Decouple generated asset classes by introducing flutter_gen_interface package

CHANGELOG.md

@@ -1,3 +1,9 @@
+## 5.15.0
+
+**Feature**
+
+- [#759](https://github.com/FlutterGen/flutter_gen/issues/759) Added `flutter_gen_interface` to allow generated asset classes to implement a shared custom interface for Modular Architectures & Design Systems.
+
 ## 5.14.1
 
 **Development**

melos.yaml

@@ -4,6 +4,7 @@ packages:
   - packages/command
   - packages/core
   - packages/runner
+  - packages/flutter_gen_interface
   - examples/example
   - examples/example_resources
   - examples/example_workspace
@@ -132,6 +133,7 @@ scripts:
         - flutter_gen
         - flutter_gen_core
         - flutter_gen_runner
+        - flutter_gen_interface
 
   publish:dry:
     run: dart pub publish --dry-run
@@ -143,3 +145,4 @@ scripts:
         - flutter_gen
         - flutter_gen_core
         - flutter_gen_runner
+        - flutter_gen_interface

packages/core/lib/generators/assets_generator.dart

@@ -77,7 +77,6 @@ Future<String> generateAssets(
       'The value of "flutter/assets:" is incorrect.',
     );
   }
-
   final integrations = <Integration>[
     if (config.flutterGen.integrations.image)
       ImageIntegration(
@@ -165,7 +164,15 @@ Future<String> generateAssets(
 
   final importsBuffer = StringBuffer();
   for (final e in imports.sorted((a, b) => a.import.compareTo(b.import))) {
-    importsBuffer.writeln(import(e));
+    if (e.import ==
+        'package:flutter_gen_interface/flutter_gen_interface.dart') {
+      importsBuffer.writeln(
+          'import \'package:flutter_gen_interface/flutter_gen_interface.dart\';');
+      importsBuffer.writeln(
+          'export \'package:flutter_gen_interface/flutter_gen_interface.dart\';');
+    } else {
+      importsBuffer.writeln(import(e));
+    }
   }
 
   final buffer = StringBuffer();

packages/core/lib/generators/integrations/image_integration.dart

@@ -25,110 +25,13 @@ class ImageIntegration extends Integration {
       isPackage ? "'packages/$packageName/\$_assetName'" : '_assetName';
 
   @override
-  List<Import> get requiredImports => const [
-        Import('package:flutter/widgets.dart'),
+  List<Import> get requiredImports => [
+        const Import(
+            'package:flutter_gen_interface/flutter_gen_interface.dart'),
       ];
 
   @override
-  String get classOutput => _classDefinition;
-
-  String get _classDefinition => '''class AssetGenImage {
-  const AssetGenImage(
-    this._assetName, {
-    this.size,
-    this.flavors = const {},
-    this.animation,
-  });
-
-  final String _assetName;
-
-${isPackage ? "\n  static const String package = '$packageName';" : ''}
-
-  final Size? size;
-  final Set<String> flavors;
-  final AssetGenImageAnimation? animation;
-
-  Image image({
-    Key? key,
-    AssetBundle? bundle,
-    ImageFrameBuilder? frameBuilder,
-    ImageErrorWidgetBuilder? errorBuilder,
-    String? semanticLabel,
-    bool excludeFromSemantics = false,
-    double? scale,
-    double? width,
-    double? height,
-    Color? color,
-    Animation<double>? opacity,
-    BlendMode? colorBlendMode,
-    BoxFit? fit,
-    AlignmentGeometry alignment = Alignment.center,
-    ImageRepeat repeat = ImageRepeat.noRepeat,
-    Rect? centerSlice,
-    bool matchTextDirection = false,
-    bool gaplessPlayback = true,
-    bool isAntiAlias = false,
-    ${isPackage ? '$deprecationMessagePackage\n' : ''}String? package$packageParameter,
-    FilterQuality filterQuality = FilterQuality.medium,
-    int? cacheWidth,
-    int? cacheHeight,
-  }) {
-    return Image.asset(
-      _assetName,
-      key: key,
-      bundle: bundle,
-      frameBuilder: frameBuilder,
-      errorBuilder: errorBuilder,
-      semanticLabel: semanticLabel,
-      excludeFromSemantics: excludeFromSemantics,
-      scale: scale,
-      width: width,
-      height: height,
-      color: color,
-      opacity: opacity,
-      colorBlendMode: colorBlendMode,
-      fit: fit,
-      alignment: alignment,
-      repeat: repeat,
-      centerSlice: centerSlice,
-      matchTextDirection: matchTextDirection,
-      gaplessPlayback: gaplessPlayback,
-      isAntiAlias: isAntiAlias,
-      package: package,
-      filterQuality: filterQuality,
-      cacheWidth: cacheWidth,
-      cacheHeight: cacheHeight,
-    );
-  }
-
-  ImageProvider provider({
-    AssetBundle? bundle,
-    ${isPackage ? '$deprecationMessagePackage\n' : ''}String? package$packageParameter,
-  }) {
-    return AssetImage(
-      _assetName,
-      bundle: bundle,
-      package: package,
-    );
-  }
-
-  String get path => _assetName;
-
-  String get keyName => $keyName;
-}
-
-class AssetGenImageAnimation {
-  const AssetGenImageAnimation({
-    required this.isAnimation,
-    required this.duration,
-    required this.frames,
-  });
-
-  final bool isAnimation;
-  final Duration duration;
-  final int frames;
-}
-''';
+  String get classOutput => '';
 
   @override
   String get className => 'AssetGenImage';
@@ -157,7 +60,10 @@ class AssetGenImageAnimation {
       final flavors = asset.flavors.map((e) => '\'$e\'').join(', ');
       buffer.write(flavors);
       buffer.write('}');
-      buffer.write(','); // Better formatting.
+      if (!isPackage) buffer.write(','); // Better formatting.
+    }
+    if (isPackage) {
+      buffer.write(', package: \'$packageName\',');
     }
     buffer.write(')');
     return buffer.toString();

packages/core/lib/generators/integrations/svg_integration.dart

@@ -13,95 +13,13 @@ class SvgIntegration extends Integration {
   String get packageExpression => isPackage ? ' = package' : '';
 
   @override
-  List<Import> get requiredImports => const [
-        Import('package:flutter/widgets.dart'),
-        Import('package:flutter/services.dart'),
-        Import('package:flutter_svg/flutter_svg.dart', alias: '_svg'),
-        Import('package:vector_graphics/vector_graphics.dart', alias: '_vg'),
+  List<Import> get requiredImports => [
+        const Import(
+            'package:flutter_gen_interface/flutter_gen_interface.dart'),
       ];
 
   @override
-  String get classOutput => _classDefinition;
-
-  String get _classDefinition => '''class SvgGenImage {
-  const SvgGenImage(
-    this._assetName, {
-    this.size,
-    this.flavors = const {},
-  }) : _isVecFormat = false;
-
-  const SvgGenImage.vec(
-    this._assetName, {
-    this.size,
-    this.flavors = const {},
-  }) : _isVecFormat = true;
-
-  final String _assetName;
-  final Size? size;
-  final Set<String> flavors;
-  final bool _isVecFormat;
-
-${isPackage ? "\n  static const String package = '$packageName';" : ''}
-
-  _svg.SvgPicture svg({
-    Key? key,
-    bool matchTextDirection = false,
-    AssetBundle? bundle,
-    ${isPackage ? '$deprecationMessagePackage\n' : ''}String? package$packageExpression,
-    double? width,
-    double? height,
-    BoxFit fit = BoxFit.contain,
-    AlignmentGeometry alignment = Alignment.center,
-    bool allowDrawingOutsideViewBox = false,
-    WidgetBuilder? placeholderBuilder,
-    String? semanticsLabel,
-    bool excludeFromSemantics = false,
-    _svg.SvgTheme? theme,
-    _svg.ColorMapper? colorMapper,
-    ColorFilter? colorFilter,
-    Clip clipBehavior = Clip.hardEdge,
-    @deprecated Color? color,
-    @deprecated BlendMode colorBlendMode = BlendMode.srcIn,
-    @deprecated bool cacheColorFilter = false,
-  }) {
-    final _svg.BytesLoader loader;
-    if (_isVecFormat) {
-      loader = _vg.AssetBytesLoader(
-        _assetName,
-        assetBundle: bundle,
-        packageName: package,
-      );
-    } else {
-      loader = _svg.SvgAssetLoader(
-        _assetName,
-        assetBundle: bundle,
-        packageName: package,
-        theme: theme,
-        colorMapper: colorMapper,
-      );
-    }
-    return _svg.SvgPicture(
-      loader,
-      key: key,
-      matchTextDirection: matchTextDirection,
-      width: width,
-      height: height,
-      fit: fit,
-      alignment: alignment,
-      allowDrawingOutsideViewBox: allowDrawingOutsideViewBox,
-      placeholderBuilder: placeholderBuilder,
-      semanticsLabel: semanticsLabel,
-      excludeFromSemantics: excludeFromSemantics,
-      colorFilter: colorFilter ?? (color == null ? null : ColorFilter.mode(color, colorBlendMode)),
-      clipBehavior: clipBehavior,
-      cacheColorFilter: cacheColorFilter,
-    );
-  }
-
-  String get path => _assetName;
-
-  String get keyName => ${isPackage ? '\'packages/$packageName/\$_assetName\'' : '_assetName'};
-}''';
+  String get classOutput => '';
 
   @override
   String get className => 'SvgGenImage';
@@ -127,7 +45,10 @@ ${isPackage ? "\n  static const String package = '$packageName';" : ''}
       final flavors = asset.flavors.map((e) => '\'$e\'').join(', ');
       buffer.write(flavors);
       buffer.write('}');
-      buffer.write(','); // Better formatting.
+      if (!isPackage) buffer.write(','); // Better formatting.
+    }
+    if (isPackage) {
+      buffer.write(', package: \'$packageName\',');
     }
     buffer.write(')');
     return buffer.toString();

packages/core/test/assets_gen_integrations_test.dart

@@ -174,21 +174,6 @@ void main() {
         isFalse,
       );
       expect(integration.isConstConstructor, isTrue);
-      expect(integration.classOutput.contains('String? package,'), isTrue);
-
-      final integrationWithPackage = SvgIntegration('package_name');
-      expect(
-        integrationWithPackage.classOutput.contains(
-          'String? package = package,',
-        ),
-        isTrue,
-      );
-      expect(
-        integrationWithPackage.classOutput.contains(
-          "static const String package = 'package_name';",
-        ),
-        isTrue,
-      );
     });
 
     test('Assets with Rive integrations on pubspec.yaml', () async {

packages/core/test/assets_gen_test.dart

@@ -59,13 +59,6 @@ void main() {
 
       // The generated classes have `package` fields.
       expect(content, contains("static const String package = 'test';"));
-      expect(
-        content,
-        contains(
-          "@Deprecated('Do not specify package for a generated library asset')",
-        ),
-      );
-      expect(content, contains('String? package = package,'));
     });
 
     test('Assets with directory path enabled', () async {