Merge pull request #79 from MerlinDE/fix_register_class

Fixes possible duplicate objc class registration.

examples/popover.rs

@@ -15,35 +15,29 @@ use cacao::text::{Font, Label};
 use cacao::view::{Popover, PopoverConfig, View, ViewController, ViewDelegate};
 
 struct BasicApp {
-    window: WindowController<MyWindow>,
+    window: WindowController<MyWindow>
 }
 
 impl AppDelegate for BasicApp {
     fn did_finish_launching(&self) {
         App::set_menu(vec![
-            Menu::new(
+            Menu::new("", vec![
-                "",
+                MenuItem::Services,
-                vec![
+                MenuItem::Separator,
-                    MenuItem::Services,
+                MenuItem::Hide,
-                    MenuItem::Separator,
+                MenuItem::HideOthers,
-                    MenuItem::Hide,
+                MenuItem::ShowAll,
-                    MenuItem::HideOthers,
+                MenuItem::Separator,
-                    MenuItem::ShowAll,
+                MenuItem::Quit,
-                    MenuItem::Separator,
+            ]),
-                    MenuItem::Quit,
-                ],
-            ),
             Menu::new("File", vec![MenuItem::CloseWindow]),
             Menu::new("View", vec![MenuItem::EnterFullScreen]),
-            Menu::new(
+            Menu::new("Window", vec![
-                "Window",
+                MenuItem::Minimize,
-                vec![
+                MenuItem::Zoom,
-                    MenuItem::Minimize,
+                MenuItem::Separator,
-                    MenuItem::Zoom,
+                MenuItem::new("Bring All to Front"),
-                    MenuItem::Separator,
+            ]),
-                    MenuItem::new("Bring All to Front"),
-                ],
-            ),
         ]);
 
         App::activate();
@@ -58,7 +52,7 @@ impl AppDelegate for BasicApp {
 
 #[derive(Default)]
 struct MyWindow {
-    controller: Option<ViewController<PopoverExampleContentView>>,
+    controller: Option<ViewController<PopoverExampleContentView>>
 }
 
 impl WindowDelegate for MyWindow {
@@ -87,25 +81,22 @@ impl MyWindow {
 }
 
 fn main() {
-    App::new(
+    App::new("com.test.window-delegate", BasicApp {
-        "com.test.window-delegate",
+        window: WindowController::with(WindowConfig::default(), MyWindow::default())
-        BasicApp {
+    })
-            window: WindowController::with(WindowConfig::default(), MyWindow::default()),
-        },
-    )
     .run();
 }
 
 #[derive(Clone, Debug)]
 pub enum Msg {
-    Click,
+    Click
 }
 
 #[derive(Debug, Default)]
 struct PopoverExampleContentView {
     view: Option<View>,
     button: Option<Button>,
-    popover: Option<Popover<PopoverExampleContentViewController>>,
+    popover: Option<Popover<PopoverExampleContentViewController>>
 }
 
 impl PopoverExampleContentView {
@@ -113,7 +104,7 @@ impl PopoverExampleContentView {
         Self {
             view: None,
             button: None,
-            popover: None,
+            popover: None
         }
     }
 
@@ -123,7 +114,7 @@ impl PopoverExampleContentView {
                 let Some(ref popover) = self.popover else { return };
                 let Some(ref button) = self.button else { return };
                 popover.show_popover(Rect::zero(), button, Edge::MaxY);
-            },
+            }
         }
     }
 }
@@ -147,7 +138,7 @@ impl ViewDelegate for PopoverExampleContentView {
 
         LayoutConstraint::activate(&[
             button.center_x.constraint_equal_to(&view.center_x),
-            button.center_y.constraint_equal_to(&view.center_y),
+            button.center_y.constraint_equal_to(&view.center_y)
         ]);
 
         self.view = Some(view);
@@ -173,7 +164,7 @@ impl Dispatcher for BasicApp {
 
 #[derive(Debug)]
 struct PopoverExampleContentViewController {
-    pub label: Label,
+    pub label: Label
 }
 
 impl PopoverExampleContentViewController {

src/appkit/app/class.rs

@@ -2,22 +2,11 @@
 //! creates a custom `NSApplication` subclass that currently does nothing; this is meant as a hook
 //! for potential future use.
 
-use std::sync::Once;
-
-use objc::class;
-use objc::declare::ClassDecl;
 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 {
-    static mut APP_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSApplication", "RSTApplication", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSApplication);
-        let decl = ClassDecl::new("RSTApplication", superclass).unwrap();
-        APP_CLASS = decl.register();
-    });
-
-    unsafe { APP_CLASS }
 }

src/appkit/app/delegate.rs

@@ -3,24 +3,19 @@
 //! for potential future use.
 
 use std::ffi::c_void;
-use std::sync::Once;
 
 use block::Block;
-
-use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel};
-use objc::{class, msg_send, sel, sel_impl};
+use objc::{msg_send, sel, sel_impl};
-
 use url::Url;
 
 use crate::appkit::app::{AppDelegate, APP_PTR};
 use crate::appkit::printing::PrintSettings;
-use crate::error::Error;
-use crate::foundation::{id, nil, to_bool, NSArray, NSString, NSUInteger, BOOL, NO, YES};
-use crate::user_activity::UserActivity;
-
 #[cfg(feature = "cloudkit")]
 use crate::cloudkit::share::CKShareMetaData;
+use crate::error::Error;
+use crate::foundation::{id, load_or_register_class, nil, to_bool, NSArray, NSString, NSUInteger, BOOL, NO, YES};
+use crate::user_activity::UserActivity;
 
 /// A handy method for grabbing our `AppDelegate` from the pointer. This is different from our
 /// standard `utils` version as this doesn't require `RefCell` backing.
@@ -295,13 +290,7 @@ extern "C" fn delegate_handles_key<T: AppDelegate>(this: &Object, _: Sel, _: id,
 /// Registers an `NSObject` application delegate, and configures it for the various callbacks and
 /// pointers we need to have.
 pub(crate) fn register_app_delegate_class<T: AppDelegate + AppDelegate>() -> *const Class {
-    static mut DELEGATE_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSObject", "RSTAppDelegate", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSObject);
-        let mut decl = ClassDecl::new("RSTAppDelegate", superclass).unwrap();
-
         decl.add_ivar::<usize>(APP_PTR);
 
         // Launching Applications
@@ -461,9 +450,5 @@ pub(crate) fn register_app_delegate_class<T: AppDelegate + AppDelegate>() -> *co
             sel!(application:delegateHandlesKey:),
             delegate_handles_key::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
         );
-
+    })
-        DELEGATE_CLASS = decl.register();
-    });
-
-    unsafe { DELEGATE_CLASS }
 }

src/appkit/menu/item.rs

@@ -3,16 +3,13 @@
 //! now.
 
 use std::fmt;
-use std::sync::Once;
 
-use block::ConcreteBlock;
-use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel};
 use objc::{class, msg_send, sel, sel_impl};
 use objc_id::Id;
 
 use crate::events::EventModifierFlag;
-use crate::foundation::{id, nil, NSString, NSUInteger};
+use crate::foundation::{id, load_or_register_class, NSString, NSUInteger};
 
 static BLOCK_PTR: &'static str = "cacaoMenuItemBlockPtr";
 
@@ -314,19 +311,10 @@ extern "C" fn fire_block_action(this: &Object, _: Sel, _item: id) {
 /// In general, we do not want to do more than we need to here - menus are one of the last areas
 /// where Carbon still lurks, and subclassing things can get weird.
 pub(crate) fn register_menu_item_class() -> *const Class {
-    static mut APP_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSMenuItem", "CacaoMenuItem", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSMenuItem);
-        let mut decl = ClassDecl::new("CacaoMenuItem", superclass).unwrap();
         decl.add_ivar::<usize>(BLOCK_PTR);
 
         decl.add_method(sel!(dealloc), dealloc_cacao_menuitem as extern "C" fn(&Object, _));
         decl.add_method(sel!(fireBlockAction:), fire_block_action as extern "C" fn(&Object, _, id));
-
+    })
-        APP_CLASS = decl.register();
-    });
-
-    unsafe { APP_CLASS }
 }

src/appkit/window/controller/class.rs

@@ -1,26 +1,15 @@
 //! Everything useful for the `WindowController`. Handles injecting an `NSWindowController` subclass
 //! into the Objective C runtime, which loops back to give us lifecycle methods.
 
-use std::sync::Once;
-
-use objc::class;
-use objc::declare::ClassDecl;
 use objc::runtime::Class;
 
 use crate::appkit::window::{WindowDelegate, WINDOW_DELEGATE_PTR};
+use crate::foundation::load_or_register_class;
 
 /// Injects an `NSWindowController` subclass, with some callback and pointer ivars for what we
 /// need to do.
 pub(crate) fn register_window_controller_class<T: WindowDelegate>() -> *const Class {
-    static mut DELEGATE_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSWindowController", "RSTWindowController", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSWindowController);
-        let mut decl = ClassDecl::new("RSTWindowController", superclass).unwrap();
         decl.add_ivar::<usize>(WINDOW_DELEGATE_PTR);
-        DELEGATE_CLASS = decl.register();
+    })
-    });
-
-    unsafe { DELEGATE_CLASS }
 }

src/appkit/window/mod.rs

@@ -110,14 +110,14 @@ impl Window {
 
         Window {
             objc: objc,
-            delegate: None,
+            delegate: None
         }
     }
 
     pub(crate) unsafe fn existing(window: *mut Object) -> Window {
         Window {
             objc: ShareId::from_ptr(window),
-            delegate: None,
+            delegate: None
         }
     }
 }

src/button/mod.rs

@@ -21,36 +21,28 @@
 //! my_view.add_subview(&button);
 //! ```
 
-use std::fmt;
+use objc::runtime::{Class, Object};
-use std::sync::Once;
+use objc::{msg_send, sel, sel_impl};
-
-use std::cell::RefCell;
-use std::rc::Rc;
-
-use objc::declare::ClassDecl;
-use objc::runtime::{Class, Object, Sel};
-use objc::{class, msg_send, sel, sel_impl};
 use objc_id::ShareId;
 
+pub use enums::*;
+
+#[cfg(feature = "appkit")]
+use crate::appkit::FocusRingType;
 use crate::color::Color;
 use crate::control::Control;
-use crate::foundation::{id, nil, NSString, NSUInteger, BOOL, NO, YES};
+use crate::foundation::{id, load_or_register_class, nil, NSString, NSUInteger, NO, YES};
 use crate::image::Image;
 use crate::invoker::TargetActionHandler;
 use crate::keys::Key;
 use crate::layout::Layout;
-use crate::objc_access::ObjcAccess;
-use crate::text::{AttributedString, Font};
-use crate::utils::{load, properties::ObjcProperty};
-
 #[cfg(feature = "autolayout")]
 use crate::layout::{LayoutAnchorDimension, LayoutAnchorX, LayoutAnchorY};
-
+use crate::objc_access::ObjcAccess;
-#[cfg(feature = "appkit")]
+use crate::text::{AttributedString, Font};
-use crate::appkit::FocusRingType;
+use crate::utils::properties::ObjcProperty;
 
 mod enums;
-pub use enums::*;
 
 /// Wraps `NSButton` on appkit, and `UIButton` on iOS and tvOS.
 ///
@@ -313,6 +305,7 @@ impl ObjcAccess for Button {
 }
 
 impl Layout for Button {}
+
 impl Control for Button {}
 
 impl ObjcAccess for &Button {
@@ -326,6 +319,7 @@ impl ObjcAccess for &Button {
 }
 
 impl Layout for &Button {}
+
 impl Control for &Button {}
 
 impl Drop for Button {
@@ -343,14 +337,5 @@ impl Drop for Button {
 /// Registers an `NSButton` subclass, and configures it to hold some ivars
 /// for various things we need to store.
 fn register_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSButton", "RSTButton", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSButton);
-        let decl = ClassDecl::new("RSTButton", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/color/appkit_dynamic_color.rs

@@ -10,16 +10,11 @@
 //! that enables this functionality, we want to be able to provide this with some level of
 //! backwards compatibility for Mojave, as that's still a supported OS.
 
-use std::os::raw::c_void;
-use std::sync::Once;
-
 use core_graphics::base::CGFloat;
-
+use objc::runtime::{Class, Object, Sel};
-use objc::declare::ClassDecl;
-use objc::runtime::{Class, Object, Sel, BOOL};
 use objc::{class, msg_send, sel, sel_impl};
 
-use crate::foundation::{id, nil, NSArray, NSInteger, NSString, NSUInteger, NO, YES};
+use crate::foundation::{id, load_or_register_class, nil, NSArray, NSInteger};
 use crate::utils::os;
 
 pub(crate) const AQUA_LIGHT_COLOR_NORMAL_CONTRAST: &'static str = "AQUA_LIGHT_COLOR_NORMAL_CONTRAST";
@@ -259,13 +254,7 @@ extern "C" fn color_with_system_effect(this: &Object, _: Sel, effect: NSInteger)
 }
 
 pub(crate) fn register_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSColor", "CacaoDynamicColor", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSColor);
-        let mut decl = ClassDecl::new("CacaoDynamicColor", superclass).unwrap();
-
         // These methods all need to be forwarded, so let's hook them up.
         decl.add_method(sel!(colorSpace), color_space as extern "C" fn(&Object, _) -> id);
         decl.add_method(
@@ -359,9 +348,5 @@ pub(crate) fn register_class() -> *const Class {
         decl.add_ivar::<id>(AQUA_LIGHT_COLOR_HIGH_CONTRAST);
         decl.add_ivar::<id>(AQUA_DARK_COLOR_NORMAL_CONTRAST);
         decl.add_ivar::<id>(AQUA_DARK_COLOR_HIGH_CONTRAST);
-
+    })
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/geometry.rs

@@ -47,7 +47,7 @@ pub enum Edge {
     MinX = 0,
     MinY = 1,
     MaxX = 2,
-    MaxY = 3,
+    MaxY = 3
 }
 impl From<Rect> for CGRect {
     fn from(rect: Rect) -> CGRect {

src/image/appkit.rs

@@ -7,33 +7,15 @@
 //! for in the modern era. It also implements a few helpers for things like setting a background
 //! color, and enforcing layer backing by default.
 
-use std::sync::Once;
+use objc::runtime::Class;
 
-use objc::declare::ClassDecl;
+use crate::foundation::load_or_register_class;
-use objc::runtime::{Class, Object, Sel, BOOL};
-use objc::{class, sel, sel_impl};
-use objc_id::Id;
-
-use crate::dragdrop::DragInfo;
-use crate::foundation::{id, NSUInteger, NO, YES};
-use crate::utils::load;
-use crate::view::{ViewDelegate, VIEW_DELEGATE_PTR};
 
 /// Injects an `NSView` subclass. This is used for the default views that don't use delegates - we
 /// have separate classes here since we don't want to waste cycles on methods that will never be
 /// used if there's no delegates.
 pub(crate) fn register_image_view_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSImageView", "RSTImageView", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSImageView);
-        let decl = ClassDecl::new("RSTImageView", superclass).unwrap();
-
         //decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
-
+    })
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/image/uikit.rs

@@ -1,26 +1,10 @@
-use std::sync::Once;
+use objc::runtime::Class;
 
-use objc::declare::ClassDecl;
+use crate::foundation::load_or_register_class;
-use objc::runtime::{Class, Object, Sel, BOOL};
-use objc::{class, sel, sel_impl};
-use objc_id::Id;
-
-use crate::foundation::{id, NSUInteger, NO, YES};
-use crate::utils::load;
-use crate::view::{ViewDelegate, VIEW_DELEGATE_PTR};
 
 /// Injects an `NSView` subclass. This is used for the default views that don't use delegates - we
 /// have separate classes here since we don't want to waste cycles on methods that will never be
 /// used if there's no delegates.
 pub(crate) fn register_image_view_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("UIImageView", "RSTImageView", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIImageView);
-        let mut decl = ClassDecl::new("RSTImageView", superclass).expect("Failed to get RSTVIEW");
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/input/appkit.rs

@@ -1,12 +1,7 @@
-use std::sync::Once;
-
-use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel, BOOL};
-use objc::{class, msg_send, sel, sel_impl};
+use objc::{msg_send, sel, sel_impl};
-use objc_id::Id;
 
-use crate::dragdrop::DragInfo;
+use crate::foundation::{id, load_or_register_class, NSString, NO, YES};
-use crate::foundation::{id, load_or_register_class, NSString, NSUInteger, NO, YES};
 use crate::input::{TextFieldDelegate, TEXTFIELD_DELEGATE_PTR};
 use crate::utils::load;
 
@@ -52,16 +47,7 @@ extern "C" fn text_should_end_editing<T: TextFieldDelegate>(this: &mut Object, _
 /// have separate classes here since we don't want to waste cycles on methods that will never be
 /// used if there's no delegates.
 pub(crate) fn register_view_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSTextField", "RSTTextInputField", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSTextField);
-        let decl = ClassDecl::new("RSTTextInputField", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }
 
 /// Injects an `NSTextField` subclass, with some callback and pointer ivars for what we

src/invoker.rs

@@ -9,15 +9,12 @@
 //! is going away.
 
 use std::fmt;
-use std::sync::{Arc, Mutex, Once};
 
-use block::{Block, ConcreteBlock, RcBlock};
-use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel};
-use objc::{class, msg_send, sel, sel_impl};
+use objc::{msg_send, sel, sel_impl};
 use objc_id::ShareId;
 
-use crate::foundation::{id, nil, NSString};
+use crate::foundation::{id, load_or_register_class};
 use crate::utils::load;
 
 pub static ACTION_CALLBACK_PTR: &str = "rstTargetActionPtr";
@@ -95,18 +92,8 @@ extern "C" fn perform<F: Fn() + 'static>(this: &mut Object, _: Sel, _sender: id)
 /// on drop. We handle the heap copy on the Rust side, so setting the block
 /// is just an ivar.
 pub(crate) fn register_invoker_class<F: Fn() + 'static>() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSObject", "RSTTargetActionHandler", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSObject);
-        let mut decl = ClassDecl::new("RSTTargetActionHandler", superclass).unwrap();
-
         decl.add_ivar::<usize>(ACTION_CALLBACK_PTR);
         decl.add_method(sel!(perform:), perform::<F> as extern "C" fn(&mut Object, _, id));
-
+    })
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/listview/appkit.rs

@@ -7,16 +7,13 @@
 //! for in the modern era. It also implements a few helpers for things like setting a background
 //! color, and enforcing layer backing by default.
 
-use std::sync::Once;
-
-use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel, BOOL};
-use objc::{class, msg_send, sel, sel_impl};
+use objc::{msg_send, sel, sel_impl};
 use objc_id::Id;
 
-use crate::appkit::menu::{Menu, MenuItem};
+use crate::appkit::menu::Menu;
 use crate::dragdrop::DragInfo;
-use crate::foundation::{id, load_or_register_class, nil, NSArray, NSInteger, NSUInteger, NO, YES};
+use crate::foundation::{id, load_or_register_class, NSArray, NSInteger, NSUInteger, NO, YES};
 use crate::listview::{ListViewDelegate, RowEdge, LISTVIEW_DELEGATE_PTR};
 use crate::utils::load;
 
@@ -185,16 +182,7 @@ extern "C" fn dragging_exited<T: ListViewDelegate>(this: &mut Object, _: Sel, in
 /// `UITableView` semantics; if `NSTableView`'s multi column behavior is needed, then it can
 /// be added in.
 pub(crate) fn register_listview_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSTableView", "RSTListView", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSTableView);
-        let decl = ClassDecl::new("RSTListView", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }
 
 /// Injects an `NSTableView` subclass, with some callback and pointer ivars for what we

src/listview/row/appkit.rs

@@ -7,15 +7,12 @@
 //! for in the modern era. It also implements a few helpers for things like setting a background
 //! color, and enforcing layer backing by default.
 
-use std::sync::Once;
-
-use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel, BOOL};
 use objc::{class, msg_send, sel, sel_impl};
 use objc_id::Id;
 
 use crate::dragdrop::DragInfo;
-use crate::foundation::{id, nil, NSUInteger, NO, YES};
+use crate::foundation::{id, load_or_register_class, nil, NSUInteger, NO, YES};
 use crate::listview::row::{ViewDelegate, BACKGROUND_COLOR, LISTVIEW_ROW_DELEGATE_PTR};
 use crate::utils::load;
 
@@ -107,31 +104,15 @@ extern "C" fn dealloc<T: ViewDelegate>(this: &Object, _: Sel) {
 /// have separate classes here since we don't want to waste cycles on methods that will never be
 /// used if there's no delegates.
 pub(crate) fn register_listview_row_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSView", "RSTTableViewRow", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSView);
-        let mut decl = ClassDecl::new("RSTTableViewRow", superclass).unwrap();
-
         decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
-
+    })
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }
 
 /// Injects an `NSView` subclass, with some callback and pointer ivars for what we
 /// need to do.
 pub(crate) fn register_listview_row_class_with_delegate<T: ViewDelegate>() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSView", "RSTableViewRowWithDelegate", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSView);
-        let mut decl = ClassDecl::new("RSTableViewRowWithDelegate", superclass).unwrap();
-
         // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
         // move.
         decl.add_ivar::<usize>(LISTVIEW_ROW_DELEGATE_PTR);
@@ -164,9 +145,5 @@ pub(crate) fn register_listview_row_class_with_delegate<T: ViewDelegate>() -> *c
 
         // Cleanup
         decl.add_method(sel!(dealloc), dealloc::<T> as extern "C" fn(&Object, _));
-
+    })
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/listview/row/uikit.rs

@@ -1,45 +1,24 @@
-use std::sync::Once;
-
 use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel, BOOL};
 use objc::{class, sel, sel_impl};
 use objc_id::Id;
 
-use crate::foundation::{id, YES, NO, NSUInteger};
 use crate::dragdrop::DragInfo;
-use crate::view::{VIEW_DELEGATE_PTR, ViewDelegate};
+use crate::foundation::{id, NSUInteger, NO, YES};
 use crate::utils::load;
+use crate::view::{ViewDelegate, VIEW_DELEGATE_PTR};
 
 /// Injects an `NSView` subclass. This is used for the default views that don't use delegates - we
 /// have separate classes here since we don't want to waste cycles on methods that will never be
 /// used if there's no delegates.
 pub(crate) fn register_view_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("UIView", "RSTView", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIView);
-        let mut decl = ClassDecl::new("RSTView", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }
 
 /// Injects an `NSView` subclass, with some callback and pointer ivars for what we
 /// need to do.
 pub(crate) fn register_view_class_with_delegate<T: ViewDelegate>() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("UIView", "RSTViewWithDelegate", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIView);
-        let mut decl = ClassDecl::new("RSTViewWithDelegate", superclass).unwrap();
         decl.add_ivar::<usize>(VIEW_DELEGATE_PTR);
-        VIEW_CLASS = decl.register();
+    })
-    });
-
-    unsafe {
-        VIEW_CLASS
-    }
 }

src/scrollview/appkit.rs

@@ -7,15 +7,12 @@
 //! for in the modern era. It also implements a few helpers for things like setting a background
 //! color, and enforcing layer backing by default.
 
-use std::sync::Once;
-
-use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel, BOOL};
-use objc::{class, sel, sel_impl};
+use objc::{sel, sel_impl};
 use objc_id::Id;
 
 use crate::dragdrop::DragInfo;
-use crate::foundation::{id, NSUInteger, NO, YES};
+use crate::foundation::{id, load_or_register_class, NSUInteger, NO, YES};
 use crate::scrollview::{ScrollViewDelegate, SCROLLVIEW_DELEGATE_PTR};
 use crate::utils::load;
 
@@ -77,28 +74,13 @@ extern "C" fn dragging_exited<T: ScrollViewDelegate>(this: &mut Object, _: Sel,
 
 /// Injects an `NSScrollView` subclass.
 pub(crate) fn register_scrollview_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSScrollView", "RSTScrollView", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSScrollView);
-        let decl = ClassDecl::new("RSTScrollView", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }
 
 /// Injects an `NSView` subclass, with some callback and pointer ivars for what we
 /// need to do.
 pub(crate) fn register_scrollview_class_with_delegate<T: ScrollViewDelegate>() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSScrollView", "RSTScrollViewWithDelegate", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSScrollView);
-        let mut decl = ClassDecl::new("RSTScrollViewWithDelegate", superclass).unwrap();
-
         // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
         // move.
         decl.add_ivar::<usize>(SCROLLVIEW_DELEGATE_PTR);
@@ -126,9 +108,5 @@ pub(crate) fn register_scrollview_class_with_delegate<T: ScrollViewDelegate>() -
             sel!(draggingExited:),
             dragging_exited::<T> as extern "C" fn(&mut Object, _, _)
         );
-
+    })
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/select/mod.rs

@@ -1,24 +1,19 @@
 //! Implements a Select-style dropdown. By default this uses NSPopupSelect on macOS.
 
-use std::sync::Once;
-
 use core_graphics::geometry::CGRect;
-
+use objc::runtime::{Class, Object};
-use objc::declare::ClassDecl;
+use objc::{msg_send, sel, sel_impl};
-use objc::runtime::{Class, Object, Sel};
-use objc::{class, msg_send, sel, sel_impl};
 use objc_id::ShareId;
 
 use crate::control::Control;
-use crate::foundation::{id, nil, NSInteger, NSString, NO, YES};
+use crate::foundation::{id, load_or_register_class, nil, NSInteger, NSString, NO, YES};
 use crate::geometry::Rect;
 use crate::invoker::TargetActionHandler;
 use crate::layout::Layout;
-use crate::objc_access::ObjcAccess;
-use crate::utils::properties::ObjcProperty;
-
 #[cfg(feature = "autolayout")]
 use crate::layout::{LayoutAnchorDimension, LayoutAnchorX, LayoutAnchorY};
+use crate::objc_access::ObjcAccess;
+use crate::utils::properties::ObjcProperty;
 
 /// Wraps `NSPopUpSelect` on AppKit. Not currently implemented for iOS.
 ///
@@ -268,14 +263,5 @@ impl Drop for Select {
 /// Registers an `NSSelect` subclass, and configures it to hold some ivars
 /// for various things we need to store.
 fn register_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSPopUpButton", "CacaoSelect", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSPopUpButton);
-        let decl = ClassDecl::new("CacaoSelect", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/switch.rs

@@ -1,22 +1,17 @@
 //! A wrapper for NSSwitch. Currently the epitome of jank - if you're poking around here, expect
 //! that this will change at some point.
 
-use std::fmt;
+use objc::runtime::{Class, Object};
-use std::sync::Once;
+use objc::{msg_send, sel, sel_impl};
-
-use objc::declare::ClassDecl;
-use objc::runtime::{Class, Object, Sel};
-use objc::{class, msg_send, sel, sel_impl};
 use objc_id::ShareId;
 
-use crate::foundation::{id, nil, NSString, BOOL, NO, YES};
+use crate::foundation::{id, load_or_register_class, nil, NSString, NO};
 use crate::invoker::TargetActionHandler;
 use crate::layout::Layout;
-use crate::objc_access::ObjcAccess;
-use crate::utils::{load, properties::ObjcProperty};
-
 #[cfg(feature = "autolayout")]
 use crate::layout::{LayoutAnchorDimension, LayoutAnchorX, LayoutAnchorY};
+use crate::objc_access::ObjcAccess;
+use crate::utils::properties::ObjcProperty;
 
 /// A wrapper for `NSSwitch`. Holds (retains) pointers for the Objective-C runtime
 /// where our `NSSwitch` lives.
@@ -178,14 +173,5 @@ impl Drop for Switch {
 /// Registers an `NSButton` subclass, and configures it to hold some ivars
 /// for various things we need to store.
 fn register_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSButton", "RSTSwitch", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSButton);
-        let decl = ClassDecl::new("RSTSwitch", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/text/label/appkit.rs

@@ -7,50 +7,24 @@
 //! for in the modern era. It also implements a few helpers for things like setting a background
 //! color, and enforcing layer backing by default.
 
-use std::sync::Once;
+use objc::runtime::Class;
 
-use objc::declare::ClassDecl;
+use crate::foundation::load_or_register_class;
-use objc::runtime::{Class, Object, Sel, BOOL};
-use objc::{class, sel, sel_impl};
-use objc_id::Id;
-
-use crate::dragdrop::DragInfo;
-use crate::foundation::{id, NSUInteger, NO, YES};
 use crate::text::label::{LabelDelegate, LABEL_DELEGATE_PTR};
-use crate::utils::load;
 
 /// Injects an `NSTextField` subclass. This is used for the default views that don't use delegates - we
 /// have separate classes here since we don't want to waste cycles on methods that will never be
 /// used if there's no delegates.
 pub(crate) fn register_view_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSTextField", "RSTTextField", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSTextField);
-        let decl = ClassDecl::new("RSTTextField", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }
 
 /// Injects an `NSTextField` subclass, with some callback and pointer ivars for what we
 /// need to do.
 pub(crate) fn register_view_class_with_delegate<T: LabelDelegate>() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSView", "RSTTextFieldWithDelegate", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSView);
-        let mut decl = ClassDecl::new("RSTTextFieldWithDelegate", superclass).unwrap();
-
         // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
         // move.
         decl.add_ivar::<usize>(LABEL_DELEGATE_PTR);
-
+    })
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }

src/uikit/app/class.rs

@@ -2,22 +2,11 @@
 //! creates a custom `UIApplication` subclass that currently does nothing; this is meant as a hook
 //! for potential future use.
 
-use std::sync::Once;
-
-use objc::class;
-use objc::declare::ClassDecl;
 use objc::runtime::Class;
 
+use crate::foundation::load_or_register_class;
+
 /// Used for injecting a custom UIApplication. Currently does nothing.
 pub(crate) fn register_app_class() -> *const Class {
-    static mut APP_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("UIApplication", "RSTApplication", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIApplication);
-        let decl = ClassDecl::new("RSTApplication", superclass).unwrap();
-        APP_CLASS = decl.register();
-    });
-
-    unsafe { APP_CLASS }
 }

src/uikit/app/delegate.rs

@@ -2,28 +2,20 @@
 //! creates a custom `UIApplication` subclass that currently does nothing; this is meant as a hook
 //! for potential future use.
 
-//use std::ffi::c_void;
+use objc::runtime::{Class, Object, Sel};
-use std::sync::Once;
+use objc::{sel, sel_impl};
+
+//use crate::error::Error;
+use crate::foundation::{id, load_or_register_class, BOOL, YES};
+use crate::uikit::app::{AppDelegate, APP_DELEGATE};
+use crate::uikit::scene::{SceneConnectionOptions, SceneSession};
+
 //use std::unreachable;
 
 //use block::Block;
 
-use objc::declare::ClassDecl;
-use objc::runtime::{Class, Object, Sel};
-use objc::{class, msg_send, sel, sel_impl};
-
-use url::Url;
-
-//use crate::error::Error;
-use crate::foundation::{id, nil, NSArray, NSString, NSUInteger, BOOL, NO, YES};
 //use crate::user_activity::UserActivity;
 
-use crate::uikit::app::{AppDelegate, APP_DELEGATE};
-use crate::uikit::scene::{SceneConfig, SceneConnectionOptions, SceneSession};
-
-#[cfg(feature = "cloudkit")]
-use crate::cloudkit::share::CKShareMetaData;
-
 /// A handy method for grabbing our `AppDelegate` from the pointer. This is different from our
 /// standard `utils` version as this doesn't require `RefCell` backing.
 fn app<T>(this: &Object) -> &T {
@@ -49,13 +41,7 @@ extern "C" fn configuration_for_scene_session<T: AppDelegate>(this: &Object, _:
 /// Registers an `NSObject` application delegate, and configures it for the various callbacks and
 /// pointers we need to have.
 pub(crate) fn register_app_delegate_class<T: AppDelegate>() -> *const Class {
-    static mut DELEGATE_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSObject", "RSTAppDelegate", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSObject);
-        let mut decl = ClassDecl::new("RSTAppDelegate", superclass).unwrap();
-
         // Launching Applications
         decl.add_method(
             sel!(application:didFinishLaunchingWithOptions:),
@@ -71,9 +57,5 @@ pub(crate) fn register_app_delegate_class<T: AppDelegate>() -> *const Class {
             sel!(application:didDiscardSceneSessions:),
             did_discard_scene_sessions::<T> as extern "C" fn(&Object, _, _, id)
         );*/
-
+    })
-        DELEGATE_CLASS = decl.register();
-    });
-
-    unsafe { DELEGATE_CLASS }
 }

src/uikit/scene/delegate.rs

@@ -1,25 +1,10 @@
-use std::ffi::c_void;
+use objc::runtime::{Class, Object, Protocol, Sel};
-use std::sync::Once;
-use std::unreachable;
-
-use block::Block;
-
-use objc::declare::ClassDecl;
-use objc::runtime::{Class, Object, Sel};
 use objc::{class, msg_send, sel, sel_impl};
 
-use url::Url;
+use crate::foundation::{id, load_or_register_class};
-
-use crate::error::Error;
-use crate::foundation::{id, nil, NSArray, NSString, NSUInteger, BOOL, NO, YES};
-use crate::user_activity::UserActivity;
-use crate::utils::load;
-
 use crate::uikit::app::SCENE_DELEGATE_VENDOR;
-use crate::uikit::scene::{Scene, SceneConfig, SceneConnectionOptions, SceneSession, WindowSceneDelegate};
+use crate::uikit::scene::{Scene, SceneConnectionOptions, SceneSession, WindowSceneDelegate};
-
+use crate::utils::load;
-#[cfg(feature = "cloudkit")]
-use crate::cloudkit::share::CKShareMetaData;
 
 pub(crate) static WINDOW_SCENE_PTR: &str = "rstWindowSceneDelegatePtr";
 
@@ -60,14 +45,7 @@ extern "C" fn scene_will_connect_to_session_with_options<T: WindowSceneDelegate>
 /// Registers an `NSObject` application delegate, and configures it for the various callbacks and
 /// pointers we need to have.
 pub(crate) fn register_window_scene_delegate_class<T: WindowSceneDelegate, F: Fn() -> Box<T>>() -> *const Class {
-    static mut DELEGATE_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("UIResponder", "RSTWindowSceneDelegate", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    use objc::runtime::{class_addProtocol, Protocol};
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIResponder);
-        let mut decl = ClassDecl::new("RSTWindowSceneDelegate", superclass).unwrap();
-
         let p = Protocol::get("UIWindowSceneDelegate").unwrap();
 
         // A spot to hold a pointer to
@@ -82,10 +60,5 @@ pub(crate) fn register_window_scene_delegate_class<T: WindowSceneDelegate, F: Fn
             sel!(scene:willConnectToSession:options:),
             scene_will_connect_to_session_with_options::<T> as extern "C" fn(&Object, _, _, _, _)
         );
-
+    })
-        // Launching Applications
-        DELEGATE_CLASS = decl.register();
-    });
-
-    unsafe { DELEGATE_CLASS }
 }

src/view/appkit.rs

@@ -7,8 +7,6 @@
 //! for in the modern era. It also implements a few helpers for things like setting a background
 //! color, and enforcing layer backing by default.
 
-use std::sync::Once;
-
 use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel, BOOL};
 use objc::{class, msg_send, sel, sel_impl};
@@ -92,23 +90,13 @@ extern "C" fn update_layer(this: &Object, _: Sel) {
 /// have separate classes here since we don't want to waste cycles on methods that will never be
 /// used if there's no delegates.
 pub(crate) fn register_view_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("NSView", "RSTView", |decl| unsafe {
-    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!(updateLayer), update_layer as extern "C" fn(&Object, _));
         decl.add_method(sel!(wantsUpdateLayer), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
 
         decl.add_ivar::<id>(BACKGROUND_COLOR);
-
+    })
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }
 
 /// Injects an `NSView` subclass, with some callback and pointer ivars for what we

src/view/popover/mod.rs

@@ -20,14 +20,14 @@ pub enum PopoverBehaviour {
     /// The system will close the popover when the user interacts with a user interface element outside the popover.
     Transient = 1,
     /// The system will close the popover when the user interacts with user interface elements in the window containing the popover's positioning view.
-    Semitransient = 2,
+    Semitransient = 2
 }
 
 #[derive(Debug)]
 pub struct PopoverConfig {
     pub content_size: CGSize,
     pub animates: bool,
-    pub behaviour: PopoverBehaviour,
+    pub behaviour: PopoverBehaviour
 }
 
 impl Default for PopoverConfig {
@@ -35,10 +35,10 @@ impl Default for PopoverConfig {
         Self {
             content_size: CGSize {
                 width: 320.0,
-                height: 320.0,
+                height: 320.0
             },
             animates: true,
-            behaviour: PopoverBehaviour::Transient,
+            behaviour: PopoverBehaviour::Transient
         }
     }
 }
@@ -49,12 +49,12 @@ pub struct Popover<Content> {
     pub objc: ShareId<Object>,
 
     /// The wrapped ViewController.
-    pub view_controller: ViewController<Content>,
+    pub view_controller: ViewController<Content>
 }
 
 impl<Content> Popover<Content>
 where
-    Content: ViewDelegate + 'static,
+    Content: ViewDelegate + 'static
 {
     pub fn new(content: Content, config: PopoverConfig) -> Self {
         let view_controller = ViewController::new(content);

src/view/splitviewcontroller/ios.rs

@@ -1,18 +1,15 @@
-use std::sync::Once;
-use std::unreachable;
-
 use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel};
 use objc::{class, msg_send, sel, sel_impl};
 
-use crate::foundation::{BOOL};
+use crate::foundation::BOOL;
-use crate::view::{VIEW_DELEGATE_PTR, ViewDelegate};
+use crate::utils::{as_bool, load};
-use crate::utils::{load, as_bool};
+use crate::view::{ViewDelegate, VIEW_DELEGATE_PTR};
 
 /// Called when the view controller receives a `viewWillAppear:` message.
 extern "C" fn will_appear<T: ViewDelegate>(this: &mut Object, _: Sel, animated: BOOL) {
     unsafe {
-        let _: () = msg_send![super(this, class!(UIViewController)), viewWillAppear:animated];
+        let _: () = msg_send![super(this, class!(UIViewController)), viewWillAppear: animated];
     }
 
     let controller = load::<T>(this, VIEW_DELEGATE_PTR);
@@ -22,7 +19,7 @@ extern "C" fn will_appear<T: ViewDelegate>(this: &mut Object, _: Sel, animated:
 /// Called when the view controller receives a `viewDidAppear:` message.
 extern "C" fn did_appear<T: ViewDelegate>(this: &mut Object, _: Sel, animated: BOOL) {
     unsafe {
-        let _: () = msg_send![super(this, class!(UIViewController)), viewDidAppear:animated];
+        let _: () = msg_send![super(this, class!(UIViewController)), viewDidAppear: animated];
     }
 
     let controller = load::<T>(this, VIEW_DELEGATE_PTR);
@@ -32,7 +29,7 @@ extern "C" fn did_appear<T: ViewDelegate>(this: &mut Object, _: Sel, animated: B
 /// Called when the view controller receives a `viewWillDisappear:` message.
 extern "C" fn will_disappear<T: ViewDelegate>(this: &mut Object, _: Sel, animated: BOOL) {
     unsafe {
-        let _: () = msg_send![super(this, class!(UIViewController)), viewWillDisappear:animated];
+        let _: () = msg_send![super(this, class!(UIViewController)), viewWillDisappear: animated];
     }
 
     let controller = load::<T>(this, VIEW_DELEGATE_PTR);
@@ -42,7 +39,7 @@ extern "C" fn will_disappear<T: ViewDelegate>(this: &mut Object, _: Sel, animate
 /// Called when the view controller receives a `viewDidDisappear:` message.
 extern "C" fn did_disappear<T: ViewDelegate>(this: &mut Object, _: Sel, animated: BOOL) {
     unsafe {
-        let _: () = msg_send![super(this, class!(UIViewController)), viewDidDisappear:animated];
+        let _: () = msg_send![super(this, class!(UIViewController)), viewDidDisappear: animated];
     }
 
     let controller = load::<T>(this, VIEW_DELEGATE_PTR);
@@ -51,22 +48,18 @@ extern "C" fn did_disappear<T: ViewDelegate>(this: &mut Object, _: Sel, animated
 
 /// Registers an `NSViewDelegate`.
 pub(crate) fn register_view_controller_class<T: ViewDelegate + 'static>() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("UIViewController", "RSTViewController", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIViewController);
-        let mut decl = ClassDecl::new("RSTViewController", superclass).unwrap();
-
         decl.add_ivar::<usize>(VIEW_DELEGATE_PTR);
 
         decl.add_method(sel!(viewWillAppear:), will_appear::<T> as extern "C" fn(&mut Object, _, BOOL));
         decl.add_method(sel!(viewDidAppear:), did_appear::<T> as extern "C" fn(&mut Object, _, BOOL));
-        decl.add_method(sel!(viewWillDisappear:), will_disappear::<T> as extern "C" fn(&mut Object, _, BOOL));
+        decl.add_method(
-        decl.add_method(sel!(viewDidDisappear:), did_disappear::<T> as extern "C" fn(&mut Object, _, BOOL));
+            sel!(viewWillDisappear:),
-
+            will_disappear::<T> as extern "C" fn(&mut Object, _, BOOL)
-        VIEW_CLASS = decl.register();
+        );
-    });
+        decl.add_method(
-
+            sel!(viewDidDisappear:),
-    unsafe { VIEW_CLASS }
+            did_disappear::<T> as extern "C" fn(&mut Object, _, BOOL)
+        );
+    })
 }

src/view/uikit.rs

@@ -1,5 +1,3 @@
-use std::sync::Once;
-
 use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel, BOOL};
 use objc::{class, sel, sel_impl};
@@ -14,16 +12,7 @@ use crate::view::{ViewDelegate, VIEW_DELEGATE_PTR};
 /// have separate classes here since we don't want to waste cycles on methods that will never be
 /// used if there's no delegates.
 pub(crate) fn register_view_class() -> *const Class {
-    static mut VIEW_CLASS: *const Class = 0 as *const Class;
+    load_or_register_class("UIView", "RSTView", |decl| unsafe {})
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIView);
-        let mut decl = ClassDecl::new("RSTView", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe { VIEW_CLASS }
 }
 
 /// Injects a `UIView` subclass, with some callback and pointer ivars for what we

src/webview/process_pool.rs

@@ -4,41 +4,23 @@
 //!
 //! If you use that feature, there are no guarantees you'll be accepted into the App Store.
 
-use std::sync::Once;
-use std::ffi::c_void;
-
 use block::Block;
-
+use cocoa::foundation::{NSArray, NSInteger, NSPoint, NSRect, NSSize, NSString};
-use cocoa::foundation::{NSRect, NSPoint, NSSize, NSString, NSArray, NSInteger};
-
 use objc::declare::ClassDecl;
 use objc::runtime::{Class, Object, Sel, BOOL};
 use objc::{class, msg_send, sel, sel_impl};
 
-use crate::foundation::{id, nil, YES, NO};
+use crate::foundation::{id, nil, NO, YES};
 use crate::webview::traits::WebViewController;
 
 extern "C" fn download_delegate(this: &Object, _: Sel) -> id {
     println!("YO!");
-    unsafe {
+    unsafe { NSString::alloc(nil).init_str("") }
-    NSString::alloc(nil).init_str("")
-    }
 }
 
 pub fn register_process_pool() -> *const Object {
-    static mut PROCESS_POOL: *const Object = 0 as *const Object;
+    load_or_register_class("WKProcessPool", "RSTWebViewProcessPool", |decl| unsafe {
-    static INIT: Once = Once::new();
-
-    INIT.call_once(|| unsafe {
-        let superclass = Class::get("WKProcessPool").unwrap();
-        let mut decl = ClassDecl::new("RSTWebViewProcessPool", superclass).unwrap();
-
         //decl.add_ivar::<id>(DOWNLOAD_DELEGATE_PTR);
         decl.add_method(sel!(_downloadDelegate), download_delegate as extern "C" fn(&Object, _) -> id);
-
+    })
-        //PROCESS_POOL = decl.register();
-        PROCESS_POOL = msg_send![decl.register(), new];
-    });
-
-    unsafe { PROCESS_POOL }
 }