Third part of soft transition to async FragmentProgram.fromAsset

lib/ui/painting.dart

@@ -4039,14 +4039,16 @@ class FragmentProgram extends NativeFieldWrapperClass1 {
   /// The asset must be a file produced as the output of the `impellerc`
   /// compiler. The constructed object should then be reused via the [shader]
   /// method to create [Shader] objects that can be used by [Shader.paint].
-  static FragmentProgram fromAsset(String assetKey) {
+  static Future<FragmentProgram> fromAsset(String assetKey) {
     FragmentProgram? program = _shaderRegistry[assetKey]?.target;
-    if (program == null) {
-      program = FragmentProgram._fromAsset(assetKey);
-      _shaderRegistry[assetKey] = WeakReference<FragmentProgram>(program);
+    if (program != null) {
+      return Future<FragmentProgram>.value(program);
     }
-
-    return program;
+    return Future<FragmentProgram>.microtask(() {
+      final FragmentProgram program = FragmentProgram._fromAsset(assetKey);
+      _shaderRegistry[assetKey] = WeakReference<FragmentProgram>(program);
+      return program;
+    });
   }
 
   // TODO(zra): This is part of a soft transition of the framework to this

lib/web_ui/lib/painting.dart

@@ -835,7 +835,7 @@ class ImageDescriptor {
 }
 
 class FragmentProgram {
-  static FragmentProgram fromAsset(String assetKey) {
+  static Future<FragmentProgram> fromAsset(String assetKey) {
     throw UnsupportedError('FragmentProgram is not supported for the CanvasKit or HTML renderers.');
   }
 

testing/dart/fragment_shader_test.dart

@@ -15,7 +15,7 @@ import 'shader_test_file_utils.dart';
 
 void main() async {
   test('simple shader renders correctly', () async {
-    final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram program = await FragmentProgram.fromAsset(
       'functions.frag.iplr',
     );
     final Shader shader = program.shader(
@@ -25,7 +25,7 @@ void main() async {
   });
 
   test('blue-green image renders green', () async {
-    final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram program = await FragmentProgram.fromAsset(
       'blue_green_sampler.frag.iplr',
     );
     final Image blueGreenImage = await _createBlueGreenImage();
@@ -39,7 +39,7 @@ void main() async {
   });
 
   test('shader with uniforms renders correctly', () async {
-    final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram program = await FragmentProgram.fromAsset(
       'uniforms.frag.iplr',
     );
 
@@ -65,7 +65,7 @@ void main() async {
   });
 
   test('The ink_sparkle shader is accepted', () async {
-    final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram program = await FragmentProgram.fromAsset(
       'ink_sparkle.frag.iplr',
     );
     final Shader shader = program.shader(
@@ -79,7 +79,7 @@ void main() async {
   });
 
   test('Uniforms are sorted correctly', () async {
-    final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram program = await FragmentProgram.fromAsset(
       'uniforms_sorted.frag.iplr',
     );
 
@@ -97,7 +97,7 @@ void main() async {
   test('fromAsset throws an exception on invalid assetKey', () async {
     bool throws = false;
     try {
-      final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+      await FragmentProgram.fromAsset(
         '<invalid>',
       );
     } catch (e) {
@@ -109,7 +109,7 @@ void main() async {
   test('fromAsset throws an exception on invalid data', () async {
     bool throws = false;
     try {
-      final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+      await FragmentProgram.fromAsset(
         'DashInNooglerHat.jpg',
       );
     } catch (e) {
@@ -119,7 +119,7 @@ void main() async {
   });
 
   test('fromAsset accepts a shader with no uniforms', () async {
-    final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram program = await FragmentProgram.fromAsset(
       'no_uniforms.frag.iplr',
     );
     final Shader shader = program.shader();
@@ -143,7 +143,7 @@ void main() async {
   _expectIplrShadersRenderGreen(iplrSupportedOpShaders);
 
   test('Equality depends on floatUniforms', () async {
-    final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram program = await FragmentProgram.fromAsset(
       'simple.frag.iplr',
     );
     final Float32List ones = Float32List.fromList(<double>[1]);
@@ -165,10 +165,10 @@ void main() async {
   });
 
   test('Equality depends on data', () async {
-    final FragmentProgram programA = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram programA = await FragmentProgram.fromAsset(
       'simple.frag.iplr',
     );
-    final FragmentProgram programB = await FragmentProgram.fromAssetAsync(
+    final FragmentProgram programB = await FragmentProgram.fromAsset(
       'uniforms.frag.iplr',
     );
     final Shader a = programA.shader();
@@ -242,7 +242,7 @@ Future<Map<String, FragmentProgram>> _loadShaderAssets(
       .where((FileSystemEntity entry) => path.extension(entry.path) == ext),
     (FileSystemEntity entry) async {
       final String key = path.basenameWithoutExtension(entry.path);
-      out[key] = await FragmentProgram.fromAssetAsync(
+      out[key] = await FragmentProgram.fromAsset(
         path.basename(entry.path),
       );
     },

testing/dart/observatory/shader_reload_test.dart

@@ -14,12 +14,13 @@ void main() {
   test('simple iplr shader can be re-initialized', () async {
     vms.VmService? vmService;
     try {
-      final FragmentProgram program = await FragmentProgram.fromAssetAsync(
+      final FragmentProgram program = await FragmentProgram.fromAsset(
         'functions.frag.iplr',
       );
       final Shader shader = program.shader(
         floatUniforms: Float32List.fromList(<double>[1]),
       );
+      _use(shader);
 
       final developer.ServiceProtocolInfo info = await developer.Service.getInfo();
 
@@ -48,3 +49,7 @@ void main() {
     }
   });
 }
+
+void _use(Shader shader) {
+
+}