1use crate::{
2 executor,
3 geometry::{
4 rect::RectF,
5 vector::{vec2f, Vector2F},
6 },
7 keymap::Keystroke,
8 platform::{self, Event, WindowBounds, WindowContext},
9 Scene,
10};
11use block::ConcreteBlock;
12use cocoa::{
13 appkit::{
14 CGPoint, NSApplication, NSBackingStoreBuffered, NSScreen, NSView, NSViewHeightSizable,
15 NSViewWidthSizable, NSWindow, NSWindowButton, NSWindowStyleMask,
16 },
17 base::{id, nil},
18 foundation::{NSAutoreleasePool, NSInteger, NSSize, NSString},
19 quartzcore::AutoresizingMask,
20};
21use core_graphics::display::CGRect;
22use ctor::ctor;
23use foreign_types::ForeignType as _;
24use objc::{
25 class,
26 declare::ClassDecl,
27 msg_send,
28 runtime::{Class, Object, Protocol, Sel, BOOL, NO, YES},
29 sel, sel_impl,
30};
31use postage::oneshot;
32use smol::Timer;
33use std::{
34 any::Any,
35 cell::{Cell, RefCell},
36 convert::TryInto,
37 ffi::c_void,
38 mem, ptr,
39 rc::{Rc, Weak},
40 sync::Arc,
41 time::Duration,
42};
43
44use super::{geometry::RectFExt, renderer::Renderer};
45
46const WINDOW_STATE_IVAR: &'static str = "windowState";
47
48static mut WINDOW_CLASS: *const Class = ptr::null();
49static mut VIEW_CLASS: *const Class = ptr::null();
50
51#[allow(non_upper_case_globals)]
52const NSViewLayerContentsRedrawDuringViewResize: NSInteger = 2;
53
54#[ctor]
55unsafe fn build_classes() {
56 WINDOW_CLASS = {
57 let mut decl = ClassDecl::new("GPUIWindow", class!(NSWindow)).unwrap();
58 decl.add_ivar::<*mut c_void>(WINDOW_STATE_IVAR);
59 decl.add_method(sel!(dealloc), dealloc_window as extern "C" fn(&Object, Sel));
60 decl.add_method(
61 sel!(canBecomeMainWindow),
62 yes as extern "C" fn(&Object, Sel) -> BOOL,
63 );
64 decl.add_method(
65 sel!(canBecomeKeyWindow),
66 yes as extern "C" fn(&Object, Sel) -> BOOL,
67 );
68 decl.add_method(
69 sel!(sendEvent:),
70 send_event as extern "C" fn(&Object, Sel, id),
71 );
72 decl.add_method(
73 sel!(windowDidResize:),
74 window_did_resize as extern "C" fn(&Object, Sel, id),
75 );
76 decl.add_method(sel!(close), close_window as extern "C" fn(&Object, Sel));
77 decl.register()
78 };
79
80 VIEW_CLASS = {
81 let mut decl = ClassDecl::new("GPUIView", class!(NSView)).unwrap();
82 decl.add_ivar::<*mut c_void>(WINDOW_STATE_IVAR);
83
84 decl.add_method(sel!(dealloc), dealloc_view as extern "C" fn(&Object, Sel));
85
86 decl.add_method(
87 sel!(keyDown:),
88 handle_view_event as extern "C" fn(&Object, Sel, id),
89 );
90 decl.add_method(
91 sel!(mouseDown:),
92 handle_view_event as extern "C" fn(&Object, Sel, id),
93 );
94 decl.add_method(
95 sel!(mouseUp:),
96 handle_view_event as extern "C" fn(&Object, Sel, id),
97 );
98 decl.add_method(
99 sel!(rightMouseDown:),
100 handle_view_event as extern "C" fn(&Object, Sel, id),
101 );
102 decl.add_method(
103 sel!(rightMouseUp:),
104 handle_view_event as extern "C" fn(&Object, Sel, id),
105 );
106 decl.add_method(
107 sel!(otherMouseDown:),
108 handle_view_event as extern "C" fn(&Object, Sel, id),
109 );
110 decl.add_method(
111 sel!(otherMouseUp:),
112 handle_view_event as extern "C" fn(&Object, Sel, id),
113 );
114 decl.add_method(
115 sel!(mouseMoved:),
116 handle_view_event as extern "C" fn(&Object, Sel, id),
117 );
118 decl.add_method(
119 sel!(mouseDragged:),
120 handle_view_event as extern "C" fn(&Object, Sel, id),
121 );
122 decl.add_method(
123 sel!(scrollWheel:),
124 handle_view_event as extern "C" fn(&Object, Sel, id),
125 );
126 decl.add_method(
127 sel!(cancelOperation:),
128 cancel_operation as extern "C" fn(&Object, Sel, id),
129 );
130
131 decl.add_method(
132 sel!(makeBackingLayer),
133 make_backing_layer as extern "C" fn(&Object, Sel) -> id,
134 );
135
136 decl.add_protocol(Protocol::get("CALayerDelegate").unwrap());
137 decl.add_method(
138 sel!(viewDidChangeBackingProperties),
139 view_did_change_backing_properties as extern "C" fn(&Object, Sel),
140 );
141 decl.add_method(
142 sel!(setFrameSize:),
143 set_frame_size as extern "C" fn(&Object, Sel, NSSize),
144 );
145 decl.add_method(
146 sel!(displayLayer:),
147 display_layer as extern "C" fn(&Object, Sel, id),
148 );
149
150 decl.register()
151 };
152}
153
154pub struct Window(Rc<RefCell<WindowState>>);
155
156struct WindowState {
157 id: usize,
158 native_window: id,
159 event_callback: Option<Box<dyn FnMut(Event)>>,
160 resize_callback: Option<Box<dyn FnMut()>>,
161 close_callback: Option<Box<dyn FnOnce()>>,
162 synthetic_drag_counter: usize,
163 executor: Rc<executor::Foreground>,
164 scene_to_render: Option<Scene>,
165 renderer: Renderer,
166 command_queue: metal::CommandQueue,
167 last_fresh_keydown: Option<(Keystroke, Option<String>)>,
168 layer: id,
169 traffic_light_position: Option<Vector2F>,
170}
171
172impl Window {
173 pub fn open(
174 id: usize,
175 options: platform::WindowOptions,
176 executor: Rc<executor::Foreground>,
177 fonts: Arc<dyn platform::FontSystem>,
178 ) -> Self {
179 const PIXEL_FORMAT: metal::MTLPixelFormat = metal::MTLPixelFormat::BGRA8Unorm;
180
181 unsafe {
182 let pool = NSAutoreleasePool::new(nil);
183
184 let frame = match options.bounds {
185 WindowBounds::Maximized => RectF::new(Default::default(), vec2f(1024., 768.)),
186 WindowBounds::Fixed(rect) => rect,
187 }
188 .to_ns_rect();
189 let mut style_mask = NSWindowStyleMask::NSClosableWindowMask
190 | NSWindowStyleMask::NSMiniaturizableWindowMask
191 | NSWindowStyleMask::NSResizableWindowMask
192 | NSWindowStyleMask::NSTitledWindowMask;
193
194 if options.titlebar_appears_transparent {
195 style_mask |= NSWindowStyleMask::NSFullSizeContentViewWindowMask;
196 }
197
198 let native_window: id = msg_send![WINDOW_CLASS, alloc];
199 let native_window = native_window.initWithContentRect_styleMask_backing_defer_(
200 frame,
201 style_mask,
202 NSBackingStoreBuffered,
203 NO,
204 );
205 assert!(!native_window.is_null());
206
207 if matches!(options.bounds, WindowBounds::Maximized) {
208 let screen = native_window.screen();
209 native_window.setFrame_display_(screen.visibleFrame(), YES);
210 }
211
212 let device =
213 metal::Device::system_default().expect("could not find default metal device");
214
215 let layer: id = msg_send![class!(CAMetalLayer), layer];
216 let _: () = msg_send![layer, setDevice: device.as_ptr()];
217 let _: () = msg_send![layer, setPixelFormat: PIXEL_FORMAT];
218 let _: () = msg_send![layer, setAllowsNextDrawableTimeout: NO];
219 let _: () = msg_send![layer, setNeedsDisplayOnBoundsChange: YES];
220 let _: () = msg_send![layer, setPresentsWithTransaction: YES];
221 let _: () = msg_send![
222 layer,
223 setAutoresizingMask: AutoresizingMask::WIDTH_SIZABLE
224 | AutoresizingMask::HEIGHT_SIZABLE
225 ];
226
227 let native_view: id = msg_send![VIEW_CLASS, alloc];
228 let native_view = NSView::init(native_view);
229 assert!(!native_view.is_null());
230
231 let window = Self(Rc::new(RefCell::new(WindowState {
232 id,
233 native_window,
234 event_callback: None,
235 resize_callback: None,
236 close_callback: None,
237 synthetic_drag_counter: 0,
238 executor,
239 scene_to_render: Default::default(),
240 renderer: Renderer::new(
241 device.clone(),
242 PIXEL_FORMAT,
243 get_scale_factor(native_window),
244 fonts,
245 ),
246 command_queue: device.new_command_queue(),
247 last_fresh_keydown: None,
248 layer,
249 traffic_light_position: options.traffic_light_position,
250 })));
251
252 (*native_window).set_ivar(
253 WINDOW_STATE_IVAR,
254 Rc::into_raw(window.0.clone()) as *const c_void,
255 );
256 native_window.setDelegate_(native_window);
257 (*native_view).set_ivar(
258 WINDOW_STATE_IVAR,
259 Rc::into_raw(window.0.clone()) as *const c_void,
260 );
261
262 if let Some(title) = options.title.as_ref() {
263 native_window.setTitle_(NSString::alloc(nil).init_str(title));
264 }
265 if options.titlebar_appears_transparent {
266 native_window.setTitlebarAppearsTransparent_(YES);
267 }
268 native_window.setAcceptsMouseMovedEvents_(YES);
269
270 native_view.setAutoresizingMask_(NSViewWidthSizable | NSViewHeightSizable);
271 native_view.setWantsBestResolutionOpenGLSurface_(YES);
272
273 // From winit crate: On Mojave, views automatically become layer-backed shortly after
274 // being added to a native_window. Changing the layer-backedness of a view breaks the
275 // association between the view and its associated OpenGL context. To work around this,
276 // on we explicitly make the view layer-backed up front so that AppKit doesn't do it
277 // itself and break the association with its context.
278 native_view.setWantsLayer(YES);
279 let _: () = msg_send![
280 native_view,
281 setLayerContentsRedrawPolicy: NSViewLayerContentsRedrawDuringViewResize
282 ];
283
284 native_window.setContentView_(native_view.autorelease());
285 native_window.makeFirstResponder_(native_view);
286
287 native_window.center();
288 native_window.makeKeyAndOrderFront_(nil);
289
290 window.0.borrow().move_traffic_light();
291 pool.drain();
292
293 window
294 }
295 }
296
297 pub fn key_window_id() -> Option<usize> {
298 unsafe {
299 let app = NSApplication::sharedApplication(nil);
300 let key_window: id = msg_send![app, keyWindow];
301 if msg_send![key_window, isKindOfClass: WINDOW_CLASS] {
302 let id = get_window_state(&*key_window).borrow().id;
303 Some(id)
304 } else {
305 None
306 }
307 }
308 }
309}
310
311impl Drop for Window {
312 fn drop(&mut self) {
313 unsafe {
314 self.0.as_ref().borrow().native_window.close();
315 }
316 }
317}
318
319impl platform::Window for Window {
320 fn as_any_mut(&mut self) -> &mut dyn Any {
321 self
322 }
323
324 fn on_event(&mut self, callback: Box<dyn FnMut(Event)>) {
325 self.0.as_ref().borrow_mut().event_callback = Some(callback);
326 }
327
328 fn on_resize(&mut self, callback: Box<dyn FnMut()>) {
329 self.0.as_ref().borrow_mut().resize_callback = Some(callback);
330 }
331
332 fn on_close(&mut self, callback: Box<dyn FnOnce()>) {
333 self.0.as_ref().borrow_mut().close_callback = Some(callback);
334 }
335
336 fn prompt(
337 &self,
338 level: platform::PromptLevel,
339 msg: &str,
340 answers: &[&str],
341 ) -> oneshot::Receiver<usize> {
342 unsafe {
343 let alert: id = msg_send![class!(NSAlert), alloc];
344 let alert: id = msg_send![alert, init];
345 let alert_style = match level {
346 platform::PromptLevel::Info => 1,
347 platform::PromptLevel::Warning => 0,
348 platform::PromptLevel::Critical => 2,
349 };
350 let _: () = msg_send![alert, setAlertStyle: alert_style];
351 let _: () = msg_send![alert, setMessageText: ns_string(msg)];
352 for (ix, answer) in answers.into_iter().enumerate() {
353 let button: id = msg_send![alert, addButtonWithTitle: ns_string(answer)];
354 let _: () = msg_send![button, setTag: ix as NSInteger];
355 }
356 let (done_tx, done_rx) = oneshot::channel();
357 let done_tx = Cell::new(Some(done_tx));
358 let block = ConcreteBlock::new(move |answer: NSInteger| {
359 if let Some(mut done_tx) = done_tx.take() {
360 let _ = postage::sink::Sink::try_send(&mut done_tx, answer.try_into().unwrap());
361 }
362 });
363 let block = block.copy();
364 let _: () = msg_send![
365 alert,
366 beginSheetModalForWindow: self.0.borrow().native_window
367 completionHandler: block
368 ];
369 done_rx
370 }
371 }
372
373 fn activate(&self) {
374 unsafe {
375 let _: () = msg_send![self.0.borrow().native_window, makeKeyAndOrderFront: nil];
376 }
377 }
378}
379
380impl platform::WindowContext for Window {
381 fn size(&self) -> Vector2F {
382 self.0.as_ref().borrow().size()
383 }
384
385 fn scale_factor(&self) -> f32 {
386 self.0.as_ref().borrow().scale_factor()
387 }
388
389 fn present_scene(&mut self, scene: Scene) {
390 self.0.as_ref().borrow_mut().present_scene(scene);
391 }
392
393 fn titlebar_height(&self) -> f32 {
394 self.0.as_ref().borrow().titlebar_height()
395 }
396}
397
398impl WindowState {
399 fn move_traffic_light(&self) {
400 if let Some(traffic_light_position) = self.traffic_light_position {
401 let titlebar_height = self.titlebar_height();
402
403 unsafe {
404 let close_button: id = msg_send![
405 self.native_window,
406 standardWindowButton: NSWindowButton::NSWindowCloseButton
407 ];
408 let min_button: id = msg_send![
409 self.native_window,
410 standardWindowButton: NSWindowButton::NSWindowMiniaturizeButton
411 ];
412 let zoom_button: id = msg_send![
413 self.native_window,
414 standardWindowButton: NSWindowButton::NSWindowZoomButton
415 ];
416
417 let mut close_button_frame: CGRect = msg_send![close_button, frame];
418 let mut min_button_frame: CGRect = msg_send![min_button, frame];
419 let mut zoom_button_frame: CGRect = msg_send![zoom_button, frame];
420 let mut origin = vec2f(
421 traffic_light_position.x(),
422 titlebar_height
423 - traffic_light_position.y()
424 - close_button_frame.size.height as f32,
425 );
426 let button_spacing =
427 (min_button_frame.origin.x - close_button_frame.origin.x) as f32;
428
429 close_button_frame.origin = CGPoint::new(origin.x() as f64, origin.y() as f64);
430 let _: () = msg_send![close_button, setFrame: close_button_frame];
431 origin.set_x(origin.x() + button_spacing);
432
433 min_button_frame.origin = CGPoint::new(origin.x() as f64, origin.y() as f64);
434 let _: () = msg_send![min_button, setFrame: min_button_frame];
435 origin.set_x(origin.x() + button_spacing);
436
437 zoom_button_frame.origin = CGPoint::new(origin.x() as f64, origin.y() as f64);
438 let _: () = msg_send![zoom_button, setFrame: zoom_button_frame];
439 }
440 }
441 }
442}
443
444impl platform::WindowContext for WindowState {
445 fn size(&self) -> Vector2F {
446 let NSSize { width, height, .. } =
447 unsafe { NSView::frame(self.native_window.contentView()) }.size;
448 vec2f(width as f32, height as f32)
449 }
450
451 fn scale_factor(&self) -> f32 {
452 get_scale_factor(self.native_window)
453 }
454
455 fn titlebar_height(&self) -> f32 {
456 unsafe {
457 let frame = NSWindow::frame(self.native_window);
458 let content_layout_rect: CGRect = msg_send![self.native_window, contentLayoutRect];
459 (frame.size.height - content_layout_rect.size.height) as f32
460 }
461 }
462
463 fn present_scene(&mut self, scene: Scene) {
464 self.scene_to_render = Some(scene);
465 unsafe {
466 let _: () = msg_send![self.native_window.contentView(), setNeedsDisplay: YES];
467 }
468 }
469}
470
471fn get_scale_factor(native_window: id) -> f32 {
472 unsafe {
473 let screen: id = msg_send![native_window, screen];
474 NSScreen::backingScaleFactor(screen) as f32
475 }
476}
477
478unsafe fn get_window_state(object: &Object) -> Rc<RefCell<WindowState>> {
479 let raw: *mut c_void = *object.get_ivar(WINDOW_STATE_IVAR);
480 let rc1 = Rc::from_raw(raw as *mut RefCell<WindowState>);
481 let rc2 = rc1.clone();
482 mem::forget(rc1);
483 rc2
484}
485
486unsafe fn drop_window_state(object: &Object) {
487 let raw: *mut c_void = *object.get_ivar(WINDOW_STATE_IVAR);
488 Rc::from_raw(raw as *mut RefCell<WindowState>);
489}
490
491extern "C" fn yes(_: &Object, _: Sel) -> BOOL {
492 YES
493}
494
495extern "C" fn dealloc_window(this: &Object, _: Sel) {
496 unsafe {
497 drop_window_state(this);
498 let () = msg_send![super(this, class!(NSWindow)), dealloc];
499 }
500}
501
502extern "C" fn dealloc_view(this: &Object, _: Sel) {
503 unsafe {
504 drop_window_state(this);
505 let () = msg_send![super(this, class!(NSView)), dealloc];
506 }
507}
508
509extern "C" fn handle_view_event(this: &Object, _: Sel, native_event: id) {
510 let window_state = unsafe { get_window_state(this) };
511 let weak_window_state = Rc::downgrade(&window_state);
512 let mut window_state_borrow = window_state.as_ref().borrow_mut();
513
514 let event = unsafe { Event::from_native(native_event, Some(window_state_borrow.size().y())) };
515
516 if let Some(event) = event {
517 match &event {
518 Event::LeftMouseDragged { position } => {
519 window_state_borrow.synthetic_drag_counter += 1;
520 window_state_borrow
521 .executor
522 .spawn(synthetic_drag(
523 weak_window_state,
524 window_state_borrow.synthetic_drag_counter,
525 *position,
526 ))
527 .detach();
528 }
529 Event::LeftMouseUp { .. } => {
530 window_state_borrow.synthetic_drag_counter += 1;
531 }
532
533 // Ignore events from held-down keys after some of the initially-pressed keys
534 // were released.
535 Event::KeyDown {
536 input,
537 keystroke,
538 is_held,
539 } => {
540 let keydown = (keystroke.clone(), input.clone());
541 if *is_held {
542 if window_state_borrow.last_fresh_keydown.as_ref() != Some(&keydown) {
543 return;
544 }
545 } else {
546 window_state_borrow.last_fresh_keydown = Some(keydown);
547 }
548 }
549
550 _ => {}
551 }
552
553 if let Some(mut callback) = window_state_borrow.event_callback.take() {
554 drop(window_state_borrow);
555 callback(event);
556 window_state.borrow_mut().event_callback = Some(callback);
557 }
558 }
559}
560
561// Allows us to receive `cmd-.` (the shortcut for closing a dialog)
562// https://bugs.eclipse.org/bugs/show_bug.cgi?id=300620#c6
563extern "C" fn cancel_operation(this: &Object, _sel: Sel, _sender: id) {
564 let window_state = unsafe { get_window_state(this) };
565 let mut window_state_borrow = window_state.as_ref().borrow_mut();
566
567 let chars = ".".to_string();
568 let keystroke = Keystroke {
569 cmd: true,
570 ctrl: false,
571 alt: false,
572 shift: false,
573 key: chars.clone(),
574 };
575 let event = Event::KeyDown {
576 keystroke: keystroke.clone(),
577 input: Some(chars.clone()),
578 is_held: false,
579 };
580
581 window_state_borrow.last_fresh_keydown = Some((keystroke, Some(chars)));
582 if let Some(mut callback) = window_state_borrow.event_callback.take() {
583 drop(window_state_borrow);
584 callback(event);
585 window_state.borrow_mut().event_callback = Some(callback);
586 }
587}
588
589extern "C" fn send_event(this: &Object, _: Sel, native_event: id) {
590 unsafe {
591 let () = msg_send![super(this, class!(NSWindow)), sendEvent: native_event];
592 }
593}
594
595extern "C" fn window_did_resize(this: &Object, _: Sel, _: id) {
596 let window_state = unsafe { get_window_state(this) };
597 window_state.as_ref().borrow().move_traffic_light();
598}
599
600extern "C" fn close_window(this: &Object, _: Sel) {
601 unsafe {
602 let close_callback = {
603 let window_state = get_window_state(this);
604 window_state
605 .as_ref()
606 .try_borrow_mut()
607 .ok()
608 .and_then(|mut window_state| window_state.close_callback.take())
609 };
610
611 if let Some(callback) = close_callback {
612 callback();
613 }
614
615 let () = msg_send![super(this, class!(NSWindow)), close];
616 }
617}
618
619extern "C" fn make_backing_layer(this: &Object, _: Sel) -> id {
620 let window_state = unsafe { get_window_state(this) };
621 let window_state = window_state.as_ref().borrow();
622 window_state.layer
623}
624
625extern "C" fn view_did_change_backing_properties(this: &Object, _: Sel) {
626 let window_state = unsafe { get_window_state(this) };
627 let mut window_state_borrow = window_state.as_ref().borrow_mut();
628
629 unsafe {
630 let _: () = msg_send![window_state_borrow.layer, setContentsScale: window_state_borrow.scale_factor() as f64];
631 }
632
633 if let Some(mut callback) = window_state_borrow.resize_callback.take() {
634 drop(window_state_borrow);
635 callback();
636 window_state.as_ref().borrow_mut().resize_callback = Some(callback);
637 };
638}
639
640extern "C" fn set_frame_size(this: &Object, _: Sel, size: NSSize) {
641 let window_state = unsafe { get_window_state(this) };
642 let mut window_state_borrow = window_state.as_ref().borrow_mut();
643
644 if window_state_borrow.size() == vec2f(size.width as f32, size.height as f32) {
645 return;
646 }
647
648 unsafe {
649 let _: () = msg_send![super(this, class!(NSView)), setFrameSize: size];
650 }
651
652 let scale_factor = window_state_borrow.scale_factor() as f64;
653 let drawable_size: NSSize = NSSize {
654 width: size.width * scale_factor,
655 height: size.height * scale_factor,
656 };
657
658 unsafe {
659 let _: () = msg_send![window_state_borrow.layer, setDrawableSize: drawable_size];
660 }
661
662 if let Some(mut callback) = window_state_borrow.resize_callback.take() {
663 drop(window_state_borrow);
664 callback();
665 window_state.borrow_mut().resize_callback = Some(callback);
666 };
667}
668
669extern "C" fn display_layer(this: &Object, _: Sel, _: id) {
670 unsafe {
671 let window_state = get_window_state(this);
672 let mut window_state = window_state.as_ref().borrow_mut();
673
674 if let Some(scene) = window_state.scene_to_render.take() {
675 let drawable: &metal::MetalDrawableRef = msg_send![window_state.layer, nextDrawable];
676 let command_queue = window_state.command_queue.clone();
677 let command_buffer = command_queue.new_command_buffer();
678
679 let size = window_state.size();
680 let scale_factor = window_state.scale_factor();
681
682 window_state.renderer.render(
683 &scene,
684 size * scale_factor,
685 command_buffer,
686 drawable.texture(),
687 );
688
689 command_buffer.commit();
690 command_buffer.wait_until_completed();
691 drawable.present();
692 };
693 }
694}
695
696async fn synthetic_drag(
697 window_state: Weak<RefCell<WindowState>>,
698 drag_id: usize,
699 position: Vector2F,
700) {
701 loop {
702 Timer::after(Duration::from_millis(16)).await;
703 if let Some(window_state) = window_state.upgrade() {
704 let mut window_state_borrow = window_state.borrow_mut();
705 if window_state_borrow.synthetic_drag_counter == drag_id {
706 if let Some(mut callback) = window_state_borrow.event_callback.take() {
707 drop(window_state_borrow);
708 callback(Event::LeftMouseDragged { position });
709 window_state.borrow_mut().event_callback = Some(callback);
710 }
711 } else {
712 break;
713 }
714 }
715 }
716}
717
718unsafe fn ns_string(string: &str) -> id {
719 NSString::alloc(nil).init_str(string).autorelease()
720}