[pigeon] Adds @SwiftClass annotation

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 17.3.0
+
+* [swift] Adds `@SwiftClass` annotation to allow choice between `struct` and `class` for data classes.
+
 ## 17.2.0
 
 * [dart] Adds implementation for `@ProxyApi`.

packages/pigeon/lib/ast.dart

@@ -639,6 +639,7 @@ class Class extends Node {
   Class({
     required this.name,
     required this.fields,
+    this.isSwiftClass = false,
     this.documentationComments = const <String>[],
   });
 
@@ -648,6 +649,12 @@ class Class extends Node {
   /// All the fields contained in the class.
   List<NamedType> fields;
 
+  /// Determines whether the defined class should be represented as a struct or
+  /// a class in Swift generation.
+  ///
+  /// Defaults to false, which would represent a struct.
+  bool isSwiftClass;
+
   /// List of documentation comments, separated by line.
   ///
   /// Lines should not include the comment marker itself, but should include any

packages/pigeon/lib/generator_tools.dart

@@ -13,7 +13,7 @@ import 'ast.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '17.2.0';
+const String pigeonVersion = '17.3.0';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/lib/pigeon_lib.dart

@@ -1550,6 +1550,7 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
       _currentClass = Class(
         name: node.name.lexeme,
         fields: <NamedType>[],
+        isSwiftClass: _hasMetadata(node.metadata, 'SwiftClass'),
         documentationComments:
             _documentationCommentsParser(node.documentationComment?.tokens),
       );

packages/pigeon/lib/swift_generator.dart

@@ -125,11 +125,26 @@ class SwiftGenerator extends StructuredGenerator<SwiftOptions> {
         indent, classDefinition.documentationComments, _docCommentSpec,
         generatorComments: generatedComments);
 
-    indent.write('struct ${classDefinition.name} ');
+    if (classDefinition.isSwiftClass) {
+      indent.write('class ${classDefinition.name} ');
+    } else {
+      indent.write('struct ${classDefinition.name} ');
+    }
     indent.addScoped('{', '}', () {
-      getFieldsInSerializationOrder(classDefinition).forEach((NamedType field) {
+      final Iterable<NamedType> fields =
+          getFieldsInSerializationOrder(classDefinition);
+
+      if (classDefinition.isSwiftClass) {
+        _writeClassInit(indent, fields.toList());
+      }
+
+      for (final NamedType field in fields) {
+        addDocumentationComments(
+            indent, field.documentationComments, _docCommentSpec);
+        indent.write('var ');
         _writeClassField(indent, field);
-      });
+        indent.newln();
+      }
 
       indent.newln();
       writeClassDecode(
@@ -149,6 +164,35 @@ class SwiftGenerator extends StructuredGenerator<SwiftOptions> {
     });
   }
 
+  void _writeClassInit(Indent indent, List<NamedType> fields) {
+    indent.writeScoped('init(', ')', () {
+      for (int i = 0; i < fields.length; i++) {
+        indent.write('');
+        _writeClassField(indent, fields[i]);
+        if (i == fields.length - 1) {
+          indent.newln();
+        } else {
+          indent.addln(',');
+        }
+      }
+    }, addTrailingNewline: false);
+    indent.addScoped(' {', '}', () {
+      for (final NamedType field in fields) {
+        _writeClassFieldInit(indent, field);
+      }
+    });
+  }
+
+  void _writeClassField(Indent indent, NamedType field) {
+    indent.add('${field.name}: ${_nullsafeSwiftTypeForDartType(field.type)}');
+    final String defaultNil = field.type.isNullable ? ' = nil' : '';
+    indent.add(defaultNil);
+  }
+
+  void _writeClassFieldInit(Indent indent, NamedType field) {
+    indent.writeln('self.${field.name} = ${field.name}');
+  }
+
   @override
   void writeClassEncode(
     SwiftOptions generatorOptions,
@@ -222,16 +266,6 @@ class SwiftGenerator extends StructuredGenerator<SwiftOptions> {
     });
   }
 
-  void _writeClassField(Indent indent, NamedType field) {
-    addDocumentationComments(
-        indent, field.documentationComments, _docCommentSpec);
-
-    indent.write(
-        'var ${field.name}: ${_nullsafeSwiftTypeForDartType(field.type)}');
-    final String defaultNil = field.type.isNullable ? ' = nil' : '';
-    indent.addln(defaultNil);
-  }
-
   @override
   void writeApis(
     SwiftOptions generatorOptions,

packages/pigeon/pigeons/core_tests.dart

@@ -48,6 +48,7 @@ class AllTypes {
 }
 
 /// A class containing all supported nullable types.
+@SwiftClass()
 class AllNullableTypes {
   AllNullableTypes(
     this.aNullableBool,
@@ -66,6 +67,7 @@ class AllNullableTypes {
     this.aNullableEnum,
     this.aNullableString,
     this.aNullableObject,
+    this.allNullableTypes,
   );
 
   bool? aNullableBool;
@@ -86,6 +88,7 @@ class AllNullableTypes {
   AnEnum? aNullableEnum;
   String? aNullableString;
   Object? aNullableObject;
+  AllNullableTypes? allNullableTypes;
 }
 
 /// A class for testing nested class handling.

packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/CoreTests.java

@@ -612,6 +612,16 @@ public void setANullableObject(@Nullable Object setterArg) {
       this.aNullableObject = setterArg;
     }
 
+    private @Nullable AllNullableTypes allNullableTypes;
+
+    public @Nullable AllNullableTypes getAllNullableTypes() {
+      return allNullableTypes;
+    }
+
+    public void setAllNullableTypes(@Nullable AllNullableTypes setterArg) {
+      this.allNullableTypes = setterArg;
+    }
+
     public static final class Builder {
 
       private @Nullable Boolean aNullableBool;
@@ -743,6 +753,14 @@ public static final class Builder {
         return this;
       }
 
+      private @Nullable AllNullableTypes allNullableTypes;
+
+      @CanIgnoreReturnValue
+      public @NonNull Builder setAllNullableTypes(@Nullable AllNullableTypes setterArg) {
+        this.allNullableTypes = setterArg;
+        return this;
+      }
+
       public @NonNull AllNullableTypes build() {
         AllNullableTypes pigeonReturn = new AllNullableTypes();
         pigeonReturn.setANullableBool(aNullableBool);
@@ -761,13 +779,14 @@ public static final class Builder {
         pigeonReturn.setANullableEnum(aNullableEnum);
         pigeonReturn.setANullableString(aNullableString);
         pigeonReturn.setANullableObject(aNullableObject);
+        pigeonReturn.setAllNullableTypes(allNullableTypes);
         return pigeonReturn;
       }
     }
 
     @NonNull
     ArrayList<Object> toList() {
-      ArrayList<Object> toListResult = new ArrayList<Object>(16);
+      ArrayList<Object> toListResult = new ArrayList<Object>(17);
       toListResult.add(aNullableBool);
       toListResult.add(aNullableInt);
       toListResult.add(aNullableInt64);
@@ -784,6 +803,7 @@ ArrayList<Object> toList() {
       toListResult.add(aNullableEnum == null ? null : aNullableEnum.index);
       toListResult.add(aNullableString);
       toListResult.add(aNullableObject);
+      toListResult.add((allNullableTypes == null) ? null : allNullableTypes.toList());
       return toListResult;
     }
 
@@ -830,6 +850,11 @@ ArrayList<Object> toList() {
       pigeonResult.setANullableString((String) aNullableString);
       Object aNullableObject = list.get(15);
       pigeonResult.setANullableObject(aNullableObject);
+      Object allNullableTypes = list.get(16);
+      pigeonResult.setAllNullableTypes(
+          (allNullableTypes == null)
+              ? null
+              : AllNullableTypes.fromList((ArrayList<Object>) allNullableTypes));
       return pigeonResult;
     }
   }

packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.h

@@ -83,7 +83,8 @@ typedef NS_ENUM(NSUInteger, FLTAnEnum) {
                 nullableMapWithObject:(nullable NSDictionary<NSString *, id> *)nullableMapWithObject
                         aNullableEnum:(nullable FLTAnEnumBox *)aNullableEnum
                       aNullableString:(nullable NSString *)aNullableString
-                      aNullableObject:(nullable id)aNullableObject;
+                      aNullableObject:(nullable id)aNullableObject
+                     allNullableTypes:(nullable FLTAllNullableTypes *)allNullableTypes;
 @property(nonatomic, strong, nullable) NSNumber *aNullableBool;
 @property(nonatomic, strong, nullable) NSNumber *aNullableInt;
 @property(nonatomic, strong, nullable) NSNumber *aNullableInt64;
@@ -101,6 +102,7 @@ typedef NS_ENUM(NSUInteger, FLTAnEnum) {
 @property(nonatomic, strong, nullable) FLTAnEnumBox *aNullableEnum;
 @property(nonatomic, copy, nullable) NSString *aNullableString;
 @property(nonatomic, strong, nullable) id aNullableObject;
+@property(nonatomic, strong, nullable) FLTAllNullableTypes *allNullableTypes;
 @end
 
 /// A class for testing nested class handling.

packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/CoreTests.gen.m

@@ -160,7 +160,8 @@ + (instancetype)makeWithANullableBool:(nullable NSNumber *)aNullableBool
                 nullableMapWithObject:(nullable NSDictionary<NSString *, id> *)nullableMapWithObject
                         aNullableEnum:(nullable FLTAnEnumBox *)aNullableEnum
                       aNullableString:(nullable NSString *)aNullableString
-                      aNullableObject:(nullable id)aNullableObject {
+                      aNullableObject:(nullable id)aNullableObject
+                     allNullableTypes:(nullable FLTAllNullableTypes *)allNullableTypes {
   FLTAllNullableTypes *pigeonResult = [[FLTAllNullableTypes alloc] init];
   pigeonResult.aNullableBool = aNullableBool;
   pigeonResult.aNullableInt = aNullableInt;
@@ -178,6 +179,7 @@ + (instancetype)makeWithANullableBool:(nullable NSNumber *)aNullableBool
   pigeonResult.aNullableEnum = aNullableEnum;
   pigeonResult.aNullableString = aNullableString;
   pigeonResult.aNullableObject = aNullableObject;
+  pigeonResult.allNullableTypes = allNullableTypes;
   return pigeonResult;
 }
 + (FLTAllNullableTypes *)fromList:(NSArray *)list {
@@ -203,6 +205,8 @@ + (FLTAllNullableTypes *)fromList:(NSArray *)list {
   pigeonResult.aNullableEnum = aNullableEnum;
   pigeonResult.aNullableString = GetNullableObjectAtIndex(list, 14);
   pigeonResult.aNullableObject = GetNullableObjectAtIndex(list, 15);
+  pigeonResult.allNullableTypes =
+      [FLTAllNullableTypes nullableFromList:(GetNullableObjectAtIndex(list, 16))];
   return pigeonResult;
 }
 + (nullable FLTAllNullableTypes *)nullableFromList:(NSArray *)list {
@@ -227,6 +231,7 @@ - (NSArray *)toList {
                                : [NSNumber numberWithInteger:self.aNullableEnum.value]),
     self.aNullableString ?: [NSNull null],
     self.aNullableObject ?: [NSNull null],
+    (self.allNullableTypes ? [self.allNullableTypes toList] : [NSNull null]),
   ];
 }
 @end

packages/pigeon/platform_tests/alternate_language_test_plugin/macos/Classes/CoreTests.gen.h

@@ -83,7 +83,8 @@ typedef NS_ENUM(NSUInteger, AnEnum) {
                 nullableMapWithObject:(nullable NSDictionary<NSString *, id> *)nullableMapWithObject
                         aNullableEnum:(nullable AnEnumBox *)aNullableEnum
                       aNullableString:(nullable NSString *)aNullableString
-                      aNullableObject:(nullable id)aNullableObject;
+                      aNullableObject:(nullable id)aNullableObject
+                     allNullableTypes:(nullable AllNullableTypes *)allNullableTypes;
 @property(nonatomic, strong, nullable) NSNumber *aNullableBool;
 @property(nonatomic, strong, nullable) NSNumber *aNullableInt;
 @property(nonatomic, strong, nullable) NSNumber *aNullableInt64;
@@ -101,6 +102,7 @@ typedef NS_ENUM(NSUInteger, AnEnum) {
 @property(nonatomic, strong, nullable) AnEnumBox *aNullableEnum;
 @property(nonatomic, copy, nullable) NSString *aNullableString;
 @property(nonatomic, strong, nullable) id aNullableObject;
+@property(nonatomic, strong, nullable) AllNullableTypes *allNullableTypes;
 @end
 
 /// A class for testing nested class handling.

packages/pigeon/platform_tests/alternate_language_test_plugin/macos/Classes/CoreTests.gen.m

@@ -160,7 +160,8 @@ + (instancetype)makeWithANullableBool:(nullable NSNumber *)aNullableBool
                 nullableMapWithObject:(nullable NSDictionary<NSString *, id> *)nullableMapWithObject
                         aNullableEnum:(nullable AnEnumBox *)aNullableEnum
                       aNullableString:(nullable NSString *)aNullableString
-                      aNullableObject:(nullable id)aNullableObject {
+                      aNullableObject:(nullable id)aNullableObject
+                     allNullableTypes:(nullable AllNullableTypes *)allNullableTypes {
   AllNullableTypes *pigeonResult = [[AllNullableTypes alloc] init];
   pigeonResult.aNullableBool = aNullableBool;
   pigeonResult.aNullableInt = aNullableInt;
@@ -178,6 +179,7 @@ + (instancetype)makeWithANullableBool:(nullable NSNumber *)aNullableBool
   pigeonResult.aNullableEnum = aNullableEnum;
   pigeonResult.aNullableString = aNullableString;
   pigeonResult.aNullableObject = aNullableObject;
+  pigeonResult.allNullableTypes = allNullableTypes;
   return pigeonResult;
 }
 + (AllNullableTypes *)fromList:(NSArray *)list {
@@ -203,6 +205,8 @@ + (AllNullableTypes *)fromList:(NSArray *)list {
   pigeonResult.aNullableEnum = aNullableEnum;
   pigeonResult.aNullableString = GetNullableObjectAtIndex(list, 14);
   pigeonResult.aNullableObject = GetNullableObjectAtIndex(list, 15);
+  pigeonResult.allNullableTypes =
+      [AllNullableTypes nullableFromList:(GetNullableObjectAtIndex(list, 16))];
   return pigeonResult;
 }
 + (nullable AllNullableTypes *)nullableFromList:(NSArray *)list {
@@ -227,6 +231,7 @@ - (NSArray *)toList {
                                : [NSNumber numberWithInteger:self.aNullableEnum.value]),
     self.aNullableString ?: [NSNull null],
     self.aNullableObject ?: [NSNull null],
+    (self.allNullableTypes ? [self.allNullableTypes toList] : [NSNull null]),
   ];
 }
 @end