window.rs

   1use super::{ns_string, renderer, MacDisplay, NSRange};
   2use crate::{
   3    platform::PlatformInputHandler, point, px, size, AnyWindowHandle, Bounds, DevicePixels,
   4    DisplayLink, ExternalPaths, FileDropEvent, ForegroundExecutor, KeyDownEvent, Keystroke,
   5    Modifiers, ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent,
   6    Pixels, PlatformAtlas, PlatformDisplay, PlatformInput, PlatformWindow, Point, PromptLevel,
   7    Size, Timer, WindowAppearance, WindowBackgroundAppearance, WindowBounds, WindowKind,
   8    WindowParams,
   9};
  10use block::ConcreteBlock;
  11use cocoa::{
  12    appkit::{
  13        CGPoint, NSApplication, NSBackingStoreBuffered, NSColor, NSEvent, NSEventModifierFlags,
  14        NSFilenamesPboardType, NSPasteboard, NSScreen, NSView, NSViewHeightSizable,
  15        NSViewWidthSizable, NSWindow, NSWindowButton, NSWindowCollectionBehavior,
  16        NSWindowOcclusionState, NSWindowStyleMask, NSWindowTitleVisibility,
  17    },
  18    base::{id, nil},
  19    foundation::{
  20        NSArray, NSAutoreleasePool, NSDictionary, NSFastEnumeration, NSInteger, NSPoint, NSRect,
  21        NSSize, NSString, NSUInteger,
  22    },
  23};
  24use core_graphics::display::{CGDirectDisplayID, CGRect};
  25use ctor::ctor;
  26use futures::channel::oneshot;
  27use objc::{
  28    class,
  29    declare::ClassDecl,
  30    msg_send,
  31    runtime::{Class, Object, Protocol, Sel, BOOL, NO, YES},
  32    sel, sel_impl,
  33};
  34use parking_lot::Mutex;
  35use raw_window_handle as rwh;
  36use smallvec::SmallVec;
  37use std::{
  38    cell::Cell,
  39    ffi::{c_void, CStr},
  40    mem,
  41    ops::Range,
  42    os::raw::c_char,
  43    path::PathBuf,
  44    ptr::{self, NonNull},
  45    rc::Rc,
  46    sync::{Arc, Weak},
  47    time::Duration,
  48};
  49use util::ResultExt;
  50
  51const WINDOW_STATE_IVAR: &str = "windowState";
  52
  53static mut WINDOW_CLASS: *const Class = ptr::null();
  54static mut PANEL_CLASS: *const Class = ptr::null();
  55static mut VIEW_CLASS: *const Class = ptr::null();
  56
  57#[allow(non_upper_case_globals)]
  58const NSWindowStyleMaskNonactivatingPanel: NSWindowStyleMask =
  59    unsafe { NSWindowStyleMask::from_bits_unchecked(1 << 7) };
  60#[allow(non_upper_case_globals)]
  61const NSNormalWindowLevel: NSInteger = 0;
  62#[allow(non_upper_case_globals)]
  63const NSPopUpWindowLevel: NSInteger = 101;
  64#[allow(non_upper_case_globals)]
  65const NSTrackingMouseEnteredAndExited: NSUInteger = 0x01;
  66#[allow(non_upper_case_globals)]
  67const NSTrackingMouseMoved: NSUInteger = 0x02;
  68#[allow(non_upper_case_globals)]
  69const NSTrackingActiveAlways: NSUInteger = 0x80;
  70#[allow(non_upper_case_globals)]
  71const NSTrackingInVisibleRect: NSUInteger = 0x200;
  72#[allow(non_upper_case_globals)]
  73const NSWindowAnimationBehaviorUtilityWindow: NSInteger = 4;
  74#[allow(non_upper_case_globals)]
  75const NSViewLayerContentsRedrawDuringViewResize: NSInteger = 2;
  76// https://developer.apple.com/documentation/appkit/nsdragoperation
  77type NSDragOperation = NSUInteger;
  78#[allow(non_upper_case_globals)]
  79const NSDragOperationNone: NSDragOperation = 0;
  80#[allow(non_upper_case_globals)]
  81const NSDragOperationCopy: NSDragOperation = 1;
  82
  83#[link(name = "CoreGraphics", kind = "framework")]
  84extern "C" {
  85    // Widely used private APIs; Apple uses them for their Terminal.app.
  86    fn CGSMainConnectionID() -> id;
  87    fn CGSSetWindowBackgroundBlurRadius(
  88        connection_id: id,
  89        window_id: NSInteger,
  90        radius: i64,
  91    ) -> i32;
  92}
  93
  94#[ctor]
  95unsafe fn build_classes() {
  96    WINDOW_CLASS = build_window_class("GPUIWindow", class!(NSWindow));
  97    PANEL_CLASS = build_window_class("GPUIPanel", class!(NSPanel));
  98    VIEW_CLASS = {
  99        let mut decl = ClassDecl::new("GPUIView", class!(NSView)).unwrap();
 100        decl.add_ivar::<*mut c_void>(WINDOW_STATE_IVAR);
 101
 102        decl.add_method(sel!(dealloc), dealloc_view as extern "C" fn(&Object, Sel));
 103
 104        decl.add_method(
 105            sel!(performKeyEquivalent:),
 106            handle_key_equivalent as extern "C" fn(&Object, Sel, id) -> BOOL,
 107        );
 108        decl.add_method(
 109            sel!(keyDown:),
 110            handle_key_down as extern "C" fn(&Object, Sel, id),
 111        );
 112        decl.add_method(
 113            sel!(mouseDown:),
 114            handle_view_event as extern "C" fn(&Object, Sel, id),
 115        );
 116        decl.add_method(
 117            sel!(mouseUp:),
 118            handle_view_event as extern "C" fn(&Object, Sel, id),
 119        );
 120        decl.add_method(
 121            sel!(rightMouseDown:),
 122            handle_view_event as extern "C" fn(&Object, Sel, id),
 123        );
 124        decl.add_method(
 125            sel!(rightMouseUp:),
 126            handle_view_event as extern "C" fn(&Object, Sel, id),
 127        );
 128        decl.add_method(
 129            sel!(otherMouseDown:),
 130            handle_view_event as extern "C" fn(&Object, Sel, id),
 131        );
 132        decl.add_method(
 133            sel!(otherMouseUp:),
 134            handle_view_event as extern "C" fn(&Object, Sel, id),
 135        );
 136        decl.add_method(
 137            sel!(mouseMoved:),
 138            handle_view_event as extern "C" fn(&Object, Sel, id),
 139        );
 140        decl.add_method(
 141            sel!(mouseExited:),
 142            handle_view_event as extern "C" fn(&Object, Sel, id),
 143        );
 144        decl.add_method(
 145            sel!(mouseDragged:),
 146            handle_view_event as extern "C" fn(&Object, Sel, id),
 147        );
 148        decl.add_method(
 149            sel!(scrollWheel:),
 150            handle_view_event as extern "C" fn(&Object, Sel, id),
 151        );
 152        decl.add_method(
 153            sel!(flagsChanged:),
 154            handle_view_event as extern "C" fn(&Object, Sel, id),
 155        );
 156        decl.add_method(
 157            sel!(cancelOperation:),
 158            cancel_operation as extern "C" fn(&Object, Sel, id),
 159        );
 160
 161        decl.add_method(
 162            sel!(makeBackingLayer),
 163            make_backing_layer as extern "C" fn(&Object, Sel) -> id,
 164        );
 165
 166        decl.add_protocol(Protocol::get("CALayerDelegate").unwrap());
 167        decl.add_method(
 168            sel!(viewDidChangeBackingProperties),
 169            view_did_change_backing_properties as extern "C" fn(&Object, Sel),
 170        );
 171        decl.add_method(
 172            sel!(setFrameSize:),
 173            set_frame_size as extern "C" fn(&Object, Sel, NSSize),
 174        );
 175        decl.add_method(
 176            sel!(displayLayer:),
 177            display_layer as extern "C" fn(&Object, Sel, id),
 178        );
 179
 180        decl.add_protocol(Protocol::get("NSTextInputClient").unwrap());
 181        decl.add_method(
 182            sel!(validAttributesForMarkedText),
 183            valid_attributes_for_marked_text as extern "C" fn(&Object, Sel) -> id,
 184        );
 185        decl.add_method(
 186            sel!(hasMarkedText),
 187            has_marked_text as extern "C" fn(&Object, Sel) -> BOOL,
 188        );
 189        decl.add_method(
 190            sel!(markedRange),
 191            marked_range as extern "C" fn(&Object, Sel) -> NSRange,
 192        );
 193        decl.add_method(
 194            sel!(selectedRange),
 195            selected_range as extern "C" fn(&Object, Sel) -> NSRange,
 196        );
 197        decl.add_method(
 198            sel!(firstRectForCharacterRange:actualRange:),
 199            first_rect_for_character_range as extern "C" fn(&Object, Sel, NSRange, id) -> NSRect,
 200        );
 201        decl.add_method(
 202            sel!(insertText:replacementRange:),
 203            insert_text as extern "C" fn(&Object, Sel, id, NSRange),
 204        );
 205        decl.add_method(
 206            sel!(setMarkedText:selectedRange:replacementRange:),
 207            set_marked_text as extern "C" fn(&Object, Sel, id, NSRange, NSRange),
 208        );
 209        decl.add_method(sel!(unmarkText), unmark_text as extern "C" fn(&Object, Sel));
 210        decl.add_method(
 211            sel!(attributedSubstringForProposedRange:actualRange:),
 212            attributed_substring_for_proposed_range
 213                as extern "C" fn(&Object, Sel, NSRange, *mut c_void) -> id,
 214        );
 215        decl.add_method(
 216            sel!(viewDidChangeEffectiveAppearance),
 217            view_did_change_effective_appearance as extern "C" fn(&Object, Sel),
 218        );
 219
 220        // Suppress beep on keystrokes with modifier keys.
 221        decl.add_method(
 222            sel!(doCommandBySelector:),
 223            do_command_by_selector as extern "C" fn(&Object, Sel, Sel),
 224        );
 225
 226        decl.add_method(
 227            sel!(acceptsFirstMouse:),
 228            accepts_first_mouse as extern "C" fn(&Object, Sel, id) -> BOOL,
 229        );
 230
 231        decl.register()
 232    };
 233}
 234
 235pub(crate) fn convert_mouse_position(position: NSPoint, window_height: Pixels) -> Point<Pixels> {
 236    point(
 237        px(position.x as f32),
 238        // MacOS screen coordinates are relative to bottom left
 239        window_height - px(position.y as f32),
 240    )
 241}
 242
 243unsafe fn build_window_class(name: &'static str, superclass: &Class) -> *const Class {
 244    let mut decl = ClassDecl::new(name, superclass).unwrap();
 245    decl.add_ivar::<*mut c_void>(WINDOW_STATE_IVAR);
 246    decl.add_method(sel!(dealloc), dealloc_window as extern "C" fn(&Object, Sel));
 247    decl.add_method(
 248        sel!(canBecomeMainWindow),
 249        yes as extern "C" fn(&Object, Sel) -> BOOL,
 250    );
 251    decl.add_method(
 252        sel!(canBecomeKeyWindow),
 253        yes as extern "C" fn(&Object, Sel) -> BOOL,
 254    );
 255    decl.add_method(
 256        sel!(windowDidResize:),
 257        window_did_resize as extern "C" fn(&Object, Sel, id),
 258    );
 259    decl.add_method(
 260        sel!(windowDidChangeOcclusionState:),
 261        window_did_change_occlusion_state as extern "C" fn(&Object, Sel, id),
 262    );
 263    decl.add_method(
 264        sel!(windowWillEnterFullScreen:),
 265        window_will_enter_fullscreen as extern "C" fn(&Object, Sel, id),
 266    );
 267    decl.add_method(
 268        sel!(windowDidMove:),
 269        window_did_move as extern "C" fn(&Object, Sel, id),
 270    );
 271    decl.add_method(
 272        sel!(windowDidChangeScreen:),
 273        window_did_change_screen as extern "C" fn(&Object, Sel, id),
 274    );
 275    decl.add_method(
 276        sel!(windowDidBecomeKey:),
 277        window_did_change_key_status as extern "C" fn(&Object, Sel, id),
 278    );
 279    decl.add_method(
 280        sel!(windowDidResignKey:),
 281        window_did_change_key_status as extern "C" fn(&Object, Sel, id),
 282    );
 283    decl.add_method(
 284        sel!(windowShouldClose:),
 285        window_should_close as extern "C" fn(&Object, Sel, id) -> BOOL,
 286    );
 287
 288    decl.add_method(sel!(close), close_window as extern "C" fn(&Object, Sel));
 289
 290    decl.add_method(
 291        sel!(draggingEntered:),
 292        dragging_entered as extern "C" fn(&Object, Sel, id) -> NSDragOperation,
 293    );
 294    decl.add_method(
 295        sel!(draggingUpdated:),
 296        dragging_updated as extern "C" fn(&Object, Sel, id) -> NSDragOperation,
 297    );
 298    decl.add_method(
 299        sel!(draggingExited:),
 300        dragging_exited as extern "C" fn(&Object, Sel, id),
 301    );
 302    decl.add_method(
 303        sel!(performDragOperation:),
 304        perform_drag_operation as extern "C" fn(&Object, Sel, id) -> BOOL,
 305    );
 306    decl.add_method(
 307        sel!(concludeDragOperation:),
 308        conclude_drag_operation as extern "C" fn(&Object, Sel, id),
 309    );
 310
 311    decl.register()
 312}
 313
 314#[allow(clippy::enum_variant_names)]
 315enum ImeInput {
 316    InsertText(String, Option<Range<usize>>),
 317    SetMarkedText(String, Option<Range<usize>>, Option<Range<usize>>),
 318    UnmarkText,
 319}
 320
 321struct MacWindowState {
 322    handle: AnyWindowHandle,
 323    executor: ForegroundExecutor,
 324    native_window: id,
 325    native_view: NonNull<Object>,
 326    display_link: Option<DisplayLink>,
 327    renderer: renderer::Renderer,
 328    request_frame_callback: Option<Box<dyn FnMut()>>,
 329    event_callback: Option<Box<dyn FnMut(PlatformInput) -> crate::DispatchEventResult>>,
 330    activate_callback: Option<Box<dyn FnMut(bool)>>,
 331    resize_callback: Option<Box<dyn FnMut(Size<Pixels>, f32)>>,
 332    moved_callback: Option<Box<dyn FnMut()>>,
 333    should_close_callback: Option<Box<dyn FnMut() -> bool>>,
 334    close_callback: Option<Box<dyn FnOnce()>>,
 335    appearance_changed_callback: Option<Box<dyn FnMut()>>,
 336    input_handler: Option<PlatformInputHandler>,
 337    last_key_equivalent: Option<KeyDownEvent>,
 338    synthetic_drag_counter: usize,
 339    last_fresh_keydown: Option<Keystroke>,
 340    traffic_light_position: Option<Point<Pixels>>,
 341    previous_modifiers_changed_event: Option<PlatformInput>,
 342    // State tracking what the IME did after the last request
 343    input_during_keydown: Option<SmallVec<[ImeInput; 1]>>,
 344    previous_keydown_inserted_text: Option<String>,
 345    external_files_dragged: bool,
 346    // Whether the next left-mouse click is also the focusing click.
 347    first_mouse: bool,
 348    fullscreen_restore_bounds: Bounds<DevicePixels>,
 349}
 350
 351impl MacWindowState {
 352    fn move_traffic_light(&self) {
 353        if let Some(traffic_light_position) = self.traffic_light_position {
 354            if self.is_fullscreen() {
 355                // Moving traffic lights while fullscreen doesn't work,
 356                // see https://github.com/zed-industries/zed/issues/4712
 357                return;
 358            }
 359
 360            let titlebar_height = self.titlebar_height();
 361
 362            unsafe {
 363                let close_button: id = msg_send![
 364                    self.native_window,
 365                    standardWindowButton: NSWindowButton::NSWindowCloseButton
 366                ];
 367                let min_button: id = msg_send![
 368                    self.native_window,
 369                    standardWindowButton: NSWindowButton::NSWindowMiniaturizeButton
 370                ];
 371                let zoom_button: id = msg_send![
 372                    self.native_window,
 373                    standardWindowButton: NSWindowButton::NSWindowZoomButton
 374                ];
 375
 376                let mut close_button_frame: CGRect = msg_send![close_button, frame];
 377                let mut min_button_frame: CGRect = msg_send![min_button, frame];
 378                let mut zoom_button_frame: CGRect = msg_send![zoom_button, frame];
 379                let mut origin = point(
 380                    traffic_light_position.x,
 381                    titlebar_height
 382                        - traffic_light_position.y
 383                        - px(close_button_frame.size.height as f32),
 384                );
 385                let button_spacing =
 386                    px((min_button_frame.origin.x - close_button_frame.origin.x) as f32);
 387
 388                close_button_frame.origin = CGPoint::new(origin.x.into(), origin.y.into());
 389                let _: () = msg_send![close_button, setFrame: close_button_frame];
 390                origin.x += button_spacing;
 391
 392                min_button_frame.origin = CGPoint::new(origin.x.into(), origin.y.into());
 393                let _: () = msg_send![min_button, setFrame: min_button_frame];
 394                origin.x += button_spacing;
 395
 396                zoom_button_frame.origin = CGPoint::new(origin.x.into(), origin.y.into());
 397                let _: () = msg_send![zoom_button, setFrame: zoom_button_frame];
 398                origin.x += button_spacing;
 399            }
 400        }
 401    }
 402
 403    fn start_display_link(&mut self) {
 404        self.stop_display_link();
 405        unsafe {
 406            if !self
 407                .native_window
 408                .occlusionState()
 409                .contains(NSWindowOcclusionState::NSWindowOcclusionStateVisible)
 410            {
 411                return;
 412            }
 413        }
 414        let display_id = unsafe { display_id_for_screen(self.native_window.screen()) };
 415        if let Some(mut display_link) =
 416            DisplayLink::new(display_id, self.native_view.as_ptr() as *mut c_void, step).log_err()
 417        {
 418            display_link.start().log_err();
 419            self.display_link = Some(display_link);
 420        }
 421    }
 422
 423    fn stop_display_link(&mut self) {
 424        self.display_link = None;
 425    }
 426
 427    fn is_maximized(&self) -> bool {
 428        unsafe {
 429            let bounds = self.bounds();
 430            let screen_size = self.native_window.screen().visibleFrame().into();
 431            bounds.size == screen_size
 432        }
 433    }
 434
 435    fn is_fullscreen(&self) -> bool {
 436        unsafe {
 437            let style_mask = self.native_window.styleMask();
 438            style_mask.contains(NSWindowStyleMask::NSFullScreenWindowMask)
 439        }
 440    }
 441
 442    fn bounds(&self) -> Bounds<DevicePixels> {
 443        let mut window_frame = unsafe { NSWindow::frame(self.native_window) };
 444        let screen_frame = unsafe {
 445            let screen = NSWindow::screen(self.native_window);
 446            NSScreen::frame(screen)
 447        };
 448
 449        // Flip the y coordinate to be top-left origin
 450        window_frame.origin.y =
 451            screen_frame.size.height - window_frame.origin.y - window_frame.size.height;
 452
 453        let bounds = Bounds::new(
 454            point(
 455                ((window_frame.origin.x - screen_frame.origin.x) as i32).into(),
 456                ((window_frame.origin.y - screen_frame.origin.y) as i32).into(),
 457            ),
 458            size(
 459                (window_frame.size.width as i32).into(),
 460                (window_frame.size.height as i32).into(),
 461            ),
 462        );
 463        bounds
 464    }
 465
 466    fn content_size(&self) -> Size<Pixels> {
 467        let NSSize { width, height, .. } =
 468            unsafe { NSView::frame(self.native_window.contentView()) }.size;
 469        size(px(width as f32), px(height as f32))
 470    }
 471
 472    fn scale_factor(&self) -> f32 {
 473        get_scale_factor(self.native_window)
 474    }
 475
 476    fn update_drawable_size(&mut self, drawable_size: NSSize) {
 477        self.renderer.update_drawable_size(Size {
 478            width: drawable_size.width,
 479            height: drawable_size.height,
 480        })
 481    }
 482
 483    fn titlebar_height(&self) -> Pixels {
 484        unsafe {
 485            let frame = NSWindow::frame(self.native_window);
 486            let content_layout_rect: CGRect = msg_send![self.native_window, contentLayoutRect];
 487            px((frame.size.height - content_layout_rect.size.height) as f32)
 488        }
 489    }
 490
 491    fn window_bounds(&self) -> WindowBounds {
 492        if self.is_fullscreen() {
 493            WindowBounds::Fullscreen(self.fullscreen_restore_bounds)
 494        } else {
 495            WindowBounds::Windowed(self.bounds())
 496        }
 497    }
 498}
 499
 500unsafe impl Send for MacWindowState {}
 501
 502pub(crate) struct MacWindow(Arc<Mutex<MacWindowState>>);
 503
 504impl MacWindow {
 505    pub fn open(
 506        handle: AnyWindowHandle,
 507        WindowParams {
 508            window_background,
 509            bounds,
 510            titlebar,
 511            kind,
 512            is_movable,
 513            focus,
 514            show,
 515            display_id,
 516        }: WindowParams,
 517        executor: ForegroundExecutor,
 518        renderer_context: renderer::Context,
 519    ) -> Self {
 520        unsafe {
 521            let pool = NSAutoreleasePool::new(nil);
 522
 523            let mut style_mask;
 524            if let Some(titlebar) = titlebar.as_ref() {
 525                style_mask = NSWindowStyleMask::NSClosableWindowMask
 526                    | NSWindowStyleMask::NSMiniaturizableWindowMask
 527                    | NSWindowStyleMask::NSResizableWindowMask
 528                    | NSWindowStyleMask::NSTitledWindowMask;
 529
 530                if titlebar.appears_transparent {
 531                    style_mask |= NSWindowStyleMask::NSFullSizeContentViewWindowMask;
 532                }
 533            } else {
 534                style_mask = NSWindowStyleMask::NSTitledWindowMask
 535                    | NSWindowStyleMask::NSFullSizeContentViewWindowMask;
 536            }
 537
 538            let native_window: id = match kind {
 539                WindowKind::Normal => msg_send![WINDOW_CLASS, alloc],
 540                WindowKind::PopUp => {
 541                    style_mask |= NSWindowStyleMaskNonactivatingPanel;
 542                    msg_send![PANEL_CLASS, alloc]
 543                }
 544            };
 545
 546            let display = display_id
 547                .and_then(MacDisplay::find_by_id)
 548                .unwrap_or_else(|| MacDisplay::primary());
 549
 550            let mut target_screen = nil;
 551            let mut screen_frame = None;
 552
 553            let screens = NSScreen::screens(nil);
 554            let count: u64 = cocoa::foundation::NSArray::count(screens);
 555            for i in 0..count {
 556                let screen = cocoa::foundation::NSArray::objectAtIndex(screens, i);
 557                let frame = NSScreen::visibleFrame(screen);
 558                let display_id = display_id_for_screen(screen);
 559                if display_id == display.0 {
 560                    screen_frame = Some(frame);
 561                    target_screen = screen;
 562                }
 563            }
 564
 565            let screen_frame = screen_frame.unwrap_or_else(|| {
 566                let screen = NSScreen::mainScreen(nil);
 567                target_screen = screen;
 568                NSScreen::visibleFrame(screen)
 569            });
 570
 571            let window_rect = NSRect::new(
 572                NSPoint::new(
 573                    screen_frame.origin.x + bounds.origin.x.0 as f64,
 574                    screen_frame.origin.y
 575                        + (display.bounds().size.height - bounds.origin.y).0 as f64,
 576                ),
 577                NSSize::new(bounds.size.width.0 as f64, bounds.size.height.0 as f64),
 578            );
 579
 580            let native_window = native_window.initWithContentRect_styleMask_backing_defer_screen_(
 581                window_rect,
 582                style_mask,
 583                NSBackingStoreBuffered,
 584                NO,
 585                target_screen,
 586            );
 587            assert!(!native_window.is_null());
 588            let () = msg_send![
 589                native_window,
 590                registerForDraggedTypes:
 591                    NSArray::arrayWithObject(nil, NSFilenamesPboardType)
 592            ];
 593            let () = msg_send![
 594                native_window,
 595                setReleasedWhenClosed: NO
 596            ];
 597
 598            let native_view: id = msg_send![VIEW_CLASS, alloc];
 599            let native_view = NSView::init(native_view);
 600            assert!(!native_view.is_null());
 601
 602            let window_size = {
 603                let scale = get_scale_factor(native_window);
 604                size(
 605                    bounds.size.width.0 as f32 * scale,
 606                    bounds.size.height.0 as f32 * scale,
 607                )
 608            };
 609
 610            let mut window = Self(Arc::new(Mutex::new(MacWindowState {
 611                handle,
 612                executor,
 613                native_window,
 614                native_view: NonNull::new_unchecked(native_view),
 615                display_link: None,
 616                renderer: renderer::new_renderer(
 617                    renderer_context,
 618                    native_window as *mut _,
 619                    native_view as *mut _,
 620                    window_size,
 621                    window_background != WindowBackgroundAppearance::Opaque,
 622                ),
 623                request_frame_callback: None,
 624                event_callback: None,
 625                activate_callback: None,
 626                resize_callback: None,
 627                moved_callback: None,
 628                should_close_callback: None,
 629                close_callback: None,
 630                appearance_changed_callback: None,
 631                input_handler: None,
 632                last_key_equivalent: None,
 633                synthetic_drag_counter: 0,
 634                last_fresh_keydown: None,
 635                traffic_light_position: titlebar
 636                    .as_ref()
 637                    .and_then(|titlebar| titlebar.traffic_light_position),
 638                previous_modifiers_changed_event: None,
 639                input_during_keydown: None,
 640                previous_keydown_inserted_text: None,
 641                external_files_dragged: false,
 642                first_mouse: false,
 643                fullscreen_restore_bounds: Bounds::default(),
 644            })));
 645
 646            (*native_window).set_ivar(
 647                WINDOW_STATE_IVAR,
 648                Arc::into_raw(window.0.clone()) as *const c_void,
 649            );
 650            native_window.setDelegate_(native_window);
 651            (*native_view).set_ivar(
 652                WINDOW_STATE_IVAR,
 653                Arc::into_raw(window.0.clone()) as *const c_void,
 654            );
 655
 656            if let Some(title) = titlebar
 657                .as_ref()
 658                .and_then(|t| t.title.as_ref().map(AsRef::as_ref))
 659            {
 660                native_window.setTitle_(NSString::alloc(nil).init_str(title));
 661            }
 662
 663            native_window.setMovable_(is_movable as BOOL);
 664
 665            if titlebar.map_or(true, |titlebar| titlebar.appears_transparent) {
 666                native_window.setTitlebarAppearsTransparent_(YES);
 667                native_window.setTitleVisibility_(NSWindowTitleVisibility::NSWindowTitleHidden);
 668            }
 669
 670            native_view.setAutoresizingMask_(NSViewWidthSizable | NSViewHeightSizable);
 671            native_view.setWantsBestResolutionOpenGLSurface_(YES);
 672
 673            // From winit crate: On Mojave, views automatically become layer-backed shortly after
 674            // being added to a native_window. Changing the layer-backedness of a view breaks the
 675            // association between the view and its associated OpenGL context. To work around this,
 676            // on we explicitly make the view layer-backed up front so that AppKit doesn't do it
 677            // itself and break the association with its context.
 678            native_view.setWantsLayer(YES);
 679            let _: () = msg_send![
 680                native_view,
 681                setLayerContentsRedrawPolicy: NSViewLayerContentsRedrawDuringViewResize
 682            ];
 683
 684            native_window.setContentView_(native_view.autorelease());
 685            native_window.makeFirstResponder_(native_view);
 686
 687            window.set_background_appearance(window_background);
 688
 689            match kind {
 690                WindowKind::Normal => {
 691                    native_window.setLevel_(NSNormalWindowLevel);
 692                    native_window.setAcceptsMouseMovedEvents_(YES);
 693                }
 694                WindowKind::PopUp => {
 695                    // Use a tracking area to allow receiving MouseMoved events even when
 696                    // the window or application aren't active, which is often the case
 697                    // e.g. for notification windows.
 698                    let tracking_area: id = msg_send![class!(NSTrackingArea), alloc];
 699                    let _: () = msg_send![
 700                        tracking_area,
 701                        initWithRect: NSRect::new(NSPoint::new(0., 0.), NSSize::new(0., 0.))
 702                        options: NSTrackingMouseEnteredAndExited | NSTrackingMouseMoved | NSTrackingActiveAlways | NSTrackingInVisibleRect
 703                        owner: native_view
 704                        userInfo: nil
 705                    ];
 706                    let _: () =
 707                        msg_send![native_view, addTrackingArea: tracking_area.autorelease()];
 708
 709                    native_window.setLevel_(NSPopUpWindowLevel);
 710                    let _: () = msg_send![
 711                        native_window,
 712                        setAnimationBehavior: NSWindowAnimationBehaviorUtilityWindow
 713                    ];
 714                    native_window.setCollectionBehavior_(
 715                        NSWindowCollectionBehavior::NSWindowCollectionBehaviorCanJoinAllSpaces |
 716                        NSWindowCollectionBehavior::NSWindowCollectionBehaviorFullScreenAuxiliary
 717                    );
 718                }
 719            }
 720
 721            if focus {
 722                native_window.makeKeyAndOrderFront_(nil);
 723            } else if show {
 724                native_window.orderFront_(nil);
 725            }
 726
 727            // Set the initial position of the window to the specified origin.
 728            // Although we already specified the position using `initWithContentRect_styleMask_backing_defer_screen_`,
 729            // the window position might be incorrect if the main screen (the screen that contains the window that has focus)
 730            //  is different from the primary screen.
 731            NSWindow::setFrameTopLeftPoint_(native_window, window_rect.origin);
 732            window.0.lock().move_traffic_light();
 733
 734            pool.drain();
 735
 736            window
 737        }
 738    }
 739
 740    pub fn active_window() -> Option<AnyWindowHandle> {
 741        unsafe {
 742            let app = NSApplication::sharedApplication(nil);
 743            let main_window: id = msg_send![app, mainWindow];
 744            if msg_send![main_window, isKindOfClass: WINDOW_CLASS] {
 745                let handle = get_window_state(&*main_window).lock().handle;
 746                Some(handle)
 747            } else {
 748                None
 749            }
 750        }
 751    }
 752}
 753
 754impl Drop for MacWindow {
 755    fn drop(&mut self) {
 756        let mut this = self.0.lock();
 757        this.renderer.destroy();
 758        let window = this.native_window;
 759        this.display_link.take();
 760        unsafe {
 761            this.native_window.setDelegate_(nil);
 762        }
 763        this.executor
 764            .spawn(async move {
 765                unsafe {
 766                    window.close();
 767                    window.autorelease();
 768                }
 769            })
 770            .detach();
 771    }
 772}
 773
 774impl PlatformWindow for MacWindow {
 775    fn bounds(&self) -> Bounds<DevicePixels> {
 776        self.0.as_ref().lock().bounds()
 777    }
 778
 779    fn window_bounds(&self) -> WindowBounds {
 780        self.0.as_ref().lock().window_bounds()
 781    }
 782
 783    fn is_maximized(&self) -> bool {
 784        self.0.as_ref().lock().is_maximized()
 785    }
 786
 787    fn content_size(&self) -> Size<Pixels> {
 788        self.0.as_ref().lock().content_size()
 789    }
 790
 791    fn scale_factor(&self) -> f32 {
 792        self.0.as_ref().lock().scale_factor()
 793    }
 794
 795    fn appearance(&self) -> WindowAppearance {
 796        unsafe {
 797            let appearance: id = msg_send![self.0.lock().native_window, effectiveAppearance];
 798            WindowAppearance::from_native(appearance)
 799        }
 800    }
 801
 802    fn display(&self) -> Rc<dyn PlatformDisplay> {
 803        unsafe {
 804            let screen = self.0.lock().native_window.screen();
 805            let device_description: id = msg_send![screen, deviceDescription];
 806            let screen_number: id = NSDictionary::valueForKey_(
 807                device_description,
 808                NSString::alloc(nil).init_str("NSScreenNumber"),
 809            );
 810
 811            let screen_number: u32 = msg_send![screen_number, unsignedIntValue];
 812
 813            Rc::new(MacDisplay(screen_number))
 814        }
 815    }
 816
 817    fn mouse_position(&self) -> Point<Pixels> {
 818        let position = unsafe {
 819            self.0
 820                .lock()
 821                .native_window
 822                .mouseLocationOutsideOfEventStream()
 823        };
 824        convert_mouse_position(position, self.content_size().height)
 825    }
 826
 827    fn modifiers(&self) -> Modifiers {
 828        unsafe {
 829            let modifiers: NSEventModifierFlags = msg_send![class!(NSEvent), modifierFlags];
 830
 831            let control = modifiers.contains(NSEventModifierFlags::NSControlKeyMask);
 832            let alt = modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask);
 833            let shift = modifiers.contains(NSEventModifierFlags::NSShiftKeyMask);
 834            let command = modifiers.contains(NSEventModifierFlags::NSCommandKeyMask);
 835            let function = modifiers.contains(NSEventModifierFlags::NSFunctionKeyMask);
 836
 837            Modifiers {
 838                control,
 839                alt,
 840                shift,
 841                platform: command,
 842                function,
 843            }
 844        }
 845    }
 846
 847    fn set_input_handler(&mut self, input_handler: PlatformInputHandler) {
 848        self.0.as_ref().lock().input_handler = Some(input_handler);
 849    }
 850
 851    fn take_input_handler(&mut self) -> Option<PlatformInputHandler> {
 852        self.0.as_ref().lock().input_handler.take()
 853    }
 854
 855    fn prompt(
 856        &self,
 857        level: PromptLevel,
 858        msg: &str,
 859        detail: Option<&str>,
 860        answers: &[&str],
 861    ) -> Option<oneshot::Receiver<usize>> {
 862        // macOs applies overrides to modal window buttons after they are added.
 863        // Two most important for this logic are:
 864        // * Buttons with "Cancel" title will be displayed as the last buttons in the modal
 865        // * Last button added to the modal via `addButtonWithTitle` stays focused
 866        // * Focused buttons react on "space"/" " keypresses
 867        // * Usage of `keyEquivalent`, `makeFirstResponder` or `setInitialFirstResponder` does not change the focus
 868        //
 869        // See also https://developer.apple.com/documentation/appkit/nsalert/1524532-addbuttonwithtitle#discussion
 870        // ```
 871        // By default, the first button has a key equivalent of Return,
 872        // any button with a title of “Cancel” has a key equivalent of Escape,
 873        // and any button with the title “Don’t Save” has a key equivalent of Command-D (but only if it’s not the first button).
 874        // ```
 875        //
 876        // To avoid situations when the last element added is "Cancel" and it gets the focus
 877        // (hence stealing both ESC and Space shortcuts), we find and add one non-Cancel button
 878        // last, so it gets focus and a Space shortcut.
 879        // This way, "Save this file? Yes/No/Cancel"-ish modals will get all three buttons mapped with a key.
 880        let latest_non_cancel_label = answers
 881            .iter()
 882            .enumerate()
 883            .rev()
 884            .find(|(_, &label)| label != "Cancel")
 885            .filter(|&(label_index, _)| label_index > 0);
 886
 887        unsafe {
 888            let alert: id = msg_send![class!(NSAlert), alloc];
 889            let alert: id = msg_send![alert, init];
 890            let alert_style = match level {
 891                PromptLevel::Info => 1,
 892                PromptLevel::Warning => 0,
 893                PromptLevel::Critical | PromptLevel::Destructive => 2,
 894            };
 895            let _: () = msg_send![alert, setAlertStyle: alert_style];
 896            let _: () = msg_send![alert, setMessageText: ns_string(msg)];
 897            if let Some(detail) = detail {
 898                let _: () = msg_send![alert, setInformativeText: ns_string(detail)];
 899            }
 900
 901            for (ix, answer) in answers
 902                .iter()
 903                .enumerate()
 904                .filter(|&(ix, _)| Some(ix) != latest_non_cancel_label.map(|(ix, _)| ix))
 905            {
 906                let button: id = msg_send![alert, addButtonWithTitle: ns_string(answer)];
 907                let _: () = msg_send![button, setTag: ix as NSInteger];
 908                if level == PromptLevel::Destructive && answer != &"Cancel" {
 909                    let _: () = msg_send![button, setHasDestructiveAction: YES];
 910                }
 911            }
 912            if let Some((ix, answer)) = latest_non_cancel_label {
 913                let button: id = msg_send![alert, addButtonWithTitle: ns_string(answer)];
 914                let _: () = msg_send![button, setTag: ix as NSInteger];
 915                if level == PromptLevel::Destructive {
 916                    let _: () = msg_send![button, setHasDestructiveAction: YES];
 917                }
 918            }
 919
 920            let (done_tx, done_rx) = oneshot::channel();
 921            let done_tx = Cell::new(Some(done_tx));
 922            let block = ConcreteBlock::new(move |answer: NSInteger| {
 923                if let Some(done_tx) = done_tx.take() {
 924                    let _ = done_tx.send(answer.try_into().unwrap());
 925                }
 926            });
 927            let block = block.copy();
 928            let native_window = self.0.lock().native_window;
 929            let executor = self.0.lock().executor.clone();
 930            executor
 931                .spawn(async move {
 932                    let _: () = msg_send![
 933                        alert,
 934                        beginSheetModalForWindow: native_window
 935                        completionHandler: block
 936                    ];
 937                })
 938                .detach();
 939
 940            Some(done_rx)
 941        }
 942    }
 943
 944    fn activate(&self) {
 945        let window = self.0.lock().native_window;
 946        let executor = self.0.lock().executor.clone();
 947        executor
 948            .spawn(async move {
 949                unsafe {
 950                    let _: () = msg_send![window, makeKeyAndOrderFront: nil];
 951                }
 952            })
 953            .detach();
 954    }
 955
 956    fn is_active(&self) -> bool {
 957        unsafe { self.0.lock().native_window.isKeyWindow() == YES }
 958    }
 959
 960    fn set_title(&mut self, title: &str) {
 961        unsafe {
 962            let app = NSApplication::sharedApplication(nil);
 963            let window = self.0.lock().native_window;
 964            let title = ns_string(title);
 965            let _: () = msg_send![app, changeWindowsItem:window title:title filename:false];
 966            let _: () = msg_send![window, setTitle: title];
 967            self.0.lock().move_traffic_light();
 968        }
 969    }
 970
 971    fn set_app_id(&mut self, _app_id: &str) {}
 972
 973    fn set_background_appearance(&mut self, background_appearance: WindowBackgroundAppearance) {
 974        let mut this = self.0.as_ref().lock();
 975        this.renderer
 976            .update_transparency(background_appearance != WindowBackgroundAppearance::Opaque);
 977
 978        let blur_radius = if background_appearance == WindowBackgroundAppearance::Blurred {
 979            80
 980        } else {
 981            0
 982        };
 983        let opaque = if background_appearance == WindowBackgroundAppearance::Opaque {
 984            YES
 985        } else {
 986            NO
 987        };
 988        unsafe {
 989            this.native_window.setOpaque_(opaque);
 990            // Shadows for transparent windows cause artifacts and performance issues
 991            this.native_window.setHasShadow_(opaque);
 992            let clear_color = if opaque == YES {
 993                NSColor::colorWithSRGBRed_green_blue_alpha_(nil, 0f64, 0f64, 0f64, 1f64)
 994            } else {
 995                NSColor::clearColor(nil)
 996            };
 997            this.native_window.setBackgroundColor_(clear_color);
 998            let window_number = this.native_window.windowNumber();
 999            CGSSetWindowBackgroundBlurRadius(CGSMainConnectionID(), window_number, blur_radius);
1000        }
1001    }
1002
1003    fn set_edited(&mut self, edited: bool) {
1004        unsafe {
1005            let window = self.0.lock().native_window;
1006            msg_send![window, setDocumentEdited: edited as BOOL]
1007        }
1008
1009        // Changing the document edited state resets the traffic light position,
1010        // so we have to move it again.
1011        self.0.lock().move_traffic_light();
1012    }
1013
1014    fn show_character_palette(&self) {
1015        let this = self.0.lock();
1016        let window = this.native_window;
1017        this.executor
1018            .spawn(async move {
1019                unsafe {
1020                    let app = NSApplication::sharedApplication(nil);
1021                    let _: () = msg_send![app, orderFrontCharacterPalette: window];
1022                }
1023            })
1024            .detach();
1025    }
1026
1027    fn minimize(&self) {
1028        let window = self.0.lock().native_window;
1029        unsafe {
1030            window.miniaturize_(nil);
1031        }
1032    }
1033
1034    fn zoom(&self) {
1035        let this = self.0.lock();
1036        let window = this.native_window;
1037        this.executor
1038            .spawn(async move {
1039                unsafe {
1040                    window.zoom_(nil);
1041                }
1042            })
1043            .detach();
1044    }
1045
1046    fn toggle_fullscreen(&self) {
1047        let this = self.0.lock();
1048        let window = this.native_window;
1049        this.executor
1050            .spawn(async move {
1051                unsafe {
1052                    window.toggleFullScreen_(nil);
1053                }
1054            })
1055            .detach();
1056    }
1057
1058    fn is_fullscreen(&self) -> bool {
1059        let this = self.0.lock();
1060        let window = this.native_window;
1061
1062        unsafe {
1063            window
1064                .styleMask()
1065                .contains(NSWindowStyleMask::NSFullScreenWindowMask)
1066        }
1067    }
1068
1069    fn on_request_frame(&self, callback: Box<dyn FnMut()>) {
1070        self.0.as_ref().lock().request_frame_callback = Some(callback);
1071    }
1072
1073    fn on_input(&self, callback: Box<dyn FnMut(PlatformInput) -> crate::DispatchEventResult>) {
1074        self.0.as_ref().lock().event_callback = Some(callback);
1075    }
1076
1077    fn on_active_status_change(&self, callback: Box<dyn FnMut(bool)>) {
1078        self.0.as_ref().lock().activate_callback = Some(callback);
1079    }
1080
1081    fn on_resize(&self, callback: Box<dyn FnMut(Size<Pixels>, f32)>) {
1082        self.0.as_ref().lock().resize_callback = Some(callback);
1083    }
1084
1085    fn on_moved(&self, callback: Box<dyn FnMut()>) {
1086        self.0.as_ref().lock().moved_callback = Some(callback);
1087    }
1088
1089    fn on_should_close(&self, callback: Box<dyn FnMut() -> bool>) {
1090        self.0.as_ref().lock().should_close_callback = Some(callback);
1091    }
1092
1093    fn on_close(&self, callback: Box<dyn FnOnce()>) {
1094        self.0.as_ref().lock().close_callback = Some(callback);
1095    }
1096
1097    fn on_appearance_changed(&self, callback: Box<dyn FnMut()>) {
1098        self.0.lock().appearance_changed_callback = Some(callback);
1099    }
1100
1101    fn draw(&self, scene: &crate::Scene) {
1102        let mut this = self.0.lock();
1103        this.renderer.draw(scene);
1104    }
1105
1106    fn sprite_atlas(&self) -> Arc<dyn PlatformAtlas> {
1107        self.0.lock().renderer.sprite_atlas().clone()
1108    }
1109}
1110
1111impl rwh::HasWindowHandle for MacWindow {
1112    fn window_handle(&self) -> Result<rwh::WindowHandle<'_>, rwh::HandleError> {
1113        // SAFETY: The AppKitWindowHandle is a wrapper around a pointer to an NSView
1114        unsafe {
1115            Ok(rwh::WindowHandle::borrow_raw(rwh::RawWindowHandle::AppKit(
1116                rwh::AppKitWindowHandle::new(self.0.lock().native_view.cast()),
1117            )))
1118        }
1119    }
1120}
1121
1122impl rwh::HasDisplayHandle for MacWindow {
1123    fn display_handle(&self) -> Result<rwh::DisplayHandle<'_>, rwh::HandleError> {
1124        // SAFETY: This is a no-op on macOS
1125        unsafe {
1126            Ok(rwh::DisplayHandle::borrow_raw(
1127                rwh::AppKitDisplayHandle::new().into(),
1128            ))
1129        }
1130    }
1131}
1132
1133fn get_scale_factor(native_window: id) -> f32 {
1134    let factor = unsafe {
1135        let screen: id = msg_send![native_window, screen];
1136        NSScreen::backingScaleFactor(screen) as f32
1137    };
1138
1139    // We are not certain what triggers this, but it seems that sometimes
1140    // this method would return 0 (https://github.com/zed-industries/zed/issues/6412)
1141    // It seems most likely that this would happen if the window has no screen
1142    // (if it is off-screen), though we'd expect to see viewDidChangeBackingProperties before
1143    // it was rendered for real.
1144    // Regardless, attempt to avoid the issue here.
1145    if factor == 0.0 {
1146        2.
1147    } else {
1148        factor
1149    }
1150}
1151
1152unsafe fn get_window_state(object: &Object) -> Arc<Mutex<MacWindowState>> {
1153    let raw: *mut c_void = *object.get_ivar(WINDOW_STATE_IVAR);
1154    let rc1 = Arc::from_raw(raw as *mut Mutex<MacWindowState>);
1155    let rc2 = rc1.clone();
1156    mem::forget(rc1);
1157    rc2
1158}
1159
1160unsafe fn drop_window_state(object: &Object) {
1161    let raw: *mut c_void = *object.get_ivar(WINDOW_STATE_IVAR);
1162    Arc::from_raw(raw as *mut Mutex<MacWindowState>);
1163}
1164
1165extern "C" fn yes(_: &Object, _: Sel) -> BOOL {
1166    YES
1167}
1168
1169extern "C" fn dealloc_window(this: &Object, _: Sel) {
1170    unsafe {
1171        drop_window_state(this);
1172        let _: () = msg_send![super(this, class!(NSWindow)), dealloc];
1173    }
1174}
1175
1176extern "C" fn dealloc_view(this: &Object, _: Sel) {
1177    unsafe {
1178        drop_window_state(this);
1179        let _: () = msg_send![super(this, class!(NSView)), dealloc];
1180    }
1181}
1182
1183extern "C" fn handle_key_equivalent(this: &Object, _: Sel, native_event: id) -> BOOL {
1184    handle_key_event(this, native_event, true)
1185}
1186
1187extern "C" fn handle_key_down(this: &Object, _: Sel, native_event: id) {
1188    handle_key_event(this, native_event, false);
1189}
1190
1191// Things to test if you're modifying this method:
1192//  Brazilian layout:
1193//   - `" space` should type a quote
1194//   - `" backspace` should delete the marked quote
1195//   - `" up` should type the quote, unmark it, and move up one line
1196//   - `" cmd-down` should not leave a marked quote behind (it maybe should dispatch the key though?)
1197//   - `cmd-ctrl-space` and clicking on an emoji should type it
1198//  Czech (QWERTY) layout:
1199//   - in vim mode `option-4`  should go to end of line (same as $)
1200extern "C" fn handle_key_event(this: &Object, native_event: id, key_equivalent: bool) -> BOOL {
1201    let window_state = unsafe { get_window_state(this) };
1202    let mut lock = window_state.as_ref().lock();
1203
1204    let window_height = lock.content_size().height;
1205    let event = unsafe { PlatformInput::from_native(native_event, Some(window_height)) };
1206
1207    if let Some(PlatformInput::KeyDown(mut event)) = event {
1208        // For certain keystrokes, macOS will first dispatch a "key equivalent" event.
1209        // If that event isn't handled, it will then dispatch a "key down" event. GPUI
1210        // makes no distinction between these two types of events, so we need to ignore
1211        // the "key down" event if we've already just processed its "key equivalent" version.
1212        if key_equivalent {
1213            lock.last_key_equivalent = Some(event.clone());
1214        } else if lock.last_key_equivalent.take().as_ref() == Some(&event) {
1215            return NO;
1216        }
1217
1218        let keydown = event.keystroke.clone();
1219        let fn_modifier = keydown.modifiers.function;
1220        // Ignore events from held-down keys after some of the initially-pressed keys
1221        // were released.
1222        if event.is_held {
1223            if lock.last_fresh_keydown.as_ref() != Some(&keydown) {
1224                return YES;
1225            }
1226        } else {
1227            lock.last_fresh_keydown = Some(keydown.clone());
1228        }
1229        lock.input_during_keydown = Some(SmallVec::new());
1230        drop(lock);
1231
1232        // Send the event to the input context for IME handling, unless the `fn` modifier is
1233        // being pressed.
1234        // this will call back into `insert_text`, etc.
1235        if !fn_modifier {
1236            unsafe {
1237                let input_context: id = msg_send![this, inputContext];
1238                let _: BOOL = msg_send![input_context, handleEvent: native_event];
1239            }
1240        }
1241
1242        let mut handled = false;
1243        let mut lock = window_state.lock();
1244        let previous_keydown_inserted_text = lock.previous_keydown_inserted_text.take();
1245        let mut input_during_keydown = lock.input_during_keydown.take().unwrap();
1246        let mut callback = lock.event_callback.take();
1247        drop(lock);
1248
1249        let last_ime = input_during_keydown.pop();
1250        // on a brazilian keyboard typing `"` and then hitting `up` will cause two IME
1251        // events, one to unmark the quote, and one to send the up arrow.
1252        for ime in input_during_keydown {
1253            send_to_input_handler(this, ime);
1254        }
1255
1256        let is_composing =
1257            with_input_handler(this, |input_handler| input_handler.marked_text_range())
1258                .flatten()
1259                .is_some();
1260
1261        if let Some(ime) = last_ime {
1262            if let ImeInput::InsertText(text, _) = &ime {
1263                if !is_composing {
1264                    window_state.lock().previous_keydown_inserted_text = Some(text.clone());
1265                    if let Some(callback) = callback.as_mut() {
1266                        event.keystroke.ime_key = Some(text.clone());
1267                        handled = !callback(PlatformInput::KeyDown(event)).propagate;
1268                    }
1269                }
1270            }
1271
1272            if !handled {
1273                handled = true;
1274                send_to_input_handler(this, ime);
1275            }
1276        } else if !is_composing {
1277            let is_held = event.is_held;
1278
1279            if let Some(callback) = callback.as_mut() {
1280                handled = !callback(PlatformInput::KeyDown(event)).propagate;
1281            }
1282
1283            if !handled && is_held {
1284                if let Some(text) = previous_keydown_inserted_text {
1285                    // MacOS IME is a bit funky, and even when you've told it there's nothing to
1286                    // enter it will still swallow certain keys (e.g. 'f', 'j') and not others
1287                    // (e.g. 'n'). This is a problem for certain kinds of views, like the terminal.
1288                    with_input_handler(this, |input_handler| {
1289                        if input_handler.selected_text_range().is_none() {
1290                            handled = true;
1291                            input_handler.replace_text_in_range(None, &text)
1292                        }
1293                    });
1294                    window_state.lock().previous_keydown_inserted_text = Some(text);
1295                }
1296            }
1297        }
1298
1299        window_state.lock().event_callback = callback;
1300
1301        handled as BOOL
1302    } else {
1303        NO
1304    }
1305}
1306
1307extern "C" fn handle_view_event(this: &Object, _: Sel, native_event: id) {
1308    let window_state = unsafe { get_window_state(this) };
1309    let weak_window_state = Arc::downgrade(&window_state);
1310    let mut lock = window_state.as_ref().lock();
1311    let window_height = lock.content_size().height;
1312    let event = unsafe { PlatformInput::from_native(native_event, Some(window_height)) };
1313
1314    if let Some(mut event) = event {
1315        match &mut event {
1316            PlatformInput::MouseDown(
1317                event @ MouseDownEvent {
1318                    button: MouseButton::Left,
1319                    modifiers: Modifiers { control: true, .. },
1320                    ..
1321                },
1322            ) => {
1323                // On mac, a ctrl-left click should be handled as a right click.
1324                *event = MouseDownEvent {
1325                    button: MouseButton::Right,
1326                    modifiers: Modifiers {
1327                        control: false,
1328                        ..event.modifiers
1329                    },
1330                    click_count: 1,
1331                    ..*event
1332                };
1333            }
1334
1335            // Handles focusing click.
1336            PlatformInput::MouseDown(
1337                event @ MouseDownEvent {
1338                    button: MouseButton::Left,
1339                    ..
1340                },
1341            ) if (lock.first_mouse) => {
1342                *event = MouseDownEvent {
1343                    first_mouse: true,
1344                    ..*event
1345                };
1346                lock.first_mouse = false;
1347            }
1348
1349            // Because we map a ctrl-left_down to a right_down -> right_up let's ignore
1350            // the ctrl-left_up to avoid having a mismatch in button down/up events if the
1351            // user is still holding ctrl when releasing the left mouse button
1352            PlatformInput::MouseUp(
1353                event @ MouseUpEvent {
1354                    button: MouseButton::Left,
1355                    modifiers: Modifiers { control: true, .. },
1356                    ..
1357                },
1358            ) => {
1359                *event = MouseUpEvent {
1360                    button: MouseButton::Right,
1361                    modifiers: Modifiers {
1362                        control: false,
1363                        ..event.modifiers
1364                    },
1365                    click_count: 1,
1366                    ..*event
1367                };
1368            }
1369
1370            _ => {}
1371        };
1372
1373        match &event {
1374            PlatformInput::MouseMove(
1375                event @ MouseMoveEvent {
1376                    pressed_button: Some(_),
1377                    ..
1378                },
1379            ) => {
1380                // Synthetic drag is used for selecting long buffer contents while buffer is being scrolled.
1381                // External file drag and drop is able to emit its own synthetic mouse events which will conflict
1382                // with these ones.
1383                if !lock.external_files_dragged {
1384                    lock.synthetic_drag_counter += 1;
1385                    let executor = lock.executor.clone();
1386                    executor
1387                        .spawn(synthetic_drag(
1388                            weak_window_state,
1389                            lock.synthetic_drag_counter,
1390                            event.clone(),
1391                        ))
1392                        .detach();
1393                }
1394            }
1395
1396            PlatformInput::MouseUp(MouseUpEvent { .. }) => {
1397                lock.synthetic_drag_counter += 1;
1398            }
1399
1400            PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers }) => {
1401                // Only raise modifiers changed event when they have actually changed
1402                if let Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1403                    modifiers: prev_modifiers,
1404                })) = &lock.previous_modifiers_changed_event
1405                {
1406                    if prev_modifiers == modifiers {
1407                        return;
1408                    }
1409                }
1410
1411                lock.previous_modifiers_changed_event = Some(event.clone());
1412            }
1413
1414            _ => {}
1415        }
1416
1417        if let Some(mut callback) = lock.event_callback.take() {
1418            drop(lock);
1419            callback(event);
1420            window_state.lock().event_callback = Some(callback);
1421        }
1422    }
1423}
1424
1425// Allows us to receive `cmd-.` (the shortcut for closing a dialog)
1426// https://bugs.eclipse.org/bugs/show_bug.cgi?id=300620#c6
1427extern "C" fn cancel_operation(this: &Object, _sel: Sel, _sender: id) {
1428    let window_state = unsafe { get_window_state(this) };
1429    let mut lock = window_state.as_ref().lock();
1430
1431    let keystroke = Keystroke {
1432        modifiers: Default::default(),
1433        key: ".".into(),
1434        ime_key: None,
1435    };
1436    let event = PlatformInput::KeyDown(KeyDownEvent {
1437        keystroke: keystroke.clone(),
1438        is_held: false,
1439    });
1440
1441    lock.last_fresh_keydown = Some(keystroke);
1442    if let Some(mut callback) = lock.event_callback.take() {
1443        drop(lock);
1444        callback(event);
1445        window_state.lock().event_callback = Some(callback);
1446    }
1447}
1448
1449extern "C" fn window_did_change_occlusion_state(this: &Object, _: Sel, _: id) {
1450    let window_state = unsafe { get_window_state(this) };
1451    let lock = &mut *window_state.lock();
1452    unsafe {
1453        if lock
1454            .native_window
1455            .occlusionState()
1456            .contains(NSWindowOcclusionState::NSWindowOcclusionStateVisible)
1457        {
1458            lock.start_display_link();
1459        } else {
1460            lock.stop_display_link();
1461        }
1462    }
1463}
1464
1465extern "C" fn window_did_resize(this: &Object, _: Sel, _: id) {
1466    let window_state = unsafe { get_window_state(this) };
1467    window_state.as_ref().lock().move_traffic_light();
1468}
1469
1470extern "C" fn window_will_enter_fullscreen(this: &Object, _: Sel, _: id) {
1471    let window_state = unsafe { get_window_state(this) };
1472    let mut lock = window_state.as_ref().lock();
1473    lock.fullscreen_restore_bounds = lock.bounds();
1474}
1475
1476extern "C" fn window_did_move(this: &Object, _: Sel, _: id) {
1477    let window_state = unsafe { get_window_state(this) };
1478    let mut lock = window_state.as_ref().lock();
1479    if let Some(mut callback) = lock.moved_callback.take() {
1480        drop(lock);
1481        callback();
1482        window_state.lock().moved_callback = Some(callback);
1483    }
1484}
1485
1486extern "C" fn window_did_change_screen(this: &Object, _: Sel, _: id) {
1487    let window_state = unsafe { get_window_state(this) };
1488    let mut lock = window_state.as_ref().lock();
1489    lock.start_display_link();
1490}
1491
1492extern "C" fn window_did_change_key_status(this: &Object, selector: Sel, _: id) {
1493    let window_state = unsafe { get_window_state(this) };
1494    let lock = window_state.lock();
1495    let is_active = unsafe { lock.native_window.isKeyWindow() == YES };
1496
1497    // When opening a pop-up while the application isn't active, Cocoa sends a spurious
1498    // `windowDidBecomeKey` message to the previous key window even though that window
1499    // isn't actually key. This causes a bug if the application is later activated while
1500    // the pop-up is still open, making it impossible to activate the previous key window
1501    // even if the pop-up gets closed. The only way to activate it again is to de-activate
1502    // the app and re-activate it, which is a pretty bad UX.
1503    // The following code detects the spurious event and invokes `resignKeyWindow`:
1504    // in theory, we're not supposed to invoke this method manually but it balances out
1505    // the spurious `becomeKeyWindow` event and helps us work around that bug.
1506    if selector == sel!(windowDidBecomeKey:) && !is_active {
1507        unsafe {
1508            let _: () = msg_send![lock.native_window, resignKeyWindow];
1509            return;
1510        }
1511    }
1512
1513    let executor = lock.executor.clone();
1514    drop(lock);
1515    executor
1516        .spawn(async move {
1517            let mut lock = window_state.as_ref().lock();
1518            if let Some(mut callback) = lock.activate_callback.take() {
1519                drop(lock);
1520                callback(is_active);
1521                window_state.lock().activate_callback = Some(callback);
1522            };
1523        })
1524        .detach();
1525}
1526
1527extern "C" fn window_should_close(this: &Object, _: Sel, _: id) -> BOOL {
1528    let window_state = unsafe { get_window_state(this) };
1529    let mut lock = window_state.as_ref().lock();
1530    if let Some(mut callback) = lock.should_close_callback.take() {
1531        drop(lock);
1532        let should_close = callback();
1533        window_state.lock().should_close_callback = Some(callback);
1534        should_close as BOOL
1535    } else {
1536        YES
1537    }
1538}
1539
1540extern "C" fn close_window(this: &Object, _: Sel) {
1541    unsafe {
1542        let close_callback = {
1543            let window_state = get_window_state(this);
1544            let mut lock = window_state.as_ref().lock();
1545            lock.close_callback.take()
1546        };
1547
1548        if let Some(callback) = close_callback {
1549            callback();
1550        }
1551
1552        let _: () = msg_send![super(this, class!(NSWindow)), close];
1553    }
1554}
1555
1556extern "C" fn make_backing_layer(this: &Object, _: Sel) -> id {
1557    let window_state = unsafe { get_window_state(this) };
1558    let window_state = window_state.as_ref().lock();
1559    window_state.renderer.layer_ptr() as id
1560}
1561
1562extern "C" fn view_did_change_backing_properties(this: &Object, _: Sel) {
1563    let window_state = unsafe { get_window_state(this) };
1564    let mut lock = window_state.as_ref().lock();
1565
1566    let scale_factor = lock.scale_factor() as f64;
1567    let size = lock.content_size();
1568    let drawable_size: NSSize = NSSize {
1569        width: f64::from(size.width) * scale_factor,
1570        height: f64::from(size.height) * scale_factor,
1571    };
1572    unsafe {
1573        let _: () = msg_send![
1574            lock.renderer.layer(),
1575            setContentsScale: scale_factor
1576        ];
1577    }
1578
1579    lock.update_drawable_size(drawable_size);
1580
1581    if let Some(mut callback) = lock.resize_callback.take() {
1582        let content_size = lock.content_size();
1583        let scale_factor = lock.scale_factor();
1584        drop(lock);
1585        callback(content_size, scale_factor);
1586        window_state.as_ref().lock().resize_callback = Some(callback);
1587    };
1588}
1589
1590extern "C" fn set_frame_size(this: &Object, _: Sel, size: NSSize) {
1591    let window_state = unsafe { get_window_state(this) };
1592    let mut lock = window_state.as_ref().lock();
1593
1594    if lock.content_size() == size.into() {
1595        return;
1596    }
1597
1598    unsafe {
1599        let _: () = msg_send![super(this, class!(NSView)), setFrameSize: size];
1600    }
1601
1602    let scale_factor = lock.scale_factor() as f64;
1603    let drawable_size: NSSize = NSSize {
1604        width: size.width * scale_factor,
1605        height: size.height * scale_factor,
1606    };
1607
1608    lock.update_drawable_size(drawable_size);
1609
1610    drop(lock);
1611    let mut lock = window_state.lock();
1612    if let Some(mut callback) = lock.resize_callback.take() {
1613        let content_size = lock.content_size();
1614        let scale_factor = lock.scale_factor();
1615        drop(lock);
1616        callback(content_size, scale_factor);
1617        window_state.lock().resize_callback = Some(callback);
1618    };
1619}
1620
1621extern "C" fn display_layer(this: &Object, _: Sel, _: id) {
1622    let window_state = unsafe { get_window_state(this) };
1623    let mut lock = window_state.lock();
1624    if let Some(mut callback) = lock.request_frame_callback.take() {
1625        #[cfg(not(feature = "macos-blade"))]
1626        lock.renderer.set_presents_with_transaction(true);
1627        lock.stop_display_link();
1628        drop(lock);
1629        callback();
1630
1631        let mut lock = window_state.lock();
1632        lock.request_frame_callback = Some(callback);
1633        #[cfg(not(feature = "macos-blade"))]
1634        lock.renderer.set_presents_with_transaction(false);
1635        lock.start_display_link();
1636    }
1637}
1638
1639unsafe extern "C" fn step(view: *mut c_void) {
1640    let view = view as id;
1641    let window_state = unsafe { get_window_state(&*view) };
1642    let mut lock = window_state.lock();
1643
1644    if let Some(mut callback) = lock.request_frame_callback.take() {
1645        drop(lock);
1646        callback();
1647        window_state.lock().request_frame_callback = Some(callback);
1648    }
1649}
1650
1651extern "C" fn valid_attributes_for_marked_text(_: &Object, _: Sel) -> id {
1652    unsafe { msg_send![class!(NSArray), array] }
1653}
1654
1655extern "C" fn has_marked_text(this: &Object, _: Sel) -> BOOL {
1656    with_input_handler(this, |input_handler| input_handler.marked_text_range())
1657        .flatten()
1658        .is_some() as BOOL
1659}
1660
1661extern "C" fn marked_range(this: &Object, _: Sel) -> NSRange {
1662    with_input_handler(this, |input_handler| input_handler.marked_text_range())
1663        .flatten()
1664        .map_or(NSRange::invalid(), |range| range.into())
1665}
1666
1667extern "C" fn selected_range(this: &Object, _: Sel) -> NSRange {
1668    with_input_handler(this, |input_handler| input_handler.selected_text_range())
1669        .flatten()
1670        .map_or(NSRange::invalid(), |range| range.into())
1671}
1672
1673extern "C" fn first_rect_for_character_range(
1674    this: &Object,
1675    _: Sel,
1676    range: NSRange,
1677    _: id,
1678) -> NSRect {
1679    let frame = unsafe {
1680        let window = get_window_state(this).lock().native_window;
1681        NSView::frame(window)
1682    };
1683    with_input_handler(this, |input_handler| {
1684        input_handler.bounds_for_range(range.to_range()?)
1685    })
1686    .flatten()
1687    .map_or(
1688        NSRect::new(NSPoint::new(0., 0.), NSSize::new(0., 0.)),
1689        |bounds| {
1690            NSRect::new(
1691                NSPoint::new(
1692                    frame.origin.x + bounds.origin.x.0 as f64,
1693                    frame.origin.y + frame.size.height
1694                        - bounds.origin.y.0 as f64
1695                        - bounds.size.height.0 as f64,
1696                ),
1697                NSSize::new(bounds.size.width.0 as f64, bounds.size.height.0 as f64),
1698            )
1699        },
1700    )
1701}
1702
1703extern "C" fn insert_text(this: &Object, _: Sel, text: id, replacement_range: NSRange) {
1704    unsafe {
1705        let is_attributed_string: BOOL =
1706            msg_send![text, isKindOfClass: [class!(NSAttributedString)]];
1707        let text: id = if is_attributed_string == YES {
1708            msg_send![text, string]
1709        } else {
1710            text
1711        };
1712        let text = CStr::from_ptr(text.UTF8String() as *mut c_char)
1713            .to_str()
1714            .unwrap();
1715        let replacement_range = replacement_range.to_range();
1716        send_to_input_handler(
1717            this,
1718            ImeInput::InsertText(text.to_string(), replacement_range),
1719        );
1720    }
1721}
1722
1723extern "C" fn set_marked_text(
1724    this: &Object,
1725    _: Sel,
1726    text: id,
1727    selected_range: NSRange,
1728    replacement_range: NSRange,
1729) {
1730    unsafe {
1731        let is_attributed_string: BOOL =
1732            msg_send![text, isKindOfClass: [class!(NSAttributedString)]];
1733        let text: id = if is_attributed_string == YES {
1734            msg_send![text, string]
1735        } else {
1736            text
1737        };
1738        let selected_range = selected_range.to_range();
1739        let replacement_range = replacement_range.to_range();
1740        let text = CStr::from_ptr(text.UTF8String() as *mut c_char)
1741            .to_str()
1742            .unwrap();
1743
1744        send_to_input_handler(
1745            this,
1746            ImeInput::SetMarkedText(text.to_string(), replacement_range, selected_range),
1747        );
1748    }
1749}
1750extern "C" fn unmark_text(this: &Object, _: Sel) {
1751    send_to_input_handler(this, ImeInput::UnmarkText);
1752}
1753
1754extern "C" fn attributed_substring_for_proposed_range(
1755    this: &Object,
1756    _: Sel,
1757    range: NSRange,
1758    _actual_range: *mut c_void,
1759) -> id {
1760    with_input_handler(this, |input_handler| {
1761        let range = range.to_range()?;
1762        if range.is_empty() {
1763            return None;
1764        }
1765
1766        let selected_text = input_handler.text_for_range(range)?;
1767        unsafe {
1768            let string: id = msg_send![class!(NSAttributedString), alloc];
1769            let string: id = msg_send![string, initWithString: ns_string(&selected_text)];
1770            Some(string)
1771        }
1772    })
1773    .flatten()
1774    .unwrap_or(nil)
1775}
1776
1777extern "C" fn do_command_by_selector(_: &Object, _: Sel, _: Sel) {}
1778
1779extern "C" fn view_did_change_effective_appearance(this: &Object, _: Sel) {
1780    unsafe {
1781        let state = get_window_state(this);
1782        let mut lock = state.as_ref().lock();
1783        if let Some(mut callback) = lock.appearance_changed_callback.take() {
1784            drop(lock);
1785            callback();
1786            state.lock().appearance_changed_callback = Some(callback);
1787        }
1788    }
1789}
1790
1791extern "C" fn accepts_first_mouse(this: &Object, _: Sel, _: id) -> BOOL {
1792    let window_state = unsafe { get_window_state(this) };
1793    let mut lock = window_state.as_ref().lock();
1794    lock.first_mouse = true;
1795    YES
1796}
1797
1798extern "C" fn dragging_entered(this: &Object, _: Sel, dragging_info: id) -> NSDragOperation {
1799    let window_state = unsafe { get_window_state(this) };
1800    let position = drag_event_position(&window_state, dragging_info);
1801    let paths = external_paths_from_event(dragging_info);
1802    if let Some(event) =
1803        paths.map(|paths| PlatformInput::FileDrop(FileDropEvent::Entered { position, paths }))
1804    {
1805        if send_new_event(&window_state, event) {
1806            window_state.lock().external_files_dragged = true;
1807            return NSDragOperationCopy;
1808        }
1809    }
1810    NSDragOperationNone
1811}
1812
1813extern "C" fn dragging_updated(this: &Object, _: Sel, dragging_info: id) -> NSDragOperation {
1814    let window_state = unsafe { get_window_state(this) };
1815    let position = drag_event_position(&window_state, dragging_info);
1816    if send_new_event(
1817        &window_state,
1818        PlatformInput::FileDrop(FileDropEvent::Pending { position }),
1819    ) {
1820        NSDragOperationCopy
1821    } else {
1822        NSDragOperationNone
1823    }
1824}
1825
1826extern "C" fn dragging_exited(this: &Object, _: Sel, _: id) {
1827    let window_state = unsafe { get_window_state(this) };
1828    send_new_event(
1829        &window_state,
1830        PlatformInput::FileDrop(FileDropEvent::Exited),
1831    );
1832    window_state.lock().external_files_dragged = false;
1833}
1834
1835extern "C" fn perform_drag_operation(this: &Object, _: Sel, dragging_info: id) -> BOOL {
1836    let window_state = unsafe { get_window_state(this) };
1837    let position = drag_event_position(&window_state, dragging_info);
1838    if send_new_event(
1839        &window_state,
1840        PlatformInput::FileDrop(FileDropEvent::Submit { position }),
1841    ) {
1842        YES
1843    } else {
1844        NO
1845    }
1846}
1847
1848fn external_paths_from_event(dragging_info: *mut Object) -> Option<ExternalPaths> {
1849    let mut paths = SmallVec::new();
1850    let pasteboard: id = unsafe { msg_send![dragging_info, draggingPasteboard] };
1851    let filenames = unsafe { NSPasteboard::propertyListForType(pasteboard, NSFilenamesPboardType) };
1852    if filenames == nil {
1853        return None;
1854    }
1855    for file in unsafe { filenames.iter() } {
1856        let path = unsafe {
1857            let f = NSString::UTF8String(file);
1858            CStr::from_ptr(f).to_string_lossy().into_owned()
1859        };
1860        paths.push(PathBuf::from(path))
1861    }
1862    Some(ExternalPaths(paths))
1863}
1864
1865extern "C" fn conclude_drag_operation(this: &Object, _: Sel, _: id) {
1866    let window_state = unsafe { get_window_state(this) };
1867    send_new_event(
1868        &window_state,
1869        PlatformInput::FileDrop(FileDropEvent::Exited),
1870    );
1871}
1872
1873async fn synthetic_drag(
1874    window_state: Weak<Mutex<MacWindowState>>,
1875    drag_id: usize,
1876    event: MouseMoveEvent,
1877) {
1878    loop {
1879        Timer::after(Duration::from_millis(16)).await;
1880        if let Some(window_state) = window_state.upgrade() {
1881            let mut lock = window_state.lock();
1882            if lock.synthetic_drag_counter == drag_id {
1883                if let Some(mut callback) = lock.event_callback.take() {
1884                    drop(lock);
1885                    callback(PlatformInput::MouseMove(event.clone()));
1886                    window_state.lock().event_callback = Some(callback);
1887                }
1888            } else {
1889                break;
1890            }
1891        }
1892    }
1893}
1894
1895fn send_new_event(window_state_lock: &Mutex<MacWindowState>, e: PlatformInput) -> bool {
1896    let window_state = window_state_lock.lock().event_callback.take();
1897    if let Some(mut callback) = window_state {
1898        callback(e);
1899        window_state_lock.lock().event_callback = Some(callback);
1900        true
1901    } else {
1902        false
1903    }
1904}
1905
1906fn drag_event_position(window_state: &Mutex<MacWindowState>, dragging_info: id) -> Point<Pixels> {
1907    let drag_location: NSPoint = unsafe { msg_send![dragging_info, draggingLocation] };
1908    convert_mouse_position(drag_location, window_state.lock().content_size().height)
1909}
1910
1911fn with_input_handler<F, R>(window: &Object, f: F) -> Option<R>
1912where
1913    F: FnOnce(&mut PlatformInputHandler) -> R,
1914{
1915    let window_state = unsafe { get_window_state(window) };
1916    let mut lock = window_state.as_ref().lock();
1917    if let Some(mut input_handler) = lock.input_handler.take() {
1918        drop(lock);
1919        let result = f(&mut input_handler);
1920        window_state.lock().input_handler = Some(input_handler);
1921        Some(result)
1922    } else {
1923        None
1924    }
1925}
1926
1927fn send_to_input_handler(window: &Object, ime: ImeInput) {
1928    unsafe {
1929        let window_state = get_window_state(window);
1930        let mut lock = window_state.lock();
1931        if let Some(ime_input) = lock.input_during_keydown.as_mut() {
1932            ime_input.push(ime);
1933            return;
1934        }
1935        if let Some(mut input_handler) = lock.input_handler.take() {
1936            drop(lock);
1937            match ime {
1938                ImeInput::InsertText(text, range) => {
1939                    input_handler.replace_text_in_range(range, &text)
1940                }
1941                ImeInput::SetMarkedText(text, range, marked_range) => {
1942                    input_handler.replace_and_mark_text_in_range(range, &text, marked_range)
1943                }
1944                ImeInput::UnmarkText => input_handler.unmark_text(),
1945            }
1946            window_state.lock().input_handler = Some(input_handler);
1947        }
1948    }
1949}
1950
1951unsafe fn display_id_for_screen(screen: id) -> CGDirectDisplayID {
1952    let device_description = NSScreen::deviceDescription(screen);
1953    let screen_number_key: id = NSString::alloc(nil).init_str("NSScreenNumber");
1954    let screen_number = device_description.objectForKey_(screen_number_key);
1955    let screen_number: NSUInteger = msg_send![screen_number, unsignedIntegerValue];
1956    screen_number as CGDirectDisplayID
1957}