[Cupertino] Fix static to static readonly

Author: IIzzaya

Runtime/cupertino/button.cs

@@ -12,10 +12,10 @@
 
 namespace Unity.UIWidgets.cupertino {
     public class CupertinoButtonUtils {
-        public static Color _kDisabledBackground = new Color(0xFFA9A9A9);
-        public static Color _kDisabledForeground = new Color(0xFFD1D1D1);
-        public static EdgeInsets _kButtonPadding = EdgeInsets.all(16.0f);
-        public static EdgeInsets _kBackgroundButtonPadding = EdgeInsets.symmetric(vertical: 14.0f, horizontal: 64.0f);
+        public static readonly Color _kDisabledBackground = new Color(0xFFA9A9A9);
+        public static readonly Color _kDisabledForeground = new Color(0xFFD1D1D1);
+        public static readonly EdgeInsets _kButtonPadding = EdgeInsets.all(16.0f);
+        public static readonly EdgeInsets _kBackgroundButtonPadding = EdgeInsets.symmetric(vertical: 14.0f, horizontal: 64.0f);
     }
 
     public class CupertinoButton : StatefulWidget {

Runtime/cupertino/colors.cs

@@ -2,24 +2,24 @@
 
 namespace Unity.UIWidgets.cupertino {
     public class CupertinoColors {
-        public static Color activeBlue = new Color(0xFF007AFF);
+        public static readonly Color activeBlue = new Color(0xFF007AFF);
 
-        public static Color activeGreen = new Color(0xFF4CD964);
+        public static readonly Color activeGreen = new Color(0xFF4CD964);
 
-        public static Color activeOrange = new Color(0xFFFF9500);
+        public static readonly Color activeOrange = new Color(0xFFFF9500);
 
-        public static Color white = new Color(0xFFFFFFFF);
+        public static readonly Color white = new Color(0xFFFFFFFF);
 
-        public static Color black = new Color(0xFF000000);
+        public static readonly Color black = new Color(0xFF000000);
 
-        public static Color lightBackgroundGray = new Color(0xFFE5E5EA);
+        public static readonly Color lightBackgroundGray = new Color(0xFFE5E5EA);
 
-        public static Color extraLightBackgroundGray = new Color(0xFFEFEFF4);
+        public static readonly Color extraLightBackgroundGray = new Color(0xFFEFEFF4);
 
-        public static Color darkBackgroundGray = new Color(0xFF171717);
+        public static readonly Color darkBackgroundGray = new Color(0xFF171717);
 
-        public static Color inactiveGray = new Color(0xFF8E8E93);
+        public static readonly Color inactiveGray = new Color(0xFF8E8E93);
 
-        public static Color destructiveRed = new Color(0xFFFF3B30);
+        public static readonly Color destructiveRed = new Color(0xFFFF3B30);
     }
 }

Runtime/cupertino/dialog.cs

@@ -13,7 +13,7 @@
 
 namespace Unity.UIWidgets.cupertino {
     class CupertinoDialogUtils {
-        public static TextStyle _kCupertinoDialogTitleStyle = new TextStyle(
+        public static readonly TextStyle _kCupertinoDialogTitleStyle = new TextStyle(
             fontFamily: ".SF UI Display",
             fontSize: 18.0f,
             fontWeight: FontWeight.w600,
@@ -22,7 +22,7 @@ class CupertinoDialogUtils {
             textBaseline: TextBaseline.alphabetic
         );
 
-        public static TextStyle _kCupertinoDialogContentStyle = new TextStyle(
+        public static readonly TextStyle _kCupertinoDialogContentStyle = new TextStyle(
             fontFamily: ".SF UI Text",
             fontSize: 13.4f,
             fontWeight: FontWeight.w400,
@@ -32,7 +32,7 @@ class CupertinoDialogUtils {
             textBaseline: TextBaseline.alphabetic
         );
 
-        public static TextStyle _kCupertinoDialogActionStyle = new TextStyle(
+        public static readonly TextStyle _kCupertinoDialogActionStyle = new TextStyle(
             fontFamily: ".SF UI Text",
             fontSize: 16.8f,
             fontWeight: FontWeight.w400,
@@ -43,7 +43,7 @@ class CupertinoDialogUtils {
         public const float _kCupertinoDialogWidth = 270.0f;
         public const float _kAccessibilityCupertinoDialogWidth = 310.0f;
 
-        public static BoxDecoration _kCupertinoDialogBlurOverlayDecoration = new BoxDecoration(
+        public static readonly BoxDecoration _kCupertinoDialogBlurOverlayDecoration = new BoxDecoration(
             color: CupertinoColors.white,
             backgroundBlendMode: BlendMode.overlay
         );
@@ -54,14 +54,12 @@ class CupertinoDialogUtils {
         public const float _kMinButtonFontSize = 10.0f;
         public const float _kDialogCornerRadius = 12.0f;
         public const float _kDividerThickness = 1.0f;
-
-        public static Color _kDialogColor = new Color(0xC0FFFFFF);
-        public static Color _kDialogPressedColor = new Color(0x90FFFFFF);
-        public static Color _kButtonDividerColor = new Color(0x40FFFFFF);
-
-
         public const float _kMaxRegularTextScaleFactor = 1.4f;
 
+        public static readonly Color _kDialogColor = new Color(0xC0FFFFFF);
+        public static readonly Color _kDialogPressedColor = new Color(0x90FFFFFF);
+        public static readonly Color _kButtonDividerColor = new Color(0x40FFFFFF);
+
         public static bool _isInAccessibilityMode(BuildContext context) {
             MediaQueryData data = MediaQuery.of(context, nullOk: true);
             return data != null && data.textScaleFactor > _kMaxRegularTextScaleFactor;