Improve message sending to superclasses

objc2/CHANGELOG.md

@@ -19,8 +19,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   methods that `extern_class!` and `declare_class!` generated to that. This
   means you'll have to `use objc2::ClassType` whenever you want to use e.g.
   `NSData::class()`.
-* Added `Id::into_superclass`.
+* Added `Id::into_super`.
 * Added `extern_methods!` macro.
+* Added ability to call `msg_send![super(obj), ...]` without explicitly
+  specifying the superclass.
 
 ### Changed
 * **BREAKING**: Change syntax in `extern_class!` macro to be more Rust-like.

objc2/examples/class_with_lifetime.rs

@@ -65,7 +65,7 @@ impl<'a> MyObject<'a> {
 }
 
 unsafe impl<'a> ClassType for MyObject<'a> {
-    type Superclass = NSObject;
+    type Super = NSObject;
 
     fn class() -> &'static Class {
         // TODO: Use std::lazy::LazyCell
@@ -117,6 +117,14 @@ unsafe impl<'a> ClassType for MyObject<'a> {
 
         Class::get("MyObject").unwrap()
     }
+
+    fn as_super(&self) -> &Self::Super {
+        &self.superclass
+    }
+
+    fn as_super_mut(&mut self) -> &mut Self::Super {
+        &mut self.superclass
+    }
 }
 
 fn main() {
@@ -125,7 +133,7 @@ fn main() {
 
     // It is not possible to convert to `Id<NSObject, Owned>` since that would
     // loose the lifetime information that `MyObject` stores
-    // let obj = Id::into_superclass(obj);
+    // let obj = Id::into_super(obj);
 
     println!("Number: {}", obj.get());
 

objc2/examples/delegate.rs

@@ -13,7 +13,7 @@ extern_class!(
     struct NSResponder;
 
     unsafe impl ClassType for NSResponder {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 
@@ -26,13 +26,13 @@ declare_class!(
 
     unsafe impl ClassType for CustomAppDelegate {
         #[inherits(NSObject)]
-        type Superclass = NSResponder;
+        type Super = NSResponder;
     }
 
     unsafe impl CustomAppDelegate {
         #[sel(initWith:another:)]
         fn init_with(self: &mut Self, ivar: u8, another_ivar: Bool) -> *mut Self {
-            let this: *mut Self = unsafe { msg_send![super(self, NSResponder::class()), init] };
+            let this: *mut Self = unsafe { msg_send![super(self), init] };
             if let Some(this) = unsafe { this.as_mut() } {
                 // TODO: Allow initialization through MaybeUninit
                 *this.ivar = ivar;

objc2/examples/nspasteboard.rs

@@ -28,7 +28,7 @@ extern_class!(
 
     // SAFETY: NSPasteboard actually inherits from NSObject.
     unsafe impl ClassType for NSPasteboard {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/examples/speech_synthethis.rs

@@ -31,7 +31,7 @@ mod appkit {
         pub struct NSSpeechSynthesizer;
 
         unsafe impl ClassType for NSSpeechSynthesizer {
-            type Superclass = NSObject;
+            type Super = NSObject;
         }
     );
 
@@ -110,7 +110,7 @@ mod avfaudio {
         pub struct AVSpeechSynthesizer;
 
         unsafe impl ClassType for AVSpeechSynthesizer {
-            type Superclass = NSObject;
+            type Super = NSObject;
         }
     );
 
@@ -136,7 +136,7 @@ mod avfaudio {
         pub struct AVSpeechUtterance;
 
         unsafe impl ClassType for AVSpeechUtterance {
-            type Superclass = NSObject;
+            type Super = NSObject;
         }
     );
 

objc2/src/class_type.rs

@@ -17,11 +17,12 @@ use crate::Message;
 /// # Safety
 ///
 /// The class returned by [`Self::class`] must be a subclass of the class that
-/// [`Self::Superclass`] represents.
+/// [`Self::Super`] represents, and `as_super`/`as_super_mut` must be
+/// implemented correctly.
 ///
 /// In pseudocode:
 /// ```ignore
-/// Self::class().superclass() == <Self::Superclass as ClassType>::class()
+/// Self::class().superclass() == <Self::Super as ClassType>::class()
 /// ```
 ///
 ///
@@ -48,7 +49,7 @@ use crate::Message;
 ///     struct MyClass;
 ///
 ///     unsafe impl ClassType for MyClass {
-///         type Superclass = NSObject;
+///         type Super = NSObject;
 ///     }
 /// );
 ///
@@ -65,7 +66,7 @@ pub unsafe trait ClassType: Message {
     /// [`Deref`]: std::ops::Deref
     /// [`Deref::Target`]: std::ops::Deref::Target
     /// [`runtime::Object`]: crate::runtime::Object
-    type Superclass: Message;
+    type Super: Message;
 
     /// Get a reference to the Objective-C class that this type represents.
     ///
@@ -78,4 +79,12 @@ pub unsafe trait ClassType: Message {
     /// class, e.g. if the program is not properly linked to the framework
     /// that defines the class.
     fn class() -> &'static Class;
+
+    /// Get an immutable reference to the superclass.
+    // Note: It'd be safe to provide a default impl using transmute here if
+    // we wanted to!
+    fn as_super(&self) -> &Self::Super;
+
+    /// Get a mutable reference to the superclass.
+    fn as_super_mut(&mut self) -> &mut Self::Super;
 }

objc2/src/foundation/array.rs

@@ -58,7 +58,7 @@ __inner_extern_class!(
     }
 
     unsafe impl<T: Message, O: Ownership> ClassType for NSArray<T, O> {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/attributed_string.rs

@@ -25,7 +25,7 @@ extern_class!(
     pub struct NSAttributedString;
 
     unsafe impl ClassType for NSAttributedString {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/data.rs

@@ -21,7 +21,7 @@ extern_class!(
     pub struct NSData;
 
     unsafe impl ClassType for NSData {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/dictionary.rs

@@ -18,7 +18,7 @@ __inner_extern_class!(
     }
 
     unsafe impl<K: Message, V: Message> ClassType for NSDictionary<K, V> {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/error.rs

@@ -19,7 +19,7 @@ extern_class!(
     pub struct NSError;
 
     unsafe impl ClassType for NSError {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/exception.rs

@@ -22,7 +22,7 @@ extern_class!(
     pub struct NSException;
 
     unsafe impl ClassType for NSException {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/mod.rs

@@ -39,13 +39,13 @@
 //! want to use the objects!
 //!
 //! All objects also implement [`AsRef`] and [`AsMut`] to their superclass,
-//! and can be used in [`Id::into_superclass`], so if you favour explicit
+//! and can be used in [`Id::into_super`], so if you favour explicit
 //! conversion, that is a possibility too.
 //!
 //! [`Deref`]: std::ops::Deref
 //! [`ClassType`]: crate::ClassType
 //! [anti-pattern-deref]: https://rust-unofficial.github.io/patterns/anti_patterns/deref.html
-//! [`Id::into_superclass`]: crate::rc::Id::into_superclass
+//! [`Id::into_super`]: crate::rc::Id::into_super
 
 // TODO: Remove these
 #![allow(missing_docs)]

objc2/src/foundation/mutable_array.rs

@@ -27,7 +27,7 @@ __inner_extern_class!(
 
     unsafe impl<T: Message, O: Ownership> ClassType for NSMutableArray<T, O> {
         #[inherits(NSObject)]
-        type Superclass = NSArray<T, O>;
+        type Super = NSArray<T, O>;
     }
 );
 

objc2/src/foundation/mutable_attributed_string.rs

@@ -13,7 +13,7 @@ extern_class!(
 
     unsafe impl ClassType for NSMutableAttributedString {
         #[inherits(NSObject)]
-        type Superclass = NSAttributedString;
+        type Super = NSAttributedString;
     }
 );
 

objc2/src/foundation/mutable_data.rs

@@ -24,7 +24,7 @@ extern_class!(
 
     unsafe impl ClassType for NSMutableData {
         #[inherits(NSObject)]
-        type Superclass = NSData;
+        type Super = NSData;
     }
 );
 

objc2/src/foundation/mutable_string.rs

@@ -16,7 +16,7 @@ extern_class!(
 
     unsafe impl ClassType for NSMutableString {
         #[inherits(NSObject)]
-        type Superclass = NSString;
+        type Super = NSString;
     }
 );
 

objc2/src/foundation/number.rs

@@ -43,7 +43,7 @@ extern_class!(
 
     unsafe impl ClassType for NSNumber {
         #[inherits(NSObject)]
-        type Superclass = NSValue;
+        type Super = NSValue;
     }
 );
 

objc2/src/foundation/object.rs

@@ -16,12 +16,20 @@ __inner_extern_class! {
 }
 
 unsafe impl ClassType for NSObject {
-    type Superclass = Object;
+    type Super = Object;
 
     #[inline]
     fn class() -> &'static Class {
         class!(NSObject)
     }
+
+    fn as_super(&self) -> &Self::Super {
+        &self.__inner
+    }
+
+    fn as_super_mut(&mut self) -> &mut Self::Super {
+        &mut self.__inner
+    }
 }
 
 extern_methods!(

objc2/src/foundation/process_info.rs

@@ -13,7 +13,7 @@ extern_class!(
     pub struct NSProcessInfo;
 
     unsafe impl ClassType for NSProcessInfo {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/string.rs

@@ -40,7 +40,7 @@ extern_class!(
     // TODO: Check if performance of NSSelectorFromString is worthwhile
 
     unsafe impl ClassType for NSString {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/thread.rs

@@ -14,7 +14,7 @@ extern_class!(
     pub struct NSThread;
 
     unsafe impl ClassType for NSThread {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/uuid.rs

@@ -20,7 +20,7 @@ extern_class!(
     pub struct NSUUID;
 
     unsafe impl ClassType for NSUUID {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );
 

objc2/src/foundation/value.rs

@@ -35,7 +35,7 @@ extern_class!(
     pub struct NSValue;
 
     unsafe impl ClassType for NSValue {
-        type Superclass = NSObject;
+        type Super = NSObject;
     }
 );