Initial conversion to objc2 (#30)

* Use objc2

* Replace `objc_id`

* Remove sel_impl import

* Fix `add_method` calls

* Fix accessing raw FFI functions

* Fix Encode impl

* Fix message sends arguments that do not implement `Encode`

* Use immutable reference in a few places where now necessary

See madsmtm/objc2#150 for a bit of background

* Add a few Send + Sync bounds where examples require it

This is something we'll need to look into properly

* Use `&'static Class` instead of `*const Class`

Safer and more ergonomic. Also required for `msg_send_id!` macro

* Use msg_send_id! and rc::Id

* Update objc2 to v0.3.0-beta.2

* Replace `BOOL` with `Bool` when declaring delegates

This makes cacao compile on Aarch64 again

* Remove a few impossible to use correctly `into_inner` functions

These consumed `self`, and hence also dropped `Id` variable that was responsible for keeping the returned pointer alive

* Remove a few impossible to use correctly `From` implementations

* Quickly fix UB with using BACKGROUND_COLOR ivar

* Fix double-freeing of windows

* Fix double freeing of strings

* Fix a few remaining double-frees

ARCHITECTURE.md

@@ -209,9 +209,7 @@ impl View {
             center_x: LayoutAnchorX::center(view),
             center_y: LayoutAnchorY::center(view),
 
-            layer: Layer::wrap(unsafe {
-                msg_send![view, layer]
-            }),
+            layer: Layer::from_id(unsafe { msg_send_id![view, layer] }),
 
             objc: ObjcProperty::retain(view),
         }
@@ -293,7 +291,8 @@ impl<T> View<T> {
 
         #[cfg(target_os = "macos")]
         self.objc.with_mut(|obj| unsafe {
-            (&mut *obj).set_ivar(BACKGROUND_COLOR, color);
+            // TODO: Fix this unnecessary retain!
+            (&mut *obj).set_ivar::<id>(BACKGROUND_COLOR, msg_send![color, retain]);
         });
 
         #[cfg(target_os = "ios")]
@@ -352,22 +351,22 @@ We'll step through an example (abridged) `View` bridge below, for macOS. You sho
 For our basic `View` type, we want to just map to the corresponding class on the Objective-C side (in this case, `NSView`), and maybe do a bit of tweaking for sanity reasons.
 
 ``` rust
-pub(crate) fn register_view_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+pub(crate) fn register_view_class() -> &'static Class {
+    static mut VIEW_CLASS: Option<'static Class> = None;
     static INIT: Once = Once::new();
 
     INIT.call_once(|| unsafe {
         let superclass = class!(NSView);
         let mut decl = ClassDecl::new("RSTView", superclass).unwrap();
 
-        decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
+        decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(_, _) -> _);
 
         decl.add_ivar::<id>(BACKGROUND_COLOR);
 
-        VIEW_CLASS = decl.register();
+        VIEW_CLASS = Some(decl.register());
     });
 
-    unsafe { VIEW_CLASS }
+    unsafe { VIEW_CLASS.unwrap() }
 }
 ```
 
@@ -377,19 +376,19 @@ Objective-C method signatures, as well as provision space for variable storage (
 For our _delegate_ types, we need a different class creation method - one that creates a subclass per-unique-type:
 
 ``` rust
-pub(crate) fn register_view_class_with_delegate<T: ViewDelegate>(instance: &T) -> *const Class {
+pub(crate) fn register_view_class_with_delegate<T: ViewDelegate>(instance: &T) -> &'static Class {
     load_or_register_class("NSView", instance.subclass_name(), |decl| unsafe {
         decl.add_ivar::<usize>(VIEW_DELEGATE_PTR);
         decl.add_ivar::<id>(BACKGROUND_COLOR);
 
         decl.add_method(
             sel!(isFlipped),
-            enforce_normalcy as extern "C" fn(&Object, _) -> BOOL
+            enforce_normalcy as extern "C" fn(_, _) -> _,
         );
 
         decl.add_method(
             sel!(draggingEntered:),
-            dragging_entered::<T> as extern "C" fn (&mut Object, _, _) -> NSUInteger
+            dragging_entered::<T> as extern "C" fn (_, _, _) -> _,
         );
     })
 }
@@ -401,18 +400,18 @@ to the Rust `ViewDelegate` implementation.
 The methods we're setting up can range from simple to complex - take `isFlipped`:
 
 ``` rust
-extern "C" fn is_flipped(_: &Object, _: Sel) -> BOOL {
-    return YES;
+extern "C" fn is_flipped(_: &Object, _: Sel) -> Bool {
+    return Bool::YES;
 }
 ```
 
-Here, we just want to tell `NSView` to use top,left as the origin point, so we need to respond `YES` in this subclass method.
+Here, we just want to tell `NSView` to use top,left as the origin point, so we need to respond `Bool::YES` in this subclass method.
 
 ``` rust
 extern "C" fn dragging_entered<T: ViewDelegate>(this: &mut Object, _: Sel, info: id) -> NSUInteger {
     let view = utils::load::<T>(this, VIEW_DELEGATE_PTR);
     view.dragging_entered(DragInfo {
-        info: unsafe { Id::from_ptr(info) }
+        info: unsafe { Id::retain(info).unwrap() }
     }).into()
 }
 ```

Cargo.toml

@@ -20,15 +20,16 @@ rustdoc-args = ["--cfg", "docsrs"]
 
 [dependencies]
 bitmask-enum = "2.2.1"
-block = "0.1.6"
-core-foundation = "0.9"
-core-graphics = "0.23"
+objc = { version = "=0.3.0-beta.2", package = "objc2" }
+block = { version = "=0.2.0-alpha.6", package = "block2" }
+# Temporary: Patched versions that implement `Encode` for common types
+# Branch: `objc2`
+core-foundation = { git = "https://github.com/madsmtm/core-foundation-rs.git", rev = "7d593d016175755e492a92ef89edca68ac3bd5cd" }
+core-graphics = { git = "https://github.com/madsmtm/core-foundation-rs.git", rev = "7d593d016175755e492a92ef89edca68ac3bd5cd" }
 dispatch = "0.2.0"
 infer = { version = "0.15", optional = true }
 lazy_static = "1.4.0"
 libc = "0.2"
-objc = "0.2.7"
-objc_id = "0.1.1"
 os_info = "3.0.1"
 url = "2.1.1"
 uuid = { version = "1.1", features = ["v4"], optional = true }

examples/browser/toolbar.rs

@@ -1,4 +1,4 @@
-use cacao::objc::{msg_send, sel, sel_impl};
+use cacao::objc::{msg_send, sel};
 
 use cacao::button::Button;
 use cacao::input::{TextField, TextFieldDelegate};
@@ -35,12 +35,12 @@ impl BrowserToolbar {
         let back_button = Button::new("Back");
         let mut back_item = ToolbarItem::new(BACK_BUTTON);
         back_item.set_button(back_button);
-        back_item.set_action(|| Action::Back.dispatch());
+        back_item.set_action(|_| Action::Back.dispatch());
 
         let forwards_button = Button::new("Forwards");
         let mut forwards_item = ToolbarItem::new(FWDS_BUTTON);
         forwards_item.set_button(forwards_button);
-        forwards_item.set_action(|| Action::Forwards.dispatch());
+        forwards_item.set_action(|_| Action::Forwards.dispatch());
 
         let url_bar = TextField::with(URLBar);
         let url_bar_item = ToolbarItem::new(URL_BAR);

src/appkit/alert.rs

@@ -24,16 +24,16 @@
 //! }
 //! ```
 
+use objc::rc::{Id, Owned};
 use objc::runtime::Object;
-use objc::{class, msg_send, sel, sel_impl};
-use objc_id::Id;
+use objc::{class, msg_send, msg_send_id, sel};
 
 use crate::foundation::{id, NSString};
 
 /// Represents an `NSAlert`. Has no information other than the retained pointer to the Objective C
 /// side, so... don't bother inspecting this.
 #[derive(Debug)]
-pub struct Alert(Id<Object>);
+pub struct Alert(Id<Object, Owned>);
 
 impl Alert {
     /// Creates a basic `NSAlert`, storing a pointer to it in the Objective C runtime.
@@ -44,11 +44,11 @@ impl Alert {
         let ok = NSString::new("OK");
 
         Alert(unsafe {
-            let alert: id = msg_send![class!(NSAlert), new];
-            let _: () = msg_send![alert, setMessageText: title];
-            let _: () = msg_send![alert, setInformativeText: message];
-            let _: () = msg_send![alert, addButtonWithTitle: ok];
-            Id::from_ptr(alert)
+            let mut alert = msg_send_id![class!(NSAlert), new];
+            let _: () = msg_send![&mut alert, setMessageText: &*title];
+            let _: () = msg_send![&mut alert, setInformativeText: &*message];
+            let _: () = msg_send![&mut alert, addButtonWithTitle: &*ok];
+            alert
         })
     }
 

src/appkit/animation.rs

@@ -1,5 +1,5 @@
 use block::ConcreteBlock;
-use objc::{class, msg_send, sel, sel_impl};
+use objc::{class, msg_send, sel};
 
 use crate::foundation::id;
 
@@ -39,7 +39,7 @@ impl AnimationContext {
 
         unsafe {
             //let context: id = msg_send![class!(NSAnimationContext), currentContext];
-            let _: () = msg_send![class!(NSAnimationContext), runAnimationGroup: block];
+            let _: () = msg_send![class!(NSAnimationContext), runAnimationGroup: &*block];
         }
     }
 
@@ -66,8 +66,11 @@ impl AnimationContext {
 
         unsafe {
             //let context: id = msg_send![class!(NSAnimationContext), currentContext];
-            let _: () = msg_send![class!(NSAnimationContext), runAnimationGroup:block
-                completionHandler:completion_block];
+            let _: () = msg_send![
+                class!(NSAnimationContext),
+                runAnimationGroup: &*block,
+                completionHandler: &*completion_block,
+            ];
         }
     }
 }

src/appkit/app/class.rs

@@ -7,6 +7,6 @@ use objc::runtime::Class;
 use crate::foundation::load_or_register_class;
 
 /// Used for injecting a custom NSApplication. Currently does nothing.
-pub(crate) fn register_app_class() -> *const Class {
+pub(crate) fn register_app_class() -> &'static Class {
     load_or_register_class("NSApplication", "RSTApplication", |decl| unsafe {})
 }