Report error when instantiating CanvasKit network image (flutter#22159)

Author: Harry Terkelsen

lib/web_ui/lib/src/engine/canvaskit/image.dart

@@ -15,24 +15,33 @@ void skiaInstantiateImageCodec(Uint8List list, Callback<ui.Codec> callback,
   callback(codec);
 }
 
-/// Instantiates a [ui.Codec] backed by an `SkAnimatedImage` from Skia after requesting from URI.
-void skiaInstantiateWebImageCodec(String src, Callback<ui.Codec> callback,
-    WebOnlyImageCodecChunkCallback? chunkCallback) {
-  chunkCallback?.call(0, 100);
+/// Instantiates a [ui.Codec] backed by an `SkAnimatedImage` from Skia after
+/// requesting from URI.
+Future<ui.Codec> skiaInstantiateWebImageCodec(
+    String src, WebOnlyImageCodecChunkCallback? chunkCallback) {
+  Completer<ui.Codec> completer = Completer<ui.Codec>();
   //TODO: Switch to using MakeImageFromCanvasImageSource when animated images are supported.
-  html.HttpRequest.request(
-    src,
-    responseType: "arraybuffer",
-  ).then((html.HttpRequest response) {
-    chunkCallback?.call(100, 100);
+  html.HttpRequest.request(src, responseType: "arraybuffer",
+      onProgress: (html.ProgressEvent event) {
+    if (event.lengthComputable) {
+      chunkCallback?.call(event.loaded!, event.total!);
+    }
+  }).then((html.HttpRequest response) {
+    if (response.status != 200) {
+      completer.completeError(Exception(
+          'Network image request failed with status: ${response.status}'));
+    }
     final Uint8List list =
         new Uint8List.view((response.response as ByteBuffer));
     final SkAnimatedImage skAnimatedImage =
         canvasKit.MakeAnimatedImageFromEncoded(list);
     final CkAnimatedImage animatedImage = CkAnimatedImage(skAnimatedImage);
     final CkAnimatedImageCodec codec = CkAnimatedImageCodec(animatedImage);
-    callback(codec);
+    completer.complete(codec);
+  }, onError: (dynamic error) {
+    completer.completeError(error);
   });
+  return completer.future;
 }
 
 /// A wrapper for `SkAnimatedImage`.
@@ -43,7 +52,8 @@ class CkAnimatedImage implements ui.Image {
   // being garbage-collected, or by an explicit call to [delete].
   late final SkiaObjectBox box;
 
-  CkAnimatedImage(SkAnimatedImage skAnimatedImage) : this._(skAnimatedImage, null);
+  CkAnimatedImage(SkAnimatedImage skAnimatedImage)
+      : this._(skAnimatedImage, null);
 
   CkAnimatedImage._(this._skAnimatedImage, SkiaObjectBox? boxToClone) {
     if (boxToClone != null) {
@@ -66,19 +76,21 @@ class CkAnimatedImage implements ui.Image {
     if (assertionsEnabled) {
       return _disposed;
     }
-    throw StateError('Image.debugDisposed is only available when asserts are enabled.');
+    throw StateError(
+        'Image.debugDisposed is only available when asserts are enabled.');
   }
 
   ui.Image clone() => CkAnimatedImage._(_skAnimatedImage, box);
 
   @override
   bool isCloneOf(ui.Image other) {
-    return other is CkAnimatedImage
-        && other._skAnimatedImage.isAliasOf(_skAnimatedImage);
+    return other is CkAnimatedImage &&
+        other._skAnimatedImage.isAliasOf(_skAnimatedImage);
   }
 
   @override
-  List<StackTrace>? debugGetOpenHandleStackTraces() => box.debugGetStackTraces();
+  List<StackTrace>? debugGetOpenHandleStackTraces() =>
+      box.debugGetStackTraces();
 
   int get frameCount => _skAnimatedImage.getFrameCount();
 
@@ -115,8 +127,9 @@ class CkAnimatedImage implements ui.Image {
       );
       bytes = _skAnimatedImage.readPixels(imageInfo, 0, 0);
     } else {
-      final SkData skData = _skAnimatedImage.encodeToData(); //defaults to PNG 100%
-      // make a copy that we can return
+      // Defaults to PNG 100%.
+      final SkData skData = _skAnimatedImage.encodeToData();
+      // Make a copy that we can return.
       bytes = Uint8List.fromList(canvasKit.getSkDataBytes(skData));
     }
 
@@ -162,20 +175,21 @@ class CkImage implements ui.Image {
     if (assertionsEnabled) {
       return _disposed;
     }
-    throw StateError('Image.debugDisposed is only available when asserts are enabled.');
+    throw StateError(
+        'Image.debugDisposed is only available when asserts are enabled.');
   }
 
   @override
   ui.Image clone() => CkImage._(skImage, box);
 
   @override
   bool isCloneOf(ui.Image other) {
-    return other is CkImage
-        && other.skImage.isAliasOf(skImage);
+    return other is CkImage && other.skImage.isAliasOf(skImage);
   }
 
   @override
-  List<StackTrace>? debugGetOpenHandleStackTraces() => box.debugGetStackTraces();
+  List<StackTrace>? debugGetOpenHandleStackTraces() =>
+      box.debugGetStackTraces();
 
   @override
   int get width => skImage.width();

lib/web_ui/lib/src/ui/painting.dart

@@ -462,23 +462,23 @@ String? _instantiateImageCodec(Uint8List list, engine.Callback<Codec> callback)
 }
 
 Future<Codec> webOnlyInstantiateImageCodecFromUrl(Uri uri,
-    {engine.WebOnlyImageCodecChunkCallback? chunkCallback}) {
-  return _futurize<Codec>((engine.Callback<Codec> callback) =>
+  {engine.WebOnlyImageCodecChunkCallback? chunkCallback}) {
+  if (engine.useCanvasKit) {
+    return engine.skiaInstantiateWebImageCodec(
+      uri.toString(), chunkCallback);
+  } else {
+    return _futurize<Codec>((engine.Callback<Codec> callback) =>
       _instantiateImageCodecFromUrl(uri, chunkCallback, callback));
+  }
 }
 
 String? _instantiateImageCodecFromUrl(
   Uri uri,
   engine.WebOnlyImageCodecChunkCallback? chunkCallback,
   engine.Callback<Codec> callback,
 ) {
-  if (engine.useCanvasKit) {
-    engine.skiaInstantiateWebImageCodec(uri.toString(), callback, chunkCallback);
-    return null;
-  } else {
-    callback(engine.HtmlCodec(uri.toString(), chunkCallback: chunkCallback));
-    return null;
-  }
+  callback(engine.HtmlCodec(uri.toString(), chunkCallback: chunkCallback));
+  return null;
 }
 
 void decodeImageFromList(Uint8List list, ImageDecoderCallback callback) {

lib/web_ui/test/canvaskit/image_test.dart

@@ -3,6 +3,8 @@
 // found in the LICENSE file.
 
 // @dart = 2.6
+import 'dart:html' show ProgressEvent;
+
 import 'package:test/bootstrap/browser.dart';
 import 'package:test/test.dart';
 import 'package:ui/src/engine.dart';
@@ -22,14 +24,16 @@ void testMain() {
     });
 
     test('CkAnimatedImage toString', () {
-      final SkAnimatedImage skAnimatedImage = canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage);
+      final SkAnimatedImage skAnimatedImage =
+          canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage);
       final CkAnimatedImage image = CkAnimatedImage(skAnimatedImage);
       expect(image.toString(), '[1×1]');
       image.dispose();
     });
 
     test('CkAnimatedImage can be explicitly disposed of', () {
-      final SkAnimatedImage skAnimatedImage = canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage);
+      final SkAnimatedImage skAnimatedImage =
+          canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage);
       final CkAnimatedImage image = CkAnimatedImage(skAnimatedImage);
       expect(image.box.isDeleted, false);
       expect(image.debugDisposed, false);
@@ -42,7 +46,8 @@ void testMain() {
     });
 
     test('CkAnimatedImage can be cloned and explicitly disposed of', () async {
-      final SkAnimatedImage skAnimatedImage = canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage);
+      final SkAnimatedImage skAnimatedImage =
+          canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage);
       final CkAnimatedImage image = CkAnimatedImage(skAnimatedImage);
       final CkAnimatedImage imageClone = image.clone();
 
@@ -63,14 +68,18 @@ void testMain() {
     });
 
     test('CkImage toString', () {
-      final SkImage skImage = canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage).getCurrentFrame();
+      final SkImage skImage =
+          canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage)
+              .getCurrentFrame();
       final CkImage image = CkImage(skImage);
       expect(image.toString(), '[1×1]');
       image.dispose();
     });
 
     test('CkImage can be explicitly disposed of', () {
-      final SkImage skImage = canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage).getCurrentFrame();
+      final SkImage skImage =
+          canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage)
+              .getCurrentFrame();
       final CkImage image = CkImage(skImage);
       expect(image.debugDisposed, false);
       expect(image.box.isDeleted, false);
@@ -83,7 +92,9 @@ void testMain() {
     });
 
     test('CkImage can be explicitly disposed of when cloned', () async {
-      final SkImage skImage = canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage).getCurrentFrame();
+      final SkImage skImage =
+          canvasKit.MakeAnimatedImageFromEncoded(kTransparentImage)
+              .getCurrentFrame();
       final CkImage image = CkImage(skImage);
       final CkImage imageClone = image.clone();
 
@@ -102,6 +113,12 @@ void testMain() {
       await Future<void>.delayed(Duration.zero);
       expect(skImage.isDeleted(), true);
     });
-  // TODO: https://github.com/flutter/flutter/issues/60040
+
+    test('skiaInstantiateWebImageCodec throws exception if given invalid URL',
+        () async {
+      expect(skiaInstantiateWebImageCodec('invalid-url', null),
+          throwsA(isA<ProgressEvent>()));
+    });
+    // TODO: https://github.com/flutter/flutter/issues/60040
   }, skip: isIosSafari);
 }