move

Author: mkustermann

lib/web_ui/lib/src/engine/dart_js_conversion.dart

@@ -7,14 +7,12 @@ import 'dart:js_interop';
 import 'dart:math' as math;
 import 'dart:typed_data';
 
+import 'package:ui/src/engine/skwasm/skwasm_stub.dart' if (dart.library.ffi) 'package:ui/src/engine/skwasm/skwasm_impl.dart';
 import 'package:js/js_util.dart' as js_util;
 import 'package:meta/meta.dart';
 
 import 'browser_detection.dart';
 
-import 'dart_js_conversion.dart';
-export 'dart_js_conversion.dart';
-
 /// This file contains static interop classes for interacting with the DOM and
 /// some helpers. All of the classes in this file are named after their
 /// counterparts in the DOM. To extend any of these classes, simply add an
@@ -28,6 +26,41 @@ export 'dart_js_conversion.dart';
 // the boundary between Dart and JS interop exists, we should expose JS types
 // directly to the engine.
 
+/// Conversions methods to facilitate migrating to JS types.
+///
+/// The existing behavior across the JS interop boundary involves many implicit
+/// conversions. For efficiency reasons, on JS backends we still want those
+/// implicit conversions, but on Wasm backends we need to 'shallowly' convert
+/// these types.
+///
+/// Note: Due to discrepancies between how `null`, `JSNull`, and `JSUndefined`
+/// are currently represented across web backends, these extensions should be
+/// used carefully and only on types that are known to not contains `JSNull` and
+/// `JSUndefined`.
+
+extension ObjectToJSAnyExtension on Object {
+  // Once `Object.toJSBox` is faster (see
+  // https://github.com/dart-lang/sdk/issues/55183) we can remove this
+  // backend-specific workaround.
+  @pragma('wasm:prefer-inline')
+  @pragma('dart2js:tryInline')
+  JSAny get toJSAnyShallow => dartToJsWrapper(this);
+
+  @pragma('wasm:prefer-inline')
+  @pragma('dart2js:tryInline')
+  JSAny get toJSAnyDeep => js_util.jsify(this) as JSAny;
+}
+
+extension JSAnyToObjectExtension on JSAny {
+  @pragma('wasm:prefer-inline')
+  @pragma('dart2js:tryInline')
+  Object get toObjectShallow => jsWrapperToDart(this);
+
+  @pragma('wasm:prefer-inline')
+  @pragma('dart2js:tryInline')
+  Object get toObjectDeep => js_util.dartify(this)!;
+}
+
 @JS('Object')
 external DomObjectConstructor get objectConstructor;
 

lib/web_ui/lib/src/engine/dom.dart

@@ -11,6 +11,7 @@ import 'dart:ffi';
 
 export 'skwasm_impl/canvas.dart';
 export 'skwasm_impl/codecs.dart';
+export 'skwasm_impl/dart_js_conversion.dart';
 export 'skwasm_impl/filters.dart';
 export 'skwasm_impl/font_collection.dart';
 export 'skwasm_impl/image.dart';

lib/web_ui/lib/src/engine/skwasm/skwasm_impl.dart

@@ -6,4 +6,5 @@
 // ignore: unnecessary_library_directive
 library skwasm_stub;
 
+export 'skwasm_stub/dart_js_conversion.dart';
 export 'skwasm_stub/renderer.dart';

lib/web_ui/lib/src/engine/dart_js_conversion_wasm.dart renamed to lib/web_ui/lib/src/engine/skwasm/skwasm_impl/dart_js_conversion.dart

@@ -10,4 +10,4 @@ JSAny dartToJsWrapper(Object object) => object as JSAny;
 
 @pragma('wasm:prefer-inline')
 @pragma('dart2js:tryInline')
-Object jsWrapperToDart(JSAny jsWrapper) => this;
+Object jsWrapperToDart(JSAny jsWrapper) => jsWrapper;