Add missing deprecations to CupertinoDynamicColor. (flutter#171160)

Closes flutter#171059

### Description
- Adds missing deprecations to `CupertinoDynamicColor`
- Adds dart fixes for some of the deprecations

## Pre-launch Checklist

- [X] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [X] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [X] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [X] I signed the [CLA].
- [X] I listed at least one issue that this PR fixes in the description
above.
- [ ] I updated/added relevant documentation (doc comments with `///`).
- [X] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [X] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [X] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

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[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
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[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

---------

Co-authored-by: Kate Lovett <katelovett@google.com>
Co-authored-by: Tong Mu <dkwingsmt@users.noreply.github.com>

Author: 3 people

engine/src/flutter/lib/ui/painting.dart

@@ -215,7 +215,7 @@ class Color {
   final ColorSpace colorSpace;
 
   static int _floatToInt8(double x) {
-    return (x * 255.0).round() & 0xff;
+    return (x * 255.0).round().clamp(0, 255);
   }
 
   /// A 32 bit value representing this color.
@@ -233,7 +233,7 @@ class Color {
   ///
   /// Unlike accessing the floating point equivalent channels individually
   /// ([a], [r], [g], [b]), this method is intentionally _lossy_, and scales
-  /// each channel using `(channel * 255.0).round() & 0xff`.
+  /// each channel using `(channel * 255.0).round().clamp(0, 255)`.
   ///
   /// While useful for storing a 32-bit integer value, prefer accessing the
   /// individual channels (and storing the double equivalent) where higher
@@ -263,7 +263,7 @@ class Color {
   ///
   /// A value of 0 means this color is fully transparent. A value of 255 means
   /// this color is fully opaque.
-  @Deprecated('Use (*.a * 255.0).round() & 0xff')
+  @Deprecated('Use (*.a * 255.0).round().clamp(0, 255)')
   int get alpha => (0xff000000 & value) >> 24;
 
   /// The alpha channel of this color as a double.
@@ -274,15 +274,15 @@ class Color {
   double get opacity => alpha / 0xFF;
 
   /// The red channel of this color in an 8 bit value.
-  @Deprecated('Use (*.r * 255.0).round() & 0xff')
+  @Deprecated('Use (*.r * 255.0).round().clamp(0, 255)')
   int get red => (0x00ff0000 & value) >> 16;
 
   /// The green channel of this color in an 8 bit value.
-  @Deprecated('Use (*.g * 255.0).round() & 0xff')
+  @Deprecated('Use (*.g * 255.0).round().clamp(0, 255)')
   int get green => (0x0000ff00 & value) >> 8;
 
   /// The blue channel of this color in an 8 bit value.
-  @Deprecated('Use (*.b * 255.0).round() & 0xff')
+  @Deprecated('Use (*.b * 255.0).round().clamp(0, 255)')
   int get blue => (0x000000ff & value) >> 0;
 
   /// Returns a new color with the provided components updated.

packages/flutter/lib/fix_data/fix_cupertino.yaml

@@ -451,4 +451,53 @@ transforms:
       pageBuilder:
         kind: fragment
         value: 'arguments[pageBuilder]'
-# Before adding a new fix: read instructions at the top of this file.
+
+  # Changes made in https://github.com/flutter/flutter/pull/171160
+  - title: "Rename from 'opacity' to 'a'"
+    date: 2025-06-24
+    element:
+      uris: [ 'cupertino.dart' ]
+      method: 'opacity'
+      inClass: 'CupertinoDynamicColor'
+    changes:
+      - kind: 'rename'
+        newName: 'a'
+
+  # Changes made in https://github.com/flutter/flutter/pull/171160
+  - title: "Replace 'value' with 'toARGB32()'"
+    date: 2025-06-24
+    element:
+      uris: [ 'cupertino.dart' ]
+      method: 'value'
+      inClass: 'CupertinoDynamicColor'
+    changes:
+      - kind: 'replacedBy'
+        newElement:
+          uris: [ 'cupertino.dart' ]
+          method: 'toARGB32'
+          inClass: 'CupertinoDynamicColor'
+
+  # Changes made in https://github.com/flutter/flutter/pull/171160
+  - title: "Rename 'withOpacity'"
+    date: 2025-06-24
+    element:
+      uris: [ 'cupertino.dart' ]
+      method: 'withOpacity'
+      inClass: 'CupertinoDynamicColor'
+    changes:
+      - kind: 'rename'
+        newName: 'withValues'
+      - kind: 'removeParameter'
+        index: 0
+      - kind: 'addParameter'
+        index: 0
+        name: 'alpha'
+        style: optional_named
+        argumentValue:
+          expression: '{% opacity %}'
+          requiredIf: "opacity != ''"
+    variables:
+      opacity:
+        kind: 'fragment'
+        value: 'arguments[0]'
+# Before adding a new fix: read instructions at the top of this file.

packages/flutter/lib/src/cupertino/colors.dart

@@ -1157,27 +1157,51 @@ class CupertinoDynamicColor with Diagnosticable implements Color {
     }
   }
 
+  @Deprecated(
+    'Use component accessors like .r or .g, or toARGB32 for an explicit conversion. '
+    'This feature was deprecated after v3.33.0-1.0.pre.',
+  )
   @override
   int get value => _effectiveColor.value;
 
   @override
-  int toARGB32() => value;
+  int toARGB32() => _effectiveColor.toARGB32();
 
+  @Deprecated(
+    'Use (*.a * 255.0).round().clamp(0, 255). '
+    'This feature was deprecated after v3.33.0-1.0.pre.',
+  )
   @override
   int get alpha => _effectiveColor.alpha;
 
+  @Deprecated(
+    'Use (*.b * 255.0).round().clamp(0, 255). '
+    'This feature was deprecated after v3.33.0-1.0.pre.',
+  )
   @override
   int get blue => _effectiveColor.blue;
 
   @override
   double computeLuminance() => _effectiveColor.computeLuminance();
 
+  @Deprecated(
+    'Use (*.g * 255.0).round().clamp(0, 255). '
+    'This feature was deprecated after v3.33.0-1.0.pre.',
+  )
   @override
   int get green => _effectiveColor.green;
 
+  @Deprecated(
+    'Use .a. '
+    'This feature was deprecated after v3.33.0-1.0.pre.',
+  )
   @override
   double get opacity => _effectiveColor.opacity;
 
+  @Deprecated(
+    'Use (*.r * 255.0).round().clamp(0, 255). '
+    'This feature was deprecated after v3.33.0-1.0.pre.',
+  )
   @override
   int get red => _effectiveColor.red;
 
@@ -1190,6 +1214,10 @@ class CupertinoDynamicColor with Diagnosticable implements Color {
   @override
   Color withGreen(int g) => _effectiveColor.withGreen(g);
 
+  @Deprecated(
+    'Use .withValues() to avoid precision loss. '
+    'This feature was deprecated after v3.33.0-1.0.pre.',
+  )
   @override
   Color withOpacity(double opacity) => _effectiveColor.withOpacity(opacity);
 

packages/flutter/test_fixes/cupertino/cupertino.dart

@@ -295,4 +295,13 @@ void main() {
     context: context,
     pageBuilder: (BuildContext context) => Container(),
   );
+
+  // https://github.com/flutter/flutter/pull/171160
+  CupertinoDynamicColor dynamicColor = CupertinoDynamicColor.withBrightness(
+    color: Color(0xFF000000),
+    darkColor: Color(0xFF000001),
+  );
+  dynamicColor.opacity;
+  dynamicColor.value;
+  dynamicColor = dynamicColor.withOpacity(0.55);
 }

packages/flutter/test_fixes/cupertino/cupertino.dart.expect

@@ -313,4 +313,13 @@ void main() {
     context: context,
     builder: (BuildContext context) => Container(),
   );
+
+  // https://github.com/flutter/flutter/pull/171160
+  CupertinoDynamicColor dynamicColor = CupertinoDynamicColor.withBrightness(
+    color: Color(0xFF000000),
+    darkColor: Color(0xFF000001),
+  );
+  dynamicColor.a;
+  dynamicColor.toARGB32();
+  dynamicColor = dynamicColor.withValues(alpha: 0.55);
 }