Make constraints a covariant argument in RenderBox.computeDryLayout() (#136432)

Some render box subclasses have a specific layout contract that is tightly coupled with other render box subclasses (e.g. two private classes in a local project file). In these cases, it is also possible that they use a constraints object that is a subclass of `BoxConstraints`. To allow for this, this change makes the `constraints` argument to `RenderBox.computeDryLayout()` a covariant argument.

For completeness' sake, this updates the other render objects in the rendering package to also use the covariant keyword for this argument.

Author: tvolkert

packages/flutter/lib/src/rendering/animated_size.dart

@@ -264,7 +264,8 @@ class RenderAnimatedSize extends RenderAligningShiftedBox {
   }
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     if (child == null || constraints.isTight) {
       return constraints.smallest;
     }

packages/flutter/lib/src/rendering/box.dart

@@ -1906,7 +1906,7 @@ abstract class RenderBox extends RenderObject {
   /// [debugCannotComputeDryLayout] from within an assert and return a dummy
   /// value of `const Size(0, 0)`.
   @protected
-  Size computeDryLayout(BoxConstraints constraints) {
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     assert(debugCannotComputeDryLayout(
       error: FlutterError.fromParts(<DiagnosticsNode>[
         ErrorSummary('The ${objectRuntimeType(this, 'RenderBox')} class does not implement "computeDryLayout".'),

packages/flutter/lib/src/rendering/custom_layout.dart

@@ -393,7 +393,8 @@ class RenderCustomMultiChildLayoutBox extends RenderBox
   }
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     return _getSize(constraints);
   }
 

packages/flutter/lib/src/rendering/editable.dart

@@ -2270,7 +2270,8 @@ class RenderEditable extends RenderBox with RelayoutWhenSystemFontsChangeMixin,
   bool get _canComputeIntrinsics => _canComputeIntrinsicsCached ??= _canComputeDryLayoutForInlineWidgets();
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     if (!_canComputeIntrinsics) {
       assert(debugCannotComputeDryLayout(
         reason: 'Dry layout not available for alignments that require baseline.',
@@ -2630,7 +2631,8 @@ class _RenderEditableCustomPaint extends RenderBox {
   }
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) => constraints.biggest;
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) => constraints.biggest;
 }
 
 /// An interface that paints within a [RenderEditable]'s bounds, above or

packages/flutter/lib/src/rendering/error.dart

@@ -4,6 +4,8 @@
 
 import 'dart:ui' as ui show Paragraph, ParagraphBuilder, ParagraphConstraints, ParagraphStyle, TextStyle;
 
+import 'package:flutter/foundation.dart';
+
 import 'box.dart';
 import 'object.dart';
 
@@ -77,7 +79,8 @@ class RenderErrorBox extends RenderBox {
   bool hitTestSelf(Offset position) => true;
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     return constraints.constrain(const Size(_kMaxWidth, _kMaxHeight));
   }
 

packages/flutter/lib/src/rendering/flex.dart

@@ -653,7 +653,8 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
   }
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     if (!_canComputeIntrinsics) {
       assert(debugCannotComputeDryLayout(
         reason: 'Dry layout cannot be computed for CrossAxisAlignment.baseline, which requires a full layout.',

packages/flutter/lib/src/rendering/flow.dart

@@ -299,7 +299,8 @@ class RenderFlow extends RenderBox
   }
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     return _getSize(constraints);
   }
 

packages/flutter/lib/src/rendering/image.dart

@@ -5,6 +5,7 @@
 import 'dart:ui' as ui show Image;
 
 import 'package:flutter/animation.dart';
+import 'package:flutter/foundation.dart';
 
 import 'box.dart';
 import 'object.dart';
@@ -401,7 +402,8 @@ class RenderImage extends RenderBox {
   bool hitTestSelf(Offset position) => true;
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     return _sizeForConstraints(constraints);
   }
 

packages/flutter/lib/src/rendering/list_body.dart

@@ -4,6 +4,8 @@
 
 import 'dart:math' as math;
 
+import 'package:flutter/foundation.dart';
+
 import 'box.dart';
 import 'object.dart';
 
@@ -62,7 +64,8 @@ class RenderListBody extends RenderBox
   Axis get mainAxis => axisDirectionToAxis(axisDirection);
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     assert(_debugCheckConstraints(constraints));
     double mainAxisExtent = 0.0;
     RenderBox? child = firstChild;

packages/flutter/lib/src/rendering/list_wheel_viewport.dart

@@ -5,6 +5,7 @@
 import 'dart:math' as math;
 
 import 'package:flutter/animation.dart';
+import 'package:flutter/foundation.dart';
 import 'package:vector_math/vector_math_64.dart' show Matrix4;
 
 import 'box.dart';
@@ -615,7 +616,8 @@ class RenderListWheelViewport
   bool get sizedByParent => true;
 
   @override
-  Size computeDryLayout(BoxConstraints constraints) {
+  @protected
+  Size computeDryLayout(covariant BoxConstraints constraints) {
     return constraints.biggest;
   }