events.rs

   1use std::rc::Rc;
   2
   3use ::util::ResultExt;
   4use anyhow::Context as _;
   5use windows::{
   6    Win32::{
   7        Foundation::*,
   8        Graphics::Gdi::*,
   9        System::SystemServices::*,
  10        UI::{
  11            Controls::*,
  12            HiDpi::*,
  13            Input::{Ime::*, KeyboardAndMouse::*},
  14            WindowsAndMessaging::*,
  15        },
  16    },
  17    core::PCWSTR,
  18};
  19
  20use crate::*;
  21use gpui::*;
  22
  23pub(crate) const WM_GPUI_CURSOR_STYLE_CHANGED: u32 = WM_USER + 1;
  24pub(crate) const WM_GPUI_CLOSE_ONE_WINDOW: u32 = WM_USER + 2;
  25pub(crate) const WM_GPUI_TASK_DISPATCHED_ON_MAIN_THREAD: u32 = WM_USER + 3;
  26pub(crate) const WM_GPUI_DOCK_MENU_ACTION: u32 = WM_USER + 4;
  27pub(crate) const WM_GPUI_FORCE_UPDATE_WINDOW: u32 = WM_USER + 5;
  28pub(crate) const WM_GPUI_KEYBOARD_LAYOUT_CHANGED: u32 = WM_USER + 6;
  29pub(crate) const WM_GPUI_GPU_DEVICE_LOST: u32 = WM_USER + 7;
  30pub(crate) const WM_GPUI_KEYDOWN: u32 = WM_USER + 8;
  31
  32const SIZE_MOVE_LOOP_TIMER_ID: usize = 1;
  33
  34impl WindowsWindowInner {
  35    pub(crate) fn handle_msg(
  36        self: &Rc<Self>,
  37        handle: HWND,
  38        msg: u32,
  39        wparam: WPARAM,
  40        lparam: LPARAM,
  41    ) -> LRESULT {
  42        let handled = match msg {
  43            // eagerly activate the window, so calls to `active_window` will work correctly
  44            WM_MOUSEACTIVATE => {
  45                unsafe { SetActiveWindow(handle).ok() };
  46                None
  47            }
  48            WM_ACTIVATE => self.handle_activate_msg(wparam),
  49            WM_CREATE => self.handle_create_msg(handle),
  50            WM_MOVE => self.handle_move_msg(handle, lparam),
  51            WM_SIZE => self.handle_size_msg(wparam, lparam),
  52            WM_GETMINMAXINFO => self.handle_get_min_max_info_msg(lparam),
  53            WM_ENTERSIZEMOVE | WM_ENTERMENULOOP => self.handle_size_move_loop(handle),
  54            WM_EXITSIZEMOVE | WM_EXITMENULOOP => self.handle_size_move_loop_exit(handle),
  55            WM_TIMER => self.handle_timer_msg(handle, wparam),
  56            WM_NCCALCSIZE => self.handle_calc_client_size(handle, wparam, lparam),
  57            WM_DPICHANGED => self.handle_dpi_changed_msg(handle, wparam, lparam),
  58            WM_DISPLAYCHANGE => self.handle_display_change_msg(handle),
  59            WM_NCHITTEST => self.handle_hit_test_msg(handle, lparam),
  60            WM_PAINT => self.handle_paint_msg(handle),
  61            WM_CLOSE => self.handle_close_msg(),
  62            WM_DESTROY => self.handle_destroy_msg(handle),
  63            WM_MOUSEMOVE => self.handle_mouse_move_msg(handle, lparam, wparam),
  64            WM_MOUSELEAVE | WM_NCMOUSELEAVE => self.handle_mouse_leave_msg(),
  65            WM_NCMOUSEMOVE => self.handle_nc_mouse_move_msg(handle, lparam),
  66            // Treat double click as a second single click, since we track the double clicks ourselves.
  67            // If you don't interact with any elements, this will fall through to the windows default
  68            // behavior of toggling whether the window is maximized.
  69            WM_NCLBUTTONDBLCLK | WM_NCLBUTTONDOWN => {
  70                self.handle_nc_mouse_down_msg(handle, MouseButton::Left, wparam, lparam)
  71            }
  72            WM_NCRBUTTONDOWN => {
  73                self.handle_nc_mouse_down_msg(handle, MouseButton::Right, wparam, lparam)
  74            }
  75            WM_NCMBUTTONDOWN => {
  76                self.handle_nc_mouse_down_msg(handle, MouseButton::Middle, wparam, lparam)
  77            }
  78            WM_NCLBUTTONUP => {
  79                self.handle_nc_mouse_up_msg(handle, MouseButton::Left, wparam, lparam)
  80            }
  81            WM_NCRBUTTONUP => {
  82                self.handle_nc_mouse_up_msg(handle, MouseButton::Right, wparam, lparam)
  83            }
  84            WM_NCMBUTTONUP => {
  85                self.handle_nc_mouse_up_msg(handle, MouseButton::Middle, wparam, lparam)
  86            }
  87            WM_LBUTTONDOWN => self.handle_mouse_down_msg(handle, MouseButton::Left, lparam),
  88            WM_RBUTTONDOWN => self.handle_mouse_down_msg(handle, MouseButton::Right, lparam),
  89            WM_MBUTTONDOWN => self.handle_mouse_down_msg(handle, MouseButton::Middle, lparam),
  90            WM_XBUTTONDOWN => {
  91                self.handle_xbutton_msg(handle, wparam, lparam, Self::handle_mouse_down_msg)
  92            }
  93            WM_LBUTTONUP => self.handle_mouse_up_msg(handle, MouseButton::Left, lparam),
  94            WM_RBUTTONUP => self.handle_mouse_up_msg(handle, MouseButton::Right, lparam),
  95            WM_MBUTTONUP => self.handle_mouse_up_msg(handle, MouseButton::Middle, lparam),
  96            WM_XBUTTONUP => {
  97                self.handle_xbutton_msg(handle, wparam, lparam, Self::handle_mouse_up_msg)
  98            }
  99            WM_MOUSEWHEEL => self.handle_mouse_wheel_msg(handle, wparam, lparam),
 100            WM_MOUSEHWHEEL => self.handle_mouse_horizontal_wheel_msg(handle, wparam, lparam),
 101            WM_SYSKEYUP => self.handle_syskeyup_msg(wparam, lparam),
 102            WM_KEYUP => self.handle_keyup_msg(wparam, lparam),
 103            WM_GPUI_KEYDOWN => self.handle_keydown_msg(wparam, lparam),
 104            WM_CHAR => self.handle_char_msg(wparam),
 105            WM_IME_STARTCOMPOSITION => self.handle_ime_position(handle),
 106            WM_IME_COMPOSITION => self.handle_ime_composition(handle, lparam),
 107            WM_SETCURSOR => self.handle_set_cursor(handle, lparam),
 108            WM_SETTINGCHANGE => self.handle_system_settings_changed(handle, wparam, lparam),
 109            WM_INPUTLANGCHANGE => self.handle_input_language_changed(),
 110            WM_SHOWWINDOW => self.handle_window_visibility_changed(handle, wparam),
 111            WM_GPUI_CURSOR_STYLE_CHANGED => self.handle_cursor_changed(lparam),
 112            WM_GPUI_FORCE_UPDATE_WINDOW => self.draw_window(handle, true),
 113            WM_GPUI_GPU_DEVICE_LOST => self.handle_device_lost(lparam),
 114            _ => None,
 115        };
 116        if let Some(n) = handled {
 117            LRESULT(n)
 118        } else {
 119            unsafe { DefWindowProcW(handle, msg, wparam, lparam) }
 120        }
 121    }
 122
 123    fn handle_move_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 124        let origin = logical_point(
 125            lparam.signed_loword() as f32,
 126            lparam.signed_hiword() as f32,
 127            self.state.scale_factor.get(),
 128        );
 129        self.state.origin.set(origin);
 130        let size = self.state.logical_size.get();
 131        let center_x = origin.x.as_f32() + size.width.as_f32() / 2.;
 132        let center_y = origin.y.as_f32() + size.height.as_f32() / 2.;
 133        let monitor_bounds = self.state.display.get().bounds();
 134        if center_x < monitor_bounds.left().as_f32()
 135            || center_x > monitor_bounds.right().as_f32()
 136            || center_y < monitor_bounds.top().as_f32()
 137            || center_y > monitor_bounds.bottom().as_f32()
 138        {
 139            // center of the window may have moved to another monitor
 140            let monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 141            // minimize the window can trigger this event too, in this case,
 142            // monitor is invalid, we do nothing.
 143            if !monitor.is_invalid() && self.state.display.get().handle != monitor {
 144                // we will get the same monitor if we only have one
 145                self.state
 146                    .display
 147                    .set(WindowsDisplay::new_with_handle(monitor).log_err()?);
 148            }
 149        }
 150        if let Some(mut callback) = self.state.callbacks.moved.take() {
 151            callback();
 152            self.state.callbacks.moved.set(Some(callback));
 153        }
 154        Some(0)
 155    }
 156
 157    fn handle_get_min_max_info_msg(&self, lparam: LPARAM) -> Option<isize> {
 158        let min_size = self.state.min_size?;
 159        let scale_factor = self.state.scale_factor.get();
 160        let boarder_offset = &self.state.border_offset;
 161
 162        unsafe {
 163            let minmax_info = &mut *(lparam.0 as *mut MINMAXINFO);
 164            minmax_info.ptMinTrackSize.x = min_size.width.scale(scale_factor).as_f32() as i32
 165                + boarder_offset.width_offset.get();
 166            minmax_info.ptMinTrackSize.y = min_size.height.scale(scale_factor).as_f32() as i32
 167                + boarder_offset.height_offset.get();
 168        }
 169        Some(0)
 170    }
 171
 172    fn handle_size_msg(&self, wparam: WPARAM, lparam: LPARAM) -> Option<isize> {
 173        // Don't resize the renderer when the window is minimized, but record that it was minimized so
 174        // that on restore the swap chain can be recreated via `update_drawable_size_even_if_unchanged`.
 175        if wparam.0 == SIZE_MINIMIZED as usize {
 176            self.state
 177                .restore_from_minimized
 178                .set(self.state.callbacks.request_frame.take());
 179            return Some(0);
 180        }
 181
 182        let width = lparam.loword().max(1) as i32;
 183        let height = lparam.hiword().max(1) as i32;
 184        let new_size = size(DevicePixels(width), DevicePixels(height));
 185
 186        let scale_factor = self.state.scale_factor.get();
 187        let mut should_resize_renderer = false;
 188        if let Some(restore_from_minimized) = self.state.restore_from_minimized.take() {
 189            self.state
 190                .callbacks
 191                .request_frame
 192                .set(Some(restore_from_minimized));
 193        } else {
 194            should_resize_renderer = true;
 195        }
 196
 197        self.handle_size_change(new_size, scale_factor, should_resize_renderer);
 198        Some(0)
 199    }
 200
 201    fn handle_size_change(
 202        &self,
 203        device_size: Size<DevicePixels>,
 204        scale_factor: f32,
 205        should_resize_renderer: bool,
 206    ) {
 207        let new_logical_size = device_size.to_pixels(scale_factor);
 208
 209        self.state.logical_size.set(new_logical_size);
 210        if should_resize_renderer
 211            && let Err(e) = self.state.renderer.borrow_mut().resize(device_size)
 212        {
 213            log::error!("Failed to resize renderer, invalidating devices: {}", e);
 214            self.state
 215                .invalidate_devices
 216                .store(true, std::sync::atomic::Ordering::Release);
 217        }
 218        if let Some(mut callback) = self.state.callbacks.resize.take() {
 219            callback(new_logical_size, scale_factor);
 220            self.state.callbacks.resize.set(Some(callback));
 221        }
 222    }
 223
 224    fn handle_size_move_loop(&self, handle: HWND) -> Option<isize> {
 225        unsafe {
 226            let ret = SetTimer(
 227                Some(handle),
 228                SIZE_MOVE_LOOP_TIMER_ID,
 229                USER_TIMER_MINIMUM,
 230                None,
 231            );
 232            if ret == 0 {
 233                log::error!(
 234                    "unable to create timer: {}",
 235                    std::io::Error::last_os_error()
 236                );
 237            }
 238        }
 239        None
 240    }
 241
 242    fn handle_size_move_loop_exit(&self, handle: HWND) -> Option<isize> {
 243        unsafe {
 244            KillTimer(Some(handle), SIZE_MOVE_LOOP_TIMER_ID).log_err();
 245        }
 246        None
 247    }
 248
 249    fn handle_timer_msg(&self, handle: HWND, wparam: WPARAM) -> Option<isize> {
 250        if wparam.0 == SIZE_MOVE_LOOP_TIMER_ID {
 251            let mut runnables = self.main_receiver.clone().try_iter();
 252            while let Some(Ok(runnable)) = runnables.next() {
 253                WindowsDispatcher::execute_runnable(runnable);
 254            }
 255            self.handle_paint_msg(handle)
 256        } else {
 257            None
 258        }
 259    }
 260
 261    fn handle_paint_msg(&self, handle: HWND) -> Option<isize> {
 262        self.draw_window(handle, false)
 263    }
 264
 265    fn handle_close_msg(&self) -> Option<isize> {
 266        let mut callback = self.state.callbacks.should_close.take()?;
 267        let should_close = callback();
 268        self.state.callbacks.should_close.set(Some(callback));
 269        if should_close { None } else { Some(0) }
 270    }
 271
 272    fn handle_destroy_msg(&self, handle: HWND) -> Option<isize> {
 273        let callback = { self.state.callbacks.close.take() };
 274        // Re-enable parent window if this was a modal dialog
 275        if let Some(parent_hwnd) = self.parent_hwnd {
 276            unsafe {
 277                let _ = EnableWindow(parent_hwnd, true);
 278                let _ = SetForegroundWindow(parent_hwnd);
 279            }
 280        }
 281
 282        if let Some(callback) = callback {
 283            callback();
 284        }
 285        unsafe {
 286            PostMessageW(
 287                Some(self.platform_window_handle),
 288                WM_GPUI_CLOSE_ONE_WINDOW,
 289                WPARAM(self.validation_number),
 290                LPARAM(handle.0 as isize),
 291            )
 292            .log_err();
 293        }
 294        Some(0)
 295    }
 296
 297    fn handle_mouse_move_msg(&self, handle: HWND, lparam: LPARAM, wparam: WPARAM) -> Option<isize> {
 298        self.start_tracking_mouse(handle, TME_LEAVE);
 299
 300        let Some(mut func) = self.state.callbacks.input.take() else {
 301            return Some(1);
 302        };
 303        let scale_factor = self.state.scale_factor.get();
 304
 305        let pressed_button = match MODIFIERKEYS_FLAGS(wparam.loword() as u32) {
 306            flags if flags.contains(MK_LBUTTON) => Some(MouseButton::Left),
 307            flags if flags.contains(MK_RBUTTON) => Some(MouseButton::Right),
 308            flags if flags.contains(MK_MBUTTON) => Some(MouseButton::Middle),
 309            flags if flags.contains(MK_XBUTTON1) => {
 310                Some(MouseButton::Navigate(NavigationDirection::Back))
 311            }
 312            flags if flags.contains(MK_XBUTTON2) => {
 313                Some(MouseButton::Navigate(NavigationDirection::Forward))
 314            }
 315            _ => None,
 316        };
 317        let x = lparam.signed_loword() as f32;
 318        let y = lparam.signed_hiword() as f32;
 319        let input = PlatformInput::MouseMove(MouseMoveEvent {
 320            position: logical_point(x, y, scale_factor),
 321            pressed_button,
 322            modifiers: current_modifiers(),
 323        });
 324        let handled = !func(input).propagate;
 325        self.state.callbacks.input.set(Some(func));
 326
 327        if handled { Some(0) } else { Some(1) }
 328    }
 329
 330    fn handle_mouse_leave_msg(&self) -> Option<isize> {
 331        self.state.hovered.set(false);
 332        if let Some(mut callback) = self.state.callbacks.hovered_status_change.take() {
 333            callback(false);
 334            self.state
 335                .callbacks
 336                .hovered_status_change
 337                .set(Some(callback));
 338        }
 339
 340        Some(0)
 341    }
 342
 343    fn handle_syskeyup_msg(&self, wparam: WPARAM, lparam: LPARAM) -> Option<isize> {
 344        let input = handle_key_event(wparam, lparam, &self.state, |keystroke, _| {
 345            PlatformInput::KeyUp(KeyUpEvent { keystroke })
 346        })?;
 347        let mut func = self.state.callbacks.input.take()?;
 348
 349        func(input);
 350        self.state.callbacks.input.set(Some(func));
 351
 352        // Always return 0 to indicate that the message was handled, so we could properly handle `ModifiersChanged` event.
 353        Some(0)
 354    }
 355
 356    // It's a known bug that you can't trigger `ctrl-shift-0`. See:
 357    // https://superuser.com/questions/1455762/ctrl-shift-number-key-combination-has-stopped-working-for-a-few-numbers
 358    fn handle_keydown_msg(&self, wparam: WPARAM, lparam: LPARAM) -> Option<isize> {
 359        let Some(input) = handle_key_event(
 360            wparam,
 361            lparam,
 362            &self.state,
 363            |keystroke, prefer_character_input| {
 364                PlatformInput::KeyDown(KeyDownEvent {
 365                    keystroke,
 366                    is_held: lparam.0 & (0x1 << 30) > 0,
 367                    prefer_character_input,
 368                })
 369            },
 370        ) else {
 371            return Some(1);
 372        };
 373
 374        let Some(mut func) = self.state.callbacks.input.take() else {
 375            return Some(1);
 376        };
 377
 378        let handled = !func(input).propagate;
 379
 380        self.state.callbacks.input.set(Some(func));
 381
 382        if handled { Some(0) } else { Some(1) }
 383    }
 384
 385    fn handle_keyup_msg(&self, wparam: WPARAM, lparam: LPARAM) -> Option<isize> {
 386        let Some(input) = handle_key_event(wparam, lparam, &self.state, |keystroke, _| {
 387            PlatformInput::KeyUp(KeyUpEvent { keystroke })
 388        }) else {
 389            return Some(1);
 390        };
 391
 392        let Some(mut func) = self.state.callbacks.input.take() else {
 393            return Some(1);
 394        };
 395
 396        let handled = !func(input).propagate;
 397        self.state.callbacks.input.set(Some(func));
 398
 399        if handled { Some(0) } else { Some(1) }
 400    }
 401
 402    fn handle_char_msg(&self, wparam: WPARAM) -> Option<isize> {
 403        let input = self.parse_char_message(wparam)?;
 404        self.with_input_handler(|input_handler| {
 405            input_handler.replace_text_in_range(None, &input);
 406        });
 407
 408        Some(0)
 409    }
 410
 411    fn handle_mouse_down_msg(
 412        &self,
 413        handle: HWND,
 414        button: MouseButton,
 415        lparam: LPARAM,
 416    ) -> Option<isize> {
 417        unsafe { SetCapture(handle) };
 418
 419        let Some(mut func) = self.state.callbacks.input.take() else {
 420            return Some(1);
 421        };
 422        let x = lparam.signed_loword();
 423        let y = lparam.signed_hiword();
 424        let physical_point = point(DevicePixels(x as i32), DevicePixels(y as i32));
 425        let click_count = self.state.click_state.update(button, physical_point);
 426        let scale_factor = self.state.scale_factor.get();
 427
 428        let input = PlatformInput::MouseDown(MouseDownEvent {
 429            button,
 430            position: logical_point(x as f32, y as f32, scale_factor),
 431            modifiers: current_modifiers(),
 432            click_count,
 433            first_mouse: false,
 434        });
 435        let handled = !func(input).propagate;
 436        self.state.callbacks.input.set(Some(func));
 437
 438        if handled { Some(0) } else { Some(1) }
 439    }
 440
 441    fn handle_mouse_up_msg(
 442        &self,
 443        _handle: HWND,
 444        button: MouseButton,
 445        lparam: LPARAM,
 446    ) -> Option<isize> {
 447        unsafe { ReleaseCapture().log_err() };
 448
 449        let Some(mut func) = self.state.callbacks.input.take() else {
 450            return Some(1);
 451        };
 452        let x = lparam.signed_loword() as f32;
 453        let y = lparam.signed_hiword() as f32;
 454        let click_count = self.state.click_state.current_count.get();
 455        let scale_factor = self.state.scale_factor.get();
 456
 457        let input = PlatformInput::MouseUp(MouseUpEvent {
 458            button,
 459            position: logical_point(x, y, scale_factor),
 460            modifiers: current_modifiers(),
 461            click_count,
 462        });
 463        let handled = !func(input).propagate;
 464        self.state.callbacks.input.set(Some(func));
 465
 466        if handled { Some(0) } else { Some(1) }
 467    }
 468
 469    fn handle_xbutton_msg(
 470        &self,
 471        handle: HWND,
 472        wparam: WPARAM,
 473        lparam: LPARAM,
 474        handler: impl Fn(&Self, HWND, MouseButton, LPARAM) -> Option<isize>,
 475    ) -> Option<isize> {
 476        let nav_dir = match wparam.hiword() {
 477            XBUTTON1 => NavigationDirection::Back,
 478            XBUTTON2 => NavigationDirection::Forward,
 479            _ => return Some(1),
 480        };
 481        handler(self, handle, MouseButton::Navigate(nav_dir), lparam)
 482    }
 483
 484    fn handle_mouse_wheel_msg(
 485        &self,
 486        handle: HWND,
 487        wparam: WPARAM,
 488        lparam: LPARAM,
 489    ) -> Option<isize> {
 490        let modifiers = current_modifiers();
 491
 492        let Some(mut func) = self.state.callbacks.input.take() else {
 493            return Some(1);
 494        };
 495        let scale_factor = self.state.scale_factor.get();
 496        let wheel_scroll_amount = match modifiers.shift {
 497            true => self
 498                .system_settings()
 499                .mouse_wheel_settings
 500                .wheel_scroll_chars
 501                .get(),
 502            false => self
 503                .system_settings()
 504                .mouse_wheel_settings
 505                .wheel_scroll_lines
 506                .get(),
 507        };
 508
 509        let wheel_distance =
 510            (wparam.signed_hiword() as f32 / WHEEL_DELTA as f32) * wheel_scroll_amount as f32;
 511        let mut cursor_point = POINT {
 512            x: lparam.signed_loword().into(),
 513            y: lparam.signed_hiword().into(),
 514        };
 515        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 516        let input = PlatformInput::ScrollWheel(ScrollWheelEvent {
 517            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 518            delta: ScrollDelta::Lines(match modifiers.shift {
 519                true => Point {
 520                    x: wheel_distance,
 521                    y: 0.0,
 522                },
 523                false => Point {
 524                    y: wheel_distance,
 525                    x: 0.0,
 526                },
 527            }),
 528            modifiers,
 529            touch_phase: TouchPhase::Moved,
 530        });
 531        let handled = !func(input).propagate;
 532        self.state.callbacks.input.set(Some(func));
 533
 534        if handled { Some(0) } else { Some(1) }
 535    }
 536
 537    fn handle_mouse_horizontal_wheel_msg(
 538        &self,
 539        handle: HWND,
 540        wparam: WPARAM,
 541        lparam: LPARAM,
 542    ) -> Option<isize> {
 543        let Some(mut func) = self.state.callbacks.input.take() else {
 544            return Some(1);
 545        };
 546        let scale_factor = self.state.scale_factor.get();
 547        let wheel_scroll_chars = self
 548            .system_settings()
 549            .mouse_wheel_settings
 550            .wheel_scroll_chars
 551            .get();
 552
 553        let wheel_distance =
 554            (-wparam.signed_hiword() as f32 / WHEEL_DELTA as f32) * wheel_scroll_chars as f32;
 555        let mut cursor_point = POINT {
 556            x: lparam.signed_loword().into(),
 557            y: lparam.signed_hiword().into(),
 558        };
 559        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 560        let event = PlatformInput::ScrollWheel(ScrollWheelEvent {
 561            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 562            delta: ScrollDelta::Lines(Point {
 563                x: wheel_distance,
 564                y: 0.0,
 565            }),
 566            modifiers: current_modifiers(),
 567            touch_phase: TouchPhase::Moved,
 568        });
 569        let handled = !func(event).propagate;
 570        self.state.callbacks.input.set(Some(func));
 571
 572        if handled { Some(0) } else { Some(1) }
 573    }
 574
 575    fn retrieve_caret_position(&self) -> Option<POINT> {
 576        self.with_input_handler_and_scale_factor(|input_handler, scale_factor| {
 577            let caret_range = input_handler.selected_text_range(false)?;
 578            let caret_position = input_handler.bounds_for_range(caret_range.range)?;
 579            Some(POINT {
 580                // logical to physical
 581                x: (caret_position.origin.x.as_f32() * scale_factor) as i32,
 582                y: (caret_position.origin.y.as_f32() * scale_factor) as i32
 583                    + ((caret_position.size.height.as_f32() * scale_factor) as i32 / 2),
 584            })
 585        })
 586    }
 587
 588    fn handle_ime_position(&self, handle: HWND) -> Option<isize> {
 589        if let Some(caret_position) = self.retrieve_caret_position() {
 590            self.update_ime_position(handle, caret_position);
 591        }
 592        Some(0)
 593    }
 594
 595    pub(crate) fn update_ime_position(&self, handle: HWND, caret_position: POINT) {
 596        let Some(ctx) = ImeContext::get(handle) else {
 597            return;
 598        };
 599        unsafe {
 600            ImmSetCompositionWindow(
 601                *ctx,
 602                &COMPOSITIONFORM {
 603                    dwStyle: CFS_POINT,
 604                    ptCurrentPos: caret_position,
 605                    ..Default::default()
 606                },
 607            )
 608            .ok()
 609            .log_err();
 610
 611            ImmSetCandidateWindow(
 612                *ctx,
 613                &CANDIDATEFORM {
 614                    dwStyle: CFS_CANDIDATEPOS,
 615                    ptCurrentPos: caret_position,
 616                    ..Default::default()
 617                },
 618            )
 619            .ok()
 620            .log_err();
 621        }
 622    }
 623
 624    fn update_ime_enabled(&self, handle: HWND) {
 625        let ime_enabled = self
 626            .with_input_handler(|input_handler| input_handler.query_accepts_text_input())
 627            .unwrap_or(false);
 628        if ime_enabled == self.state.ime_enabled.get() {
 629            return;
 630        }
 631        self.state.ime_enabled.set(ime_enabled);
 632        unsafe {
 633            if ime_enabled {
 634                ImmAssociateContextEx(handle, HIMC::default(), IACE_DEFAULT)
 635                    .ok()
 636                    .log_err();
 637            } else {
 638                if let Some(ctx) = ImeContext::get(handle) {
 639                    ImmNotifyIME(*ctx, NI_COMPOSITIONSTR, CPS_COMPLETE, 0)
 640                        .ok()
 641                        .log_err();
 642                }
 643                ImmAssociateContextEx(handle, HIMC::default(), 0)
 644                    .ok()
 645                    .log_err();
 646            }
 647        }
 648    }
 649
 650    fn handle_ime_composition(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 651        let ctx = ImeContext::get(handle)?;
 652        self.handle_ime_composition_inner(*ctx, lparam)
 653    }
 654
 655    fn handle_ime_composition_inner(&self, ctx: HIMC, lparam: LPARAM) -> Option<isize> {
 656        let lparam = lparam.0 as u32;
 657        if lparam == 0 {
 658            // Japanese IME may send this message with lparam = 0, which indicates that
 659            // there is no composition string.
 660            self.with_input_handler(|input_handler| {
 661                input_handler.replace_text_in_range(None, "");
 662            })?;
 663            Some(0)
 664        } else {
 665            if lparam & GCS_RESULTSTR.0 > 0 {
 666                let comp_result = parse_ime_composition_string(ctx, GCS_RESULTSTR)?;
 667                self.with_input_handler(|input_handler| {
 668                    input_handler
 669                        .replace_text_in_range(None, &String::from_utf16_lossy(&comp_result));
 670                })?;
 671            }
 672            if lparam & GCS_COMPSTR.0 > 0 {
 673                let comp_string = parse_ime_composition_string(ctx, GCS_COMPSTR)?;
 674                let caret_pos =
 675                    (!comp_string.is_empty() && lparam & GCS_CURSORPOS.0 > 0).then(|| {
 676                        let cursor_pos = retrieve_composition_cursor_position(ctx);
 677                        let pos = if should_use_ime_cursor_position(ctx, cursor_pos) {
 678                            cursor_pos
 679                        } else {
 680                            comp_string.len()
 681                        };
 682                        pos..pos
 683                    });
 684                self.with_input_handler(|input_handler| {
 685                    input_handler.replace_and_mark_text_in_range(
 686                        None,
 687                        &String::from_utf16_lossy(&comp_string),
 688                        caret_pos,
 689                    );
 690                })?;
 691            }
 692            if lparam & (GCS_RESULTSTR.0 | GCS_COMPSTR.0) > 0 {
 693                return Some(0);
 694            }
 695
 696            // currently, we don't care other stuff
 697            None
 698        }
 699    }
 700
 701    fn handle_calc_client_size(
 702        &self,
 703        handle: HWND,
 704        wparam: WPARAM,
 705        lparam: LPARAM,
 706    ) -> Option<isize> {
 707        if !self.hide_title_bar || self.state.is_fullscreen() || wparam.0 == 0 {
 708            return None;
 709        }
 710
 711        unsafe {
 712            let params = lparam.0 as *mut NCCALCSIZE_PARAMS;
 713            let saved_top = (*params).rgrc[0].top;
 714            let result = DefWindowProcW(handle, WM_NCCALCSIZE, wparam, lparam);
 715            (*params).rgrc[0].top = saved_top;
 716            if self.state.is_maximized() {
 717                let dpi = GetDpiForWindow(handle);
 718                (*params).rgrc[0].top += get_frame_thicknessx(dpi);
 719            }
 720            Some(result.0 as isize)
 721        }
 722    }
 723
 724    fn handle_activate_msg(self: &Rc<Self>, wparam: WPARAM) -> Option<isize> {
 725        let activated = wparam.loword() > 0;
 726        let this = self.clone();
 727        self.executor
 728            .spawn(async move {
 729                if let Some(mut func) = this.state.callbacks.active_status_change.take() {
 730                    func(activated);
 731                    this.state.callbacks.active_status_change.set(Some(func));
 732                }
 733            })
 734            .detach();
 735
 736        None
 737    }
 738
 739    fn handle_create_msg(&self, handle: HWND) -> Option<isize> {
 740        if self.hide_title_bar {
 741            notify_frame_changed(handle);
 742            Some(0)
 743        } else {
 744            None
 745        }
 746    }
 747
 748    fn handle_dpi_changed_msg(
 749        &self,
 750        handle: HWND,
 751        wparam: WPARAM,
 752        lparam: LPARAM,
 753    ) -> Option<isize> {
 754        let new_dpi = wparam.loword() as f32;
 755
 756        let is_maximized = self.state.is_maximized();
 757        let new_scale_factor = new_dpi / USER_DEFAULT_SCREEN_DPI as f32;
 758        self.state.scale_factor.set(new_scale_factor);
 759        self.state.border_offset.update(handle).log_err();
 760
 761        if is_maximized {
 762            // Get the monitor and its work area at the new DPI
 763            let monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONEAREST) };
 764            let mut monitor_info: MONITORINFO = unsafe { std::mem::zeroed() };
 765            monitor_info.cbSize = std::mem::size_of::<MONITORINFO>() as u32;
 766            if unsafe { GetMonitorInfoW(monitor, &mut monitor_info) }.as_bool() {
 767                let work_area = monitor_info.rcWork;
 768                let width = work_area.right - work_area.left;
 769                let height = work_area.bottom - work_area.top;
 770
 771                // Update the window size to match the new monitor work area
 772                // This will trigger WM_SIZE which will handle the size change
 773                unsafe {
 774                    SetWindowPos(
 775                        handle,
 776                        None,
 777                        work_area.left,
 778                        work_area.top,
 779                        width,
 780                        height,
 781                        SWP_NOZORDER | SWP_NOACTIVATE | SWP_FRAMECHANGED,
 782                    )
 783                    .context("unable to set maximized window position after dpi has changed")
 784                    .log_err();
 785                }
 786
 787                // SetWindowPos may not send WM_SIZE for maximized windows in some cases,
 788                // so we manually update the size to ensure proper rendering
 789                let device_size = size(DevicePixels(width), DevicePixels(height));
 790                self.handle_size_change(device_size, new_scale_factor, true);
 791            }
 792        } else {
 793            // For non-maximized windows, use the suggested RECT from the system
 794            let rect = unsafe { &*(lparam.0 as *const RECT) };
 795            let width = rect.right - rect.left;
 796            let height = rect.bottom - rect.top;
 797            // this will emit `WM_SIZE` and `WM_MOVE` right here
 798            // even before this function returns
 799            // the new size is handled in `WM_SIZE`
 800            unsafe {
 801                SetWindowPos(
 802                    handle,
 803                    None,
 804                    rect.left,
 805                    rect.top,
 806                    width,
 807                    height,
 808                    SWP_NOZORDER | SWP_NOACTIVATE,
 809                )
 810                .context("unable to set window position after dpi has changed")
 811                .log_err();
 812            }
 813        }
 814
 815        Some(0)
 816    }
 817
 818    fn handle_display_change_msg(&self, handle: HWND) -> Option<isize> {
 819        let new_monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 820        if new_monitor.is_invalid() {
 821            log::error!("No monitor detected!");
 822            return None;
 823        }
 824        let new_display = WindowsDisplay::new_with_handle(new_monitor).log_err()?;
 825        self.state.display.set(new_display);
 826        Some(0)
 827    }
 828
 829    fn handle_hit_test_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 830        if !self.is_movable || self.state.is_fullscreen() {
 831            return None;
 832        }
 833
 834        let callback = self.state.callbacks.hit_test_window_control.take();
 835        let drag_area = if let Some(mut callback) = callback {
 836            let area = callback();
 837            self.state
 838                .callbacks
 839                .hit_test_window_control
 840                .set(Some(callback));
 841            if let Some(area) = area {
 842                match area {
 843                    WindowControlArea::Drag => Some(HTCAPTION as _),
 844                    WindowControlArea::Close => return Some(HTCLOSE as _),
 845                    WindowControlArea::Max => return Some(HTMAXBUTTON as _),
 846                    WindowControlArea::Min => return Some(HTMINBUTTON as _),
 847                }
 848            } else {
 849                None
 850            }
 851        } else {
 852            None
 853        };
 854
 855        if !self.hide_title_bar {
 856            // If the OS draws the title bar, we don't need to handle hit test messages.
 857            return drag_area;
 858        }
 859
 860        let dpi = unsafe { GetDpiForWindow(handle) };
 861        // We do not use the OS title bar, so the default `DefWindowProcW` will only register a 1px edge for resizes
 862        // We need to calculate the frame thickness ourselves and do the hit test manually.
 863        let frame_y = get_frame_thicknessx(dpi);
 864        let frame_x = get_frame_thicknessy(dpi);
 865        let mut cursor_point = POINT {
 866            x: lparam.signed_loword().into(),
 867            y: lparam.signed_hiword().into(),
 868        };
 869
 870        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 871        if !self.state.is_maximized() && 0 <= cursor_point.y && cursor_point.y <= frame_y {
 872            // x-axis actually goes from -frame_x to 0
 873            return Some(if cursor_point.x <= 0 {
 874                HTTOPLEFT
 875            } else {
 876                let mut rect = Default::default();
 877                unsafe { GetWindowRect(handle, &mut rect) }.log_err();
 878                // right and bottom bounds of RECT are exclusive, thus `-1`
 879                let right = rect.right - rect.left - 1;
 880                // the bounds include the padding frames, so accomodate for both of them
 881                if right - 2 * frame_x <= cursor_point.x {
 882                    HTTOPRIGHT
 883                } else {
 884                    HTTOP
 885                }
 886            } as _);
 887        }
 888
 889        drag_area
 890    }
 891
 892    fn handle_nc_mouse_move_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 893        self.start_tracking_mouse(handle, TME_LEAVE | TME_NONCLIENT);
 894
 895        let mut func = self.state.callbacks.input.take()?;
 896        let scale_factor = self.state.scale_factor.get();
 897
 898        let mut cursor_point = POINT {
 899            x: lparam.signed_loword().into(),
 900            y: lparam.signed_hiword().into(),
 901        };
 902        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 903        let input = PlatformInput::MouseMove(MouseMoveEvent {
 904            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 905            pressed_button: None,
 906            modifiers: current_modifiers(),
 907        });
 908        let handled = !func(input).propagate;
 909        self.state.callbacks.input.set(Some(func));
 910
 911        if handled { Some(0) } else { None }
 912    }
 913
 914    fn handle_nc_mouse_down_msg(
 915        &self,
 916        handle: HWND,
 917        button: MouseButton,
 918        wparam: WPARAM,
 919        lparam: LPARAM,
 920    ) -> Option<isize> {
 921        if let Some(mut func) = self.state.callbacks.input.take() {
 922            let scale_factor = self.state.scale_factor.get();
 923            let mut cursor_point = POINT {
 924                x: lparam.signed_loword().into(),
 925                y: lparam.signed_hiword().into(),
 926            };
 927            unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 928            let physical_point = point(DevicePixels(cursor_point.x), DevicePixels(cursor_point.y));
 929            let click_count = self.state.click_state.update(button, physical_point);
 930
 931            let input = PlatformInput::MouseDown(MouseDownEvent {
 932                button,
 933                position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 934                modifiers: current_modifiers(),
 935                click_count,
 936                first_mouse: false,
 937            });
 938            let handled = !func(input).propagate;
 939            self.state.callbacks.input.set(Some(func));
 940
 941            if handled {
 942                return Some(0);
 943            }
 944        } else {
 945        };
 946
 947        // Since these are handled in handle_nc_mouse_up_msg we must prevent the default window proc
 948        if button == MouseButton::Left {
 949            match wparam.0 as u32 {
 950                HTMINBUTTON => self.state.nc_button_pressed.set(Some(HTMINBUTTON)),
 951                HTMAXBUTTON => self.state.nc_button_pressed.set(Some(HTMAXBUTTON)),
 952                HTCLOSE => self.state.nc_button_pressed.set(Some(HTCLOSE)),
 953                _ => return None,
 954            };
 955            Some(0)
 956        } else {
 957            None
 958        }
 959    }
 960
 961    fn handle_nc_mouse_up_msg(
 962        &self,
 963        handle: HWND,
 964        button: MouseButton,
 965        wparam: WPARAM,
 966        lparam: LPARAM,
 967    ) -> Option<isize> {
 968        if let Some(mut func) = self.state.callbacks.input.take() {
 969            let scale_factor = self.state.scale_factor.get();
 970
 971            let mut cursor_point = POINT {
 972                x: lparam.signed_loword().into(),
 973                y: lparam.signed_hiword().into(),
 974            };
 975            unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 976            let input = PlatformInput::MouseUp(MouseUpEvent {
 977                button,
 978                position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 979                modifiers: current_modifiers(),
 980                click_count: 1,
 981            });
 982            let handled = !func(input).propagate;
 983            self.state.callbacks.input.set(Some(func));
 984
 985            if handled {
 986                return Some(0);
 987            }
 988        } else {
 989        }
 990
 991        let last_pressed = self.state.nc_button_pressed.take();
 992        if button == MouseButton::Left
 993            && let Some(last_pressed) = last_pressed
 994        {
 995            let handled = match (wparam.0 as u32, last_pressed) {
 996                (HTMINBUTTON, HTMINBUTTON) => {
 997                    unsafe { ShowWindowAsync(handle, SW_MINIMIZE).ok().log_err() };
 998                    true
 999                }
1000                (HTMAXBUTTON, HTMAXBUTTON) => {
1001                    if self.state.is_maximized() {
1002                        unsafe { ShowWindowAsync(handle, SW_NORMAL).ok().log_err() };
1003                    } else {
1004                        unsafe { ShowWindowAsync(handle, SW_MAXIMIZE).ok().log_err() };
1005                    }
1006                    true
1007                }
1008                (HTCLOSE, HTCLOSE) => {
1009                    unsafe {
1010                        PostMessageW(Some(handle), WM_CLOSE, WPARAM::default(), LPARAM::default())
1011                            .log_err()
1012                    };
1013                    true
1014                }
1015                _ => false,
1016            };
1017            if handled {
1018                return Some(0);
1019            }
1020        }
1021
1022        None
1023    }
1024
1025    fn handle_cursor_changed(&self, lparam: LPARAM) -> Option<isize> {
1026        let had_cursor = self.state.current_cursor.get().is_some();
1027
1028        self.state.current_cursor.set(if lparam.0 == 0 {
1029            None
1030        } else {
1031            Some(HCURSOR(lparam.0 as _))
1032        });
1033
1034        if had_cursor != self.state.current_cursor.get().is_some() {
1035            unsafe { SetCursor(self.state.current_cursor.get()) };
1036        }
1037
1038        Some(0)
1039    }
1040
1041    fn handle_set_cursor(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
1042        if unsafe { !IsWindowEnabled(handle).as_bool() }
1043            || matches!(
1044                lparam.loword() as u32,
1045                HTLEFT
1046                    | HTRIGHT
1047                    | HTTOP
1048                    | HTTOPLEFT
1049                    | HTTOPRIGHT
1050                    | HTBOTTOM
1051                    | HTBOTTOMLEFT
1052                    | HTBOTTOMRIGHT
1053            )
1054        {
1055            return None;
1056        }
1057        unsafe {
1058            SetCursor(self.state.current_cursor.get());
1059        };
1060        Some(0)
1061    }
1062
1063    fn handle_system_settings_changed(
1064        &self,
1065        handle: HWND,
1066        wparam: WPARAM,
1067        lparam: LPARAM,
1068    ) -> Option<isize> {
1069        if wparam.0 != 0 {
1070            self.state.click_state.system_update(wparam.0);
1071            self.state.border_offset.update(handle).log_err();
1072            // system settings may emit a window message which wants to take the refcell self.state, so drop it
1073
1074            self.system_settings().update(wparam.0);
1075        } else {
1076            self.handle_system_theme_changed(handle, lparam)?;
1077        };
1078
1079        Some(0)
1080    }
1081
1082    fn handle_system_theme_changed(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
1083        // lParam is a pointer to a string that indicates the area containing the system parameter
1084        // that was changed.
1085        let parameter = PCWSTR::from_raw(lparam.0 as _);
1086        if unsafe { !parameter.is_null() && !parameter.is_empty() }
1087            && let Some(parameter_string) = unsafe { parameter.to_string() }.log_err()
1088        {
1089            log::info!("System settings changed: {}", parameter_string);
1090            if parameter_string.as_str() == "ImmersiveColorSet" {
1091                let new_appearance = system_appearance()
1092                    .context("unable to get system appearance when handling ImmersiveColorSet")
1093                    .log_err()?;
1094
1095                if new_appearance != self.state.appearance.get() {
1096                    self.state.appearance.set(new_appearance);
1097                    let mut callback = self.state.callbacks.appearance_changed.take()?;
1098
1099                    callback();
1100                    self.state.callbacks.appearance_changed.set(Some(callback));
1101                    configure_dwm_dark_mode(handle, new_appearance);
1102                }
1103            }
1104        }
1105        Some(0)
1106    }
1107
1108    fn handle_input_language_changed(&self) -> Option<isize> {
1109        unsafe {
1110            PostMessageW(
1111                Some(self.platform_window_handle),
1112                WM_GPUI_KEYBOARD_LAYOUT_CHANGED,
1113                WPARAM(self.validation_number),
1114                LPARAM(0),
1115            )
1116            .log_err();
1117        }
1118        Some(0)
1119    }
1120
1121    fn handle_window_visibility_changed(&self, handle: HWND, wparam: WPARAM) -> Option<isize> {
1122        if wparam.0 == 1 {
1123            self.draw_window(handle, false);
1124        }
1125        None
1126    }
1127
1128    fn handle_device_lost(&self, lparam: LPARAM) -> Option<isize> {
1129        let devices = lparam.0 as *const DirectXDevices;
1130        let devices = unsafe { &*devices };
1131        if let Err(err) = self
1132            .state
1133            .renderer
1134            .borrow_mut()
1135            .handle_device_lost(&devices)
1136        {
1137            panic!("Device lost: {err}");
1138        }
1139        Some(0)
1140    }
1141
1142    #[inline]
1143    fn draw_window(&self, handle: HWND, force_render: bool) -> Option<isize> {
1144        let mut request_frame = self.state.callbacks.request_frame.take()?;
1145
1146        // we are instructing gpui to force render a frame, this will
1147        // re-populate all the gpu textures for us so we can resume drawing in
1148        // case we disabled drawing earlier due to a device loss
1149        self.state.renderer.borrow_mut().mark_drawable();
1150        request_frame(RequestFrameOptions {
1151            require_presentation: false,
1152            force_render,
1153        });
1154
1155        self.state.callbacks.request_frame.set(Some(request_frame));
1156        self.update_ime_enabled(handle);
1157        unsafe { ValidateRect(Some(handle), None).ok().log_err() };
1158
1159        Some(0)
1160    }
1161
1162    #[inline]
1163    fn parse_char_message(&self, wparam: WPARAM) -> Option<String> {
1164        let code_point = wparam.loword();
1165
1166        // https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G2630
1167        match code_point {
1168            0xD800..=0xDBFF => {
1169                // High surrogate, wait for low surrogate
1170                self.state.pending_surrogate.set(Some(code_point));
1171                None
1172            }
1173            0xDC00..=0xDFFF => {
1174                if let Some(high_surrogate) = self.state.pending_surrogate.take() {
1175                    // Low surrogate, combine with pending high surrogate
1176                    String::from_utf16(&[high_surrogate, code_point]).ok()
1177                } else {
1178                    // Invalid low surrogate without a preceding high surrogate
1179                    log::warn!(
1180                        "Received low surrogate without a preceding high surrogate: {code_point:x}"
1181                    );
1182                    None
1183                }
1184            }
1185            _ => {
1186                self.state.pending_surrogate.set(None);
1187                char::from_u32(code_point as u32)
1188                    .filter(|c| !c.is_control())
1189                    .map(|c| c.to_string())
1190            }
1191        }
1192    }
1193
1194    fn start_tracking_mouse(&self, handle: HWND, flags: TRACKMOUSEEVENT_FLAGS) {
1195        if !self.state.hovered.get() {
1196            self.state.hovered.set(true);
1197            unsafe {
1198                TrackMouseEvent(&mut TRACKMOUSEEVENT {
1199                    cbSize: std::mem::size_of::<TRACKMOUSEEVENT>() as u32,
1200                    dwFlags: flags,
1201                    hwndTrack: handle,
1202                    dwHoverTime: HOVER_DEFAULT,
1203                })
1204                .log_err()
1205            };
1206            if let Some(mut callback) = self.state.callbacks.hovered_status_change.take() {
1207                callback(true);
1208                self.state
1209                    .callbacks
1210                    .hovered_status_change
1211                    .set(Some(callback));
1212            }
1213        }
1214    }
1215
1216    fn with_input_handler<F, R>(&self, f: F) -> Option<R>
1217    where
1218        F: FnOnce(&mut PlatformInputHandler) -> R,
1219    {
1220        let mut input_handler = self.state.input_handler.take()?;
1221        let result = f(&mut input_handler);
1222        self.state.input_handler.set(Some(input_handler));
1223        Some(result)
1224    }
1225
1226    fn with_input_handler_and_scale_factor<F, R>(&self, f: F) -> Option<R>
1227    where
1228        F: FnOnce(&mut PlatformInputHandler, f32) -> Option<R>,
1229    {
1230        let mut input_handler = self.state.input_handler.take()?;
1231        let scale_factor = self.state.scale_factor.get();
1232
1233        let result = f(&mut input_handler, scale_factor);
1234        self.state.input_handler.set(Some(input_handler));
1235        result
1236    }
1237}
1238
1239struct ImeContext {
1240    hwnd: HWND,
1241    himc: HIMC,
1242}
1243
1244impl ImeContext {
1245    fn get(hwnd: HWND) -> Option<Self> {
1246        let himc = unsafe { ImmGetContext(hwnd) };
1247        if himc.is_invalid() {
1248            return None;
1249        }
1250        Some(Self { hwnd, himc })
1251    }
1252}
1253
1254impl std::ops::Deref for ImeContext {
1255    type Target = HIMC;
1256    fn deref(&self) -> &HIMC {
1257        &self.himc
1258    }
1259}
1260
1261impl Drop for ImeContext {
1262    fn drop(&mut self) {
1263        unsafe {
1264            ImmReleaseContext(self.hwnd, self.himc).ok().log_err();
1265        }
1266    }
1267}
1268
1269fn handle_key_event<F>(
1270    wparam: WPARAM,
1271    lparam: LPARAM,
1272    state: &WindowsWindowState,
1273    f: F,
1274) -> Option<PlatformInput>
1275where
1276    F: FnOnce(Keystroke, bool) -> PlatformInput,
1277{
1278    let virtual_key = VIRTUAL_KEY(wparam.loword());
1279    let modifiers = current_modifiers();
1280
1281    match virtual_key {
1282        VK_SHIFT | VK_CONTROL | VK_MENU | VK_LMENU | VK_RMENU | VK_LWIN | VK_RWIN => {
1283            if state
1284                .last_reported_modifiers
1285                .get()
1286                .is_some_and(|prev_modifiers| prev_modifiers == modifiers)
1287            {
1288                return None;
1289            }
1290            state.last_reported_modifiers.set(Some(modifiers));
1291            Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1292                modifiers,
1293                capslock: current_capslock(),
1294            }))
1295        }
1296        VK_PACKET => None,
1297        VK_CAPITAL => {
1298            let capslock = current_capslock();
1299            if state
1300                .last_reported_capslock
1301                .get()
1302                .is_some_and(|prev_capslock| prev_capslock == capslock)
1303            {
1304                return None;
1305            }
1306            state.last_reported_capslock.set(Some(capslock));
1307            Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1308                modifiers,
1309                capslock,
1310            }))
1311        }
1312        vkey => {
1313            let keystroke = parse_normal_key(vkey, lparam, modifiers)?;
1314            Some(f(keystroke.0, keystroke.1))
1315        }
1316    }
1317}
1318
1319fn parse_immutable(vkey: VIRTUAL_KEY) -> Option<String> {
1320    Some(
1321        match vkey {
1322            VK_SPACE => "space",
1323            VK_BACK => "backspace",
1324            VK_RETURN => "enter",
1325            VK_TAB => "tab",
1326            VK_UP => "up",
1327            VK_DOWN => "down",
1328            VK_RIGHT => "right",
1329            VK_LEFT => "left",
1330            VK_HOME => "home",
1331            VK_END => "end",
1332            VK_PRIOR => "pageup",
1333            VK_NEXT => "pagedown",
1334            VK_BROWSER_BACK => "back",
1335            VK_BROWSER_FORWARD => "forward",
1336            VK_ESCAPE => "escape",
1337            VK_INSERT => "insert",
1338            VK_DELETE => "delete",
1339            VK_APPS => "menu",
1340            VK_F1 => "f1",
1341            VK_F2 => "f2",
1342            VK_F3 => "f3",
1343            VK_F4 => "f4",
1344            VK_F5 => "f5",
1345            VK_F6 => "f6",
1346            VK_F7 => "f7",
1347            VK_F8 => "f8",
1348            VK_F9 => "f9",
1349            VK_F10 => "f10",
1350            VK_F11 => "f11",
1351            VK_F12 => "f12",
1352            VK_F13 => "f13",
1353            VK_F14 => "f14",
1354            VK_F15 => "f15",
1355            VK_F16 => "f16",
1356            VK_F17 => "f17",
1357            VK_F18 => "f18",
1358            VK_F19 => "f19",
1359            VK_F20 => "f20",
1360            VK_F21 => "f21",
1361            VK_F22 => "f22",
1362            VK_F23 => "f23",
1363            VK_F24 => "f24",
1364            _ => return None,
1365        }
1366        .to_string(),
1367    )
1368}
1369
1370fn parse_normal_key(
1371    vkey: VIRTUAL_KEY,
1372    lparam: LPARAM,
1373    mut modifiers: Modifiers,
1374) -> Option<(Keystroke, bool)> {
1375    let (key_char, prefer_character_input) = process_key(vkey, lparam.hiword());
1376
1377    let key = parse_immutable(vkey).or_else(|| {
1378        let scan_code = lparam.hiword() & 0xFF;
1379        get_keystroke_key(vkey, scan_code as u32, &mut modifiers)
1380    })?;
1381
1382    Some((
1383        Keystroke {
1384            modifiers,
1385            key,
1386            key_char,
1387        },
1388        prefer_character_input,
1389    ))
1390}
1391
1392fn process_key(vkey: VIRTUAL_KEY, scan_code: u16) -> (Option<String>, bool) {
1393    let mut keyboard_state = [0u8; 256];
1394    unsafe {
1395        if GetKeyboardState(&mut keyboard_state).is_err() {
1396            return (None, false);
1397        }
1398    }
1399
1400    let mut buffer_c = [0u16; 8];
1401    let result_c = unsafe {
1402        ToUnicode(
1403            vkey.0 as u32,
1404            scan_code as u32,
1405            Some(&keyboard_state),
1406            &mut buffer_c,
1407            0x4,
1408        )
1409    };
1410
1411    if result_c == 0 {
1412        return (None, false);
1413    }
1414
1415    let c = &buffer_c[..result_c.unsigned_abs() as usize];
1416    let key_char = String::from_utf16(c)
1417        .ok()
1418        .filter(|s| !s.is_empty() && !s.chars().next().unwrap().is_control());
1419
1420    if result_c < 0 {
1421        return (key_char, true);
1422    }
1423
1424    if key_char.is_none() {
1425        return (None, false);
1426    }
1427
1428    // Workaround for some bug that makes the compiler think keyboard_state is still zeroed out
1429    let keyboard_state = std::hint::black_box(keyboard_state);
1430    let ctrl_down = (keyboard_state[VK_CONTROL.0 as usize] & 0x80) != 0;
1431    let alt_down = (keyboard_state[VK_MENU.0 as usize] & 0x80) != 0;
1432    let win_down = (keyboard_state[VK_LWIN.0 as usize] & 0x80) != 0
1433        || (keyboard_state[VK_RWIN.0 as usize] & 0x80) != 0;
1434
1435    let has_modifiers = ctrl_down || alt_down || win_down;
1436    if !has_modifiers {
1437        return (key_char, false);
1438    }
1439
1440    let mut state_no_modifiers = keyboard_state;
1441    state_no_modifiers[VK_CONTROL.0 as usize] = 0;
1442    state_no_modifiers[VK_LCONTROL.0 as usize] = 0;
1443    state_no_modifiers[VK_RCONTROL.0 as usize] = 0;
1444    state_no_modifiers[VK_MENU.0 as usize] = 0;
1445    state_no_modifiers[VK_LMENU.0 as usize] = 0;
1446    state_no_modifiers[VK_RMENU.0 as usize] = 0;
1447    state_no_modifiers[VK_LWIN.0 as usize] = 0;
1448    state_no_modifiers[VK_RWIN.0 as usize] = 0;
1449
1450    let mut buffer_c_no_modifiers = [0u16; 8];
1451    let result_c_no_modifiers = unsafe {
1452        ToUnicode(
1453            vkey.0 as u32,
1454            scan_code as u32,
1455            Some(&state_no_modifiers),
1456            &mut buffer_c_no_modifiers,
1457            0x4,
1458        )
1459    };
1460
1461    let c_no_modifiers = &buffer_c_no_modifiers[..result_c_no_modifiers.unsigned_abs() as usize];
1462    (
1463        key_char,
1464        result_c != result_c_no_modifiers || c != c_no_modifiers,
1465    )
1466}
1467
1468fn parse_ime_composition_string(ctx: HIMC, comp_type: IME_COMPOSITION_STRING) -> Option<Vec<u16>> {
1469    unsafe {
1470        let string_len = ImmGetCompositionStringW(ctx, comp_type, None, 0);
1471        if string_len >= 0 {
1472            let mut buffer = vec![0u8; string_len as usize + 2];
1473            ImmGetCompositionStringW(
1474                ctx,
1475                comp_type,
1476                Some(buffer.as_mut_ptr() as _),
1477                string_len as _,
1478            );
1479            let wstring = std::slice::from_raw_parts::<u16>(
1480                buffer.as_mut_ptr().cast::<u16>(),
1481                string_len as usize / 2,
1482            );
1483            Some(wstring.to_vec())
1484        } else {
1485            None
1486        }
1487    }
1488}
1489
1490#[inline]
1491fn retrieve_composition_cursor_position(ctx: HIMC) -> usize {
1492    unsafe { ImmGetCompositionStringW(ctx, GCS_CURSORPOS, None, 0) as usize }
1493}
1494
1495fn should_use_ime_cursor_position(ctx: HIMC, cursor_pos: usize) -> bool {
1496    let attrs_size = unsafe { ImmGetCompositionStringW(ctx, GCS_COMPATTR, None, 0) } as usize;
1497    if attrs_size == 0 {
1498        return false;
1499    }
1500
1501    let mut attrs = vec![0u8; attrs_size];
1502    let result = unsafe {
1503        ImmGetCompositionStringW(
1504            ctx,
1505            GCS_COMPATTR,
1506            Some(attrs.as_mut_ptr() as *mut _),
1507            attrs_size as u32,
1508        )
1509    };
1510    if result <= 0 {
1511        return false;
1512    }
1513
1514    // Keep the cursor adjacent to the inserted text by only using the suggested position
1515    // if it's adjacent to unconverted text.
1516    let at_cursor_is_input = cursor_pos < attrs.len() && attrs[cursor_pos] == (ATTR_INPUT as u8);
1517    let before_cursor_is_input = cursor_pos > 0
1518        && (cursor_pos - 1) < attrs.len()
1519        && attrs[cursor_pos - 1] == (ATTR_INPUT as u8);
1520
1521    at_cursor_is_input || before_cursor_is_input
1522}
1523
1524#[inline]
1525fn is_virtual_key_pressed(vkey: VIRTUAL_KEY) -> bool {
1526    unsafe { GetKeyState(vkey.0 as i32) < 0 }
1527}
1528
1529#[inline]
1530pub(crate) fn current_modifiers() -> Modifiers {
1531    Modifiers {
1532        control: is_virtual_key_pressed(VK_CONTROL),
1533        alt: is_virtual_key_pressed(VK_MENU),
1534        shift: is_virtual_key_pressed(VK_SHIFT),
1535        platform: is_virtual_key_pressed(VK_LWIN) || is_virtual_key_pressed(VK_RWIN),
1536        function: false,
1537    }
1538}
1539
1540#[inline]
1541pub(crate) fn current_capslock() -> Capslock {
1542    let on = unsafe { GetKeyState(VK_CAPITAL.0 as i32) & 1 } > 0;
1543    Capslock { on }
1544}
1545
1546// there is some additional non-visible space when talking about window
1547// borders on Windows:
1548// - SM_CXSIZEFRAME: The resize handle.
1549// - SM_CXPADDEDBORDER: Additional border space that isn't part of the resize handle.
1550fn get_frame_thicknessx(dpi: u32) -> i32 {
1551    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CXSIZEFRAME, dpi) };
1552    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1553    resize_frame_thickness + padding_thickness
1554}
1555
1556fn get_frame_thicknessy(dpi: u32) -> i32 {
1557    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CYSIZEFRAME, dpi) };
1558    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1559    resize_frame_thickness + padding_thickness
1560}
1561
1562fn notify_frame_changed(handle: HWND) {
1563    unsafe {
1564        SetWindowPos(
1565            handle,
1566            None,
1567            0,
1568            0,
1569            0,
1570            0,
1571            SWP_FRAMECHANGED
1572                | SWP_NOACTIVATE
1573                | SWP_NOCOPYBITS
1574                | SWP_NOMOVE
1575                | SWP_NOOWNERZORDER
1576                | SWP_NOREPOSITION
1577                | SWP_NOSENDCHANGING
1578                | SWP_NOSIZE
1579                | SWP_NOZORDER,
1580        )
1581        .log_err();
1582    }
1583}