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_COMPSTR.0 > 0 {
 636                let comp_string = parse_ime_composition_string(ctx, GCS_COMPSTR)?;
 637                let caret_pos =
 638                    (!comp_string.is_empty() && lparam & GCS_CURSORPOS.0 > 0).then(|| {
 639                        let pos = retrieve_composition_cursor_position(ctx);
 640                        pos..pos
 641                    });
 642                self.with_input_handler(|input_handler| {
 643                    input_handler.replace_and_mark_text_in_range(None, &comp_string, caret_pos);
 644                })?;
 645            }
 646            if lparam & GCS_RESULTSTR.0 > 0 {
 647                let comp_result = parse_ime_composition_string(ctx, GCS_RESULTSTR)?;
 648                self.with_input_handler(|input_handler| {
 649                    input_handler.replace_text_in_range(None, &comp_result);
 650                })?;
 651                return Some(0);
 652            }
 653
 654            // currently, we don't care other stuff
 655            None
 656        }
 657    }
 658
 659    /// SEE: https://learn.microsoft.com/en-us/windows/win32/winmsg/wm-nccalcsize
 660    fn handle_calc_client_size(
 661        &self,
 662        handle: HWND,
 663        wparam: WPARAM,
 664        lparam: LPARAM,
 665    ) -> Option<isize> {
 666        if !self.hide_title_bar || self.state.is_fullscreen() || wparam.0 == 0 {
 667            return None;
 668        }
 669
 670        let is_maximized = self.state.is_maximized();
 671        let insets = get_client_area_insets(handle, is_maximized, self.windows_version);
 672        // wparam is TRUE so lparam points to an NCCALCSIZE_PARAMS structure
 673        let mut params = lparam.0 as *mut NCCALCSIZE_PARAMS;
 674        let mut requested_client_rect = unsafe { &mut ((*params).rgrc) };
 675
 676        requested_client_rect[0].left += insets.left;
 677        requested_client_rect[0].top += insets.top;
 678        requested_client_rect[0].right -= insets.right;
 679        requested_client_rect[0].bottom -= insets.bottom;
 680
 681        // Fix auto hide taskbar not showing. This solution is based on the approach
 682        // used by Chrome. However, it may result in one row of pixels being obscured
 683        // in our client area. But as Chrome says, "there seems to be no better solution."
 684        if is_maximized
 685            && let Some(taskbar_position) = self.system_settings().auto_hide_taskbar_position.get()
 686        {
 687            // For the auto-hide taskbar, adjust in by 1 pixel on taskbar edge,
 688            // so the window isn't treated as a "fullscreen app", which would cause
 689            // the taskbar to disappear.
 690            match taskbar_position {
 691                AutoHideTaskbarPosition::Left => {
 692                    requested_client_rect[0].left += AUTO_HIDE_TASKBAR_THICKNESS_PX
 693                }
 694                AutoHideTaskbarPosition::Top => {
 695                    requested_client_rect[0].top += AUTO_HIDE_TASKBAR_THICKNESS_PX
 696                }
 697                AutoHideTaskbarPosition::Right => {
 698                    requested_client_rect[0].right -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 699                }
 700                AutoHideTaskbarPosition::Bottom => {
 701                    requested_client_rect[0].bottom -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 702                }
 703            }
 704        }
 705
 706        Some(0)
 707    }
 708
 709    fn handle_activate_msg(self: &Rc<Self>, wparam: WPARAM) -> Option<isize> {
 710        let activated = wparam.loword() > 0;
 711        let this = self.clone();
 712        self.executor
 713            .spawn(async move {
 714                if let Some(mut func) = this.state.callbacks.active_status_change.take() {
 715                    func(activated);
 716                    this.state.callbacks.active_status_change.set(Some(func));
 717                }
 718            })
 719            .detach();
 720
 721        None
 722    }
 723
 724    fn handle_create_msg(&self, handle: HWND) -> Option<isize> {
 725        if self.hide_title_bar {
 726            notify_frame_changed(handle);
 727            Some(0)
 728        } else {
 729            None
 730        }
 731    }
 732
 733    fn handle_dpi_changed_msg(
 734        &self,
 735        handle: HWND,
 736        wparam: WPARAM,
 737        lparam: LPARAM,
 738    ) -> Option<isize> {
 739        let new_dpi = wparam.loword() as f32;
 740
 741        let is_maximized = self.state.is_maximized();
 742        let new_scale_factor = new_dpi / USER_DEFAULT_SCREEN_DPI as f32;
 743        self.state.scale_factor.set(new_scale_factor);
 744        self.state.border_offset.update(handle).log_err();
 745
 746        if is_maximized {
 747            // Get the monitor and its work area at the new DPI
 748            let monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONEAREST) };
 749            let mut monitor_info: MONITORINFO = unsafe { std::mem::zeroed() };
 750            monitor_info.cbSize = std::mem::size_of::<MONITORINFO>() as u32;
 751            if unsafe { GetMonitorInfoW(monitor, &mut monitor_info) }.as_bool() {
 752                let work_area = monitor_info.rcWork;
 753                let width = work_area.right - work_area.left;
 754                let height = work_area.bottom - work_area.top;
 755
 756                // Update the window size to match the new monitor work area
 757                // This will trigger WM_SIZE which will handle the size change
 758                unsafe {
 759                    SetWindowPos(
 760                        handle,
 761                        None,
 762                        work_area.left,
 763                        work_area.top,
 764                        width,
 765                        height,
 766                        SWP_NOZORDER | SWP_NOACTIVATE | SWP_FRAMECHANGED,
 767                    )
 768                    .context("unable to set maximized window position after dpi has changed")
 769                    .log_err();
 770                }
 771
 772                // SetWindowPos may not send WM_SIZE for maximized windows in some cases,
 773                // so we manually update the size to ensure proper rendering
 774                let device_size = size(DevicePixels(width), DevicePixels(height));
 775                self.handle_size_change(device_size, new_scale_factor, true);
 776            }
 777        } else {
 778            // For non-maximized windows, use the suggested RECT from the system
 779            let rect = unsafe { &*(lparam.0 as *const RECT) };
 780            let width = rect.right - rect.left;
 781            let height = rect.bottom - rect.top;
 782            // this will emit `WM_SIZE` and `WM_MOVE` right here
 783            // even before this function returns
 784            // the new size is handled in `WM_SIZE`
 785            unsafe {
 786                SetWindowPos(
 787                    handle,
 788                    None,
 789                    rect.left,
 790                    rect.top,
 791                    width,
 792                    height,
 793                    SWP_NOZORDER | SWP_NOACTIVATE,
 794                )
 795                .context("unable to set window position after dpi has changed")
 796                .log_err();
 797            }
 798        }
 799
 800        Some(0)
 801    }
 802
 803    /// The following conditions will trigger this event:
 804    /// 1. The monitor on which the window is located goes offline or changes resolution.
 805    /// 2. Another monitor goes offline, is plugged in, or changes resolution.
 806    ///
 807    /// In either case, the window will only receive information from the monitor on which
 808    /// it is located.
 809    ///
 810    /// For example, in the case of condition 2, where the monitor on which the window is
 811    /// located has actually changed nothing, it will still receive this event.
 812    fn handle_display_change_msg(&self, handle: HWND) -> Option<isize> {
 813        // NOTE:
 814        // Even the `lParam` holds the resolution of the screen, we just ignore it.
 815        // Because WM_DPICHANGED, WM_MOVE, WM_SIZE will come first, window reposition and resize
 816        // are handled there.
 817        // So we only care about if monitor is disconnected.
 818        let previous_monitor = self.state.display.get();
 819        if WindowsDisplay::is_connected(previous_monitor.handle) {
 820            // we are fine, other display changed
 821            return None;
 822        }
 823        // display disconnected
 824        // in this case, the OS will move our window to another monitor, and minimize it.
 825        // we deminimize the window and query the monitor after moving
 826        unsafe {
 827            let _ = ShowWindow(handle, SW_SHOWNORMAL);
 828        };
 829        let new_monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 830        // all monitors disconnected
 831        if new_monitor.is_invalid() {
 832            log::error!("No monitor detected!");
 833            return None;
 834        }
 835        let new_display = WindowsDisplay::new_with_handle(new_monitor).log_err()?;
 836        self.state.display.set(new_display);
 837        Some(0)
 838    }
 839
 840    fn handle_hit_test_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 841        if !self.is_movable || self.state.is_fullscreen() {
 842            return None;
 843        }
 844
 845        let callback = self.state.callbacks.hit_test_window_control.take();
 846        let drag_area = if let Some(mut callback) = callback {
 847            let area = callback();
 848            self.state
 849                .callbacks
 850                .hit_test_window_control
 851                .set(Some(callback));
 852            if let Some(area) = area {
 853                match area {
 854                    WindowControlArea::Drag => Some(HTCAPTION as _),
 855                    WindowControlArea::Close => return Some(HTCLOSE as _),
 856                    WindowControlArea::Max => return Some(HTMAXBUTTON as _),
 857                    WindowControlArea::Min => return Some(HTMINBUTTON as _),
 858                }
 859            } else {
 860                None
 861            }
 862        } else {
 863            None
 864        };
 865
 866        if !self.hide_title_bar {
 867            // If the OS draws the title bar, we don't need to handle hit test messages.
 868            return drag_area;
 869        }
 870
 871        let dpi = unsafe { GetDpiForWindow(handle) };
 872        // We do not use the OS title bar, so the default `DefWindowProcW` will only register a 1px edge for resizes
 873        // We need to calculate the frame thickness ourselves and do the hit test manually.
 874        let frame_y = get_frame_thicknessx(dpi);
 875        let frame_x = get_frame_thicknessy(dpi);
 876        let mut cursor_point = POINT {
 877            x: lparam.signed_loword().into(),
 878            y: lparam.signed_hiword().into(),
 879        };
 880
 881        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 882        if !self.state.is_maximized() && 0 <= cursor_point.y && cursor_point.y <= frame_y {
 883            // x-axis actually goes from -frame_x to 0
 884            return Some(if cursor_point.x <= 0 {
 885                HTTOPLEFT
 886            } else {
 887                let mut rect = Default::default();
 888                unsafe { GetWindowRect(handle, &mut rect) }.log_err();
 889                // right and bottom bounds of RECT are exclusive, thus `-1`
 890                let right = rect.right - rect.left - 1;
 891                // the bounds include the padding frames, so accomodate for both of them
 892                if right - 2 * frame_x <= cursor_point.x {
 893                    HTTOPRIGHT
 894                } else {
 895                    HTTOP
 896                }
 897            } as _);
 898        }
 899
 900        drag_area
 901    }
 902
 903    fn handle_nc_mouse_move_msg(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
 904        self.start_tracking_mouse(handle, TME_LEAVE | TME_NONCLIENT);
 905
 906        let mut func = self.state.callbacks.input.take()?;
 907        let scale_factor = self.state.scale_factor.get();
 908
 909        let mut cursor_point = POINT {
 910            x: lparam.signed_loword().into(),
 911            y: lparam.signed_hiword().into(),
 912        };
 913        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 914        let input = PlatformInput::MouseMove(MouseMoveEvent {
 915            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 916            pressed_button: None,
 917            modifiers: current_modifiers(),
 918        });
 919        let handled = !func(input).propagate;
 920        self.state.callbacks.input.set(Some(func));
 921
 922        if handled { Some(0) } else { None }
 923    }
 924
 925    fn handle_nc_mouse_down_msg(
 926        &self,
 927        handle: HWND,
 928        button: MouseButton,
 929        wparam: WPARAM,
 930        lparam: LPARAM,
 931    ) -> Option<isize> {
 932        if let Some(mut func) = self.state.callbacks.input.take() {
 933            let scale_factor = self.state.scale_factor.get();
 934            let mut cursor_point = POINT {
 935                x: lparam.signed_loword().into(),
 936                y: lparam.signed_hiword().into(),
 937            };
 938            unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 939            let physical_point = point(DevicePixels(cursor_point.x), DevicePixels(cursor_point.y));
 940            let click_count = self.state.click_state.update(button, physical_point);
 941
 942            let input = PlatformInput::MouseDown(MouseDownEvent {
 943                button,
 944                position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 945                modifiers: current_modifiers(),
 946                click_count,
 947                first_mouse: false,
 948            });
 949            let result = func(input);
 950            let handled = !result.propagate || result.default_prevented;
 951            self.state.callbacks.input.set(Some(func));
 952
 953            if handled {
 954                return Some(0);
 955            }
 956        } else {
 957        };
 958
 959        // Since these are handled in handle_nc_mouse_up_msg we must prevent the default window proc
 960        if button == MouseButton::Left {
 961            match wparam.0 as u32 {
 962                HTMINBUTTON => self.state.nc_button_pressed.set(Some(HTMINBUTTON)),
 963                HTMAXBUTTON => self.state.nc_button_pressed.set(Some(HTMAXBUTTON)),
 964                HTCLOSE => self.state.nc_button_pressed.set(Some(HTCLOSE)),
 965                _ => return None,
 966            };
 967            Some(0)
 968        } else {
 969            None
 970        }
 971    }
 972
 973    fn handle_nc_mouse_up_msg(
 974        &self,
 975        handle: HWND,
 976        button: MouseButton,
 977        wparam: WPARAM,
 978        lparam: LPARAM,
 979    ) -> Option<isize> {
 980        if let Some(mut func) = self.state.callbacks.input.take() {
 981            let scale_factor = self.state.scale_factor.get();
 982
 983            let mut cursor_point = POINT {
 984                x: lparam.signed_loword().into(),
 985                y: lparam.signed_hiword().into(),
 986            };
 987            unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 988            let input = PlatformInput::MouseUp(MouseUpEvent {
 989                button,
 990                position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 991                modifiers: current_modifiers(),
 992                click_count: 1,
 993            });
 994            let handled = !func(input).propagate;
 995            self.state.callbacks.input.set(Some(func));
 996
 997            if handled {
 998                return Some(0);
 999            }
1000        } else {
1001        }
1002
1003        let last_pressed = self.state.nc_button_pressed.take();
1004        if button == MouseButton::Left
1005            && let Some(last_pressed) = last_pressed
1006        {
1007            let handled = match (wparam.0 as u32, last_pressed) {
1008                (HTMINBUTTON, HTMINBUTTON) => {
1009                    unsafe { ShowWindowAsync(handle, SW_MINIMIZE).ok().log_err() };
1010                    true
1011                }
1012                (HTMAXBUTTON, HTMAXBUTTON) => {
1013                    if self.state.is_maximized() {
1014                        unsafe { ShowWindowAsync(handle, SW_NORMAL).ok().log_err() };
1015                    } else {
1016                        unsafe { ShowWindowAsync(handle, SW_MAXIMIZE).ok().log_err() };
1017                    }
1018                    true
1019                }
1020                (HTCLOSE, HTCLOSE) => {
1021                    unsafe {
1022                        PostMessageW(Some(handle), WM_CLOSE, WPARAM::default(), LPARAM::default())
1023                            .log_err()
1024                    };
1025                    true
1026                }
1027                _ => false,
1028            };
1029            if handled {
1030                return Some(0);
1031            }
1032        }
1033
1034        None
1035    }
1036
1037    fn handle_cursor_changed(&self, lparam: LPARAM) -> Option<isize> {
1038        let had_cursor = self.state.current_cursor.get().is_some();
1039
1040        self.state.current_cursor.set(if lparam.0 == 0 {
1041            None
1042        } else {
1043            Some(HCURSOR(lparam.0 as _))
1044        });
1045
1046        if had_cursor != self.state.current_cursor.get().is_some() {
1047            unsafe { SetCursor(self.state.current_cursor.get()) };
1048        }
1049
1050        Some(0)
1051    }
1052
1053    fn handle_set_cursor(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
1054        if unsafe { !IsWindowEnabled(handle).as_bool() }
1055            || matches!(
1056                lparam.loword() as u32,
1057                HTLEFT
1058                    | HTRIGHT
1059                    | HTTOP
1060                    | HTTOPLEFT
1061                    | HTTOPRIGHT
1062                    | HTBOTTOM
1063                    | HTBOTTOMLEFT
1064                    | HTBOTTOMRIGHT
1065            )
1066        {
1067            return None;
1068        }
1069        unsafe {
1070            SetCursor(self.state.current_cursor.get());
1071        };
1072        Some(0)
1073    }
1074
1075    fn handle_system_settings_changed(
1076        &self,
1077        handle: HWND,
1078        wparam: WPARAM,
1079        lparam: LPARAM,
1080    ) -> Option<isize> {
1081        if wparam.0 != 0 {
1082            let display = self.state.display.get();
1083            self.state.click_state.system_update(wparam.0);
1084            self.state.border_offset.update(handle).log_err();
1085            // system settings may emit a window message which wants to take the refcell self.state, so drop it
1086
1087            self.system_settings().update(display, wparam.0);
1088        } else {
1089            self.handle_system_theme_changed(handle, lparam)?;
1090        };
1091        // Force to trigger WM_NCCALCSIZE event to ensure that we handle auto hide
1092        // taskbar correctly.
1093        notify_frame_changed(handle);
1094
1095        Some(0)
1096    }
1097
1098    fn handle_system_theme_changed(&self, handle: HWND, lparam: LPARAM) -> Option<isize> {
1099        // lParam is a pointer to a string that indicates the area containing the system parameter
1100        // that was changed.
1101        let parameter = PCWSTR::from_raw(lparam.0 as _);
1102        if unsafe { !parameter.is_null() && !parameter.is_empty() }
1103            && let Some(parameter_string) = unsafe { parameter.to_string() }.log_err()
1104        {
1105            log::info!("System settings changed: {}", parameter_string);
1106            if parameter_string.as_str() == "ImmersiveColorSet" {
1107                let new_appearance = system_appearance()
1108                    .context("unable to get system appearance when handling ImmersiveColorSet")
1109                    .log_err()?;
1110
1111                if new_appearance != self.state.appearance.get() {
1112                    self.state.appearance.set(new_appearance);
1113                    let mut callback = self.state.callbacks.appearance_changed.take()?;
1114
1115                    callback();
1116                    self.state.callbacks.appearance_changed.set(Some(callback));
1117                    configure_dwm_dark_mode(handle, new_appearance);
1118                }
1119            }
1120        }
1121        Some(0)
1122    }
1123
1124    fn handle_input_language_changed(&self) -> Option<isize> {
1125        unsafe {
1126            PostMessageW(
1127                Some(self.platform_window_handle),
1128                WM_GPUI_KEYBOARD_LAYOUT_CHANGED,
1129                WPARAM(self.validation_number),
1130                LPARAM(0),
1131            )
1132            .log_err();
1133        }
1134        Some(0)
1135    }
1136
1137    fn handle_window_visibility_changed(&self, handle: HWND, wparam: WPARAM) -> Option<isize> {
1138        if wparam.0 == 1 {
1139            self.draw_window(handle, false);
1140        }
1141        None
1142    }
1143
1144    fn handle_device_lost(&self, lparam: LPARAM) -> Option<isize> {
1145        let devices = lparam.0 as *const DirectXDevices;
1146        let devices = unsafe { &*devices };
1147        if let Err(err) = self
1148            .state
1149            .renderer
1150            .borrow_mut()
1151            .handle_device_lost(&devices)
1152        {
1153            panic!("Device lost: {err}");
1154        }
1155        Some(0)
1156    }
1157
1158    #[inline]
1159    fn draw_window(&self, handle: HWND, force_render: bool) -> Option<isize> {
1160        let mut request_frame = self.state.callbacks.request_frame.take()?;
1161
1162        // we are instructing gpui to force render a frame, this will
1163        // re-populate all the gpu textures for us so we can resume drawing in
1164        // case we disabled drawing earlier due to a device loss
1165        self.state.renderer.borrow_mut().mark_drawable();
1166        request_frame(RequestFrameOptions {
1167            require_presentation: false,
1168            force_render,
1169        });
1170
1171        self.state.callbacks.request_frame.set(Some(request_frame));
1172        unsafe { ValidateRect(Some(handle), None).ok().log_err() };
1173
1174        Some(0)
1175    }
1176
1177    #[inline]
1178    fn parse_char_message(&self, wparam: WPARAM) -> Option<String> {
1179        let code_point = wparam.loword();
1180
1181        // https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G2630
1182        match code_point {
1183            0xD800..=0xDBFF => {
1184                // High surrogate, wait for low surrogate
1185                self.state.pending_surrogate.set(Some(code_point));
1186                None
1187            }
1188            0xDC00..=0xDFFF => {
1189                if let Some(high_surrogate) = self.state.pending_surrogate.take() {
1190                    // Low surrogate, combine with pending high surrogate
1191                    String::from_utf16(&[high_surrogate, code_point]).ok()
1192                } else {
1193                    // Invalid low surrogate without a preceding high surrogate
1194                    log::warn!(
1195                        "Received low surrogate without a preceding high surrogate: {code_point:x}"
1196                    );
1197                    None
1198                }
1199            }
1200            _ => {
1201                self.state.pending_surrogate.set(None);
1202                char::from_u32(code_point as u32)
1203                    .filter(|c| !c.is_control())
1204                    .map(|c| c.to_string())
1205            }
1206        }
1207    }
1208
1209    fn start_tracking_mouse(&self, handle: HWND, flags: TRACKMOUSEEVENT_FLAGS) {
1210        if !self.state.hovered.get() {
1211            self.state.hovered.set(true);
1212            unsafe {
1213                TrackMouseEvent(&mut TRACKMOUSEEVENT {
1214                    cbSize: std::mem::size_of::<TRACKMOUSEEVENT>() as u32,
1215                    dwFlags: flags,
1216                    hwndTrack: handle,
1217                    dwHoverTime: HOVER_DEFAULT,
1218                })
1219                .log_err()
1220            };
1221            if let Some(mut callback) = self.state.callbacks.hovered_status_change.take() {
1222                callback(true);
1223                self.state
1224                    .callbacks
1225                    .hovered_status_change
1226                    .set(Some(callback));
1227            }
1228        }
1229    }
1230
1231    fn with_input_handler<F, R>(&self, f: F) -> Option<R>
1232    where
1233        F: FnOnce(&mut PlatformInputHandler) -> R,
1234    {
1235        let mut input_handler = self.state.input_handler.take()?;
1236        let result = f(&mut input_handler);
1237        self.state.input_handler.set(Some(input_handler));
1238        Some(result)
1239    }
1240
1241    fn with_input_handler_and_scale_factor<F, R>(&self, f: F) -> Option<R>
1242    where
1243        F: FnOnce(&mut PlatformInputHandler, f32) -> Option<R>,
1244    {
1245        let mut input_handler = self.state.input_handler.take()?;
1246        let scale_factor = self.state.scale_factor.get();
1247
1248        let result = f(&mut input_handler, scale_factor);
1249        self.state.input_handler.set(Some(input_handler));
1250        result
1251    }
1252}
1253
1254fn handle_key_event<F>(
1255    wparam: WPARAM,
1256    lparam: LPARAM,
1257    state: &WindowsWindowState,
1258    f: F,
1259) -> Option<PlatformInput>
1260where
1261    F: FnOnce(Keystroke, bool) -> PlatformInput,
1262{
1263    let virtual_key = VIRTUAL_KEY(wparam.loword());
1264    let modifiers = current_modifiers();
1265
1266    match virtual_key {
1267        VK_SHIFT | VK_CONTROL | VK_MENU | VK_LMENU | VK_RMENU | VK_LWIN | VK_RWIN => {
1268            if state
1269                .last_reported_modifiers
1270                .get()
1271                .is_some_and(|prev_modifiers| prev_modifiers == modifiers)
1272            {
1273                return None;
1274            }
1275            state.last_reported_modifiers.set(Some(modifiers));
1276            Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1277                modifiers,
1278                capslock: current_capslock(),
1279            }))
1280        }
1281        VK_PACKET => None,
1282        VK_CAPITAL => {
1283            let capslock = current_capslock();
1284            if state
1285                .last_reported_capslock
1286                .get()
1287                .is_some_and(|prev_capslock| prev_capslock == capslock)
1288            {
1289                return None;
1290            }
1291            state.last_reported_capslock.set(Some(capslock));
1292            Some(PlatformInput::ModifiersChanged(ModifiersChangedEvent {
1293                modifiers,
1294                capslock,
1295            }))
1296        }
1297        vkey => {
1298            let keystroke = parse_normal_key(vkey, lparam, modifiers)?;
1299            Some(f(keystroke.0, keystroke.1))
1300        }
1301    }
1302}
1303
1304fn parse_immutable(vkey: VIRTUAL_KEY) -> Option<String> {
1305    Some(
1306        match vkey {
1307            VK_SPACE => "space",
1308            VK_BACK => "backspace",
1309            VK_RETURN => "enter",
1310            VK_TAB => "tab",
1311            VK_UP => "up",
1312            VK_DOWN => "down",
1313            VK_RIGHT => "right",
1314            VK_LEFT => "left",
1315            VK_HOME => "home",
1316            VK_END => "end",
1317            VK_PRIOR => "pageup",
1318            VK_NEXT => "pagedown",
1319            VK_BROWSER_BACK => "back",
1320            VK_BROWSER_FORWARD => "forward",
1321            VK_ESCAPE => "escape",
1322            VK_INSERT => "insert",
1323            VK_DELETE => "delete",
1324            VK_APPS => "menu",
1325            VK_F1 => "f1",
1326            VK_F2 => "f2",
1327            VK_F3 => "f3",
1328            VK_F4 => "f4",
1329            VK_F5 => "f5",
1330            VK_F6 => "f6",
1331            VK_F7 => "f7",
1332            VK_F8 => "f8",
1333            VK_F9 => "f9",
1334            VK_F10 => "f10",
1335            VK_F11 => "f11",
1336            VK_F12 => "f12",
1337            VK_F13 => "f13",
1338            VK_F14 => "f14",
1339            VK_F15 => "f15",
1340            VK_F16 => "f16",
1341            VK_F17 => "f17",
1342            VK_F18 => "f18",
1343            VK_F19 => "f19",
1344            VK_F20 => "f20",
1345            VK_F21 => "f21",
1346            VK_F22 => "f22",
1347            VK_F23 => "f23",
1348            VK_F24 => "f24",
1349            _ => return None,
1350        }
1351        .to_string(),
1352    )
1353}
1354
1355fn parse_normal_key(
1356    vkey: VIRTUAL_KEY,
1357    lparam: LPARAM,
1358    mut modifiers: Modifiers,
1359) -> Option<(Keystroke, bool)> {
1360    let (key_char, prefer_character_input) = process_key(vkey, lparam.hiword());
1361
1362    let key = parse_immutable(vkey).or_else(|| {
1363        let scan_code = lparam.hiword() & 0xFF;
1364        get_keystroke_key(vkey, scan_code as u32, &mut modifiers)
1365    })?;
1366
1367    Some((
1368        Keystroke {
1369            modifiers,
1370            key,
1371            key_char,
1372        },
1373        prefer_character_input,
1374    ))
1375}
1376
1377fn process_key(vkey: VIRTUAL_KEY, scan_code: u16) -> (Option<String>, bool) {
1378    let mut keyboard_state = [0u8; 256];
1379    unsafe {
1380        if GetKeyboardState(&mut keyboard_state).is_err() {
1381            return (None, false);
1382        }
1383    }
1384
1385    let mut buffer_c = [0u16; 8];
1386    let result_c = unsafe {
1387        ToUnicode(
1388            vkey.0 as u32,
1389            scan_code as u32,
1390            Some(&keyboard_state),
1391            &mut buffer_c,
1392            0x4,
1393        )
1394    };
1395
1396    if result_c == 0 {
1397        return (None, false);
1398    }
1399
1400    let c = &buffer_c[..result_c.unsigned_abs() as usize];
1401    let key_char = String::from_utf16(c)
1402        .ok()
1403        .filter(|s| !s.is_empty() && !s.chars().next().unwrap().is_control());
1404
1405    if result_c < 0 {
1406        return (key_char, true);
1407    }
1408
1409    if key_char.is_none() {
1410        return (None, false);
1411    }
1412
1413    // Workaround for some bug that makes the compiler think keyboard_state is still zeroed out
1414    let keyboard_state = std::hint::black_box(keyboard_state);
1415    let ctrl_down = (keyboard_state[VK_CONTROL.0 as usize] & 0x80) != 0;
1416    let alt_down = (keyboard_state[VK_MENU.0 as usize] & 0x80) != 0;
1417    let win_down = (keyboard_state[VK_LWIN.0 as usize] & 0x80) != 0
1418        || (keyboard_state[VK_RWIN.0 as usize] & 0x80) != 0;
1419
1420    let has_modifiers = ctrl_down || alt_down || win_down;
1421    if !has_modifiers {
1422        return (key_char, false);
1423    }
1424
1425    let mut state_no_modifiers = keyboard_state;
1426    state_no_modifiers[VK_CONTROL.0 as usize] = 0;
1427    state_no_modifiers[VK_LCONTROL.0 as usize] = 0;
1428    state_no_modifiers[VK_RCONTROL.0 as usize] = 0;
1429    state_no_modifiers[VK_MENU.0 as usize] = 0;
1430    state_no_modifiers[VK_LMENU.0 as usize] = 0;
1431    state_no_modifiers[VK_RMENU.0 as usize] = 0;
1432    state_no_modifiers[VK_LWIN.0 as usize] = 0;
1433    state_no_modifiers[VK_RWIN.0 as usize] = 0;
1434
1435    let mut buffer_c_no_modifiers = [0u16; 8];
1436    let result_c_no_modifiers = unsafe {
1437        ToUnicode(
1438            vkey.0 as u32,
1439            scan_code as u32,
1440            Some(&state_no_modifiers),
1441            &mut buffer_c_no_modifiers,
1442            0x4,
1443        )
1444    };
1445
1446    let c_no_modifiers = &buffer_c_no_modifiers[..result_c_no_modifiers.unsigned_abs() as usize];
1447    (
1448        key_char,
1449        result_c != result_c_no_modifiers || c != c_no_modifiers,
1450    )
1451}
1452
1453fn parse_ime_composition_string(ctx: HIMC, comp_type: IME_COMPOSITION_STRING) -> Option<String> {
1454    unsafe {
1455        let string_len = ImmGetCompositionStringW(ctx, comp_type, None, 0);
1456        if string_len >= 0 {
1457            let mut buffer = vec![0u8; string_len as usize + 2];
1458            ImmGetCompositionStringW(
1459                ctx,
1460                comp_type,
1461                Some(buffer.as_mut_ptr() as _),
1462                string_len as _,
1463            );
1464            let wstring = std::slice::from_raw_parts::<u16>(
1465                buffer.as_mut_ptr().cast::<u16>(),
1466                string_len as usize / 2,
1467            );
1468            Some(String::from_utf16_lossy(wstring))
1469        } else {
1470            None
1471        }
1472    }
1473}
1474
1475#[inline]
1476fn retrieve_composition_cursor_position(ctx: HIMC) -> usize {
1477    unsafe { ImmGetCompositionStringW(ctx, GCS_CURSORPOS, None, 0) as usize }
1478}
1479
1480#[inline]
1481fn is_virtual_key_pressed(vkey: VIRTUAL_KEY) -> bool {
1482    unsafe { GetKeyState(vkey.0 as i32) < 0 }
1483}
1484
1485#[inline]
1486pub(crate) fn current_modifiers() -> Modifiers {
1487    Modifiers {
1488        control: is_virtual_key_pressed(VK_CONTROL),
1489        alt: is_virtual_key_pressed(VK_MENU),
1490        shift: is_virtual_key_pressed(VK_SHIFT),
1491        platform: is_virtual_key_pressed(VK_LWIN) || is_virtual_key_pressed(VK_RWIN),
1492        function: false,
1493    }
1494}
1495
1496#[inline]
1497pub(crate) fn current_capslock() -> Capslock {
1498    let on = unsafe { GetKeyState(VK_CAPITAL.0 as i32) & 1 } > 0;
1499    Capslock { on }
1500}
1501
1502fn get_client_area_insets(
1503    handle: HWND,
1504    is_maximized: bool,
1505    windows_version: WindowsVersion,
1506) -> RECT {
1507    // For maximized windows, Windows outdents the window rect from the screen's client rect
1508    // by `frame_thickness` on each edge, meaning `insets` must contain `frame_thickness`
1509    // on all sides (including the top) to avoid the client area extending onto adjacent
1510    // monitors.
1511    //
1512    // For non-maximized windows, things become complicated:
1513    //
1514    // - On Windows 10
1515    // The top inset must be zero, since if there is any nonclient area, Windows will draw
1516    // a full native titlebar outside the client area. (This doesn't occur in the maximized
1517    // case.)
1518    //
1519    // - On Windows 11
1520    // The top inset is calculated using an empirical formula that I derived through various
1521    // tests. Without this, the top 1-2 rows of pixels in our window would be obscured.
1522    let dpi = unsafe { GetDpiForWindow(handle) };
1523    let frame_thickness = get_frame_thicknessx(dpi);
1524    let top_insets = if is_maximized {
1525        frame_thickness
1526    } else {
1527        match windows_version {
1528            WindowsVersion::Win10 => 0,
1529            WindowsVersion::Win11 => (dpi as f32 / USER_DEFAULT_SCREEN_DPI as f32).round() as i32,
1530        }
1531    };
1532    RECT {
1533        left: frame_thickness,
1534        top: top_insets,
1535        right: frame_thickness,
1536        bottom: frame_thickness,
1537    }
1538}
1539
1540// there is some additional non-visible space when talking about window
1541// borders on Windows:
1542// - SM_CXSIZEFRAME: The resize handle.
1543// - SM_CXPADDEDBORDER: Additional border space that isn't part of the resize handle.
1544fn get_frame_thicknessx(dpi: u32) -> i32 {
1545    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CXSIZEFRAME, dpi) };
1546    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1547    resize_frame_thickness + padding_thickness
1548}
1549
1550fn get_frame_thicknessy(dpi: u32) -> i32 {
1551    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CYSIZEFRAME, dpi) };
1552    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1553    resize_frame_thickness + padding_thickness
1554}
1555
1556fn notify_frame_changed(handle: HWND) {
1557    unsafe {
1558        SetWindowPos(
1559            handle,
1560            None,
1561            0,
1562            0,
1563            0,
1564            0,
1565            SWP_FRAMECHANGED
1566                | SWP_NOACTIVATE
1567                | SWP_NOCOPYBITS
1568                | SWP_NOMOVE
1569                | SWP_NOOWNERZORDER
1570                | SWP_NOREPOSITION
1571                | SWP_NOSENDCHANGING
1572                | SWP_NOSIZE
1573                | SWP_NOZORDER,
1574        )
1575        .log_err();
1576    }
1577}