @@ 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
   ///
   /// Defaults to [Colors.white54]
-  final Color iconsColor;
+  final Color? iconsColor;
 
   /// Color of the joystick background
   ///
   /// Defaults to [Colors.blueGrey]
-  final Color backgroundColor;
+  final Color? backgroundColor;
 
   /// Color of the inner (smaller) circle background
   ///
   /// Defaults to [Colors.blueGrey]
-  final Color innerCircleColor;
+  final Color? innerCircleColor;
 
   /// Opacity of the joystick
   ///
   /// 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.
   ///
@@ -50,7 +50,7 @@ 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
   ///
@@ -69,71 +69,74 @@ class JoystickView extends StatelessWidget {
 
   @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(
+    double? actualSize;
+    if (size != null) {
+      actualSize = size;
+    } else {
+      actualSize = _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;
+    DateTime? _callbackTimestamp;
 
     return Center(
       child: StatefulBuilder(
         builder: (context, setState) {
           Widget joystick = Stack(
             children: <Widget>[
               CircleView.joystickCircle(
-                actualSize,
-                backgroundColor,
+                actualSize!,
+                backgroundColor!,
               ),
               Positioned(
+                top: joystickInnerPosition!.dy,
+                left: joystickInnerPosition!.dx,
                 child: CircleView.joystickInnerCircle(
                   actualSize / 2,
-                  innerCircleColor,
+                  innerCircleColor!,
                 ),
-                top: joystickInnerPosition.dy,
-                left: joystickInnerPosition.dx,
               ),
               if (showArrows) ...createArrows(),
             ],
           );
 
           return GestureDetector(
             onPanStart: (details) {
-              _callbackTimestamp = _processGesture(actualSize, actualSize / 2,
-                  details.localPosition, _callbackTimestamp);
+              _callbackTimestamp = _processGesture(actualSize!, actualSize / 2,
+                  details.localPosition, _callbackTimestamp!);
               setState(() => lastPosition = details.localPosition);
             },
             onPanEnd: (details) {
               _callbackTimestamp = null;
               if (onDirectionChanged != null) {
-                onDirectionChanged(0, 0);
+                onDirectionChanged!(0, 0);
               }
               joystickInnerPosition = _calculatePositionOfInnerCircle(
                   Offset(innerCircleSize, innerCircleSize),
                   innerCircleSize,
-                  actualSize,
+                  actualSize!,
                   Offset(0, 0));
               setState(() =>
                   lastPosition = Offset(innerCircleSize, innerCircleSize));
             },
             onPanUpdate: (details) {
-              _callbackTimestamp = _processGesture(actualSize, actualSize / 2,
-                  details.localPosition, _callbackTimestamp);
+              _callbackTimestamp = _processGesture(actualSize!, actualSize / 2,
+                  details.localPosition, _callbackTimestamp!);
               joystickInnerPosition = _calculatePositionOfInnerCircle(
-                  lastPosition,
+                  lastPosition!,
                   innerCircleSize,
                   actualSize,
                   details.localPosition);
 
               setState(() => lastPosition = details.localPosition);
             },
             child: (opacity != null)
-                ? Opacity(opacity: opacity, child: joystick)
+                ? Opacity(opacity: opacity!, child: joystick)
                 : joystick,
           );
         },
@@ -144,67 +147,67 @@ class JoystickView extends StatelessWidget {
   List<Widget> createArrows() {
     return [
       Positioned(
+        top: 16.0,
+        left: 0.0,
+        right: 0.0,
         child: Icon(
           Icons.arrow_upward,
           color: iconsColor,
         ),
-        top: 16.0,
-        left: 0.0,
-        right: 0.0,
       ),
       Positioned(
+        top: 0.0,
+        bottom: 0.0,
+        left: 16.0,
         child: Icon(
           Icons.arrow_back,
           color: iconsColor,
         ),
-        top: 0.0,
-        bottom: 0.0,
-        left: 16.0,
       ),
       Positioned(
+        top: 0.0,
+        bottom: 0.0,
+        right: 16.0,
         child: Icon(
           Icons.arrow_forward,
           color: iconsColor,
         ),
-        top: 0.0,
-        bottom: 0.0,
-        right: 16.0,
       ),
       Positioned(
+        bottom: 16.0,
+        left: 0.0,
+        right: 0.0,
         child: Icon(
           Icons.arrow_downward,
           color: iconsColor,
         ),
-        bottom: 16.0,
-        left: 0.0,
-        right: 0.0,
       ),
     ];
   }
 
   DateTime _processGesture(double size, double ignoreSize, Offset offset,
       DateTime callbackTimestamp) {
-    double middle = size / 2.0;
+    double? middle = size / 2.0;
 
-    double angle = _math.atan2(offset.dy - middle, offset.dx - middle);
-    double degrees = angle * 180 / _math.pi + 90;
+    double? angle = _math.atan2(offset.dy - middle, offset.dx - middle);
+    double? 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));
+    double? dx = _math.max(0, _math.min(offset.dx, size));
+    double? dy = _math.max(0, _math.min(offset.dy, size));
 
-    double distance =
+    double? distance =
         _math.sqrt(_math.pow(middle - dx, 2) + _math.pow(middle - dy, 2));
 
-    double normalizedDistance = _math.min(distance / (size / 2), 1.0);
+    double? normalizedDistance = _math.min(distance / (size / 2), 1.0);
 
-    DateTime _callbackTimestamp = callbackTimestamp;
+    DateTime? _callbackTimestamp = callbackTimestamp;
     if (onDirectionChanged != null &&
         _canCallOnDirectionChanged(callbackTimestamp)) {
       _callbackTimestamp = DateTime.now();
-      onDirectionChanged(degrees, normalizedDistance);
+      onDirectionChanged!(degrees, normalizedDistance);
     }
 
     return _callbackTimestamp;
@@ -215,10 +218,10 @@ 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) {
-    if (interval != null && callbackTimestamp != null) {
-      int intervalMilliseconds = interval.inMilliseconds;
-      int timestampMilliseconds = callbackTimestamp.millisecondsSinceEpoch;
-      int currentTimeMilliseconds = DateTime.now().millisecondsSinceEpoch;
+    if (interval != null) {
+      int? intervalMilliseconds = interval!.inMilliseconds;
+      int? timestampMilliseconds = callbackTimestamp.millisecondsSinceEpoch;
+      int? currentTimeMilliseconds = DateTime.now().millisecondsSinceEpoch;
 
       if (currentTimeMilliseconds - timestampMilliseconds <=
           intervalMilliseconds) {
@@ -231,16 +234,16 @@ class JoystickView extends StatelessWidget {
 
   Offset _calculatePositionOfInnerCircle(
       Offset lastPosition, double innerCircleSize, double size, Offset offset) {
-    double middle = size / 2.0;
+    double? middle = size / 2.0;
 
-    double angle = _math.atan2(offset.dy - middle, offset.dx - middle);
-    double degrees = angle * 180 / _math.pi;
+    double? angle = _math.atan2(offset.dy - middle, offset.dx - middle);
+    double? degrees = angle * 180 / _math.pi;
     if (offset.dx < middle && offset.dy < middle) {
       degrees = 360 + degrees;
     }
-    bool isStartPosition = lastPosition.dx == innerCircleSize &&
+    bool? isStartPosition = lastPosition.dx == innerCircleSize &&
         lastPosition.dy == innerCircleSize;
-    double lastAngleRadians =
+    double? lastAngleRadians =
         (isStartPosition) ? 0 : (degrees) * (_math.pi / 180.0);
 
     var rBig = size / 2;