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;
  32const AUTO_HIDE_TASKBAR_THICKNESS_PX: i32 = 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.0 + size.width.0 / 2.;
 132        let center_y = origin.y.0 + size.height.0 / 2.;
 133        let monitor_bounds = self.state.display.get().bounds();
 134        if center_x < monitor_bounds.left().0
 135            || center_x > monitor_bounds.right().0
 136            || center_y < monitor_bounds.top().0
 137            || center_y > monitor_bounds.bottom().0
 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 =
 165                min_size.width.scale(scale_factor).0 as i32 + boarder_offset.width_offset.get();
 166            minmax_info.ptMinTrackSize.y =
 167                min_size.height.scale(scale_factor).0 as i32 + 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.0 * scale_factor) as i32,
 582                y: (caret_position.origin.y.0 * scale_factor) as i32
 583                    + ((caret_position.size.height.0 * 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    /// SEE: https://learn.microsoft.com/en-us/windows/win32/winmsg/wm-nccalcsize
 672    fn handle_calc_client_size(
 673        &self,
 674        handle: HWND,
 675        wparam: WPARAM,
 676        lparam: LPARAM,
 677    ) -> Option<isize> {
 678        if !self.hide_title_bar || self.state.is_fullscreen() || wparam.0 == 0 {
 679            return None;
 680        }
 681
 682        let is_maximized = self.state.is_maximized();
 683        let insets = get_client_area_insets(handle, is_maximized, self.windows_version);
 684        // wparam is TRUE so lparam points to an NCCALCSIZE_PARAMS structure
 685        let mut params = lparam.0 as *mut NCCALCSIZE_PARAMS;
 686        let mut requested_client_rect = unsafe { &mut ((*params).rgrc) };
 687
 688        requested_client_rect[0].left += insets.left;
 689        requested_client_rect[0].top += insets.top;
 690        requested_client_rect[0].right -= insets.right;
 691        requested_client_rect[0].bottom -= insets.bottom;
 692
 693        // Fix auto hide taskbar not showing. This solution is based on the approach
 694        // used by Chrome. However, it may result in one row of pixels being obscured
 695        // in our client area. But as Chrome says, "there seems to be no better solution."
 696        if is_maximized
 697            && let Some(taskbar_position) = self.system_settings().auto_hide_taskbar_position.get()
 698        {
 699            // For the auto-hide taskbar, adjust in by 1 pixel on taskbar edge,
 700            // so the window isn't treated as a "fullscreen app", which would cause
 701            // the taskbar to disappear.
 702            match taskbar_position {
 703                AutoHideTaskbarPosition::Left => {
 704                    requested_client_rect[0].left += AUTO_HIDE_TASKBAR_THICKNESS_PX
 705                }
 706                AutoHideTaskbarPosition::Top => {
 707                    requested_client_rect[0].top += AUTO_HIDE_TASKBAR_THICKNESS_PX
 708                }
 709                AutoHideTaskbarPosition::Right => {
 710                    requested_client_rect[0].right -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 711                }
 712                AutoHideTaskbarPosition::Bottom => {
 713                    requested_client_rect[0].bottom -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 714                }
 715            }
 716        }
 717
 718        Some(0)
 719    }
 720
 721    fn handle_activate_msg(self: &Rc<Self>, wparam: WPARAM) -> Option<isize> {
 722        let activated = wparam.loword() > 0;
 723        let this = self.clone();
 724        self.executor
 725            .spawn(async move {
 726                if let Some(mut func) = this.state.callbacks.active_status_change.take() {
 727                    func(activated);
 728                    this.state.callbacks.active_status_change.set(Some(func));
 729                }
 730            })
 731            .detach();
 732
 733        None
 734    }
 735
 736    fn handle_create_msg(&self, handle: HWND) -> Option<isize> {
 737        if self.hide_title_bar {
 738            notify_frame_changed(handle);
 739            Some(0)
 740        } else {
 741            None
 742        }
 743    }
 744
 745    fn handle_dpi_changed_msg(
 746        &self,
 747        handle: HWND,
 748        wparam: WPARAM,
 749        lparam: LPARAM,
 750    ) -> Option<isize> {
 751        let new_dpi = wparam.loword() as f32;
 752
 753        let is_maximized = self.state.is_maximized();
 754        let new_scale_factor = new_dpi / USER_DEFAULT_SCREEN_DPI as f32;
 755        self.state.scale_factor.set(new_scale_factor);
 756        self.state.border_offset.update(handle).log_err();
 757
 758        if is_maximized {
 759            // Get the monitor and its work area at the new DPI
 760            let monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONEAREST) };
 761            let mut monitor_info: MONITORINFO = unsafe { std::mem::zeroed() };
 762            monitor_info.cbSize = std::mem::size_of::<MONITORINFO>() as u32;
 763            if unsafe { GetMonitorInfoW(monitor, &mut monitor_info) }.as_bool() {
 764                let work_area = monitor_info.rcWork;
 765                let width = work_area.right - work_area.left;
 766                let height = work_area.bottom - work_area.top;
 767
 768                // Update the window size to match the new monitor work area
 769                // This will trigger WM_SIZE which will handle the size change
 770                unsafe {
 771                    SetWindowPos(
 772                        handle,
 773                        None,
 774                        work_area.left,
 775                        work_area.top,
 776                        width,
 777                        height,
 778                        SWP_NOZORDER | SWP_NOACTIVATE | SWP_FRAMECHANGED,
 779                    )
 780                    .context("unable to set maximized window position after dpi has changed")
 781                    .log_err();
 782                }
 783
 784                // SetWindowPos may not send WM_SIZE for maximized windows in some cases,
 785                // so we manually update the size to ensure proper rendering
 786                let device_size = size(DevicePixels(width), DevicePixels(height));
 787                self.handle_size_change(device_size, new_scale_factor, true);
 788            }
 789        } else {
 790            // For non-maximized windows, use the suggested RECT from the system
 791            let rect = unsafe { &*(lparam.0 as *const RECT) };
 792            let width = rect.right - rect.left;
 793            let height = rect.bottom - rect.top;
 794            // this will emit `WM_SIZE` and `WM_MOVE` right here
 795            // even before this function returns
 796            // the new size is handled in `WM_SIZE`
 797            unsafe {
 798                SetWindowPos(
 799                    handle,
 800                    None,
 801                    rect.left,
 802                    rect.top,
 803                    width,
 804                    height,
 805                    SWP_NOZORDER | SWP_NOACTIVATE,
 806                )
 807                .context("unable to set window position after dpi has changed")
 808                .log_err();
 809            }
 810        }
 811
 812        Some(0)
 813    }
 814
 815    /// The following conditions will trigger this event:
 816    /// 1. The monitor on which the window is located goes offline or changes resolution.
 817    /// 2. Another monitor goes offline, is plugged in, or changes resolution.
 818    ///
 819    /// In either case, the window will only receive information from the monitor on which
 820    /// it is located.
 821    ///
 822    /// For example, in the case of condition 2, where the monitor on which the window is
 823    /// located has actually changed nothing, it will still receive this event.
 824    fn handle_display_change_msg(&self, handle: HWND) -> Option<isize> {
 825        // NOTE:
 826        // Even the `lParam` holds the resolution of the screen, we just ignore it.
 827        // Because WM_DPICHANGED, WM_MOVE, WM_SIZE will come first, window reposition and resize
 828        // are handled there.
 829        // So we only care about if monitor is disconnected.
 830        let previous_monitor = self.state.display.get();
 831        if WindowsDisplay::is_connected(previous_monitor.handle) {
 832            // we are fine, other display changed
 833            return None;
 834        }
 835        // display disconnected
 836        // in this case, the OS will move our window to another monitor, and minimize it.
 837        // we deminimize the window and query the monitor after moving
 838        unsafe {
 839            let _ = ShowWindow(handle, SW_SHOWNORMAL);
 840        };
 841        let new_monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 842        // all monitors disconnected
 843        if new_monitor.is_invalid() {
 844            log::error!("No monitor detected!");
 845            return None;
 846        }
 847        let new_display = WindowsDisplay::new_with_handle(new_monitor).log_err()?;
 848        self.state.display.set(new_display);
 849        Some(0)
 850    }
 851
 852    fn handle_hit_test_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 853        if !self.is_movable || self.state.is_fullscreen() {
 854            return None;
 855        }
 856
 857        let callback = self.state.callbacks.hit_test_window_control.take();
 858        let drag_area = if let Some(mut callback) = callback {
 859            let area = callback();
 860            self.state
 861                .callbacks
 862                .hit_test_window_control
 863                .set(Some(callback));
 864            if let Some(area) = area {
 865                match area {
 866                    WindowControlArea::Drag => Some(HTCAPTION as _),
 867                    WindowControlArea::Close => return Some(HTCLOSE as _),
 868                    WindowControlArea::Max => return Some(HTMAXBUTTON as _),
 869                    WindowControlArea::Min => return Some(HTMINBUTTON as _),
 870                }
 871            } else {
 872                None
 873            }
 874        } else {
 875            None
 876        };
 877
 878        if !self.hide_title_bar {
 879            // If the OS draws the title bar, we don't need to handle hit test messages.
 880            return drag_area;
 881        }
 882
 883        let dpi = unsafe { GetDpiForWindow(handle) };
 884        // We do not use the OS title bar, so the default `DefWindowProcW` will only register a 1px edge for resizes
 885        // We need to calculate the frame thickness ourselves and do the hit test manually.
 886        let frame_y = get_frame_thicknessx(dpi);
 887        let frame_x = get_frame_thicknessy(dpi);
 888        let mut cursor_point = POINT {
 889            x: lparam.signed_loword().into(),
 890            y: lparam.signed_hiword().into(),
 891        };
 892
 893        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 894        if !self.state.is_maximized() && 0 <= cursor_point.y && cursor_point.y <= frame_y {
 895            // x-axis actually goes from -frame_x to 0
 896            return Some(if cursor_point.x <= 0 {
 897                HTTOPLEFT
 898            } else {
 899                let mut rect = Default::default();
 900                unsafe { GetWindowRect(handle, &mut rect) }.log_err();
 901                // right and bottom bounds of RECT are exclusive, thus `-1`
 902                let right = rect.right - rect.left - 1;
 903                // the bounds include the padding frames, so accomodate for both of them
 904                if right - 2 * frame_x <= cursor_point.x {
 905                    HTTOPRIGHT
 906                } else {
 907                    HTTOP
 908                }
 909            } as _);
 910        }
 911
 912        drag_area
 913    }
 914
 915    fn handle_nc_mouse_move_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 916        self.start_tracking_mouse(handle, TME_LEAVE | TME_NONCLIENT);
 917
 918        let mut func = self.state.callbacks.input.take()?;
 919        let scale_factor = self.state.scale_factor.get();
 920
 921        let mut cursor_point = POINT {
 922            x: lparam.signed_loword().into(),
 923            y: lparam.signed_hiword().into(),
 924        };
 925        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 926        let input = PlatformInput::MouseMove(MouseMoveEvent {
 927            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 928            pressed_button: None,
 929            modifiers: current_modifiers(),
 930        });
 931        let handled = !func(input).propagate;
 932        self.state.callbacks.input.set(Some(func));
 933
 934        if handled { Some(0) } else { None }
 935    }
 936
 937    fn handle_nc_mouse_down_msg(
 938        &self,
 939        handle: HWND,
 940        button: MouseButton,
 941        wparam: WPARAM,
 942        lparam: LPARAM,
 943    ) -> Option<isize> {
 944        if let Some(mut func) = self.state.callbacks.input.take() {
 945            let scale_factor = self.state.scale_factor.get();
 946            let mut cursor_point = POINT {
 947                x: lparam.signed_loword().into(),
 948                y: lparam.signed_hiword().into(),
 949            };
 950            unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 951            let physical_point = point(DevicePixels(cursor_point.x), DevicePixels(cursor_point.y));
 952            let click_count = self.state.click_state.update(button, physical_point);
 953
 954            let input = PlatformInput::MouseDown(MouseDownEvent {
 955                button,
 956                position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 957                modifiers: current_modifiers(),
 958                click_count,
 959                first_mouse: false,
 960            });
 961            let result = func(input);
 962            let handled = !result.propagate || result.default_prevented;
 963            self.state.callbacks.input.set(Some(func));
 964
 965            if handled {
 966                return Some(0);
 967            }
 968        } else {
 969        };
 970
 971        // Since these are handled in handle_nc_mouse_up_msg we must prevent the default window proc
 972        if button == MouseButton::Left {
 973            match wparam.0 as u32 {
 974                HTMINBUTTON => self.state.nc_button_pressed.set(Some(HTMINBUTTON)),
 975                HTMAXBUTTON => self.state.nc_button_pressed.set(Some(HTMAXBUTTON)),
 976                HTCLOSE => self.state.nc_button_pressed.set(Some(HTCLOSE)),
 977                _ => return None,
 978            };
 979            Some(0)
 980        } else {
 981            None
 982        }
 983    }
 984
 985    fn handle_nc_mouse_up_msg(
 986        &self,
 987        handle: HWND,
 988        button: MouseButton,
 989        wparam: WPARAM,
 990        lparam: LPARAM,
 991    ) -> Option<isize> {
 992        if let Some(mut func) = self.state.callbacks.input.take() {
 993            let scale_factor = self.state.scale_factor.get();
 994
 995            let mut cursor_point = POINT {
 996                x: lparam.signed_loword().into(),
 997                y: lparam.signed_hiword().into(),
 998            };
 999            unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
1000            let input = PlatformInput::MouseUp(MouseUpEvent {
1001                button,
1002                position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
1003                modifiers: current_modifiers(),
1004                click_count: 1,
1005            });
1006            let handled = !func(input).propagate;
1007            self.state.callbacks.input.set(Some(func));
1008
1009            if handled {
1010                return Some(0);
1011            }
1012        } else {
1013        }
1014
1015        let last_pressed = self.state.nc_button_pressed.take();
1016        if button == MouseButton::Left
1017            && let Some(last_pressed) = last_pressed
1018        {
1019            let handled = match (wparam.0 as u32, last_pressed) {
1020                (HTMINBUTTON, HTMINBUTTON) => {
1021                    unsafe { ShowWindowAsync(handle, SW_MINIMIZE).ok().log_err() };
1022                    true
1023                }
1024                (HTMAXBUTTON, HTMAXBUTTON) => {
1025                    if self.state.is_maximized() {
1026                        unsafe { ShowWindowAsync(handle, SW_NORMAL).ok().log_err() };
1027                    } else {
1028                        unsafe { ShowWindowAsync(handle, SW_MAXIMIZE).ok().log_err() };
1029                    }
1030                    true
1031                }
1032                (HTCLOSE, HTCLOSE) => {
1033                    unsafe {
1034                        PostMessageW(Some(handle), WM_CLOSE, WPARAM::default(), LPARAM::default())
1035                            .log_err()
1036                    };
1037                    true
1038                }
1039                _ => false,
1040            };
1041            if handled {
1042                return Some(0);
1043            }
1044        }
1045
1046        None
1047    }
1048
1049    fn handle_cursor_changed(&self, lparam: LPARAM) -> Option<isize> {
1050        let had_cursor = self.state.current_cursor.get().is_some();
1051
1052        self.state.current_cursor.set(if lparam.0 == 0 {
1053            None
1054        } else {
1055            Some(HCURSOR(lparam.0 as _))
1056        });
1057
1058        if had_cursor != self.state.current_cursor.get().is_some() {
1059            unsafe { SetCursor(self.state.current_cursor.get()) };
1060        }
1061
1062        Some(0)
1063    }
1064
1065    fn handle_set_cursor(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
1066        if unsafe { !IsWindowEnabled(handle).as_bool() }
1067            || matches!(
1068                lparam.loword() as u32,
1069                HTLEFT
1070                    | HTRIGHT
1071                    | HTTOP
1072                    | HTTOPLEFT
1073                    | HTTOPRIGHT
1074                    | HTBOTTOM
1075                    | HTBOTTOMLEFT
1076                    | HTBOTTOMRIGHT
1077            )
1078        {
1079            return None;
1080        }
1081        unsafe {
1082            SetCursor(self.state.current_cursor.get());
1083        };
1084        Some(0)
1085    }
1086
1087    fn handle_system_settings_changed(
1088        &self,
1089        handle: HWND,
1090        wparam: WPARAM,
1091        lparam: LPARAM,
1092    ) -> Option<isize> {
1093        if wparam.0 != 0 {
1094            let display = self.state.display.get();
1095            self.state.click_state.system_update(wparam.0);
1096            self.state.border_offset.update(handle).log_err();
1097            // system settings may emit a window message which wants to take the refcell self.state, so drop it
1098
1099            self.system_settings().update(display, wparam.0);
1100        } else {
1101            self.handle_system_theme_changed(handle, lparam)?;
1102        };
1103        // Force to trigger WM_NCCALCSIZE event to ensure that we handle auto hide
1104        // taskbar correctly.
1105        notify_frame_changed(handle);
1106
1107        Some(0)
1108    }
1109
1110    fn handle_system_theme_changed(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
1111        // lParam is a pointer to a string that indicates the area containing the system parameter
1112        // that was changed.
1113        let parameter = PCWSTR::from_raw(lparam.0 as _);
1114        if unsafe { !parameter.is_null() && !parameter.is_empty() }
1115            && let Some(parameter_string) = unsafe { parameter.to_string() }.log_err()
1116        {
1117            log::info!("System settings changed: {}", parameter_string);
1118            if parameter_string.as_str() == "ImmersiveColorSet" {
1119                let new_appearance = system_appearance()
1120                    .context("unable to get system appearance when handling ImmersiveColorSet")
1121                    .log_err()?;
1122
1123                if new_appearance != self.state.appearance.get() {
1124                    self.state.appearance.set(new_appearance);
1125                    let mut callback = self.state.callbacks.appearance_changed.take()?;
1126
1127                    callback();
1128                    self.state.callbacks.appearance_changed.set(Some(callback));
1129                    configure_dwm_dark_mode(handle, new_appearance);
1130                }
1131            }
1132        }
1133        Some(0)
1134    }
1135
1136    fn handle_input_language_changed(&self) -> Option<isize> {
1137        unsafe {
1138            PostMessageW(
1139                Some(self.platform_window_handle),
1140                WM_GPUI_KEYBOARD_LAYOUT_CHANGED,
1141                WPARAM(self.validation_number),
1142                LPARAM(0),
1143            )
1144            .log_err();
1145        }
1146        Some(0)
1147    }
1148
1149    fn handle_window_visibility_changed(&self, handle: HWND, wparam: WPARAM) -> Option<isize> {
1150        if wparam.0 == 1 {
1151            self.draw_window(handle, false);
1152        }
1153        None
1154    }
1155
1156    fn handle_device_lost(&self, lparam: LPARAM) -> Option<isize> {
1157        let devices = lparam.0 as *const DirectXDevices;
1158        let devices = unsafe { &*devices };
1159        if let Err(err) = self
1160            .state
1161            .renderer
1162            .borrow_mut()
1163            .handle_device_lost(&devices)
1164        {
1165            panic!("Device lost: {err}");
1166        }
1167        Some(0)
1168    }
1169
1170    #[inline]
1171    fn draw_window(&self, handle: HWND, force_render: bool) -> Option<isize> {
1172        let mut request_frame = self.state.callbacks.request_frame.take()?;
1173
1174        // we are instructing gpui to force render a frame, this will
1175        // re-populate all the gpu textures for us so we can resume drawing in
1176        // case we disabled drawing earlier due to a device loss
1177        self.state.renderer.borrow_mut().mark_drawable();
1178        request_frame(RequestFrameOptions {
1179            require_presentation: false,
1180            force_render,
1181        });
1182
1183        self.state.callbacks.request_frame.set(Some(request_frame));
1184        unsafe { ValidateRect(Some(handle), None).ok().log_err() };
1185
1186        Some(0)
1187    }
1188
1189    #[inline]
1190    fn parse_char_message(&self, wparam: WPARAM) -> Option<String> {
1191        let code_point = wparam.loword();
1192
1193        // https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G2630
1194        match code_point {
1195            0xD800..=0xDBFF => {
1196                // High surrogate, wait for low surrogate
1197                self.state.pending_surrogate.set(Some(code_point));
1198                None
1199            }
1200            0xDC00..=0xDFFF => {
1201                if let Some(high_surrogate) = self.state.pending_surrogate.take() {
1202                    // Low surrogate, combine with pending high surrogate
1203                    String::from_utf16(&[high_surrogate, code_point]).ok()
1204                } else {
1205                    // Invalid low surrogate without a preceding high surrogate
1206                    log::warn!(
1207                        "Received low surrogate without a preceding high surrogate: {code_point:x}"
1208                    );
1209                    None
1210                }
1211            }
1212            _ => {
1213                self.state.pending_surrogate.set(None);
1214                char::from_u32(code_point as u32)
1215                    .filter(|c| !c.is_control())
1216                    .map(|c| c.to_string())
1217            }
1218        }
1219    }
1220
1221    fn start_tracking_mouse(&self, handle: HWND, flags: TRACKMOUSEEVENT_FLAGS) {
1222        if !self.state.hovered.get() {
1223            self.state.hovered.set(true);
1224            unsafe {
1225                TrackMouseEvent(&mut TRACKMOUSEEVENT {
1226                    cbSize: std::mem::size_of::<TRACKMOUSEEVENT>() as u32,
1227                    dwFlags: flags,
1228                    hwndTrack: handle,
1229                    dwHoverTime: HOVER_DEFAULT,
1230                })
1231                .log_err()
1232            };
1233            if let Some(mut callback) = self.state.callbacks.hovered_status_change.take() {
1234                callback(true);
1235                self.state
1236                    .callbacks
1237                    .hovered_status_change
1238                    .set(Some(callback));
1239            }
1240        }
1241    }
1242
1243    fn with_input_handler<F, R>(&self, f: F) -> Option<R>
1244    where
1245        F: FnOnce(&mut PlatformInputHandler) -> R,
1246    {
1247        let mut input_handler = self.state.input_handler.take()?;
1248        let result = f(&mut input_handler);
1249        self.state.input_handler.set(Some(input_handler));
1250        Some(result)
1251    }
1252
1253    fn with_input_handler_and_scale_factor<F, R>(&self, f: F) -> Option<R>
1254    where
1255        F: FnOnce(&mut PlatformInputHandler, f32) -> Option<R>,
1256    {
1257        let mut input_handler = self.state.input_handler.take()?;
1258        let scale_factor = self.state.scale_factor.get();
1259
1260        let result = f(&mut input_handler, scale_factor);
1261        self.state.input_handler.set(Some(input_handler));
1262        result
1263    }
1264}
1265
1266fn handle_key_event<F>(
1267    wparam: WPARAM,
1268    lparam: LPARAM,
1269    state: &WindowsWindowState,
1270    f: F,
1271) -> Option<PlatformInput>
1272where
1273    F: FnOnce(Keystroke, bool) -> PlatformInput,
1274{
1275    let virtual_key = VIRTUAL_KEY(wparam.loword());
1276    let modifiers = current_modifiers();
1277
1278    match virtual_key {
1279        VK_SHIFT | VK_CONTROL | VK_MENU | VK_LMENU | VK_RMENU | VK_LWIN | VK_RWIN => {
1280            if state
1281                .last_reported_modifiers
1282                .get()
1283                .is_some_and(|prev_modifiers| prev_modifiers == modifiers)
1284            {
1285                return None;
1286            }
1287            state.last_reported_modifiers.set(Some(modifiers));
1288            Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1289                modifiers,
1290                capslock: current_capslock(),
1291            }))
1292        }
1293        VK_PACKET => None,
1294        VK_CAPITAL => {
1295            let capslock = current_capslock();
1296            if state
1297                .last_reported_capslock
1298                .get()
1299                .is_some_and(|prev_capslock| prev_capslock == capslock)
1300            {
1301                return None;
1302            }
1303            state.last_reported_capslock.set(Some(capslock));
1304            Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1305                modifiers,
1306                capslock,
1307            }))
1308        }
1309        vkey => {
1310            let keystroke = parse_normal_key(vkey, lparam, modifiers)?;
1311            Some(f(keystroke.0, keystroke.1))
1312        }
1313    }
1314}
1315
1316fn parse_immutable(vkey: VIRTUAL_KEY) -> Option<String> {
1317    Some(
1318        match vkey {
1319            VK_SPACE => "space",
1320            VK_BACK => "backspace",
1321            VK_RETURN => "enter",
1322            VK_TAB => "tab",
1323            VK_UP => "up",
1324            VK_DOWN => "down",
1325            VK_RIGHT => "right",
1326            VK_LEFT => "left",
1327            VK_HOME => "home",
1328            VK_END => "end",
1329            VK_PRIOR => "pageup",
1330            VK_NEXT => "pagedown",
1331            VK_BROWSER_BACK => "back",
1332            VK_BROWSER_FORWARD => "forward",
1333            VK_ESCAPE => "escape",
1334            VK_INSERT => "insert",
1335            VK_DELETE => "delete",
1336            VK_APPS => "menu",
1337            VK_F1 => "f1",
1338            VK_F2 => "f2",
1339            VK_F3 => "f3",
1340            VK_F4 => "f4",
1341            VK_F5 => "f5",
1342            VK_F6 => "f6",
1343            VK_F7 => "f7",
1344            VK_F8 => "f8",
1345            VK_F9 => "f9",
1346            VK_F10 => "f10",
1347            VK_F11 => "f11",
1348            VK_F12 => "f12",
1349            VK_F13 => "f13",
1350            VK_F14 => "f14",
1351            VK_F15 => "f15",
1352            VK_F16 => "f16",
1353            VK_F17 => "f17",
1354            VK_F18 => "f18",
1355            VK_F19 => "f19",
1356            VK_F20 => "f20",
1357            VK_F21 => "f21",
1358            VK_F22 => "f22",
1359            VK_F23 => "f23",
1360            VK_F24 => "f24",
1361            _ => return None,
1362        }
1363        .to_string(),
1364    )
1365}
1366
1367fn parse_normal_key(
1368    vkey: VIRTUAL_KEY,
1369    lparam: LPARAM,
1370    mut modifiers: Modifiers,
1371) -> Option<(Keystroke, bool)> {
1372    let (key_char, prefer_character_input) = process_key(vkey, lparam.hiword());
1373
1374    let key = parse_immutable(vkey).or_else(|| {
1375        let scan_code = lparam.hiword() & 0xFF;
1376        get_keystroke_key(vkey, scan_code as u32, &mut modifiers)
1377    })?;
1378
1379    Some((
1380        Keystroke {
1381            modifiers,
1382            key,
1383            key_char,
1384        },
1385        prefer_character_input,
1386    ))
1387}
1388
1389fn process_key(vkey: VIRTUAL_KEY, scan_code: u16) -> (Option<String>, bool) {
1390    let mut keyboard_state = [0u8; 256];
1391    unsafe {
1392        if GetKeyboardState(&mut keyboard_state).is_err() {
1393            return (None, false);
1394        }
1395    }
1396
1397    let mut buffer_c = [0u16; 8];
1398    let result_c = unsafe {
1399        ToUnicode(
1400            vkey.0 as u32,
1401            scan_code as u32,
1402            Some(&keyboard_state),
1403            &mut buffer_c,
1404            0x4,
1405        )
1406    };
1407
1408    if result_c == 0 {
1409        return (None, false);
1410    }
1411
1412    let c = &buffer_c[..result_c.unsigned_abs() as usize];
1413    let key_char = String::from_utf16(c)
1414        .ok()
1415        .filter(|s| !s.is_empty() && !s.chars().next().unwrap().is_control());
1416
1417    if result_c < 0 {
1418        return (key_char, true);
1419    }
1420
1421    if key_char.is_none() {
1422        return (None, false);
1423    }
1424
1425    // Workaround for some bug that makes the compiler think keyboard_state is still zeroed out
1426    let keyboard_state = std::hint::black_box(keyboard_state);
1427    let ctrl_down = (keyboard_state[VK_CONTROL.0 as usize] & 0x80) != 0;
1428    let alt_down = (keyboard_state[VK_MENU.0 as usize] & 0x80) != 0;
1429    let win_down = (keyboard_state[VK_LWIN.0 as usize] & 0x80) != 0
1430        || (keyboard_state[VK_RWIN.0 as usize] & 0x80) != 0;
1431
1432    let has_modifiers = ctrl_down || alt_down || win_down;
1433    if !has_modifiers {
1434        return (key_char, false);
1435    }
1436
1437    let mut state_no_modifiers = keyboard_state;
1438    state_no_modifiers[VK_CONTROL.0 as usize] = 0;
1439    state_no_modifiers[VK_LCONTROL.0 as usize] = 0;
1440    state_no_modifiers[VK_RCONTROL.0 as usize] = 0;
1441    state_no_modifiers[VK_MENU.0 as usize] = 0;
1442    state_no_modifiers[VK_LMENU.0 as usize] = 0;
1443    state_no_modifiers[VK_RMENU.0 as usize] = 0;
1444    state_no_modifiers[VK_LWIN.0 as usize] = 0;
1445    state_no_modifiers[VK_RWIN.0 as usize] = 0;
1446
1447    let mut buffer_c_no_modifiers = [0u16; 8];
1448    let result_c_no_modifiers = unsafe {
1449        ToUnicode(
1450            vkey.0 as u32,
1451            scan_code as u32,
1452            Some(&state_no_modifiers),
1453            &mut buffer_c_no_modifiers,
1454            0x4,
1455        )
1456    };
1457
1458    let c_no_modifiers = &buffer_c_no_modifiers[..result_c_no_modifiers.unsigned_abs() as usize];
1459    (
1460        key_char,
1461        result_c != result_c_no_modifiers || c != c_no_modifiers,
1462    )
1463}
1464
1465fn parse_ime_composition_string(ctx: HIMC, comp_type: IME_COMPOSITION_STRING) -> Option<Vec<u16>> {
1466    unsafe {
1467        let string_len = ImmGetCompositionStringW(ctx, comp_type, None, 0);
1468        if string_len >= 0 {
1469            let mut buffer = vec![0u8; string_len as usize + 2];
1470            ImmGetCompositionStringW(
1471                ctx,
1472                comp_type,
1473                Some(buffer.as_mut_ptr() as _),
1474                string_len as _,
1475            );
1476            let wstring = std::slice::from_raw_parts::<u16>(
1477                buffer.as_mut_ptr().cast::<u16>(),
1478                string_len as usize / 2,
1479            );
1480            Some(wstring.to_vec())
1481        } else {
1482            None
1483        }
1484    }
1485}
1486
1487#[inline]
1488fn retrieve_composition_cursor_position(ctx: HIMC) -> usize {
1489    unsafe { ImmGetCompositionStringW(ctx, GCS_CURSORPOS, None, 0) as usize }
1490}
1491
1492fn should_use_ime_cursor_position(ctx: HIMC, cursor_pos: usize) -> bool {
1493    let attrs_size = unsafe { ImmGetCompositionStringW(ctx, GCS_COMPATTR, None, 0) } as usize;
1494    if attrs_size == 0 {
1495        return false;
1496    }
1497
1498    let mut attrs = vec![0u8; attrs_size];
1499    let result = unsafe {
1500        ImmGetCompositionStringW(
1501            ctx,
1502            GCS_COMPATTR,
1503            Some(attrs.as_mut_ptr() as *mut _),
1504            attrs_size as u32,
1505        )
1506    };
1507    if result <= 0 {
1508        return false;
1509    }
1510
1511    // Keep the cursor adjacent to the inserted text by only using the suggested position
1512    // if it's adjacent to unconverted text.
1513    let at_cursor_is_input = cursor_pos < attrs.len() && attrs[cursor_pos] == (ATTR_INPUT as u8);
1514    let before_cursor_is_input = cursor_pos > 0
1515        && (cursor_pos - 1) < attrs.len()
1516        && attrs[cursor_pos - 1] == (ATTR_INPUT as u8);
1517
1518    at_cursor_is_input || before_cursor_is_input
1519}
1520
1521#[inline]
1522fn is_virtual_key_pressed(vkey: VIRTUAL_KEY) -> bool {
1523    unsafe { GetKeyState(vkey.0 as i32) < 0 }
1524}
1525
1526#[inline]
1527pub(crate) fn current_modifiers() -> Modifiers {
1528    Modifiers {
1529        control: is_virtual_key_pressed(VK_CONTROL),
1530        alt: is_virtual_key_pressed(VK_MENU),
1531        shift: is_virtual_key_pressed(VK_SHIFT),
1532        platform: is_virtual_key_pressed(VK_LWIN) || is_virtual_key_pressed(VK_RWIN),
1533        function: false,
1534    }
1535}
1536
1537#[inline]
1538pub(crate) fn current_capslock() -> Capslock {
1539    let on = unsafe { GetKeyState(VK_CAPITAL.0 as i32) & 1 } > 0;
1540    Capslock { on }
1541}
1542
1543fn get_client_area_insets(
1544    handle: HWND,
1545    is_maximized: bool,
1546    windows_version: WindowsVersion,
1547) -> RECT {
1548    // For maximized windows, Windows outdents the window rect from the screen's client rect
1549    // by `frame_thickness` on each edge, meaning `insets` must contain `frame_thickness`
1550    // on all sides (including the top) to avoid the client area extending onto adjacent
1551    // monitors.
1552    //
1553    // For non-maximized windows, things become complicated:
1554    //
1555    // - On Windows 10
1556    // The top inset must be zero, since if there is any nonclient area, Windows will draw
1557    // a full native titlebar outside the client area. (This doesn't occur in the maximized
1558    // case.)
1559    //
1560    // - On Windows 11
1561    // The top inset is calculated using an empirical formula that I derived through various
1562    // tests. Without this, the top 1-2 rows of pixels in our window would be obscured.
1563    let dpi = unsafe { GetDpiForWindow(handle) };
1564    let frame_thickness = get_frame_thicknessx(dpi);
1565    let top_insets = if is_maximized {
1566        frame_thickness
1567    } else {
1568        match windows_version {
1569            WindowsVersion::Win10 => 0,
1570            WindowsVersion::Win11 => (dpi as f32 / USER_DEFAULT_SCREEN_DPI as f32).round() as i32,
1571        }
1572    };
1573    RECT {
1574        left: frame_thickness,
1575        top: top_insets,
1576        right: frame_thickness,
1577        bottom: frame_thickness,
1578    }
1579}
1580
1581// there is some additional non-visible space when talking about window
1582// borders on Windows:
1583// - SM_CXSIZEFRAME: The resize handle.
1584// - SM_CXPADDEDBORDER: Additional border space that isn't part of the resize handle.
1585fn get_frame_thicknessx(dpi: u32) -> i32 {
1586    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CXSIZEFRAME, dpi) };
1587    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1588    resize_frame_thickness + padding_thickness
1589}
1590
1591fn get_frame_thicknessy(dpi: u32) -> i32 {
1592    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CYSIZEFRAME, dpi) };
1593    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1594    resize_frame_thickness + padding_thickness
1595}
1596
1597fn notify_frame_changed(handle: HWND) {
1598    unsafe {
1599        SetWindowPos(
1600            handle,
1601            None,
1602            0,
1603            0,
1604            0,
1605            0,
1606            SWP_FRAMECHANGED
1607                | SWP_NOACTIVATE
1608                | SWP_NOCOPYBITS
1609                | SWP_NOMOVE
1610                | SWP_NOOWNERZORDER
1611                | SWP_NOREPOSITION
1612                | SWP_NOSENDCHANGING
1613                | SWP_NOSIZE
1614                | SWP_NOZORDER,
1615        )
1616        .log_err();
1617    }
1618}