[vector_graphics] handle errors from bytes loader (flutter#8080)

This PR updates the VectorGraphicsWidget to handle errors from the underlying bytes loader using the existing error handling in its implementation.

*List which issues are fixed by this PR. You must list at least one issue.*
Fixes flutter/flutter#158862

Author: navaronbracke

packages/vector_graphics/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.1.15
+
+* Updates error handling in VectorGraphicWidget to handle errors when the bytes of the graphic cannot be loaded.
+
 ## 1.1.14
 
 * Relaxes dependency constraint on vector_graphics_codec.

packages/vector_graphics/lib/src/vector_graphics.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
 import 'dart:math' as math;
 import 'dart:ui' as ui;
 
@@ -315,14 +316,14 @@ class _VectorGraphicWidgetState extends State<VectorGraphic> {
   void didChangeDependencies() {
     locale = Localizations.maybeLocaleOf(context);
     textDirection = Directionality.maybeOf(context);
-    _loadAssetBytes();
+    unawaited(_loadAssetBytes());
     super.didChangeDependencies();
   }
 
   @override
   void didUpdateWidget(covariant VectorGraphic oldWidget) {
     if (oldWidget.loader != widget.loader) {
-      _loadAssetBytes();
+      unawaited(_loadAssetBytes());
     }
     super.didUpdateWidget(oldWidget);
   }
@@ -358,12 +359,6 @@ class _VectorGraphicWidgetState extends State<VectorGraphic> {
         textDirection: key.textDirection,
         clipViewbox: key.clipViewbox,
         loader: loader,
-        onError: (Object error, StackTrace? stackTrace) {
-          return _handleError(
-            error,
-            stackTrace,
-          );
-        },
       );
     }).then((PictureInfo pictureInfo) {
       return _PictureData(pictureInfo, 0, key);
@@ -376,13 +371,17 @@ class _VectorGraphicWidgetState extends State<VectorGraphic> {
   }
 
   void _handleError(Object error, StackTrace? stackTrace) {
+    if (!mounted) {
+      return;
+    }
+
     setState(() {
       _error = error;
       _stackTrace = stackTrace;
     });
   }
 
-  void _loadAssetBytes() {
+  Future<void> _loadAssetBytes() async {
     // First check if we have an avilable picture and use this immediately.
     final Object loaderKey = widget.loader.cacheKey(context);
     final _PictureKey key =
@@ -398,7 +397,9 @@ class _VectorGraphicWidgetState extends State<VectorGraphic> {
     }
     // If not, then check if there is a pending load.
     final BytesLoader loader = widget.loader;
-    _loadPicture(context, key, loader).then((_PictureData data) {
+
+    try {
+      final _PictureData data = await _loadPicture(context, key, loader);
       data.count += 1;
 
       // The widget may have changed, requesting a new vector graphic before
@@ -407,14 +408,18 @@ class _VectorGraphicWidgetState extends State<VectorGraphic> {
         _maybeReleasePicture(data);
         return;
       }
+
       if (data.count == 1) {
         _livePictureCache[key] = data;
       }
+
       setState(() {
         _maybeReleasePicture(_pictureInfo);
         _pictureInfo = data;
       });
-    });
+    } catch (error, stackTrace) {
+      _handleError(error, stackTrace);
+    }
   }
 
   static final bool _webRenderObject = useHtmlRenderObject();

packages/vector_graphics/pubspec.yaml

@@ -2,7 +2,7 @@ name: vector_graphics
 description: A vector graphics rendering package for Flutter using a binary encoding.
 repository: https://github.com/flutter/packages/tree/main/packages/vector_graphics
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+vector_graphics%22
-version: 1.1.14
+version: 1.1.15
 
 environment:
   sdk: ^3.4.0

packages/vector_graphics/test/vector_graphics_test.dart

@@ -653,6 +653,28 @@ void main() {
     expect(matrix.row0.x, -1);
     expect(matrix.row1.y, 1);
   });
+
+  testWidgets('VectorGraphicsWidget can handle errors from bytes loader',
+      (WidgetTester tester) async {
+    await tester.pumpWidget(
+      VectorGraphic(
+        loader: const ThrowingBytesLoader(),
+        width: 100,
+        height: 100,
+        errorBuilder:
+            (BuildContext context, Object error, StackTrace stackTrace) {
+          return const Directionality(
+            textDirection: TextDirection.ltr,
+            child: Text('Error is handled'),
+          );
+        },
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    expect(find.text('Error is handled'), findsOneWidget);
+    expect(tester.takeException(), isNull);
+  });
 }
 
 class TestBundle extends Fake implements AssetBundle {
@@ -719,3 +741,12 @@ class TestBytesLoader extends BytesLoader {
   @override
   String toString() => 'TestBytesLoader: $source';
 }
+
+class ThrowingBytesLoader extends BytesLoader {
+  const ThrowingBytesLoader();
+
+  @override
+  Future<ByteData> loadBytes(BuildContext? context) {
+    throw UnimplementedError('Test exception');
+  }
+}