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        unsafe {
 597            let ctx = ImmGetContext(handle);
 598            if ctx.is_invalid() {
 599                return;
 600            }
 601
 602            let config = COMPOSITIONFORM {
 603                dwStyle: CFS_POINT,
 604                ptCurrentPos: caret_position,
 605                ..Default::default()
 606            };
 607            ImmSetCompositionWindow(ctx, &config).ok().log_err();
 608            let config = CANDIDATEFORM {
 609                dwStyle: CFS_CANDIDATEPOS,
 610                ptCurrentPos: caret_position,
 611                ..Default::default()
 612            };
 613            ImmSetCandidateWindow(ctx, &config).ok().log_err();
 614            ImmReleaseContext(handle, ctx).ok().log_err();
 615        }
 616    }
 617
 618    fn handle_ime_composition(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 619        let ctx = unsafe { ImmGetContext(handle) };
 620        let result = self.handle_ime_composition_inner(ctx, lparam);
 621        unsafe { ImmReleaseContext(handle, ctx).ok().log_err() };
 622        result
 623    }
 624
 625    fn handle_ime_composition_inner(&self, ctx: HIMC, lparam: LPARAM) -> Option<isize> {
 626        let lparam = lparam.0 as u32;
 627        if lparam == 0 {
 628            // Japanese IME may send this message with lparam = 0, which indicates that
 629            // there is no composition string.
 630            self.with_input_handler(|input_handler| {
 631                input_handler.replace_text_in_range(None, "");
 632            })?;
 633            Some(0)
 634        } else {
 635            if lparam & GCS_RESULTSTR.0 > 0 {
 636                let comp_result = parse_ime_composition_string(ctx, GCS_RESULTSTR)?;
 637                self.with_input_handler(|input_handler| {
 638                    input_handler
 639                        .replace_text_in_range(None, &String::from_utf16_lossy(&comp_result));
 640                })?;
 641            }
 642            if lparam & GCS_COMPSTR.0 > 0 {
 643                let comp_string = parse_ime_composition_string(ctx, GCS_COMPSTR)?;
 644                let caret_pos =
 645                    (!comp_string.is_empty() && lparam & GCS_CURSORPOS.0 > 0).then(|| {
 646                        let cursor_pos = retrieve_composition_cursor_position(ctx);
 647                        let pos = if should_use_ime_cursor_position(ctx, cursor_pos) {
 648                            cursor_pos
 649                        } else {
 650                            comp_string.len()
 651                        };
 652                        pos..pos
 653                    });
 654                self.with_input_handler(|input_handler| {
 655                    input_handler.replace_and_mark_text_in_range(
 656                        None,
 657                        &String::from_utf16_lossy(&comp_string),
 658                        caret_pos,
 659                    );
 660                })?;
 661            }
 662            if lparam & (GCS_RESULTSTR.0 | GCS_COMPSTR.0) > 0 {
 663                return Some(0);
 664            }
 665
 666            // currently, we don't care other stuff
 667            None
 668        }
 669    }
 670
 671    fn handle_calc_client_size(
 672        &self,
 673        handle: HWND,
 674        wparam: WPARAM,
 675        lparam: LPARAM,
 676    ) -> Option<isize> {
 677        if !self.hide_title_bar || self.state.is_fullscreen() || wparam.0 == 0 {
 678            return None;
 679        }
 680
 681        unsafe {
 682            let params = lparam.0 as *mut NCCALCSIZE_PARAMS;
 683            let saved_top = (*params).rgrc[0].top;
 684            let result = DefWindowProcW(handle, WM_NCCALCSIZE, wparam, lparam);
 685            (*params).rgrc[0].top = saved_top;
 686            if self.state.is_maximized() {
 687                let dpi = GetDpiForWindow(handle);
 688                (*params).rgrc[0].top += get_frame_thicknessx(dpi);
 689            }
 690            Some(result.0 as isize)
 691        }
 692    }
 693
 694    fn handle_activate_msg(self: &Rc<Self>, wparam: WPARAM) -> Option<isize> {
 695        let activated = wparam.loword() > 0;
 696        let this = self.clone();
 697        self.executor
 698            .spawn(async move {
 699                if let Some(mut func) = this.state.callbacks.active_status_change.take() {
 700                    func(activated);
 701                    this.state.callbacks.active_status_change.set(Some(func));
 702                }
 703            })
 704            .detach();
 705
 706        None
 707    }
 708
 709    fn handle_create_msg(&self, handle: HWND) -> Option<isize> {
 710        if self.hide_title_bar {
 711            notify_frame_changed(handle);
 712            Some(0)
 713        } else {
 714            None
 715        }
 716    }
 717
 718    fn handle_dpi_changed_msg(
 719        &self,
 720        handle: HWND,
 721        wparam: WPARAM,
 722        lparam: LPARAM,
 723    ) -> Option<isize> {
 724        let new_dpi = wparam.loword() as f32;
 725
 726        let is_maximized = self.state.is_maximized();
 727        let new_scale_factor = new_dpi / USER_DEFAULT_SCREEN_DPI as f32;
 728        self.state.scale_factor.set(new_scale_factor);
 729        self.state.border_offset.update(handle).log_err();
 730
 731        if is_maximized {
 732            // Get the monitor and its work area at the new DPI
 733            let monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONEAREST) };
 734            let mut monitor_info: MONITORINFO = unsafe { std::mem::zeroed() };
 735            monitor_info.cbSize = std::mem::size_of::<MONITORINFO>() as u32;
 736            if unsafe { GetMonitorInfoW(monitor, &mut monitor_info) }.as_bool() {
 737                let work_area = monitor_info.rcWork;
 738                let width = work_area.right - work_area.left;
 739                let height = work_area.bottom - work_area.top;
 740
 741                // Update the window size to match the new monitor work area
 742                // This will trigger WM_SIZE which will handle the size change
 743                unsafe {
 744                    SetWindowPos(
 745                        handle,
 746                        None,
 747                        work_area.left,
 748                        work_area.top,
 749                        width,
 750                        height,
 751                        SWP_NOZORDER | SWP_NOACTIVATE | SWP_FRAMECHANGED,
 752                    )
 753                    .context("unable to set maximized window position after dpi has changed")
 754                    .log_err();
 755                }
 756
 757                // SetWindowPos may not send WM_SIZE for maximized windows in some cases,
 758                // so we manually update the size to ensure proper rendering
 759                let device_size = size(DevicePixels(width), DevicePixels(height));
 760                self.handle_size_change(device_size, new_scale_factor, true);
 761            }
 762        } else {
 763            // For non-maximized windows, use the suggested RECT from the system
 764            let rect = unsafe { &*(lparam.0 as *const RECT) };
 765            let width = rect.right - rect.left;
 766            let height = rect.bottom - rect.top;
 767            // this will emit `WM_SIZE` and `WM_MOVE` right here
 768            // even before this function returns
 769            // the new size is handled in `WM_SIZE`
 770            unsafe {
 771                SetWindowPos(
 772                    handle,
 773                    None,
 774                    rect.left,
 775                    rect.top,
 776                    width,
 777                    height,
 778                    SWP_NOZORDER | SWP_NOACTIVATE,
 779                )
 780                .context("unable to set window position after dpi has changed")
 781                .log_err();
 782            }
 783        }
 784
 785        Some(0)
 786    }
 787
 788    fn handle_display_change_msg(&self, handle: HWND) -> Option<isize> {
 789        let new_monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 790        if new_monitor.is_invalid() {
 791            log::error!("No monitor detected!");
 792            return None;
 793        }
 794        let new_display = WindowsDisplay::new_with_handle(new_monitor).log_err()?;
 795        self.state.display.set(new_display);
 796        Some(0)
 797    }
 798
 799    fn handle_hit_test_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 800        if !self.is_movable || self.state.is_fullscreen() {
 801            return None;
 802        }
 803
 804        let callback = self.state.callbacks.hit_test_window_control.take();
 805        let drag_area = if let Some(mut callback) = callback {
 806            let area = callback();
 807            self.state
 808                .callbacks
 809                .hit_test_window_control
 810                .set(Some(callback));
 811            if let Some(area) = area {
 812                match area {
 813                    WindowControlArea::Drag => Some(HTCAPTION as _),
 814                    WindowControlArea::Close => return Some(HTCLOSE as _),
 815                    WindowControlArea::Max => return Some(HTMAXBUTTON as _),
 816                    WindowControlArea::Min => return Some(HTMINBUTTON as _),
 817                }
 818            } else {
 819                None
 820            }
 821        } else {
 822            None
 823        };
 824
 825        if !self.hide_title_bar {
 826            // If the OS draws the title bar, we don't need to handle hit test messages.
 827            return drag_area;
 828        }
 829
 830        let dpi = unsafe { GetDpiForWindow(handle) };
 831        // We do not use the OS title bar, so the default `DefWindowProcW` will only register a 1px edge for resizes
 832        // We need to calculate the frame thickness ourselves and do the hit test manually.
 833        let frame_y = get_frame_thicknessx(dpi);
 834        let frame_x = get_frame_thicknessy(dpi);
 835        let mut cursor_point = POINT {
 836            x: lparam.signed_loword().into(),
 837            y: lparam.signed_hiword().into(),
 838        };
 839
 840        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 841        if !self.state.is_maximized() && 0 <= cursor_point.y && cursor_point.y <= frame_y {
 842            // x-axis actually goes from -frame_x to 0
 843            return Some(if cursor_point.x <= 0 {
 844                HTTOPLEFT
 845            } else {
 846                let mut rect = Default::default();
 847                unsafe { GetWindowRect(handle, &mut rect) }.log_err();
 848                // right and bottom bounds of RECT are exclusive, thus `-1`
 849                let right = rect.right - rect.left - 1;
 850                // the bounds include the padding frames, so accomodate for both of them
 851                if right - 2 * frame_x <= cursor_point.x {
 852                    HTTOPRIGHT
 853                } else {
 854                    HTTOP
 855                }
 856            } as _);
 857        }
 858
 859        drag_area
 860    }
 861
 862    fn handle_nc_mouse_move_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 863        self.start_tracking_mouse(handle, TME_LEAVE | TME_NONCLIENT);
 864
 865        let mut func = self.state.callbacks.input.take()?;
 866        let scale_factor = self.state.scale_factor.get();
 867
 868        let mut cursor_point = POINT {
 869            x: lparam.signed_loword().into(),
 870            y: lparam.signed_hiword().into(),
 871        };
 872        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 873        let input = PlatformInput::MouseMove(MouseMoveEvent {
 874            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 875            pressed_button: None,
 876            modifiers: current_modifiers(),
 877        });
 878        let handled = !func(input).propagate;
 879        self.state.callbacks.input.set(Some(func));
 880
 881        if handled { Some(0) } else { None }
 882    }
 883
 884    fn handle_nc_mouse_down_msg(
 885        &self,
 886        handle: HWND,
 887        button: MouseButton,
 888        wparam: WPARAM,
 889        lparam: LPARAM,
 890    ) -> Option<isize> {
 891        if let Some(mut func) = self.state.callbacks.input.take() {
 892            let scale_factor = self.state.scale_factor.get();
 893            let mut cursor_point = POINT {
 894                x: lparam.signed_loword().into(),
 895                y: lparam.signed_hiword().into(),
 896            };
 897            unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 898            let physical_point = point(DevicePixels(cursor_point.x), DevicePixels(cursor_point.y));
 899            let click_count = self.state.click_state.update(button, physical_point);
 900
 901            let input = PlatformInput::MouseDown(MouseDownEvent {
 902                button,
 903                position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 904                modifiers: current_modifiers(),
 905                click_count,
 906                first_mouse: false,
 907            });
 908            let handled = !func(input).propagate;
 909            self.state.callbacks.input.set(Some(func));
 910
 911            if handled {
 912                return Some(0);
 913            }
 914        } else {
 915        };
 916
 917        // Since these are handled in handle_nc_mouse_up_msg we must prevent the default window proc
 918        if button == MouseButton::Left {
 919            match wparam.0 as u32 {
 920                HTMINBUTTON => self.state.nc_button_pressed.set(Some(HTMINBUTTON)),
 921                HTMAXBUTTON => self.state.nc_button_pressed.set(Some(HTMAXBUTTON)),
 922                HTCLOSE => self.state.nc_button_pressed.set(Some(HTCLOSE)),
 923                _ => return None,
 924            };
 925            Some(0)
 926        } else {
 927            None
 928        }
 929    }
 930
 931    fn handle_nc_mouse_up_msg(
 932        &self,
 933        handle: HWND,
 934        button: MouseButton,
 935        wparam: WPARAM,
 936        lparam: LPARAM,
 937    ) -> Option<isize> {
 938        if let Some(mut func) = self.state.callbacks.input.take() {
 939            let scale_factor = self.state.scale_factor.get();
 940
 941            let mut cursor_point = POINT {
 942                x: lparam.signed_loword().into(),
 943                y: lparam.signed_hiword().into(),
 944            };
 945            unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 946            let input = PlatformInput::MouseUp(MouseUpEvent {
 947                button,
 948                position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 949                modifiers: current_modifiers(),
 950                click_count: 1,
 951            });
 952            let handled = !func(input).propagate;
 953            self.state.callbacks.input.set(Some(func));
 954
 955            if handled {
 956                return Some(0);
 957            }
 958        } else {
 959        }
 960
 961        let last_pressed = self.state.nc_button_pressed.take();
 962        if button == MouseButton::Left
 963            && let Some(last_pressed) = last_pressed
 964        {
 965            let handled = match (wparam.0 as u32, last_pressed) {
 966                (HTMINBUTTON, HTMINBUTTON) => {
 967                    unsafe { ShowWindowAsync(handle, SW_MINIMIZE).ok().log_err() };
 968                    true
 969                }
 970                (HTMAXBUTTON, HTMAXBUTTON) => {
 971                    if self.state.is_maximized() {
 972                        unsafe { ShowWindowAsync(handle, SW_NORMAL).ok().log_err() };
 973                    } else {
 974                        unsafe { ShowWindowAsync(handle, SW_MAXIMIZE).ok().log_err() };
 975                    }
 976                    true
 977                }
 978                (HTCLOSE, HTCLOSE) => {
 979                    unsafe {
 980                        PostMessageW(Some(handle), WM_CLOSE, WPARAM::default(), LPARAM::default())
 981                            .log_err()
 982                    };
 983                    true
 984                }
 985                _ => false,
 986            };
 987            if handled {
 988                return Some(0);
 989            }
 990        }
 991
 992        None
 993    }
 994
 995    fn handle_cursor_changed(&self, lparam: LPARAM) -> Option<isize> {
 996        let had_cursor = self.state.current_cursor.get().is_some();
 997
 998        self.state.current_cursor.set(if lparam.0 == 0 {
 999            None
1000        } else {
1001            Some(HCURSOR(lparam.0 as _))
1002        });
1003
1004        if had_cursor != self.state.current_cursor.get().is_some() {
1005            unsafe { SetCursor(self.state.current_cursor.get()) };
1006        }
1007
1008        Some(0)
1009    }
1010
1011    fn handle_set_cursor(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
1012        if unsafe { !IsWindowEnabled(handle).as_bool() }
1013            || matches!(
1014                lparam.loword() as u32,
1015                HTLEFT
1016                    | HTRIGHT
1017                    | HTTOP
1018                    | HTTOPLEFT
1019                    | HTTOPRIGHT
1020                    | HTBOTTOM
1021                    | HTBOTTOMLEFT
1022                    | HTBOTTOMRIGHT
1023            )
1024        {
1025            return None;
1026        }
1027        unsafe {
1028            SetCursor(self.state.current_cursor.get());
1029        };
1030        Some(0)
1031    }
1032
1033    fn handle_system_settings_changed(
1034        &self,
1035        handle: HWND,
1036        wparam: WPARAM,
1037        lparam: LPARAM,
1038    ) -> Option<isize> {
1039        if wparam.0 != 0 {
1040            self.state.click_state.system_update(wparam.0);
1041            self.state.border_offset.update(handle).log_err();
1042            // system settings may emit a window message which wants to take the refcell self.state, so drop it
1043
1044            self.system_settings().update(wparam.0);
1045        } else {
1046            self.handle_system_theme_changed(handle, lparam)?;
1047        };
1048
1049        Some(0)
1050    }
1051
1052    fn handle_system_theme_changed(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
1053        // lParam is a pointer to a string that indicates the area containing the system parameter
1054        // that was changed.
1055        let parameter = PCWSTR::from_raw(lparam.0 as _);
1056        if unsafe { !parameter.is_null() && !parameter.is_empty() }
1057            && let Some(parameter_string) = unsafe { parameter.to_string() }.log_err()
1058        {
1059            log::info!("System settings changed: {}", parameter_string);
1060            if parameter_string.as_str() == "ImmersiveColorSet" {
1061                let new_appearance = system_appearance()
1062                    .context("unable to get system appearance when handling ImmersiveColorSet")
1063                    .log_err()?;
1064
1065                if new_appearance != self.state.appearance.get() {
1066                    self.state.appearance.set(new_appearance);
1067                    let mut callback = self.state.callbacks.appearance_changed.take()?;
1068
1069                    callback();
1070                    self.state.callbacks.appearance_changed.set(Some(callback));
1071                    configure_dwm_dark_mode(handle, new_appearance);
1072                }
1073            }
1074        }
1075        Some(0)
1076    }
1077
1078    fn handle_input_language_changed(&self) -> Option<isize> {
1079        unsafe {
1080            PostMessageW(
1081                Some(self.platform_window_handle),
1082                WM_GPUI_KEYBOARD_LAYOUT_CHANGED,
1083                WPARAM(self.validation_number),
1084                LPARAM(0),
1085            )
1086            .log_err();
1087        }
1088        Some(0)
1089    }
1090
1091    fn handle_window_visibility_changed(&self, handle: HWND, wparam: WPARAM) -> Option<isize> {
1092        if wparam.0 == 1 {
1093            self.draw_window(handle, false);
1094        }
1095        None
1096    }
1097
1098    fn handle_device_lost(&self, lparam: LPARAM) -> Option<isize> {
1099        let devices = lparam.0 as *const DirectXDevices;
1100        let devices = unsafe { &*devices };
1101        if let Err(err) = self
1102            .state
1103            .renderer
1104            .borrow_mut()
1105            .handle_device_lost(&devices)
1106        {
1107            panic!("Device lost: {err}");
1108        }
1109        Some(0)
1110    }
1111
1112    #[inline]
1113    fn draw_window(&self, handle: HWND, force_render: bool) -> Option<isize> {
1114        let mut request_frame = self.state.callbacks.request_frame.take()?;
1115
1116        // we are instructing gpui to force render a frame, this will
1117        // re-populate all the gpu textures for us so we can resume drawing in
1118        // case we disabled drawing earlier due to a device loss
1119        self.state.renderer.borrow_mut().mark_drawable();
1120        request_frame(RequestFrameOptions {
1121            require_presentation: false,
1122            force_render,
1123        });
1124
1125        self.state.callbacks.request_frame.set(Some(request_frame));
1126        unsafe { ValidateRect(Some(handle), None).ok().log_err() };
1127
1128        Some(0)
1129    }
1130
1131    #[inline]
1132    fn parse_char_message(&self, wparam: WPARAM) -> Option<String> {
1133        let code_point = wparam.loword();
1134
1135        // https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G2630
1136        match code_point {
1137            0xD800..=0xDBFF => {
1138                // High surrogate, wait for low surrogate
1139                self.state.pending_surrogate.set(Some(code_point));
1140                None
1141            }
1142            0xDC00..=0xDFFF => {
1143                if let Some(high_surrogate) = self.state.pending_surrogate.take() {
1144                    // Low surrogate, combine with pending high surrogate
1145                    String::from_utf16(&[high_surrogate, code_point]).ok()
1146                } else {
1147                    // Invalid low surrogate without a preceding high surrogate
1148                    log::warn!(
1149                        "Received low surrogate without a preceding high surrogate: {code_point:x}"
1150                    );
1151                    None
1152                }
1153            }
1154            _ => {
1155                self.state.pending_surrogate.set(None);
1156                char::from_u32(code_point as u32)
1157                    .filter(|c| !c.is_control())
1158                    .map(|c| c.to_string())
1159            }
1160        }
1161    }
1162
1163    fn start_tracking_mouse(&self, handle: HWND, flags: TRACKMOUSEEVENT_FLAGS) {
1164        if !self.state.hovered.get() {
1165            self.state.hovered.set(true);
1166            unsafe {
1167                TrackMouseEvent(&mut TRACKMOUSEEVENT {
1168                    cbSize: std::mem::size_of::<TRACKMOUSEEVENT>() as u32,
1169                    dwFlags: flags,
1170                    hwndTrack: handle,
1171                    dwHoverTime: HOVER_DEFAULT,
1172                })
1173                .log_err()
1174            };
1175            if let Some(mut callback) = self.state.callbacks.hovered_status_change.take() {
1176                callback(true);
1177                self.state
1178                    .callbacks
1179                    .hovered_status_change
1180                    .set(Some(callback));
1181            }
1182        }
1183    }
1184
1185    fn with_input_handler<F, R>(&self, f: F) -> Option<R>
1186    where
1187        F: FnOnce(&mut PlatformInputHandler) -> R,
1188    {
1189        let mut input_handler = self.state.input_handler.take()?;
1190        let result = f(&mut input_handler);
1191        self.state.input_handler.set(Some(input_handler));
1192        Some(result)
1193    }
1194
1195    fn with_input_handler_and_scale_factor<F, R>(&self, f: F) -> Option<R>
1196    where
1197        F: FnOnce(&mut PlatformInputHandler, f32) -> Option<R>,
1198    {
1199        let mut input_handler = self.state.input_handler.take()?;
1200        let scale_factor = self.state.scale_factor.get();
1201
1202        let result = f(&mut input_handler, scale_factor);
1203        self.state.input_handler.set(Some(input_handler));
1204        result
1205    }
1206}
1207
1208fn handle_key_event<F>(
1209    wparam: WPARAM,
1210    lparam: LPARAM,
1211    state: &WindowsWindowState,
1212    f: F,
1213) -> Option<PlatformInput>
1214where
1215    F: FnOnce(Keystroke, bool) -> PlatformInput,
1216{
1217    let virtual_key = VIRTUAL_KEY(wparam.loword());
1218    let modifiers = current_modifiers();
1219
1220    match virtual_key {
1221        VK_SHIFT | VK_CONTROL | VK_MENU | VK_LMENU | VK_RMENU | VK_LWIN | VK_RWIN => {
1222            if state
1223                .last_reported_modifiers
1224                .get()
1225                .is_some_and(|prev_modifiers| prev_modifiers == modifiers)
1226            {
1227                return None;
1228            }
1229            state.last_reported_modifiers.set(Some(modifiers));
1230            Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1231                modifiers,
1232                capslock: current_capslock(),
1233            }))
1234        }
1235        VK_PACKET => None,
1236        VK_CAPITAL => {
1237            let capslock = current_capslock();
1238            if state
1239                .last_reported_capslock
1240                .get()
1241                .is_some_and(|prev_capslock| prev_capslock == capslock)
1242            {
1243                return None;
1244            }
1245            state.last_reported_capslock.set(Some(capslock));
1246            Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1247                modifiers,
1248                capslock,
1249            }))
1250        }
1251        vkey => {
1252            let keystroke = parse_normal_key(vkey, lparam, modifiers)?;
1253            Some(f(keystroke.0, keystroke.1))
1254        }
1255    }
1256}
1257
1258fn parse_immutable(vkey: VIRTUAL_KEY) -> Option<String> {
1259    Some(
1260        match vkey {
1261            VK_SPACE => "space",
1262            VK_BACK => "backspace",
1263            VK_RETURN => "enter",
1264            VK_TAB => "tab",
1265            VK_UP => "up",
1266            VK_DOWN => "down",
1267            VK_RIGHT => "right",
1268            VK_LEFT => "left",
1269            VK_HOME => "home",
1270            VK_END => "end",
1271            VK_PRIOR => "pageup",
1272            VK_NEXT => "pagedown",
1273            VK_BROWSER_BACK => "back",
1274            VK_BROWSER_FORWARD => "forward",
1275            VK_ESCAPE => "escape",
1276            VK_INSERT => "insert",
1277            VK_DELETE => "delete",
1278            VK_APPS => "menu",
1279            VK_F1 => "f1",
1280            VK_F2 => "f2",
1281            VK_F3 => "f3",
1282            VK_F4 => "f4",
1283            VK_F5 => "f5",
1284            VK_F6 => "f6",
1285            VK_F7 => "f7",
1286            VK_F8 => "f8",
1287            VK_F9 => "f9",
1288            VK_F10 => "f10",
1289            VK_F11 => "f11",
1290            VK_F12 => "f12",
1291            VK_F13 => "f13",
1292            VK_F14 => "f14",
1293            VK_F15 => "f15",
1294            VK_F16 => "f16",
1295            VK_F17 => "f17",
1296            VK_F18 => "f18",
1297            VK_F19 => "f19",
1298            VK_F20 => "f20",
1299            VK_F21 => "f21",
1300            VK_F22 => "f22",
1301            VK_F23 => "f23",
1302            VK_F24 => "f24",
1303            _ => return None,
1304        }
1305        .to_string(),
1306    )
1307}
1308
1309fn parse_normal_key(
1310    vkey: VIRTUAL_KEY,
1311    lparam: LPARAM,
1312    mut modifiers: Modifiers,
1313) -> Option<(Keystroke, bool)> {
1314    let (key_char, prefer_character_input) = process_key(vkey, lparam.hiword());
1315
1316    let key = parse_immutable(vkey).or_else(|| {
1317        let scan_code = lparam.hiword() & 0xFF;
1318        get_keystroke_key(vkey, scan_code as u32, &mut modifiers)
1319    })?;
1320
1321    Some((
1322        Keystroke {
1323            modifiers,
1324            key,
1325            key_char,
1326        },
1327        prefer_character_input,
1328    ))
1329}
1330
1331fn process_key(vkey: VIRTUAL_KEY, scan_code: u16) -> (Option<String>, bool) {
1332    let mut keyboard_state = [0u8; 256];
1333    unsafe {
1334        if GetKeyboardState(&mut keyboard_state).is_err() {
1335            return (None, false);
1336        }
1337    }
1338
1339    let mut buffer_c = [0u16; 8];
1340    let result_c = unsafe {
1341        ToUnicode(
1342            vkey.0 as u32,
1343            scan_code as u32,
1344            Some(&keyboard_state),
1345            &mut buffer_c,
1346            0x4,
1347        )
1348    };
1349
1350    if result_c == 0 {
1351        return (None, false);
1352    }
1353
1354    let c = &buffer_c[..result_c.unsigned_abs() as usize];
1355    let key_char = String::from_utf16(c)
1356        .ok()
1357        .filter(|s| !s.is_empty() && !s.chars().next().unwrap().is_control());
1358
1359    if result_c < 0 {
1360        return (key_char, true);
1361    }
1362
1363    if key_char.is_none() {
1364        return (None, false);
1365    }
1366
1367    // Workaround for some bug that makes the compiler think keyboard_state is still zeroed out
1368    let keyboard_state = std::hint::black_box(keyboard_state);
1369    let ctrl_down = (keyboard_state[VK_CONTROL.0 as usize] & 0x80) != 0;
1370    let alt_down = (keyboard_state[VK_MENU.0 as usize] & 0x80) != 0;
1371    let win_down = (keyboard_state[VK_LWIN.0 as usize] & 0x80) != 0
1372        || (keyboard_state[VK_RWIN.0 as usize] & 0x80) != 0;
1373
1374    let has_modifiers = ctrl_down || alt_down || win_down;
1375    if !has_modifiers {
1376        return (key_char, false);
1377    }
1378
1379    let mut state_no_modifiers = keyboard_state;
1380    state_no_modifiers[VK_CONTROL.0 as usize] = 0;
1381    state_no_modifiers[VK_LCONTROL.0 as usize] = 0;
1382    state_no_modifiers[VK_RCONTROL.0 as usize] = 0;
1383    state_no_modifiers[VK_MENU.0 as usize] = 0;
1384    state_no_modifiers[VK_LMENU.0 as usize] = 0;
1385    state_no_modifiers[VK_RMENU.0 as usize] = 0;
1386    state_no_modifiers[VK_LWIN.0 as usize] = 0;
1387    state_no_modifiers[VK_RWIN.0 as usize] = 0;
1388
1389    let mut buffer_c_no_modifiers = [0u16; 8];
1390    let result_c_no_modifiers = unsafe {
1391        ToUnicode(
1392            vkey.0 as u32,
1393            scan_code as u32,
1394            Some(&state_no_modifiers),
1395            &mut buffer_c_no_modifiers,
1396            0x4,
1397        )
1398    };
1399
1400    let c_no_modifiers = &buffer_c_no_modifiers[..result_c_no_modifiers.unsigned_abs() as usize];
1401    (
1402        key_char,
1403        result_c != result_c_no_modifiers || c != c_no_modifiers,
1404    )
1405}
1406
1407fn parse_ime_composition_string(ctx: HIMC, comp_type: IME_COMPOSITION_STRING) -> Option<Vec<u16>> {
1408    unsafe {
1409        let string_len = ImmGetCompositionStringW(ctx, comp_type, None, 0);
1410        if string_len >= 0 {
1411            let mut buffer = vec![0u8; string_len as usize + 2];
1412            ImmGetCompositionStringW(
1413                ctx,
1414                comp_type,
1415                Some(buffer.as_mut_ptr() as _),
1416                string_len as _,
1417            );
1418            let wstring = std::slice::from_raw_parts::<u16>(
1419                buffer.as_mut_ptr().cast::<u16>(),
1420                string_len as usize / 2,
1421            );
1422            Some(wstring.to_vec())
1423        } else {
1424            None
1425        }
1426    }
1427}
1428
1429#[inline]
1430fn retrieve_composition_cursor_position(ctx: HIMC) -> usize {
1431    unsafe { ImmGetCompositionStringW(ctx, GCS_CURSORPOS, None, 0) as usize }
1432}
1433
1434fn should_use_ime_cursor_position(ctx: HIMC, cursor_pos: usize) -> bool {
1435    let attrs_size = unsafe { ImmGetCompositionStringW(ctx, GCS_COMPATTR, None, 0) } as usize;
1436    if attrs_size == 0 {
1437        return false;
1438    }
1439
1440    let mut attrs = vec![0u8; attrs_size];
1441    let result = unsafe {
1442        ImmGetCompositionStringW(
1443            ctx,
1444            GCS_COMPATTR,
1445            Some(attrs.as_mut_ptr() as *mut _),
1446            attrs_size as u32,
1447        )
1448    };
1449    if result <= 0 {
1450        return false;
1451    }
1452
1453    // Keep the cursor adjacent to the inserted text by only using the suggested position
1454    // if it's adjacent to unconverted text.
1455    let at_cursor_is_input = cursor_pos < attrs.len() && attrs[cursor_pos] == (ATTR_INPUT as u8);
1456    let before_cursor_is_input = cursor_pos > 0
1457        && (cursor_pos - 1) < attrs.len()
1458        && attrs[cursor_pos - 1] == (ATTR_INPUT as u8);
1459
1460    at_cursor_is_input || before_cursor_is_input
1461}
1462
1463#[inline]
1464fn is_virtual_key_pressed(vkey: VIRTUAL_KEY) -> bool {
1465    unsafe { GetKeyState(vkey.0 as i32) < 0 }
1466}
1467
1468#[inline]
1469pub(crate) fn current_modifiers() -> Modifiers {
1470    Modifiers {
1471        control: is_virtual_key_pressed(VK_CONTROL),
1472        alt: is_virtual_key_pressed(VK_MENU),
1473        shift: is_virtual_key_pressed(VK_SHIFT),
1474        platform: is_virtual_key_pressed(VK_LWIN) || is_virtual_key_pressed(VK_RWIN),
1475        function: false,
1476    }
1477}
1478
1479#[inline]
1480pub(crate) fn current_capslock() -> Capslock {
1481    let on = unsafe { GetKeyState(VK_CAPITAL.0 as i32) & 1 } > 0;
1482    Capslock { on }
1483}
1484
1485// there is some additional non-visible space when talking about window
1486// borders on Windows:
1487// - SM_CXSIZEFRAME: The resize handle.
1488// - SM_CXPADDEDBORDER: Additional border space that isn't part of the resize handle.
1489fn get_frame_thicknessx(dpi: u32) -> i32 {
1490    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CXSIZEFRAME, dpi) };
1491    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1492    resize_frame_thickness + padding_thickness
1493}
1494
1495fn get_frame_thicknessy(dpi: u32) -> i32 {
1496    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CYSIZEFRAME, dpi) };
1497    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1498    resize_frame_thickness + padding_thickness
1499}
1500
1501fn notify_frame_changed(handle: HWND) {
1502    unsafe {
1503        SetWindowPos(
1504            handle,
1505            None,
1506            0,
1507            0,
1508            0,
1509            0,
1510            SWP_FRAMECHANGED
1511                | SWP_NOACTIVATE
1512                | SWP_NOCOPYBITS
1513                | SWP_NOMOVE
1514                | SWP_NOOWNERZORDER
1515                | SWP_NOREPOSITION
1516                | SWP_NOSENDCHANGING
1517                | SWP_NOSIZE
1518                | SWP_NOZORDER,
1519        )
1520        .log_err();
1521    }
1522}