FlutterGen · huandu · Mar 24, 2025 · Mar 24, 2025 · Apr 7, 2025 · Apr 7, 2025
@@ -135,7 +135,7 @@ fluttergen -c example/pubspec.yaml
 ## Configuration file
 
 [FlutterGen] generates dart files based on the key **`flutter`** and **`flutter_gen`** of [`pubspec.yaml`](https://dart.dev/tools/pub/pubspec).  
-Default configuration can be found [here](https://github.com/FlutterGen/flutter_gen/tree/main/packages/core/lib/settings/config_default.dart). 
+Default configuration can be found [here](https://github.com/FlutterGen/flutter_gen/tree/main/packages/core/lib/settings/config_default.dart).
 
 ```yaml
 # pubspec.yaml
@@ -173,7 +173,6 @@ flutter:
 
 You can also configure generate options in the `build.yaml`, it will be read before the `pubspec.yaml` if it exists.
 
-
 ```yaml
 # build.yaml
 # ...
@@ -276,7 +275,9 @@ Widget build(BuildContext context) {
   );
 }
 ```
+
 or
+
 ```dart
 // Explicit usage for `Image`/`SvgPicture`/`Lottie`.
 Widget build(BuildContext context) {
@@ -340,6 +341,28 @@ Widget build(BuildContext context) {
 }
 ```
 
+When we need to obtain more animation details, we can use the `parse_animation` option. This will automatically parse all animation information for GIFs and WebP files, including frames, duration, etc. As this option significantly increases generation time, it's disabled by default and needs to be manually enabled.
+
+```yaml
+flutter_gen:
+  parse_animation: true # <- Add this line (default: false)
+                        # This option implies parse_metadata: true
+```
+
+For GIF and WebP animation, several new nullable field is added to the
+generated class. For example:
+
+```dart
+AssetGenImage get animated => 
+  const AssetGenImage(
+    'assets/images/animated.webp',
+    size: Size(209.0, 49.0),
+    isAnimation: true,
+    duration: Duration(milliseconds: 1000),
+    frames: 15,
+  );
+```
+
 #### Usage Example
 
 [FlutterGen] generates [Image](https://api.flutter.dev/flutter/widgets/Image-class.html) class if the asset is Flutter supported image format.
@@ -575,7 +598,9 @@ Plugin issues that are not specific to [FlutterGen] can be filed in the [Flutter
 ### Known Issues
 
 #### Bad State: No Element when using build_runner
+
 If you get an error message like this:
+
 ```
 [SEVERE] flutter_gen_runner:flutter_gen_runner on $package$:
 
@@ -614,7 +639,7 @@ output-localization-file: app_localizations.dart
 synthetic-package: false <--- ⚠️Add this line⚠️
 ```
 
-If you get 
+If you get
 
 ## Contributing
 

@@ -1,6 +1,6 @@
 name: flutter_gen
 description: The Flutter code generator for your assets, fonts, colors, … — Get rid of all String-based APIs.
-version: 5.10.0
+version: 5.11.0
 homepage: https://github.com/FlutterGen/flutter_gen
 repository: https://github.com/FlutterGen/flutter_gen
 documentation: https://github.com/FlutterGen/flutter_gen
@@ -13,7 +13,8 @@ executables:
   fluttergen: flutter_gen_command
 
 dependencies:
-  flutter_gen_core: 5.10.0
+  flutter_gen_core: 5.11.0
+
   args: ^2.0.0
 
 dev_dependencies:

@@ -63,6 +63,7 @@ Future<String> generateAssets(
       ImageIntegration(
         config.packageParameterLiteral,
         parseMetadata: config.flutterGen.parseMetadata,
+        parseAnimation: config.flutterGen.parseAnimation,
       ),
     if (config.flutterGen.integrations.flutterSvg)
       SvgIntegration(

@@ -1,6 +1,7 @@
 import 'dart:io';
 
 import 'package:flutter_gen_core/generators/integrations/integration.dart';
+import 'package:image/image.dart' as img;
 import 'package:image_size_getter/file_input.dart';
 import 'package:image_size_getter/image_size_getter.dart';
 
@@ -11,9 +12,12 @@ import 'package:image_size_getter/image_size_getter.dart';
 class ImageIntegration extends Integration {
   ImageIntegration(
     String packageName, {
+    required this.parseAnimation,
     super.parseMetadata,
   }) : super(packageName);
 
+  final bool parseAnimation;
+
   String get packageParameter => isPackage ? ' = package' : '';
 
   String get keyName =>
@@ -32,6 +36,9 @@ class ImageIntegration extends Integration {
     this._assetName, {
     this.size,
     this.flavors = const {},
+    this.isAnimation = false,
+    this.duration = Duration.zero,
+    this.frames = 1,
   });
 
   final String _assetName;
@@ -40,6 +47,9 @@ ${isPackage ? "\n  static const String package = '$packageName';" : ''}
 
   final Size? size;
   final Set<String> flavors;
+  final bool isAnimation;
+  final Duration duration;
+  final int frames;
 
   Image image({
     Key? key,
@@ -116,12 +126,20 @@ ${isPackage ? "\n  static const String package = '$packageName';" : ''}
 
   @override
   String classInstantiate(AssetType asset) {
-    final info = parseMetadata ? _getMetadata(asset) : null;
+    final info = parseMetadata || parseAnimation ? _getMetadata(asset) : null;
     final buffer = StringBuffer(className);
     buffer.write('(');
     buffer.write('\'${asset.posixStylePath}\'');
     if (info != null) {
-      buffer.write(', size: Size(${info.width}, ${info.height})');
+      buffer.write(', size: const Size(${info.width}, ${info.height})');
+
+      if (info.animation case final animation?) {
+        buffer.write(', isAnimation: ${animation.frames > 1}');
+        buffer.write(
+          ', duration: Duration(milliseconds: ${animation.duration.inMilliseconds})',
+        );
+        buffer.write(', frames: ${animation.frames}');
+      }
     }
     if (asset.flavors.isNotEmpty) {
       buffer.write(', flavors: {');
@@ -161,11 +179,47 @@ ${isPackage ? "\n  static const String package = '$packageName';" : ''}
         FileInput(File(asset.fullPath)),
       );
       final size = result.size;
-      return ImageMetadata(size.width.toDouble(), size.height.toDouble());
+      final animation = parseAnimation ? _parseAnimation(asset) : null;
+
+      return ImageMetadata(
+        width: size.width.toDouble(),
+        height: size.height.toDouble(),
+        animation: animation,
+      );
     } catch (e) {
       stderr
           .writeln('[WARNING] Failed to parse \'${asset.path}\' metadata: $e');
     }
     return null;
   }
+
+  ImageAnimation? _parseAnimation(AssetType asset) {
+    final decoder = switch (asset.mime) {
+      'image/gif' => img.GifDecoder(),
+      'image/webp' => img.WebPDecoder(),
+      _ => null,
+    };
+
+    if (decoder == null) {
+      return null;
+    }
+
+    final file = File(asset.fullPath);
+    final bytes = file.readAsBytesSync();
+    final image = decoder.decode(bytes);
+
+    if (image == null) {
+      return null;
+    }
+
+    return ImageAnimation(
+      frames: image.frames.length,
+      duration: Duration(
+        milliseconds: image.frames.fold(
+          0,
+          (duration, frame) => duration + frame.frameDuration,
+        ),
+      ),
+    );
+  }
 }
@@ -55,8 +55,24 @@ const String deprecationMessagePackage =
 /// Currently only contains the width and height, but could contain more in
 /// future.
 class ImageMetadata {
-  const ImageMetadata(this.width, this.height);
+  const ImageMetadata({
+    required this.width,
+    required this.height,
+    this.animation,
+  });
 
   final double width;
   final double height;
+  final ImageAnimation? animation;
+}
+
+/// Metadata about the parsed animation file when [parseAnimation] is true.
+class ImageAnimation {
+  const ImageAnimation({
+    required this.frames,
+    required this.duration,
+  });
+
+  final int frames;
+  final Duration duration;
 }
@@ -132,7 +132,10 @@ ${isPackage ? "\n  static const String package = '$packageName';" : ''}
       // but it's also the same way it will be eventually rendered by Flutter.
       final svg = File(asset.fullPath).readAsStringSync();
       final vec = parseWithoutOptimizers(svg);
-      return ImageMetadata(vec.width, vec.height);
+      return ImageMetadata(
+        width: vec.width,
+        height: vec.height,
+      );
     } catch (e) {
       stderr.writeln(
         '[WARNING] Failed to parse SVG \'${asset.path}\' metadata: $e',

@@ -8,6 +8,8 @@ flutter_gen:
   line_length: 80
   # Optional
   parse_metadata: false
+  # Optional
+  parse_animation: false
 
   # Optional
   integrations:

@@ -103,6 +103,7 @@ class FlutterGen {
     required this.output,
     required this.lineLength,
     required this.parseMetadata,
+    required this.parseAnimation,
     required this.assets,
     required this.fonts,
     required this.integrations,
@@ -120,6 +121,9 @@ class FlutterGen {
   @JsonKey(name: 'parse_metadata', required: true)
   final bool parseMetadata;
 
+  @JsonKey(name: 'parse_animation', required: true)
+  final bool parseAnimation;
+
   @JsonKey(name: 'assets', required: true)
   final FlutterGenAssets assets;
 

@@ -1,2 +1,2 @@
 /// DO NOT MODIFY BY HAND, Generated by version_gen
-String packageVersion = '5.10.0';
+String packageVersion = '5.11.0';
@@ -1,6 +1,6 @@
 name: flutter_gen_core
 description: The Flutter code generator for your assets, fonts, colors, … — Get rid of all String-based APIs.
-version: 5.10.0
+version: 5.11.0
 homepage: https://github.com/FlutterGen/flutter_gen
 repository: https://github.com/FlutterGen/flutter_gen
 documentation: https://github.com/FlutterGen/flutter_gen
@@ -16,7 +16,7 @@ dependencies:
   meta: ^1.7.0
   path: ^1.8.0
   yaml: ^3.0.0
-  mime: '>=1.0.0 <3.0.0'
+  mime: ">=1.0.0 <3.0.0"
   xml: ^6.0.0
   dartx: ^1.0.0
   color: ^3.0.0
@@ -30,6 +30,7 @@ dependencies:
   pub_semver: ^2.0.0
   vector_graphics_compiler: ^1.1.9
   image_size_getter: ^2.4.0
+  image: ^4.5.4
 
 dev_dependencies:
   lints: any # Ignoring the version to allow editing across SDK versions.