[flutter_svg] Implement errorBuilder callback (flutter#8364)

closes flutter#158612

## Description
- Implemented errorBuilder callback to handle loading failures

Author: memishood

third_party/packages/flutter_svg/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.0.17
+
+* Implement errorBuilder callback
+
 ## 2.0.16
 
 * Adopts code excerpts for README.

third_party/packages/flutter_svg/lib/svg.dart

@@ -16,6 +16,14 @@ export 'src/cache.dart';
 export 'src/default_theme.dart';
 export 'src/loaders.dart';
 
+/// Builder function to create an error widget. This builder is called when
+/// the image failed loading.
+typedef SvgErrorWidgetBuilder = Widget Function(
+  BuildContext context,
+  Object error,
+  StackTrace stackTrace,
+);
+
 /// Instance for [Svg]'s utility methods, which can produce a [DrawableRoot]
 /// or [PictureInfo] from [String] or [Uint8List].
 final Svg svg = Svg._();
@@ -86,6 +94,7 @@ class SvgPicture extends StatelessWidget {
     this.semanticsLabel,
     this.excludeFromSemantics = false,
     this.clipBehavior = Clip.hardEdge,
+    this.errorBuilder,
     @Deprecated(
         'No code should use this parameter. It never was implemented properly. '
         'The SVG theme must be set on the bytesLoader.')
@@ -184,6 +193,7 @@ class SvgPicture extends StatelessWidget {
     this.semanticsLabel,
     this.excludeFromSemantics = false,
     this.clipBehavior = Clip.hardEdge,
+    this.errorBuilder,
     SvgTheme? theme,
     ui.ColorFilter? colorFilter,
     @Deprecated('Use colorFilter instead.') ui.Color? color,
@@ -248,6 +258,7 @@ class SvgPicture extends StatelessWidget {
     this.semanticsLabel,
     this.excludeFromSemantics = false,
     this.clipBehavior = Clip.hardEdge,
+    this.errorBuilder,
     @Deprecated('This no longer does anything.') bool cacheColorFilter = false,
     SvgTheme? theme,
     http.Client? httpClient,
@@ -306,6 +317,7 @@ class SvgPicture extends StatelessWidget {
     this.semanticsLabel,
     this.excludeFromSemantics = false,
     this.clipBehavior = Clip.hardEdge,
+    this.errorBuilder,
     SvgTheme? theme,
     @Deprecated('This no longer does anything.') bool cacheColorFilter = false,
   })  : bytesLoader = SvgFileLoader(file, theme: theme),
@@ -355,6 +367,7 @@ class SvgPicture extends StatelessWidget {
     this.semanticsLabel,
     this.excludeFromSemantics = false,
     this.clipBehavior = Clip.hardEdge,
+    this.errorBuilder,
     SvgTheme? theme,
     @Deprecated('This no longer does anything.') bool cacheColorFilter = false,
   })  : bytesLoader = SvgBytesLoader(bytes, theme: theme),
@@ -404,6 +417,7 @@ class SvgPicture extends StatelessWidget {
     this.semanticsLabel,
     this.excludeFromSemantics = false,
     this.clipBehavior = Clip.hardEdge,
+    this.errorBuilder,
     SvgTheme? theme,
     @Deprecated('This no longer does anything.') bool cacheColorFilter = false,
   })  : bytesLoader = SvgStringLoader(string, theme: theme),
@@ -487,6 +501,9 @@ class SvgPicture extends StatelessWidget {
   /// Defaults to [Clip.hardEdge], and must not be null.
   final Clip clipBehavior;
 
+  /// Widget displayed while the target image failed loading.
+  final SvgErrorWidgetBuilder? errorBuilder;
+
   /// The color filter, if any, to apply to this widget.
   final ColorFilter? colorFilter;
 
@@ -501,6 +518,7 @@ class SvgPicture extends StatelessWidget {
       semanticsLabel: semanticsLabel,
       excludeFromSemantics: excludeFromSemantics,
       clipBehavior: clipBehavior,
+      errorBuilder: errorBuilder,
       colorFilter: colorFilter,
       placeholderBuilder: placeholderBuilder,
       clipViewbox: !allowDrawingOutsideViewBox,

third_party/packages/flutter_svg/pubspec.yaml

@@ -2,7 +2,7 @@ name: flutter_svg
 description: An SVG rendering and widget library for Flutter, which allows painting and displaying Scalable Vector Graphics 1.1 files.
 repository: https://github.com/flutter/packages/tree/main/third_party/packages/flutter_svg
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+flutter_svg%22
-version: 2.0.16
+version: 2.0.17
 
 environment:
   sdk: ^3.4.0

third_party/packages/flutter_svg/test/widget_svg_test.dart

@@ -1,4 +1,5 @@
 import 'dart:convert';
+import 'dart:io';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
@@ -767,6 +768,107 @@ void main() {
           widgetFinder, matchesGoldenFile('golden_widget/image_$key.png'));
     }
   });
+
+  group('SvgPicture - errorBuilder', () {
+    testWidgets('SvgPicture.string handles failure',
+        (WidgetTester tester) async {
+      await tester.pumpWidget(
+        MediaQuery(
+          data: mediaQueryData,
+          child: SvgPicture.string(
+            '<!-- invalid svg -->',
+            errorBuilder: (
+              BuildContext context,
+              Object error,
+              StackTrace stackTrace,
+            ) {
+              return const Directionality(
+                textDirection: TextDirection.ltr,
+                child: Text('image failed'),
+              );
+            },
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.text('image failed'), findsOneWidget);
+    });
+
+    testWidgets('SvgPicture.memory handles failure',
+        (WidgetTester tester) async {
+      await tester.pumpWidget(
+        MediaQuery(
+          data: mediaQueryData,
+          child: SvgPicture.memory(
+            Uint8List.fromList(utf8.encode('<!-- invalid svg -->')),
+            errorBuilder: (
+              BuildContext context,
+              Object error,
+              StackTrace stackTrace,
+            ) {
+              return const Directionality(
+                textDirection: TextDirection.ltr,
+                child: Text('image failed'),
+              );
+            },
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.text('image failed'), findsOneWidget);
+    });
+
+    testWidgets('SvgPicture.asset handles failure',
+        (WidgetTester tester) async {
+      await tester.pumpWidget(
+        MediaQuery(
+          data: mediaQueryData,
+          child: SvgPicture.asset(
+            '/wrong path',
+            errorBuilder: (
+              BuildContext context,
+              Object error,
+              StackTrace stackTrace,
+            ) {
+              return const Directionality(
+                textDirection: TextDirection.ltr,
+                child: Text('image failed'),
+              );
+            },
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.text('image failed'), findsOneWidget);
+    });
+
+    testWidgets('SvgPicture.file handles failure', (WidgetTester tester) async {
+      await tester.pumpWidget(
+        MediaQuery(
+          data: mediaQueryData,
+          child: SvgPicture.file(
+            File('nosuchfile'),
+            errorBuilder: (
+              BuildContext context,
+              Object error,
+              StackTrace stackTrace,
+            ) {
+              return const Directionality(
+                textDirection: TextDirection.ltr,
+                child: Text('image failed'),
+              );
+            },
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.text('image failed'), findsOneWidget);
+    });
+  });
 }
 
 class FakeAssetBundle extends Fake implements AssetBundle {