Daco's comments

CHANGELOG.md

@@ -8,6 +8,7 @@
 - Fix ObjC methods returning instancetype having the wrong type in sublasses.
 - When generating typedefs for `Pointer<NativeFunction<Function>>`, also
   generate a typedef for the `Function`.
+- Use Dart wrapper types in args and returns of ObjCBlocks.
 - Bump min SDK version to 3.2.0-114.0.dev.
 
 # 9.0.1

lib/src/code_generator/objc_block.dart

@@ -118,12 +118,12 @@ $returnFfiDartType $closureTrampoline($blockCType block, $paramsFfiDartType) =>
     // Snippet that converts a Dart typed closure to FfiDart type. This snippet
     // is used below. Note that the closure being converted is called `fn`.
     final convertedFnArgs = params
-        .map((p) => p.type.convertFfiDartTypeToDartType(w, p.name, 'lib',
-            objCShouldRetain: true))
+        .map((p) => p.type
+            .convertFfiDartTypeToDartType(w, p.name, 'lib', objCRetain: true))
         .join(', ');
     final convFnInvocation = returnType.convertDartTypeToFfiDartType(
         w, 'fn($convertedFnArgs)',
-        objCShouldRetain: true);
+        objCRetain: true);
     final convFn = '($paramsFfiDartType) => $convFnInvocation';
 
     // Write the wrapper class.
@@ -187,14 +187,15 @@ class $name extends _ObjCBlockBase {
     // Call method.
     s.write('  ${returnType.getDartType(w)} call($paramsDartType) =>');
     final callMethodArgs = params
-        .map((p) => p.type.convertDartTypeToFfiDartType(w, p.name))
+        .map((p) =>
+            p.type.convertDartTypeToFfiDartType(w, p.name, objCRetain: false))
         .join(', ');
     final callMethodInvocation = '''
 _id.ref.invoke.cast<$natTrampFnType>().asFunction<$trampFuncFfiDartType>()(
     _id, $callMethodArgs)''';
     s.write(returnType.convertFfiDartTypeToDartType(
         w, callMethodInvocation, '_lib',
-        objCShouldRetain: false));
+        objCRetain: false));
     s.write(';\n');
 
     s.write('}\n');
@@ -231,19 +232,19 @@ _id.ref.invoke.cast<$natTrampFnType>().asFunction<$trampFuncFfiDartType>()(
   String convertDartTypeToFfiDartType(
     Writer w,
     String value, {
-    bool objCShouldRetain = false,
+    required bool objCRetain,
   }) =>
-      ObjCInterface.generateGetId(value, objCShouldRetain);
+      ObjCInterface.generateGetId(value, objCRetain);
 
   @override
   String convertFfiDartTypeToDartType(
     Writer w,
     String value,
     String library, {
-    bool objCShouldRetain = true,
+    required bool objCRetain,
     String? objCEnclosingClass,
   }) =>
-      ObjCInterface.generateConstructor(name, value, library, objCShouldRetain);
+      ObjCInterface.generateConstructor(name, value, library, objCRetain);
 
   @override
   String toString() => '($returnType (^)(${argTypes.join(', ')}))';

lib/src/code_generator/objc_interface.dart

@@ -207,15 +207,17 @@ class $name extends ${superType?.name ?? '_ObjCWrapper'} {
       s.write(isStatic ? '_lib.${_classObject.name}' : '_id');
       s.write(', _lib.${m.selObject!.name}');
       for (final p in m.params) {
-        s.write(', ${p.type.convertDartTypeToFfiDartType(w, p.name)}');
+        final convertedParam =
+            p.type.convertDartTypeToFfiDartType(w, p.name, objCRetain: false);
+        s.write(', $convertedParam');
       }
       s.write(');\n');
       if (convertReturn) {
         final result = returnType.convertFfiDartTypeToDartType(
           w,
           '_ret',
           '_lib',
-          objCShouldRetain: !m.isOwnedReturn,
+          objCRetain: !m.isOwnedReturn,
           objCEnclosingClass: name,
         );
         s.write('    return $result;');
@@ -403,30 +405,30 @@ class $name extends ${superType?.name ?? '_ObjCWrapper'} {
   String convertDartTypeToFfiDartType(
     Writer w,
     String value, {
-    bool objCShouldRetain = false,
+    required bool objCRetain,
   }) =>
-      ObjCInterface.generateGetId(value, objCShouldRetain);
+      ObjCInterface.generateGetId(value, objCRetain);
 
-  static String generateGetId(String value, bool objCShouldRetain) =>
-      objCShouldRetain ? '$value._retainAndReturnId()' : '$value._id';
+  static String generateGetId(String value, bool objCRetain) =>
+      objCRetain ? '$value._retainAndReturnId()' : '$value._id';
 
   @override
   String convertFfiDartTypeToDartType(
     Writer w,
     String value,
     String library, {
-    bool objCShouldRetain = true,
+    required bool objCRetain,
     String? objCEnclosingClass,
   }) =>
-      ObjCInterface.generateConstructor(name, value, library, objCShouldRetain);
+      ObjCInterface.generateConstructor(name, value, library, objCRetain);
 
   static String generateConstructor(
     String className,
     String value,
     String library,
-    bool objCShouldRetain,
+    bool objCRetain,
   ) {
-    final ownershipFlags = 'retain: $objCShouldRetain, release: true';
+    final ownershipFlags = 'retain: $objCRetain, release: true';
     return '$className._($value, $library, $ownershipFlags)';
   }
 

lib/src/code_generator/objc_nullable.dart

@@ -48,13 +48,13 @@ class ObjCNullable extends Type {
   String convertDartTypeToFfiDartType(
     Writer w,
     String value, {
-    bool objCShouldRetain = false,
+    required bool objCRetain,
   }) {
     // This is a bit of a hack, but works for all the types that are allowed to
     // be a child type. If we add more allowed child types, we may have to start
     // special casing each type. Turns value._id into value?._id ?? nullptr.
     final convertedValue = child.convertDartTypeToFfiDartType(w, '$value?',
-        objCShouldRetain: objCShouldRetain);
+        objCRetain: objCRetain);
     return '$convertedValue ?? ${w.ffiLibraryPrefix}.nullptr';
   }
 
@@ -63,15 +63,15 @@ class ObjCNullable extends Type {
     Writer w,
     String value,
     String library, {
-    bool objCShouldRetain = true,
+    required bool objCRetain,
     String? objCEnclosingClass,
   }) {
     // All currently supported child types have a Pointer as their FfiDartType.
     final convertedValue = child.convertFfiDartTypeToDartType(
       w,
       value,
       library,
-      objCShouldRetain: objCShouldRetain,
+      objCRetain: objCRetain,
       objCEnclosingClass: objCEnclosingClass,
     );
     return '$value.address == 0 ? null : $convertedValue';

lib/src/code_generator/pointer.dart

@@ -91,18 +91,17 @@ class ObjCObjectPointer extends PointerType {
   String convertDartTypeToFfiDartType(
     Writer w,
     String value, {
-    bool objCShouldRetain = false,
+    required bool objCRetain,
   }) =>
-      '$value._id';
+      ObjCInterface.generateGetId(value, objCRetain);
 
   @override
   String convertFfiDartTypeToDartType(
     Writer w,
     String value,
     String library, {
-    bool objCShouldRetain = true,
+    required bool objCRetain,
     String? objCEnclosingClass,
   }) =>
-      ObjCInterface.generateConstructor(
-          'NSObject', value, library, objCShouldRetain);
+      ObjCInterface.generateConstructor('NSObject', value, library, objCRetain);
 }

lib/src/code_generator/type.dart

@@ -56,20 +56,30 @@ abstract class Type {
 
   /// Returns generated Dart code that converts the given value from its
   /// DartType to its FfiDartType.
+  ///
+  /// [value] is the value to be converted. If [objCRetain] is true, the ObjC
+  /// object will be reained (ref count incremented) during conversion.
   String convertDartTypeToFfiDartType(
     Writer w,
     String value, {
-    bool objCShouldRetain = false,
+    required bool objCRetain,
   }) =>
       value;
 
   /// Returns generated Dart code that converts the given value from its
   /// FfiDartType to its DartType.
+  ///
+  /// [value] is the value to be converted, and [library] is an instance of the
+  /// native library object. If [objCRetain] is true, the ObjC wrapper object
+  /// will retain (ref count increment) the wrapped object pointer. If this
+  /// conversion is occuring in the context of an ObjC class, then
+  /// [objCEnclosingClass] should be the name of the Dart wrapper class (this is
+  /// used by instancetype).
   String convertFfiDartTypeToDartType(
     Writer w,
     String value,
     String library, {
-    bool objCShouldRetain = true,
+    required bool objCRetain,
     String? objCEnclosingClass,
   }) =>
       value;
@@ -132,7 +142,7 @@ abstract class BindingType extends NoLookUpBinding implements Type {
   String convertDartTypeToFfiDartType(
     Writer w,
     String value, {
-    bool objCShouldRetain = false,
+    required bool objCRetain,
   }) =>
       value;
 
@@ -141,7 +151,7 @@ abstract class BindingType extends NoLookUpBinding implements Type {
     Writer w,
     String value,
     String library, {
-    bool objCShouldRetain = true,
+    required bool objCRetain,
     String? objCEnclosingClass,
   }) =>
       value;

lib/src/code_generator/typealias.dart

@@ -162,24 +162,23 @@ class Typealias extends BindingType {
   String convertDartTypeToFfiDartType(
     Writer w,
     String value, {
-    bool objCShouldRetain = false,
+    required bool objCRetain,
   }) =>
-      type.convertDartTypeToFfiDartType(w, value,
-          objCShouldRetain: objCShouldRetain);
+      type.convertDartTypeToFfiDartType(w, value, objCRetain: objCRetain);
 
   @override
   String convertFfiDartTypeToDartType(
     Writer w,
     String value,
     String library, {
-    bool objCShouldRetain = true,
+    required bool objCRetain,
     String? objCEnclosingClass,
   }) =>
       type.convertFfiDartTypeToDartType(
         w,
         value,
         library,
-        objCShouldRetain: objCShouldRetain,
+        objCRetain: objCRetain,
         objCEnclosingClass: objCEnclosingClass,
       );
 
@@ -211,18 +210,20 @@ class ObjCInstanceType extends Typealias {
   String convertDartTypeToFfiDartType(
     Writer w,
     String value, {
-    bool objCShouldRetain = false,
+    required bool objCRetain,
   }) =>
-      ObjCInterface.generateGetId(value, objCShouldRetain);
+      ObjCInterface.generateGetId(value, objCRetain);
 
   @override
   String convertFfiDartTypeToDartType(
     Writer w,
     String value,
     String library, {
-    bool objCShouldRetain = true,
+    required bool objCRetain,
     String? objCEnclosingClass,
   }) =>
+      // objCEnclosingClass must be present, because instancetype can only
+      // occur inside a class.
       ObjCInterface.generateConstructor(
-          objCEnclosingClass ?? 'NSObject', value, library, objCShouldRetain);
+          objCEnclosingClass!, value, library, objCRetain);
 }

test/native_objc_test/block_config.yaml

@@ -1,5 +1,5 @@
 name: BlockTestObjCLibrary
-description: 'Tests calling Objective-C blocks'
+description: 'Tests calling Objective-C blocks.'
 language: objc
 output: 'block_bindings.dart'
 exclude-all-by-default: true