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