Remove unnecessary exceptions from analysis_options.yaml (flutter#35054)

analysis_options.yaml

@@ -9,14 +9,6 @@ analyzer:
     strict-casts: true
     strict-raw-types: true
   errors:
-    # treat missing required parameters as a warning (not a hint)
-    missing_required_param: warning
-    # treat missing returns as a warning (not a hint)
-    missing_return: warning
-    # allow having TODO comments in the code
-    todo: ignore
-    # allow dart:ui to import dart:_internal
-    import_internal_library: ignore # DIFFERENT FROM FLUTTER/FLUTTER
     # allow self-reference to deprecated members (we do this because otherwise we have
     # to annotate every member in every test, assert, etc, when we deprecate something)
     deprecated_member_use_from_same_package: ignore
@@ -150,7 +142,7 @@ linter:
     # - prefer_double_quotes # opposite of prefer_single_quotes
     - prefer_equal_for_default_values
     # - prefer_expression_function_bodies # conflicts with https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#consider-using--for-short-functions-and-methods
-    # - prefer_final_fields # DIFFERENT FROM FLUTTER/FLUTTER (we do weird things with private fields, especially on the PlatformDispatcher object)
+    - prefer_final_fields
     - prefer_final_in_for_each
     - prefer_final_locals
     # - prefer_final_parameters # we should enable this one day when it can be auto-fixed (https://github.com/dart-lang/linter/issues/3104), see also parameter_assignments
@@ -185,7 +177,7 @@ linter:
     # - sized_box_shrink_expand # not yet tested
     - slash_for_doc_comments
     - sort_child_properties_last
-    # - sort_constructors_first # DIFFERENT FROM FLUTTER/FLUTTER (we have private fake constructors)
+    - sort_constructors_first
     # - sort_pub_dependencies # prevents separating pinned transitive dependencies
     - sort_unnamed_constructors_first
     - test_types_in_equals

lib/ui/compositing.dart

@@ -240,7 +240,7 @@ class SceneBuilder extends NativeFieldWrapperClass1 {
   //
   // The key is the layer used. The value is the description of what the layer
   // is used for, e.g. "pushOpacity" or "addRetained".
-  Map<EngineLayer, String> _usedLayers = <EngineLayer, String>{};
+  final Map<EngineLayer, String> _usedLayers = <EngineLayer, String>{};
 
   // In debug mode checks that the `layer` is only used once in a given scene.
   bool _debugCheckUsedOnce(EngineLayer layer, String usage) {

lib/ui/painting.dart

@@ -1090,6 +1090,14 @@ enum Clip {
 /// Most APIs on [Canvas] take a [Paint] object to describe the style
 /// to use for that operation.
 class Paint {
+  /// Constructs an empty [Paint] object with all fields initialized to
+  /// their defaults.
+  Paint() {
+    if (enableDithering) {
+      _dither = true;
+    }
+  }
+
   // Paint objects are encoded in two buffers:
   //
   // * _data is binary data in four-byte fields, each of which is either a
@@ -1150,14 +1158,6 @@ class Paint {
   static const int _kImageFilterIndex = 2;
   static const int _kObjectCount = 3; // Must be one larger than the largest index.
 
-  /// Constructs an empty [Paint] object with all fields initialized to
-  /// their defaults.
-  Paint() {
-    if (enableDithering) {
-      _dither = true;
-    }
-  }
-
   /// Whether to apply anti-aliasing to lines and images drawn on the
   /// canvas.
   ///
@@ -1878,7 +1878,7 @@ class _Image extends NativeFieldWrapperClass1 {
   @FfiNative<Void Function(Pointer<Void>)>('Image::dispose')
   external void _dispose();
 
-  Set<Image> _handles = <Image>{};
+  final Set<Image> _handles = <Image>{};
 
   @override
   String toString() => '[$width\u00D7$height]';
@@ -2350,9 +2350,6 @@ class Path extends NativeFieldWrapperClass1 {
   @pragma('vm:entry-point')
   Path() { _constructor(); }
 
-  @FfiNative<Void Function(Handle)>('Path::Create')
-  external void _constructor();
-
   /// Avoids creating a new native backing for the path for methods that will
   /// create it later, such as [Path.from], [shift] and [transform].
   Path._();
@@ -2367,6 +2364,9 @@ class Path extends NativeFieldWrapperClass1 {
     return clonedPath;
   }
 
+  @FfiNative<Void Function(Handle)>('Path::Create')
+  external void _constructor();
+
   @FfiNative<Void Function(Pointer<Void>, Handle)>('Path::clone')
   external void _clone(Path outPath);
 
@@ -2848,7 +2848,7 @@ class PathMetricIterator implements Iterator<PathMetric> {
   PathMetricIterator._(this._pathMeasure) : assert(_pathMeasure != null);
 
   PathMetric? _pathMetric;
-  _PathMeasure _pathMeasure;
+  final _PathMeasure _pathMeasure;
 
   @override
   PathMetric get current {
@@ -3576,9 +3576,6 @@ class _ComposeImageFilter implements ImageFilter {
 /// ImageFilter, because we want ImageFilter to be efficiently comparable, so that
 /// widgets can check for ImageFilter equality to avoid repainting.
 class _ImageFilter extends NativeFieldWrapperClass1 {
-  @FfiNative<Void Function(Handle)>('ImageFilter::Create')
-  external void _constructor();
-
   /// Creates an image filter that applies a Gaussian blur.
   _ImageFilter.blur(_GaussianBlurImageFilter filter)
     : assert(filter != null),
@@ -3587,9 +3584,6 @@ class _ImageFilter extends NativeFieldWrapperClass1 {
     _initBlur(filter.sigmaX, filter.sigmaY, filter.tileMode.index);
   }
 
-  @FfiNative<Void Function(Pointer<Void>, Double, Double, Int32)>('ImageFilter::initBlur', isLeaf: true)
-  external void _initBlur(double sigmaX, double sigmaY, int tileMode);
-
   /// Creates an image filter that dilates each input pixel's channel values
   /// to the max value within the given radii along the x and y axes.
   _ImageFilter.dilate(_DilateImageFilter filter)
@@ -3598,8 +3592,6 @@ class _ImageFilter extends NativeFieldWrapperClass1 {
     _constructor();
     _initDilate(filter.radiusX, filter.radiusY);
   }
-  @FfiNative<Void Function(Pointer<Void>, Double, Double)>('ImageFilter::initDilate', isLeaf: true)
-  external void _initDilate(double radiusX, double radiusY);
 
   /// Create a filter that erodes each input pixel's channel values
   /// to the minimum channel value within the given radii along the x and y axes.
@@ -3609,8 +3601,6 @@ class _ImageFilter extends NativeFieldWrapperClass1 {
     _constructor();
     _initErode(filter.radiusX, filter.radiusY);
   }
-  @FfiNative<Void Function(Pointer<Void>, Double, Double)>('ImageFilter::initErode', isLeaf: true)
-  external void _initErode(double radiusX, double radiusY);
 
   /// Creates an image filter that applies a matrix transformation.
   ///
@@ -3626,9 +3616,6 @@ class _ImageFilter extends NativeFieldWrapperClass1 {
     _initMatrix(filter.data, filter.filterQuality.index);
   }
 
-  @FfiNative<Void Function(Pointer<Void>, Handle, Int32)>('ImageFilter::initMatrix')
-  external void _initMatrix(Float64List matrix4, int filterQuality);
-
   /// Converts a color filter to an image filter.
   _ImageFilter.fromColorFilter(ColorFilter filter)
     : assert(filter != null),
@@ -3638,9 +3625,6 @@ class _ImageFilter extends NativeFieldWrapperClass1 {
     _initColorFilter(nativeFilter);
   }
 
-  @FfiNative<Void Function(Pointer<Void>, Pointer<Void>)>('ImageFilter::initColorFilter')
-  external void _initColorFilter(_ColorFilter? colorFilter);
-
   /// Composes `_innerFilter` with `_outerFilter`.
   _ImageFilter.composed(_ComposeImageFilter filter)
     : assert(filter != null),
@@ -3651,6 +3635,24 @@ class _ImageFilter extends NativeFieldWrapperClass1 {
     _initComposed(nativeFilterOuter, nativeFilterInner);
   }
 
+  @FfiNative<Void Function(Handle)>('ImageFilter::Create')
+  external void _constructor();
+
+  @FfiNative<Void Function(Pointer<Void>, Double, Double, Int32)>('ImageFilter::initBlur', isLeaf: true)
+  external void _initBlur(double sigmaX, double sigmaY, int tileMode);
+
+  @FfiNative<Void Function(Pointer<Void>, Double, Double)>('ImageFilter::initDilate', isLeaf: true)
+  external void _initDilate(double radiusX, double radiusY);
+
+  @FfiNative<Void Function(Pointer<Void>, Double, Double)>('ImageFilter::initErode', isLeaf: true)
+  external void _initErode(double radiusX, double radiusY);
+
+  @FfiNative<Void Function(Pointer<Void>, Handle, Int32)>('ImageFilter::initMatrix')
+  external void _initMatrix(Float64List matrix4, int filterQuality);
+
+  @FfiNative<Void Function(Pointer<Void>, Pointer<Void>)>('ImageFilter::initColorFilter')
+  external void _initColorFilter(_ColorFilter? colorFilter);
+
   @FfiNative<Void Function(Pointer<Void>, Pointer<Void>, Pointer<Void>)>('ImageFilter::initComposeFilter')
   external void _initComposed(_ImageFilter outerFilter, _ImageFilter innerFilter);
 
@@ -3803,9 +3805,6 @@ Float32List _encodeTwoPoints(Offset pointA, Offset pointB) {
 ///  * [Gradient](https://api.flutter.dev/flutter/painting/Gradient-class.html), the class in the [painting] library.
 ///
 class Gradient extends Shader {
-  @FfiNative<Void Function(Handle)>('Gradient::Create')
-  external void _constructor();
-
   /// Creates a linear gradient from `from` to `to`.
   ///
   /// If `colorStops` is provided, `colorStops[i]` is a number from 0.0 to 1.0
@@ -3849,9 +3848,6 @@ class Gradient extends Shader {
     _initLinear(endPointsBuffer, colorsBuffer, colorStopsBuffer, tileMode.index, matrix4);
   }
 
-  @FfiNative<Void Function(Pointer<Void>, Handle, Handle, Handle, Int32, Handle)>('Gradient::initLinear')
-  external void _initLinear(Float32List endPoints, Int32List colors, Float32List? colorStops, int tileMode, Float64List? matrix4);
-
   /// Creates a radial gradient centered at `center` that ends at `radius`
   /// distance from the center.
   ///
@@ -3912,30 +3908,6 @@ class Gradient extends Shader {
     }
   }
 
-  @FfiNative<Void Function(Pointer<Void>, Double, Double, Double, Handle, Handle, Int32, Handle)>('Gradient::initRadial')
-  external void _initRadial(
-      double centerX,
-      double centerY,
-      double radius,
-      Int32List colors,
-      Float32List? colorStops,
-      int tileMode,
-      Float64List? matrix4);
-
-  @FfiNative<Void Function(Pointer<Void>, Double, Double, Double, Double, Double, Double, Handle, Handle, Int32, Handle)>(
-      'Gradient::initTwoPointConical')
-  external void _initConical(
-      double startX,
-      double startY,
-      double startRadius,
-      double endX,
-      double endY,
-      double endRadius,
-      Int32List colors,
-      Float32List? colorStops,
-      int tileMode,
-      Float64List? matrix4);
-
   /// Creates a sweep gradient centered at `center` that starts at `startAngle`
   /// and ends at `endAngle`.
   ///
@@ -3986,6 +3958,36 @@ class Gradient extends Shader {
     _initSweep(center.dx, center.dy, colorsBuffer, colorStopsBuffer, tileMode.index, startAngle, endAngle, matrix4);
   }
 
+  @FfiNative<Void Function(Handle)>('Gradient::Create')
+  external void _constructor();
+
+  @FfiNative<Void Function(Pointer<Void>, Handle, Handle, Handle, Int32, Handle)>('Gradient::initLinear')
+  external void _initLinear(Float32List endPoints, Int32List colors, Float32List? colorStops, int tileMode, Float64List? matrix4);
+
+  @FfiNative<Void Function(Pointer<Void>, Double, Double, Double, Handle, Handle, Int32, Handle)>('Gradient::initRadial')
+  external void _initRadial(
+      double centerX,
+      double centerY,
+      double radius,
+      Int32List colors,
+      Float32List? colorStops,
+      int tileMode,
+      Float64List? matrix4);
+
+  @FfiNative<Void Function(Pointer<Void>, Double, Double, Double, Double, Double, Double, Handle, Handle, Int32, Handle)>(
+      'Gradient::initTwoPointConical')
+  external void _initConical(
+      double startX,
+      double startY,
+      double startRadius,
+      double endX,
+      double endY,
+      double endRadius,
+      Int32List colors,
+      Float32List? colorStops,
+      int tileMode,
+      Float64List? matrix4);
+
   @FfiNative<Void Function(Pointer<Void>, Double, Double, Handle, Handle, Int32, Double, Double, Handle)>('Gradient::initSweep')
   external void _initSweep(
       double centerX,
@@ -4054,6 +4056,15 @@ class ImageShader extends Shader {
 /// [A current specification of valid SPIR-V is here.](https://github.com/flutter/engine/blob/main/lib/spirv/README.md)
 ///
 class FragmentProgram extends NativeFieldWrapperClass1 {
+  @pragma('vm:entry-point')
+  FragmentProgram._fromAsset(String assetKey) {
+    _constructor();
+    final String result = _initFromAsset(assetKey);
+    if (result.isNotEmpty) {
+      throw result; // ignore: only_throw_errors
+    }
+  }
+
   // TODO(zra): Document custom shaders on the website and add a link to it
   // here. https://github.com/flutter/flutter/issues/107929.
   /// Creates a fragment program from the asset with key [assetKey].
@@ -4078,18 +4089,9 @@ class FragmentProgram extends NativeFieldWrapperClass1 {
   // so that the case where an in-use program is requested again can be fast,
   // but programs that are no longer referenced are not retained because of the
   // cache.
-  static Map<String, WeakReference<FragmentProgram>> _shaderRegistry =
+  static final Map<String, WeakReference<FragmentProgram>> _shaderRegistry =
       <String, WeakReference<FragmentProgram>>{};
 
-  @pragma('vm:entry-point')
-  FragmentProgram._fromAsset(String assetKey) {
-    _constructor();
-    final String result = _initFromAsset(assetKey);
-    if (result.isNotEmpty) {
-      throw result; // ignore: only_throw_errors
-    }
-  }
-
   static void _reinitializeShader(String assetKey) {
     // If a shader for the assent isn't already registered, then there's no
     // need to reinitialize it. The new shader will be loaded and initialized
@@ -6010,17 +6012,6 @@ class ImmutableBuffer extends NativeFieldWrapperClass1 {
 class ImageDescriptor extends NativeFieldWrapperClass1 {
   ImageDescriptor._();
 
-  /// Creates an image descriptor from encoded data in a supported format.
-  static Future<ImageDescriptor> encoded(ImmutableBuffer buffer) {
-    final ImageDescriptor descriptor = ImageDescriptor._();
-    return _futurize((_Callback<void> callback) {
-      return descriptor._initEncoded(buffer, callback);
-    }).then((_) => descriptor);
-  }
-
-  @FfiNative<Handle Function(Handle, Pointer<Void>, Handle)>('ImageDescriptor::initEncoded')
-  external String? _initEncoded(ImmutableBuffer buffer, _Callback<void> callback);
-
   /// Creates an image descriptor from raw image pixels.
   ///
   /// The `pixels` parameter is the pixel data. They are packed in bytes in the
@@ -6045,6 +6036,17 @@ class ImageDescriptor extends NativeFieldWrapperClass1 {
     _initRaw(this, buffer, width, height, rowBytes ?? -1, pixelFormat.index);
   }
 
+  /// Creates an image descriptor from encoded data in a supported format.
+  static Future<ImageDescriptor> encoded(ImmutableBuffer buffer) {
+    final ImageDescriptor descriptor = ImageDescriptor._();
+    return _futurize((_Callback<void> callback) {
+      return descriptor._initEncoded(buffer, callback);
+    }).then((_) => descriptor);
+  }
+
+  @FfiNative<Handle Function(Handle, Pointer<Void>, Handle)>('ImageDescriptor::initEncoded')
+  external String? _initEncoded(ImmutableBuffer buffer, _Callback<void> callback);
+
   @FfiNative<Void Function(Handle, Handle, Int32, Int32, Int32, Int32)>('ImageDescriptor::initRaw')
   external static void _initRaw(ImageDescriptor outDescriptor, ImmutableBuffer buffer, int width, int height, int rowBytes, int pixelFormat);
 

lib/ui/platform_dispatcher.dart

@@ -141,10 +141,10 @@ class PlatformDispatcher {
   ///
   /// If any of their configurations change, [onMetricsChanged] will be called.
   Iterable<FlutterView> get views => _views.values;
-  Map<Object, FlutterView> _views = <Object, FlutterView>{};
+  final Map<Object, FlutterView> _views = <Object, FlutterView>{};
 
   // A map of opaque platform view identifiers to view configurations.
-  Map<Object, ViewConfiguration> _viewConfigurations = <Object, ViewConfiguration>{};
+  final Map<Object, ViewConfiguration> _viewConfigurations = <Object, ViewConfiguration>{};
 
   /// A callback that is invoked whenever the [ViewConfiguration] of any of the
   /// [views] changes.
@@ -1454,17 +1454,16 @@ class FrameTiming {
     ]);
   }
 
-  static final int _dataLength = FramePhase.values.length + _FrameTimingInfo.values.length;
-
   /// Construct [FrameTiming] with raw timestamps in microseconds.
   ///
   /// List [timestamps] must have the same number of elements as
   /// [FramePhase.values].
   ///
   /// This constructor is usually only called by the Flutter engine, or a test.
   /// To get the [FrameTiming] of your app, see [PlatformDispatcher.onReportTimings].
-  FrameTiming._(this._data)
-      : assert(_data.length == _dataLength);
+  FrameTiming._(this._data) : assert(_data.length == _dataLength);
+
+  static final int _dataLength = FramePhase.values.length + _FrameTimingInfo.values.length;
 
   /// This is a raw timestamp in microseconds from some epoch. The epoch in all
   /// [FrameTiming] is the same, but it may not match [DateTime]'s epoch.

lib/ui/plugins.dart

@@ -45,9 +45,9 @@ class PluginUtilities {
   // extended directly.
   factory PluginUtilities._() => throw UnsupportedError('Namespace');
 
-  static Map<Function, CallbackHandle?> _forwardCache =
+  static final Map<Function, CallbackHandle?> _forwardCache =
       <Function, CallbackHandle?>{};
-  static Map<CallbackHandle, Function?> _backwardCache =
+  static final Map<CallbackHandle, Function?> _backwardCache =
       <CallbackHandle, Function?>{};
 
   /// Get a handle to a named top-level or static callback function which can