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;
  26
  27const SIZE_MOVE_LOOP_TIMER_ID: usize = 1;
  28const AUTO_HIDE_TASKBAR_THICKNESS_PX: i32 = 1;
  29
  30pub(crate) fn handle_msg(
  31    handle: HWND,
  32    msg: u32,
  33    wparam: WPARAM,
  34    lparam: LPARAM,
  35    state_ptr: Rc<WindowsWindowStatePtr>,
  36) -> LRESULT {
  37    let handled = match msg {
  38        WM_ACTIVATE => handle_activate_msg(handle, wparam, state_ptr),
  39        WM_CREATE => handle_create_msg(handle, state_ptr),
  40        WM_MOVE => handle_move_msg(handle, lparam, state_ptr),
  41        WM_SIZE => handle_size_msg(wparam, lparam, state_ptr),
  42        WM_GETMINMAXINFO => handle_get_min_max_info_msg(lparam, state_ptr),
  43        WM_ENTERSIZEMOVE | WM_ENTERMENULOOP => handle_size_move_loop(handle),
  44        WM_EXITSIZEMOVE | WM_EXITMENULOOP => handle_size_move_loop_exit(handle),
  45        WM_TIMER => handle_timer_msg(handle, wparam, state_ptr),
  46        WM_NCCALCSIZE => handle_calc_client_size(handle, wparam, lparam, state_ptr),
  47        WM_DPICHANGED => handle_dpi_changed_msg(handle, wparam, lparam, state_ptr),
  48        WM_DISPLAYCHANGE => handle_display_change_msg(handle, state_ptr),
  49        WM_NCHITTEST => handle_hit_test_msg(handle, msg, wparam, lparam, state_ptr),
  50        WM_PAINT => handle_paint_msg(handle, state_ptr),
  51        WM_CLOSE => handle_close_msg(state_ptr),
  52        WM_DESTROY => handle_destroy_msg(handle, state_ptr),
  53        WM_MOUSEMOVE => handle_mouse_move_msg(handle, lparam, wparam, state_ptr),
  54        WM_MOUSELEAVE | WM_NCMOUSELEAVE => handle_mouse_leave_msg(state_ptr),
  55        WM_NCMOUSEMOVE => handle_nc_mouse_move_msg(handle, lparam, state_ptr),
  56        WM_NCLBUTTONDOWN => {
  57            handle_nc_mouse_down_msg(handle, MouseButton::Left, wparam, lparam, state_ptr)
  58        }
  59        WM_NCRBUTTONDOWN => {
  60            handle_nc_mouse_down_msg(handle, MouseButton::Right, wparam, lparam, state_ptr)
  61        }
  62        WM_NCMBUTTONDOWN => {
  63            handle_nc_mouse_down_msg(handle, MouseButton::Middle, wparam, lparam, state_ptr)
  64        }
  65        WM_NCLBUTTONUP => {
  66            handle_nc_mouse_up_msg(handle, MouseButton::Left, wparam, lparam, state_ptr)
  67        }
  68        WM_NCRBUTTONUP => {
  69            handle_nc_mouse_up_msg(handle, MouseButton::Right, wparam, lparam, state_ptr)
  70        }
  71        WM_NCMBUTTONUP => {
  72            handle_nc_mouse_up_msg(handle, MouseButton::Middle, wparam, lparam, state_ptr)
  73        }
  74        WM_LBUTTONDOWN => handle_mouse_down_msg(handle, MouseButton::Left, lparam, state_ptr),
  75        WM_RBUTTONDOWN => handle_mouse_down_msg(handle, MouseButton::Right, lparam, state_ptr),
  76        WM_MBUTTONDOWN => handle_mouse_down_msg(handle, MouseButton::Middle, lparam, state_ptr),
  77        WM_XBUTTONDOWN => {
  78            handle_xbutton_msg(handle, wparam, lparam, handle_mouse_down_msg, state_ptr)
  79        }
  80        WM_LBUTTONUP => handle_mouse_up_msg(handle, MouseButton::Left, lparam, state_ptr),
  81        WM_RBUTTONUP => handle_mouse_up_msg(handle, MouseButton::Right, lparam, state_ptr),
  82        WM_MBUTTONUP => handle_mouse_up_msg(handle, MouseButton::Middle, lparam, state_ptr),
  83        WM_XBUTTONUP => handle_xbutton_msg(handle, wparam, lparam, handle_mouse_up_msg, state_ptr),
  84        WM_MOUSEWHEEL => handle_mouse_wheel_msg(handle, wparam, lparam, state_ptr),
  85        WM_MOUSEHWHEEL => handle_mouse_horizontal_wheel_msg(handle, wparam, lparam, state_ptr),
  86        WM_SYSKEYDOWN => handle_syskeydown_msg(wparam, lparam, state_ptr),
  87        WM_SYSKEYUP => handle_syskeyup_msg(wparam, state_ptr),
  88        WM_SYSCOMMAND => handle_system_command(wparam, state_ptr),
  89        WM_KEYDOWN => handle_keydown_msg(wparam, lparam, state_ptr),
  90        WM_KEYUP => handle_keyup_msg(wparam, state_ptr),
  91        WM_CHAR => handle_char_msg(wparam, lparam, state_ptr),
  92        WM_IME_STARTCOMPOSITION => handle_ime_position(handle, state_ptr),
  93        WM_IME_COMPOSITION => handle_ime_composition(handle, lparam, state_ptr),
  94        WM_SETCURSOR => handle_set_cursor(lparam, state_ptr),
  95        WM_SETTINGCHANGE => handle_system_settings_changed(handle, lparam, state_ptr),
  96        WM_GPUI_CURSOR_STYLE_CHANGED => handle_cursor_changed(lparam, state_ptr),
  97        _ => None,
  98    };
  99    if let Some(n) = handled {
 100        LRESULT(n)
 101    } else {
 102        unsafe { DefWindowProcW(handle, msg, wparam, lparam) }
 103    }
 104}
 105
 106fn handle_move_msg(
 107    handle: HWND,
 108    lparam: LPARAM,
 109    state_ptr: Rc<WindowsWindowStatePtr>,
 110) -> Option<isize> {
 111    let mut lock = state_ptr.state.borrow_mut();
 112    let origin = logical_point(
 113        lparam.signed_loword() as f32,
 114        lparam.signed_hiword() as f32,
 115        lock.scale_factor,
 116    );
 117    lock.origin = origin;
 118    let size = lock.logical_size;
 119    let center_x = origin.x.0 + size.width.0 / 2.;
 120    let center_y = origin.y.0 + size.height.0 / 2.;
 121    let monitor_bounds = lock.display.bounds();
 122    if center_x < monitor_bounds.left().0
 123        || center_x > monitor_bounds.right().0
 124        || center_y < monitor_bounds.top().0
 125        || center_y > monitor_bounds.bottom().0
 126    {
 127        // center of the window may have moved to another monitor
 128        let monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 129        // minimize the window can trigger this event too, in this case,
 130        // monitor is invalid, we do nothing.
 131        if !monitor.is_invalid() && lock.display.handle != monitor {
 132            // we will get the same monitor if we only have one
 133            lock.display = WindowsDisplay::new_with_handle(monitor);
 134        }
 135    }
 136    if let Some(mut callback) = lock.callbacks.moved.take() {
 137        drop(lock);
 138        callback();
 139        state_ptr.state.borrow_mut().callbacks.moved = Some(callback);
 140    }
 141    Some(0)
 142}
 143
 144fn handle_get_min_max_info_msg(
 145    lparam: LPARAM,
 146    state_ptr: Rc<WindowsWindowStatePtr>,
 147) -> Option<isize> {
 148    let lock = state_ptr.state.borrow();
 149    if let Some(min_size) = lock.min_size {
 150        let scale_factor = lock.scale_factor;
 151        let boarder_offset = lock.border_offset;
 152        drop(lock);
 153
 154        unsafe {
 155            let minmax_info = &mut *(lparam.0 as *mut MINMAXINFO);
 156            minmax_info.ptMinTrackSize.x =
 157                min_size.width.scale(scale_factor).0 as i32 + boarder_offset.width_offset;
 158            minmax_info.ptMinTrackSize.y =
 159                min_size.height.scale(scale_factor).0 as i32 + boarder_offset.height_offset;
 160        }
 161        Some(0)
 162    } else {
 163        None
 164    }
 165}
 166
 167fn handle_size_msg(
 168    wparam: WPARAM,
 169    lparam: LPARAM,
 170    state_ptr: Rc<WindowsWindowStatePtr>,
 171) -> Option<isize> {
 172    let mut lock = state_ptr.state.borrow_mut();
 173
 174    // Don't resize the renderer when the window is minimized, but record that it was minimized so
 175    // that on restore the swap chain can be recreated via `update_drawable_size_even_if_unchanged`.
 176    if wparam.0 == SIZE_MINIMIZED as usize {
 177        lock.restore_from_minimized = lock.callbacks.request_frame.take();
 178        return Some(0);
 179    }
 180
 181    let width = lparam.loword().max(1) as i32;
 182    let height = lparam.hiword().max(1) as i32;
 183    let new_size = size(DevicePixels(width), DevicePixels(height));
 184    let scale_factor = lock.scale_factor;
 185    if lock.restore_from_minimized.is_some() {
 186        lock.renderer
 187            .update_drawable_size_even_if_unchanged(new_size);
 188        lock.callbacks.request_frame = lock.restore_from_minimized.take();
 189    } else {
 190        lock.renderer.update_drawable_size(new_size);
 191    }
 192    let new_size = new_size.to_pixels(scale_factor);
 193    lock.logical_size = new_size;
 194    if let Some(mut callback) = lock.callbacks.resize.take() {
 195        drop(lock);
 196        callback(new_size, scale_factor);
 197        state_ptr.state.borrow_mut().callbacks.resize = Some(callback);
 198    }
 199    Some(0)
 200}
 201
 202fn handle_size_move_loop(handle: HWND) -> Option<isize> {
 203    unsafe {
 204        let ret = SetTimer(
 205            Some(handle),
 206            SIZE_MOVE_LOOP_TIMER_ID,
 207            USER_TIMER_MINIMUM,
 208            None,
 209        );
 210        if ret == 0 {
 211            log::error!(
 212                "unable to create timer: {}",
 213                std::io::Error::last_os_error()
 214            );
 215        }
 216    }
 217    None
 218}
 219
 220fn handle_size_move_loop_exit(handle: HWND) -> Option<isize> {
 221    unsafe {
 222        KillTimer(Some(handle), SIZE_MOVE_LOOP_TIMER_ID).log_err();
 223    }
 224    None
 225}
 226
 227fn handle_timer_msg(
 228    handle: HWND,
 229    wparam: WPARAM,
 230    state_ptr: Rc<WindowsWindowStatePtr>,
 231) -> Option<isize> {
 232    if wparam.0 == SIZE_MOVE_LOOP_TIMER_ID {
 233        for runnable in state_ptr.main_receiver.drain() {
 234            runnable.run();
 235        }
 236        handle_paint_msg(handle, state_ptr)
 237    } else {
 238        None
 239    }
 240}
 241
 242fn handle_paint_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 243    let mut lock = state_ptr.state.borrow_mut();
 244    if let Some(mut request_frame) = lock.callbacks.request_frame.take() {
 245        drop(lock);
 246        request_frame(Default::default());
 247        state_ptr.state.borrow_mut().callbacks.request_frame = Some(request_frame);
 248    }
 249    unsafe { ValidateRect(Some(handle), None).ok().log_err() };
 250    Some(0)
 251}
 252
 253fn handle_close_msg(state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 254    let mut lock = state_ptr.state.borrow_mut();
 255    if let Some(mut callback) = lock.callbacks.should_close.take() {
 256        drop(lock);
 257        let should_close = callback();
 258        state_ptr.state.borrow_mut().callbacks.should_close = Some(callback);
 259        if should_close { None } else { Some(0) }
 260    } else {
 261        None
 262    }
 263}
 264
 265fn handle_destroy_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 266    let callback = {
 267        let mut lock = state_ptr.state.borrow_mut();
 268        lock.callbacks.close.take()
 269    };
 270    if let Some(callback) = callback {
 271        callback();
 272    }
 273    unsafe {
 274        PostThreadMessageW(
 275            state_ptr.main_thread_id_win32,
 276            WM_GPUI_CLOSE_ONE_WINDOW,
 277            WPARAM(state_ptr.validation_number),
 278            LPARAM(handle.0 as isize),
 279        )
 280        .log_err();
 281    }
 282    Some(0)
 283}
 284
 285fn handle_mouse_move_msg(
 286    handle: HWND,
 287    lparam: LPARAM,
 288    wparam: WPARAM,
 289    state_ptr: Rc<WindowsWindowStatePtr>,
 290) -> Option<isize> {
 291    start_tracking_mouse(handle, &state_ptr, TME_LEAVE);
 292
 293    let mut lock = state_ptr.state.borrow_mut();
 294    if let Some(mut callback) = lock.callbacks.input.take() {
 295        let scale_factor = lock.scale_factor;
 296        drop(lock);
 297        let pressed_button = match MODIFIERKEYS_FLAGS(wparam.loword() as u32) {
 298            flags if flags.contains(MK_LBUTTON) => Some(MouseButton::Left),
 299            flags if flags.contains(MK_RBUTTON) => Some(MouseButton::Right),
 300            flags if flags.contains(MK_MBUTTON) => Some(MouseButton::Middle),
 301            flags if flags.contains(MK_XBUTTON1) => {
 302                Some(MouseButton::Navigate(NavigationDirection::Back))
 303            }
 304            flags if flags.contains(MK_XBUTTON2) => {
 305                Some(MouseButton::Navigate(NavigationDirection::Forward))
 306            }
 307            _ => None,
 308        };
 309        let x = lparam.signed_loword() as f32;
 310        let y = lparam.signed_hiword() as f32;
 311        let event = MouseMoveEvent {
 312            position: logical_point(x, y, scale_factor),
 313            pressed_button,
 314            modifiers: current_modifiers(),
 315        };
 316        let result = if callback(PlatformInput::MouseMove(event)).default_prevented {
 317            Some(0)
 318        } else {
 319            Some(1)
 320        };
 321        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 322        return result;
 323    }
 324    Some(1)
 325}
 326
 327fn handle_mouse_leave_msg(state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 328    let mut lock = state_ptr.state.borrow_mut();
 329    lock.hovered = false;
 330    if let Some(mut callback) = lock.callbacks.hovered_status_change.take() {
 331        drop(lock);
 332        callback(false);
 333        state_ptr.state.borrow_mut().callbacks.hovered_status_change = Some(callback);
 334    }
 335
 336    Some(0)
 337}
 338
 339fn handle_syskeydown_msg(
 340    wparam: WPARAM,
 341    lparam: LPARAM,
 342    state_ptr: Rc<WindowsWindowStatePtr>,
 343) -> Option<isize> {
 344    let mut lock = state_ptr.state.borrow_mut();
 345    let vkey = wparam.loword();
 346    let input = if is_modifier(VIRTUAL_KEY(vkey)) {
 347        let modifiers = current_modifiers();
 348        if let Some(prev_modifiers) = lock.last_reported_modifiers {
 349            if prev_modifiers == modifiers {
 350                return Some(0);
 351            }
 352        }
 353        lock.last_reported_modifiers = Some(modifiers);
 354        PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 355    } else {
 356        let keystroke = parse_syskeydown_msg_keystroke(wparam)?;
 357        PlatformInput::KeyDown(KeyDownEvent {
 358            keystroke,
 359            is_held: lparam.0 & (0x1 << 30) > 0,
 360        })
 361    };
 362    let mut func = lock.callbacks.input.take()?;
 363    drop(lock);
 364    let result = if !func(input).propagate {
 365        state_ptr.state.borrow_mut().system_key_handled = true;
 366        Some(0)
 367    } else {
 368        // we need to call `DefWindowProcW`, or we will lose the system-wide `Alt+F4`, `Alt+{other keys}`
 369        // shortcuts.
 370        None
 371    };
 372    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 373
 374    result
 375}
 376
 377fn handle_syskeyup_msg(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 378    let mut lock = state_ptr.state.borrow_mut();
 379    let vkey = wparam.loword();
 380    let input = if is_modifier(VIRTUAL_KEY(vkey)) {
 381        let modifiers = current_modifiers();
 382        if let Some(prev_modifiers) = lock.last_reported_modifiers {
 383            if prev_modifiers == modifiers {
 384                return Some(0);
 385            }
 386        }
 387        lock.last_reported_modifiers = Some(modifiers);
 388        PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 389    } else {
 390        let keystroke = parse_syskeydown_msg_keystroke(wparam)?;
 391        PlatformInput::KeyUp(KeyUpEvent { keystroke })
 392    };
 393    let mut func = lock.callbacks.input.take()?;
 394    drop(lock);
 395    let result = if !func(input).propagate {
 396        Some(0)
 397    } else {
 398        // we need to call `DefWindowProcW`, or we will lose the system-wide `Alt+F4`, `Alt+{other keys}`
 399        // shortcuts.
 400        None
 401    };
 402    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 403
 404    result
 405}
 406
 407fn handle_keydown_msg(
 408    wparam: WPARAM,
 409    lparam: LPARAM,
 410    state_ptr: Rc<WindowsWindowStatePtr>,
 411) -> Option<isize> {
 412    let Some(keystroke_or_modifier) = parse_keystroke_from_vkey(wparam, false) else {
 413        return Some(1);
 414    };
 415    let mut lock = state_ptr.state.borrow_mut();
 416
 417    let event = match keystroke_or_modifier {
 418        KeystrokeOrModifier::Keystroke(keystroke) => PlatformInput::KeyDown(KeyDownEvent {
 419            keystroke,
 420            is_held: lparam.0 & (0x1 << 30) > 0,
 421        }),
 422        KeystrokeOrModifier::Modifier(modifiers) => {
 423            if let Some(prev_modifiers) = lock.last_reported_modifiers {
 424                if prev_modifiers == modifiers {
 425                    return Some(0);
 426                }
 427            }
 428            lock.last_reported_modifiers = Some(modifiers);
 429            PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 430        }
 431    };
 432    let Some(mut func) = lock.callbacks.input.take() else {
 433        return Some(1);
 434    };
 435    drop(lock);
 436
 437    let result = if func(event).default_prevented {
 438        Some(0)
 439    } else {
 440        Some(1)
 441    };
 442    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 443
 444    result
 445}
 446
 447fn handle_keyup_msg(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 448    let Some(keystroke_or_modifier) = parse_keystroke_from_vkey(wparam, true) else {
 449        return Some(1);
 450    };
 451    let mut lock = state_ptr.state.borrow_mut();
 452
 453    let event = match keystroke_or_modifier {
 454        KeystrokeOrModifier::Keystroke(keystroke) => PlatformInput::KeyUp(KeyUpEvent { keystroke }),
 455        KeystrokeOrModifier::Modifier(modifiers) => {
 456            if let Some(prev_modifiers) = lock.last_reported_modifiers {
 457                if prev_modifiers == modifiers {
 458                    return Some(0);
 459                }
 460            }
 461            lock.last_reported_modifiers = Some(modifiers);
 462            PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 463        }
 464    };
 465    let Some(mut func) = lock.callbacks.input.take() else {
 466        return Some(1);
 467    };
 468    drop(lock);
 469
 470    let result = if func(event).default_prevented {
 471        Some(0)
 472    } else {
 473        Some(1)
 474    };
 475    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 476
 477    result
 478}
 479
 480fn handle_char_msg(
 481    wparam: WPARAM,
 482    lparam: LPARAM,
 483    state_ptr: Rc<WindowsWindowStatePtr>,
 484) -> Option<isize> {
 485    let Some(keystroke) = parse_char_msg_keystroke(wparam) else {
 486        return Some(1);
 487    };
 488    let mut lock = state_ptr.state.borrow_mut();
 489    let Some(mut func) = lock.callbacks.input.take() else {
 490        return Some(1);
 491    };
 492    drop(lock);
 493    let key_char = keystroke.key_char.clone();
 494    let event = KeyDownEvent {
 495        keystroke,
 496        is_held: lparam.0 & (0x1 << 30) > 0,
 497    };
 498    let dispatch_event_result = func(PlatformInput::KeyDown(event));
 499    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 500
 501    if dispatch_event_result.default_prevented || !dispatch_event_result.propagate {
 502        return Some(0);
 503    }
 504    let Some(ime_char) = key_char else {
 505        return Some(1);
 506    };
 507    with_input_handler(&state_ptr, |input_handler| {
 508        input_handler.replace_text_in_range(None, &ime_char);
 509    });
 510
 511    Some(0)
 512}
 513
 514fn handle_mouse_down_msg(
 515    handle: HWND,
 516    button: MouseButton,
 517    lparam: LPARAM,
 518    state_ptr: Rc<WindowsWindowStatePtr>,
 519) -> Option<isize> {
 520    unsafe { SetCapture(handle) };
 521    let mut lock = state_ptr.state.borrow_mut();
 522    if let Some(mut callback) = lock.callbacks.input.take() {
 523        let x = lparam.signed_loword() as f32;
 524        let y = lparam.signed_hiword() as f32;
 525        let physical_point = point(DevicePixels(x as i32), DevicePixels(y as i32));
 526        let click_count = lock.click_state.update(button, physical_point);
 527        let scale_factor = lock.scale_factor;
 528        drop(lock);
 529
 530        let event = MouseDownEvent {
 531            button,
 532            position: logical_point(x, y, scale_factor),
 533            modifiers: current_modifiers(),
 534            click_count,
 535            first_mouse: false,
 536        };
 537        let result = if callback(PlatformInput::MouseDown(event)).default_prevented {
 538            Some(0)
 539        } else {
 540            Some(1)
 541        };
 542        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 543
 544        result
 545    } else {
 546        Some(1)
 547    }
 548}
 549
 550fn handle_mouse_up_msg(
 551    _handle: HWND,
 552    button: MouseButton,
 553    lparam: LPARAM,
 554    state_ptr: Rc<WindowsWindowStatePtr>,
 555) -> Option<isize> {
 556    unsafe { ReleaseCapture().log_err() };
 557    let mut lock = state_ptr.state.borrow_mut();
 558    if let Some(mut callback) = lock.callbacks.input.take() {
 559        let x = lparam.signed_loword() as f32;
 560        let y = lparam.signed_hiword() as f32;
 561        let click_count = lock.click_state.current_count;
 562        let scale_factor = lock.scale_factor;
 563        drop(lock);
 564
 565        let event = MouseUpEvent {
 566            button,
 567            position: logical_point(x, y, scale_factor),
 568            modifiers: current_modifiers(),
 569            click_count,
 570        };
 571        let result = if callback(PlatformInput::MouseUp(event)).default_prevented {
 572            Some(0)
 573        } else {
 574            Some(1)
 575        };
 576        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 577
 578        result
 579    } else {
 580        Some(1)
 581    }
 582}
 583
 584fn handle_xbutton_msg(
 585    handle: HWND,
 586    wparam: WPARAM,
 587    lparam: LPARAM,
 588    handler: impl Fn(HWND, MouseButton, LPARAM, Rc<WindowsWindowStatePtr>) -> Option<isize>,
 589    state_ptr: Rc<WindowsWindowStatePtr>,
 590) -> Option<isize> {
 591    let nav_dir = match wparam.hiword() {
 592        XBUTTON1 => NavigationDirection::Back,
 593        XBUTTON2 => NavigationDirection::Forward,
 594        _ => return Some(1),
 595    };
 596    handler(handle, MouseButton::Navigate(nav_dir), lparam, state_ptr)
 597}
 598
 599fn handle_mouse_wheel_msg(
 600    handle: HWND,
 601    wparam: WPARAM,
 602    lparam: LPARAM,
 603    state_ptr: Rc<WindowsWindowStatePtr>,
 604) -> Option<isize> {
 605    let modifiers = current_modifiers();
 606    let mut lock = state_ptr.state.borrow_mut();
 607    if let Some(mut callback) = lock.callbacks.input.take() {
 608        let scale_factor = lock.scale_factor;
 609        let wheel_scroll_amount = match modifiers.shift {
 610            true => lock.system_settings.mouse_wheel_settings.wheel_scroll_chars,
 611            false => lock.system_settings.mouse_wheel_settings.wheel_scroll_lines,
 612        };
 613        drop(lock);
 614        let wheel_distance =
 615            (wparam.signed_hiword() as f32 / WHEEL_DELTA as f32) * wheel_scroll_amount as f32;
 616        let mut cursor_point = POINT {
 617            x: lparam.signed_loword().into(),
 618            y: lparam.signed_hiword().into(),
 619        };
 620        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 621        let event = ScrollWheelEvent {
 622            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 623            delta: ScrollDelta::Lines(match modifiers.shift {
 624                true => Point {
 625                    x: wheel_distance,
 626                    y: 0.0,
 627                },
 628                false => Point {
 629                    y: wheel_distance,
 630                    x: 0.0,
 631                },
 632            }),
 633            modifiers: current_modifiers(),
 634            touch_phase: TouchPhase::Moved,
 635        };
 636        let result = if callback(PlatformInput::ScrollWheel(event)).default_prevented {
 637            Some(0)
 638        } else {
 639            Some(1)
 640        };
 641        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 642
 643        result
 644    } else {
 645        Some(1)
 646    }
 647}
 648
 649fn handle_mouse_horizontal_wheel_msg(
 650    handle: HWND,
 651    wparam: WPARAM,
 652    lparam: LPARAM,
 653    state_ptr: Rc<WindowsWindowStatePtr>,
 654) -> Option<isize> {
 655    let mut lock = state_ptr.state.borrow_mut();
 656    if let Some(mut callback) = lock.callbacks.input.take() {
 657        let scale_factor = lock.scale_factor;
 658        let wheel_scroll_chars = lock.system_settings.mouse_wheel_settings.wheel_scroll_chars;
 659        drop(lock);
 660        let wheel_distance =
 661            (-wparam.signed_hiword() as f32 / WHEEL_DELTA as f32) * wheel_scroll_chars as f32;
 662        let mut cursor_point = POINT {
 663            x: lparam.signed_loword().into(),
 664            y: lparam.signed_hiword().into(),
 665        };
 666        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 667        let event = ScrollWheelEvent {
 668            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 669            delta: ScrollDelta::Lines(Point {
 670                x: wheel_distance,
 671                y: 0.0,
 672            }),
 673            modifiers: current_modifiers(),
 674            touch_phase: TouchPhase::Moved,
 675        };
 676        let result = if callback(PlatformInput::ScrollWheel(event)).default_prevented {
 677            Some(0)
 678        } else {
 679            Some(1)
 680        };
 681        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 682
 683        result
 684    } else {
 685        Some(1)
 686    }
 687}
 688
 689fn retrieve_caret_position(state_ptr: &Rc<WindowsWindowStatePtr>) -> Option<POINT> {
 690    with_input_handler_and_scale_factor(state_ptr, |input_handler, scale_factor| {
 691        let caret_range = input_handler.selected_text_range(false)?;
 692        let caret_position = input_handler.bounds_for_range(caret_range.range)?;
 693        Some(POINT {
 694            // logical to physical
 695            x: (caret_position.origin.x.0 * scale_factor) as i32,
 696            y: (caret_position.origin.y.0 * scale_factor) as i32
 697                + ((caret_position.size.height.0 * scale_factor) as i32 / 2),
 698        })
 699    })
 700}
 701
 702fn handle_ime_position(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 703    unsafe {
 704        let ctx = ImmGetContext(handle);
 705
 706        let Some(caret_position) = retrieve_caret_position(&state_ptr) else {
 707            return Some(0);
 708        };
 709        {
 710            let config = COMPOSITIONFORM {
 711                dwStyle: CFS_POINT,
 712                ptCurrentPos: caret_position,
 713                ..Default::default()
 714            };
 715            ImmSetCompositionWindow(ctx, &config as _).ok().log_err();
 716        }
 717        {
 718            let config = CANDIDATEFORM {
 719                dwStyle: CFS_CANDIDATEPOS,
 720                ptCurrentPos: caret_position,
 721                ..Default::default()
 722            };
 723            ImmSetCandidateWindow(ctx, &config as _).ok().log_err();
 724        }
 725        ImmReleaseContext(handle, ctx).ok().log_err();
 726        Some(0)
 727    }
 728}
 729
 730fn handle_ime_composition(
 731    handle: HWND,
 732    lparam: LPARAM,
 733    state_ptr: Rc<WindowsWindowStatePtr>,
 734) -> Option<isize> {
 735    let ctx = unsafe { ImmGetContext(handle) };
 736    let result = handle_ime_composition_inner(ctx, lparam, state_ptr);
 737    unsafe { ImmReleaseContext(handle, ctx).ok().log_err() };
 738    result
 739}
 740
 741fn handle_ime_composition_inner(
 742    ctx: HIMC,
 743    lparam: LPARAM,
 744    state_ptr: Rc<WindowsWindowStatePtr>,
 745) -> Option<isize> {
 746    let mut ime_input = None;
 747    if lparam.0 as u32 & GCS_COMPSTR.0 > 0 {
 748        let (comp_string, string_len) = parse_ime_compostion_string(ctx)?;
 749        with_input_handler(&state_ptr, |input_handler| {
 750            input_handler.replace_and_mark_text_in_range(
 751                None,
 752                &comp_string,
 753                Some(string_len..string_len),
 754            );
 755        })?;
 756        ime_input = Some(comp_string);
 757    }
 758    if lparam.0 as u32 & GCS_CURSORPOS.0 > 0 {
 759        let comp_string = &ime_input?;
 760        let caret_pos = retrieve_composition_cursor_position(ctx);
 761        with_input_handler(&state_ptr, |input_handler| {
 762            input_handler.replace_and_mark_text_in_range(
 763                None,
 764                comp_string,
 765                Some(caret_pos..caret_pos),
 766            );
 767        })?;
 768    }
 769    if lparam.0 as u32 & GCS_RESULTSTR.0 > 0 {
 770        let comp_result = parse_ime_compostion_result(ctx)?;
 771        with_input_handler(&state_ptr, |input_handler| {
 772            input_handler.replace_text_in_range(None, &comp_result);
 773        })?;
 774        return Some(0);
 775    }
 776    // currently, we don't care other stuff
 777    None
 778}
 779
 780/// SEE: https://learn.microsoft.com/en-us/windows/win32/winmsg/wm-nccalcsize
 781fn handle_calc_client_size(
 782    handle: HWND,
 783    wparam: WPARAM,
 784    lparam: LPARAM,
 785    state_ptr: Rc<WindowsWindowStatePtr>,
 786) -> Option<isize> {
 787    if !state_ptr.hide_title_bar || state_ptr.state.borrow().is_fullscreen() || wparam.0 == 0 {
 788        return None;
 789    }
 790
 791    let is_maximized = state_ptr.state.borrow().is_maximized();
 792    let insets = get_client_area_insets(handle, is_maximized, state_ptr.windows_version);
 793    // wparam is TRUE so lparam points to an NCCALCSIZE_PARAMS structure
 794    let mut params = lparam.0 as *mut NCCALCSIZE_PARAMS;
 795    let mut requested_client_rect = unsafe { &mut ((*params).rgrc) };
 796
 797    requested_client_rect[0].left += insets.left;
 798    requested_client_rect[0].top += insets.top;
 799    requested_client_rect[0].right -= insets.right;
 800    requested_client_rect[0].bottom -= insets.bottom;
 801
 802    // Fix auto hide taskbar not showing. This solution is based on the approach
 803    // used by Chrome. However, it may result in one row of pixels being obscured
 804    // in our client area. But as Chrome says, "there seems to be no better solution."
 805    if is_maximized {
 806        if let Some(ref taskbar_position) = state_ptr
 807            .state
 808            .borrow()
 809            .system_settings
 810            .auto_hide_taskbar_position
 811        {
 812            // Fot the auto-hide taskbar, adjust in by 1 pixel on taskbar edge,
 813            // so the window isn't treated as a "fullscreen app", which would cause
 814            // the taskbar to disappear.
 815            match taskbar_position {
 816                AutoHideTaskbarPosition::Left => {
 817                    requested_client_rect[0].left += AUTO_HIDE_TASKBAR_THICKNESS_PX
 818                }
 819                AutoHideTaskbarPosition::Top => {
 820                    requested_client_rect[0].top += AUTO_HIDE_TASKBAR_THICKNESS_PX
 821                }
 822                AutoHideTaskbarPosition::Right => {
 823                    requested_client_rect[0].right -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 824                }
 825                AutoHideTaskbarPosition::Bottom => {
 826                    requested_client_rect[0].bottom -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 827                }
 828            }
 829        }
 830    }
 831
 832    Some(0)
 833}
 834
 835fn handle_activate_msg(
 836    handle: HWND,
 837    wparam: WPARAM,
 838    state_ptr: Rc<WindowsWindowStatePtr>,
 839) -> Option<isize> {
 840    let activated = wparam.loword() > 0;
 841    if state_ptr.hide_title_bar {
 842        if let Some(titlebar_rect) = state_ptr.state.borrow().get_titlebar_rect().log_err() {
 843            unsafe {
 844                InvalidateRect(Some(handle), Some(&titlebar_rect), false)
 845                    .ok()
 846                    .log_err()
 847            };
 848        }
 849    }
 850    let this = state_ptr.clone();
 851    state_ptr
 852        .executor
 853        .spawn(async move {
 854            let mut lock = this.state.borrow_mut();
 855            if let Some(mut cb) = lock.callbacks.active_status_change.take() {
 856                drop(lock);
 857                cb(activated);
 858                this.state.borrow_mut().callbacks.active_status_change = Some(cb);
 859            }
 860        })
 861        .detach();
 862
 863    None
 864}
 865
 866fn handle_create_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 867    if state_ptr.hide_title_bar {
 868        notify_frame_changed(handle);
 869        Some(0)
 870    } else {
 871        None
 872    }
 873}
 874
 875fn handle_dpi_changed_msg(
 876    handle: HWND,
 877    wparam: WPARAM,
 878    lparam: LPARAM,
 879    state_ptr: Rc<WindowsWindowStatePtr>,
 880) -> Option<isize> {
 881    let new_dpi = wparam.loword() as f32;
 882    let mut lock = state_ptr.state.borrow_mut();
 883    lock.scale_factor = new_dpi / USER_DEFAULT_SCREEN_DPI as f32;
 884    lock.border_offset.update(handle).log_err();
 885    drop(lock);
 886
 887    let rect = unsafe { &*(lparam.0 as *const RECT) };
 888    let width = rect.right - rect.left;
 889    let height = rect.bottom - rect.top;
 890    // this will emit `WM_SIZE` and `WM_MOVE` right here
 891    // even before this function returns
 892    // the new size is handled in `WM_SIZE`
 893    unsafe {
 894        SetWindowPos(
 895            handle,
 896            None,
 897            rect.left,
 898            rect.top,
 899            width,
 900            height,
 901            SWP_NOZORDER | SWP_NOACTIVATE,
 902        )
 903        .context("unable to set window position after dpi has changed")
 904        .log_err();
 905    }
 906
 907    Some(0)
 908}
 909
 910/// The following conditions will trigger this event:
 911/// 1. The monitor on which the window is located goes offline or changes resolution.
 912/// 2. Another monitor goes offline, is plugged in, or changes resolution.
 913///
 914/// In either case, the window will only receive information from the monitor on which
 915/// it is located.
 916///
 917/// For example, in the case of condition 2, where the monitor on which the window is
 918/// located has actually changed nothing, it will still receive this event.
 919fn handle_display_change_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 920    // NOTE:
 921    // Even the `lParam` holds the resolution of the screen, we just ignore it.
 922    // Because WM_DPICHANGED, WM_MOVE, WM_SIZE will come first, window reposition and resize
 923    // are handled there.
 924    // So we only care about if monitor is disconnected.
 925    let previous_monitor = state_ptr.as_ref().state.borrow().display;
 926    if WindowsDisplay::is_connected(previous_monitor.handle) {
 927        // we are fine, other display changed
 928        return None;
 929    }
 930    // display disconnected
 931    // in this case, the OS will move our window to another monitor, and minimize it.
 932    // we deminimize the window and query the monitor after moving
 933    unsafe {
 934        let _ = ShowWindow(handle, SW_SHOWNORMAL);
 935    };
 936    let new_monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 937    // all monitors disconnected
 938    if new_monitor.is_invalid() {
 939        log::error!("No monitor detected!");
 940        return None;
 941    }
 942    let new_display = WindowsDisplay::new_with_handle(new_monitor);
 943    state_ptr.as_ref().state.borrow_mut().display = new_display;
 944    Some(0)
 945}
 946
 947fn handle_hit_test_msg(
 948    handle: HWND,
 949    msg: u32,
 950    wparam: WPARAM,
 951    lparam: LPARAM,
 952    state_ptr: Rc<WindowsWindowStatePtr>,
 953) -> Option<isize> {
 954    if !state_ptr.is_movable {
 955        return None;
 956    }
 957    if !state_ptr.hide_title_bar {
 958        return None;
 959    }
 960
 961    // default handler for resize areas
 962    let hit = unsafe { DefWindowProcW(handle, msg, wparam, lparam) };
 963    if matches!(
 964        hit.0 as u32,
 965        HTNOWHERE
 966            | HTRIGHT
 967            | HTLEFT
 968            | HTTOPLEFT
 969            | HTTOP
 970            | HTTOPRIGHT
 971            | HTBOTTOMRIGHT
 972            | HTBOTTOM
 973            | HTBOTTOMLEFT
 974    ) {
 975        return Some(hit.0);
 976    }
 977
 978    if state_ptr.state.borrow().is_fullscreen() {
 979        return Some(HTCLIENT as _);
 980    }
 981
 982    let dpi = unsafe { GetDpiForWindow(handle) };
 983    let frame_y = unsafe { GetSystemMetricsForDpi(SM_CYFRAME, dpi) };
 984
 985    let mut cursor_point = POINT {
 986        x: lparam.signed_loword().into(),
 987        y: lparam.signed_hiword().into(),
 988    };
 989    unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 990    if !state_ptr.state.borrow().is_maximized() && cursor_point.y >= 0 && cursor_point.y <= frame_y
 991    {
 992        return Some(HTTOP as _);
 993    }
 994
 995    let titlebar_rect = state_ptr.state.borrow().get_titlebar_rect();
 996    if let Ok(titlebar_rect) = titlebar_rect {
 997        if cursor_point.y < titlebar_rect.bottom {
 998            let caption_btn_width = (state_ptr.state.borrow().caption_button_width().0
 999                * state_ptr.state.borrow().scale_factor) as i32;
1000            if cursor_point.x >= titlebar_rect.right - caption_btn_width {
1001                return Some(HTCLOSE as _);
1002            } else if cursor_point.x >= titlebar_rect.right - caption_btn_width * 2 {
1003                return Some(HTMAXBUTTON as _);
1004            } else if cursor_point.x >= titlebar_rect.right - caption_btn_width * 3 {
1005                return Some(HTMINBUTTON as _);
1006            }
1007
1008            return Some(HTCAPTION as _);
1009        }
1010    }
1011
1012    Some(HTCLIENT as _)
1013}
1014
1015fn handle_nc_mouse_move_msg(
1016    handle: HWND,
1017    lparam: LPARAM,
1018    state_ptr: Rc<WindowsWindowStatePtr>,
1019) -> Option<isize> {
1020    if !state_ptr.hide_title_bar {
1021        return None;
1022    }
1023
1024    start_tracking_mouse(handle, &state_ptr, TME_LEAVE | TME_NONCLIENT);
1025
1026    let mut lock = state_ptr.state.borrow_mut();
1027    if let Some(mut callback) = lock.callbacks.input.take() {
1028        let scale_factor = lock.scale_factor;
1029        drop(lock);
1030        let mut cursor_point = POINT {
1031            x: lparam.signed_loword().into(),
1032            y: lparam.signed_hiword().into(),
1033        };
1034        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
1035        let event = MouseMoveEvent {
1036            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
1037            pressed_button: None,
1038            modifiers: current_modifiers(),
1039        };
1040        let result = if callback(PlatformInput::MouseMove(event)).default_prevented {
1041            Some(0)
1042        } else {
1043            Some(1)
1044        };
1045        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
1046
1047        result
1048    } else {
1049        None
1050    }
1051}
1052
1053fn handle_nc_mouse_down_msg(
1054    handle: HWND,
1055    button: MouseButton,
1056    wparam: WPARAM,
1057    lparam: LPARAM,
1058    state_ptr: Rc<WindowsWindowStatePtr>,
1059) -> Option<isize> {
1060    if !state_ptr.hide_title_bar {
1061        return None;
1062    }
1063
1064    let mut lock = state_ptr.state.borrow_mut();
1065    if let Some(mut callback) = lock.callbacks.input.take() {
1066        let scale_factor = lock.scale_factor;
1067        let mut cursor_point = POINT {
1068            x: lparam.signed_loword().into(),
1069            y: lparam.signed_hiword().into(),
1070        };
1071        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
1072        let physical_point = point(DevicePixels(cursor_point.x), DevicePixels(cursor_point.y));
1073        let click_count = lock.click_state.update(button, physical_point);
1074        drop(lock);
1075        let event = MouseDownEvent {
1076            button,
1077            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
1078            modifiers: current_modifiers(),
1079            click_count,
1080            first_mouse: false,
1081        };
1082        let result = if callback(PlatformInput::MouseDown(event)).default_prevented {
1083            Some(0)
1084        } else {
1085            None
1086        };
1087        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
1088
1089        if result.is_some() {
1090            return result;
1091        }
1092    } else {
1093        drop(lock);
1094    };
1095
1096    // Since these are handled in handle_nc_mouse_up_msg we must prevent the default window proc
1097    if button == MouseButton::Left {
1098        match wparam.0 as u32 {
1099            HTMINBUTTON => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTMINBUTTON),
1100            HTMAXBUTTON => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTMAXBUTTON),
1101            HTCLOSE => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTCLOSE),
1102            _ => return None,
1103        };
1104        Some(0)
1105    } else {
1106        None
1107    }
1108}
1109
1110fn handle_nc_mouse_up_msg(
1111    handle: HWND,
1112    button: MouseButton,
1113    wparam: WPARAM,
1114    lparam: LPARAM,
1115    state_ptr: Rc<WindowsWindowStatePtr>,
1116) -> Option<isize> {
1117    if !state_ptr.hide_title_bar {
1118        return None;
1119    }
1120
1121    let mut lock = state_ptr.state.borrow_mut();
1122    if let Some(mut callback) = lock.callbacks.input.take() {
1123        let scale_factor = lock.scale_factor;
1124        drop(lock);
1125        let mut cursor_point = POINT {
1126            x: lparam.signed_loword().into(),
1127            y: lparam.signed_hiword().into(),
1128        };
1129        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
1130        let event = MouseUpEvent {
1131            button,
1132            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
1133            modifiers: current_modifiers(),
1134            click_count: 1,
1135        };
1136        let result = if callback(PlatformInput::MouseUp(event)).default_prevented {
1137            Some(0)
1138        } else {
1139            None
1140        };
1141        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
1142        if result.is_some() {
1143            return result;
1144        }
1145    } else {
1146        drop(lock);
1147    }
1148
1149    let last_pressed = state_ptr.state.borrow_mut().nc_button_pressed.take();
1150    if button == MouseButton::Left && last_pressed.is_some() {
1151        let last_button = last_pressed.unwrap();
1152        let mut handled = false;
1153        match wparam.0 as u32 {
1154            HTMINBUTTON => {
1155                if last_button == HTMINBUTTON {
1156                    unsafe { ShowWindowAsync(handle, SW_MINIMIZE).ok().log_err() };
1157                    handled = true;
1158                }
1159            }
1160            HTMAXBUTTON => {
1161                if last_button == HTMAXBUTTON {
1162                    if state_ptr.state.borrow().is_maximized() {
1163                        unsafe { ShowWindowAsync(handle, SW_NORMAL).ok().log_err() };
1164                    } else {
1165                        unsafe { ShowWindowAsync(handle, SW_MAXIMIZE).ok().log_err() };
1166                    }
1167                    handled = true;
1168                }
1169            }
1170            HTCLOSE => {
1171                if last_button == HTCLOSE {
1172                    unsafe {
1173                        PostMessageW(Some(handle), WM_CLOSE, WPARAM::default(), LPARAM::default())
1174                            .log_err()
1175                    };
1176                    handled = true;
1177                }
1178            }
1179            _ => {}
1180        };
1181        if handled {
1182            return Some(0);
1183        }
1184    }
1185
1186    None
1187}
1188
1189fn handle_cursor_changed(lparam: LPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1190    let mut state = state_ptr.state.borrow_mut();
1191    let had_cursor = state.current_cursor.is_some();
1192
1193    state.current_cursor = if lparam.0 == 0 {
1194        None
1195    } else {
1196        Some(HCURSOR(lparam.0 as _))
1197    };
1198
1199    if had_cursor != state.current_cursor.is_some() {
1200        unsafe { SetCursor(state.current_cursor) };
1201    }
1202
1203    Some(0)
1204}
1205
1206fn handle_set_cursor(lparam: LPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1207    if matches!(
1208        lparam.loword() as u32,
1209        HTLEFT | HTRIGHT | HTTOP | HTTOPLEFT | HTTOPRIGHT | HTBOTTOM | HTBOTTOMLEFT | HTBOTTOMRIGHT
1210    ) {
1211        return None;
1212    }
1213    unsafe {
1214        SetCursor(state_ptr.state.borrow().current_cursor);
1215    };
1216    Some(1)
1217}
1218
1219fn handle_system_settings_changed(
1220    handle: HWND,
1221    lparam: LPARAM,
1222    state_ptr: Rc<WindowsWindowStatePtr>,
1223) -> Option<isize> {
1224    let mut lock = state_ptr.state.borrow_mut();
1225    let display = lock.display;
1226    // system settings
1227    lock.system_settings.update(display);
1228    // mouse double click
1229    lock.click_state.system_update();
1230    // window border offset
1231    lock.border_offset.update(handle).log_err();
1232    drop(lock);
1233
1234    // lParam is a pointer to a string that indicates the area containing the system parameter
1235    // that was changed.
1236    let parameter = PCWSTR::from_raw(lparam.0 as _);
1237    if unsafe { !parameter.is_null() && !parameter.is_empty() } {
1238        if let Some(parameter_string) = unsafe { parameter.to_string() }.log_err() {
1239            log::info!("System settings changed: {}", parameter_string);
1240            match parameter_string.as_str() {
1241                "ImmersiveColorSet" => {
1242                    handle_system_theme_changed(handle, state_ptr);
1243                }
1244                _ => {}
1245            }
1246        }
1247    }
1248
1249    // Force to trigger WM_NCCALCSIZE event to ensure that we handle auto hide
1250    // taskbar correctly.
1251    notify_frame_changed(handle);
1252    Some(0)
1253}
1254
1255fn handle_system_command(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1256    if wparam.0 == SC_KEYMENU as usize {
1257        let mut lock = state_ptr.state.borrow_mut();
1258        if lock.system_key_handled {
1259            lock.system_key_handled = false;
1260            return Some(0);
1261        }
1262    }
1263    None
1264}
1265
1266fn handle_system_theme_changed(
1267    handle: HWND,
1268    state_ptr: Rc<WindowsWindowStatePtr>,
1269) -> Option<isize> {
1270    let mut callback = state_ptr
1271        .state
1272        .borrow_mut()
1273        .callbacks
1274        .appearance_changed
1275        .take()?;
1276    callback();
1277    state_ptr.state.borrow_mut().callbacks.appearance_changed = Some(callback);
1278    configure_dwm_dark_mode(handle);
1279    Some(0)
1280}
1281
1282fn parse_syskeydown_msg_keystroke(wparam: WPARAM) -> Option<Keystroke> {
1283    let modifiers = current_modifiers();
1284    let vk_code = wparam.loword();
1285
1286    // on Windows, F10 can trigger this event, not just the alt key,
1287    // so when F10 was pressed, handle only it
1288    if !modifiers.alt {
1289        if vk_code == VK_F10.0 {
1290            let offset = vk_code - VK_F1.0;
1291            return Some(Keystroke {
1292                modifiers,
1293                key: format!("f{}", offset + 1),
1294                key_char: None,
1295            });
1296        } else {
1297            return None;
1298        }
1299    }
1300
1301    let key = match VIRTUAL_KEY(vk_code) {
1302        VK_BACK => "backspace",
1303        VK_RETURN => "enter",
1304        VK_TAB => "tab",
1305        VK_UP => "up",
1306        VK_DOWN => "down",
1307        VK_RIGHT => "right",
1308        VK_LEFT => "left",
1309        VK_HOME => "home",
1310        VK_END => "end",
1311        VK_PRIOR => "pageup",
1312        VK_NEXT => "pagedown",
1313        VK_BROWSER_BACK => "back",
1314        VK_BROWSER_FORWARD => "forward",
1315        VK_ESCAPE => "escape",
1316        VK_INSERT => "insert",
1317        VK_DELETE => "delete",
1318        VK_APPS => "menu",
1319        _ => {
1320            let basic_key = basic_vkcode_to_string(vk_code, modifiers);
1321            if basic_key.is_some() {
1322                return basic_key;
1323            } else {
1324                if vk_code >= VK_F1.0 && vk_code <= VK_F24.0 {
1325                    let offset = vk_code - VK_F1.0;
1326                    return Some(Keystroke {
1327                        modifiers,
1328                        key: format!("f{}", offset + 1),
1329                        key_char: None,
1330                    });
1331                } else {
1332                    return None;
1333                }
1334            }
1335        }
1336    }
1337    .to_owned();
1338
1339    Some(Keystroke {
1340        modifiers,
1341        key,
1342        key_char: None,
1343    })
1344}
1345
1346enum KeystrokeOrModifier {
1347    Keystroke(Keystroke),
1348    Modifier(Modifiers),
1349}
1350
1351fn parse_keystroke_from_vkey(wparam: WPARAM, is_keyup: bool) -> Option<KeystrokeOrModifier> {
1352    let vk_code = wparam.loword();
1353
1354    let modifiers = current_modifiers();
1355
1356    let key = match VIRTUAL_KEY(vk_code) {
1357        VK_BACK => "backspace",
1358        VK_RETURN => "enter",
1359        VK_TAB => "tab",
1360        VK_UP => "up",
1361        VK_DOWN => "down",
1362        VK_RIGHT => "right",
1363        VK_LEFT => "left",
1364        VK_HOME => "home",
1365        VK_END => "end",
1366        VK_PRIOR => "pageup",
1367        VK_NEXT => "pagedown",
1368        VK_BROWSER_BACK => "back",
1369        VK_BROWSER_FORWARD => "forward",
1370        VK_ESCAPE => "escape",
1371        VK_INSERT => "insert",
1372        VK_DELETE => "delete",
1373        VK_APPS => "menu",
1374        _ => {
1375            if is_modifier(VIRTUAL_KEY(vk_code)) {
1376                return Some(KeystrokeOrModifier::Modifier(modifiers));
1377            }
1378
1379            if modifiers.control || modifiers.alt || is_keyup {
1380                let basic_key = basic_vkcode_to_string(vk_code, modifiers);
1381                if let Some(basic_key) = basic_key {
1382                    return Some(KeystrokeOrModifier::Keystroke(basic_key));
1383                }
1384            }
1385
1386            if vk_code >= VK_F1.0 && vk_code <= VK_F24.0 {
1387                let offset = vk_code - VK_F1.0;
1388                return Some(KeystrokeOrModifier::Keystroke(Keystroke {
1389                    modifiers,
1390                    key: format!("f{}", offset + 1),
1391                    key_char: None,
1392                }));
1393            };
1394            return None;
1395        }
1396    }
1397    .to_owned();
1398
1399    Some(KeystrokeOrModifier::Keystroke(Keystroke {
1400        modifiers,
1401        key,
1402        key_char: None,
1403    }))
1404}
1405
1406fn parse_char_msg_keystroke(wparam: WPARAM) -> Option<Keystroke> {
1407    let first_char = char::from_u32((wparam.0 as u16).into())?;
1408    if first_char.is_control() {
1409        None
1410    } else {
1411        let mut modifiers = current_modifiers();
1412        // for characters that use 'shift' to type it is expected that the
1413        // shift is not reported if the uppercase/lowercase are the same and instead only the key is reported
1414        if first_char.to_ascii_uppercase() == first_char.to_ascii_lowercase() {
1415            modifiers.shift = false;
1416        }
1417        let key = match first_char {
1418            ' ' => "space".to_string(),
1419            first_char => first_char.to_lowercase().to_string(),
1420        };
1421        Some(Keystroke {
1422            modifiers,
1423            key,
1424            key_char: Some(first_char.to_string()),
1425        })
1426    }
1427}
1428
1429fn parse_ime_compostion_string(ctx: HIMC) -> Option<(String, usize)> {
1430    unsafe {
1431        let string_len = ImmGetCompositionStringW(ctx, GCS_COMPSTR, None, 0);
1432        if string_len >= 0 {
1433            let mut buffer = vec![0u8; string_len as usize + 2];
1434            ImmGetCompositionStringW(
1435                ctx,
1436                GCS_COMPSTR,
1437                Some(buffer.as_mut_ptr() as _),
1438                string_len as _,
1439            );
1440            let wstring = std::slice::from_raw_parts::<u16>(
1441                buffer.as_mut_ptr().cast::<u16>(),
1442                string_len as usize / 2,
1443            );
1444            let string = String::from_utf16_lossy(wstring);
1445            Some((string, string_len as usize / 2))
1446        } else {
1447            None
1448        }
1449    }
1450}
1451
1452#[inline]
1453fn retrieve_composition_cursor_position(ctx: HIMC) -> usize {
1454    unsafe { ImmGetCompositionStringW(ctx, GCS_CURSORPOS, None, 0) as usize }
1455}
1456
1457fn parse_ime_compostion_result(ctx: HIMC) -> Option<String> {
1458    unsafe {
1459        let string_len = ImmGetCompositionStringW(ctx, GCS_RESULTSTR, None, 0);
1460        if string_len >= 0 {
1461            let mut buffer = vec![0u8; string_len as usize + 2];
1462            ImmGetCompositionStringW(
1463                ctx,
1464                GCS_RESULTSTR,
1465                Some(buffer.as_mut_ptr() as _),
1466                string_len as _,
1467            );
1468            let wstring = std::slice::from_raw_parts::<u16>(
1469                buffer.as_mut_ptr().cast::<u16>(),
1470                string_len as usize / 2,
1471            );
1472            let string = String::from_utf16_lossy(wstring);
1473            Some(string)
1474        } else {
1475            None
1476        }
1477    }
1478}
1479
1480fn basic_vkcode_to_string(code: u16, modifiers: Modifiers) -> Option<Keystroke> {
1481    let mapped_code = unsafe { MapVirtualKeyW(code as u32, MAPVK_VK_TO_CHAR) };
1482
1483    let key = match mapped_code {
1484        0 => None,
1485        raw_code => char::from_u32(raw_code),
1486    }?
1487    .to_ascii_lowercase();
1488
1489    let key = if matches!(code as u32, 112..=135) {
1490        format!("f{key}")
1491    } else {
1492        key.to_string()
1493    };
1494
1495    Some(Keystroke {
1496        modifiers,
1497        key,
1498        key_char: None,
1499    })
1500}
1501
1502#[inline]
1503fn is_virtual_key_pressed(vkey: VIRTUAL_KEY) -> bool {
1504    unsafe { GetKeyState(vkey.0 as i32) < 0 }
1505}
1506
1507fn is_modifier(virtual_key: VIRTUAL_KEY) -> bool {
1508    matches!(
1509        virtual_key,
1510        VK_CONTROL | VK_MENU | VK_SHIFT | VK_LWIN | VK_RWIN
1511    )
1512}
1513
1514#[inline]
1515pub(crate) fn current_modifiers() -> Modifiers {
1516    Modifiers {
1517        control: is_virtual_key_pressed(VK_CONTROL),
1518        alt: is_virtual_key_pressed(VK_MENU),
1519        shift: is_virtual_key_pressed(VK_SHIFT),
1520        platform: is_virtual_key_pressed(VK_LWIN) || is_virtual_key_pressed(VK_RWIN),
1521        function: false,
1522    }
1523}
1524
1525fn get_client_area_insets(
1526    handle: HWND,
1527    is_maximized: bool,
1528    windows_version: WindowsVersion,
1529) -> RECT {
1530    // For maximized windows, Windows outdents the window rect from the screen's client rect
1531    // by `frame_thickness` on each edge, meaning `insets` must contain `frame_thickness`
1532    // on all sides (including the top) to avoid the client area extending onto adjacent
1533    // monitors.
1534    //
1535    // For non-maximized windows, things become complicated:
1536    //
1537    // - On Windows 10
1538    // The top inset must be zero, since if there is any nonclient area, Windows will draw
1539    // a full native titlebar outside the client area. (This doesn't occur in the maximized
1540    // case.)
1541    //
1542    // - On Windows 11
1543    // The top inset is calculated using an empirical formula that I derived through various
1544    // tests. Without this, the top 1-2 rows of pixels in our window would be obscured.
1545    let dpi = unsafe { GetDpiForWindow(handle) };
1546    let frame_thickness = get_frame_thickness(dpi);
1547    let top_insets = if is_maximized {
1548        frame_thickness
1549    } else {
1550        match windows_version {
1551            WindowsVersion::Win10 => 0,
1552            WindowsVersion::Win11 => (dpi as f32 / USER_DEFAULT_SCREEN_DPI as f32).round() as i32,
1553        }
1554    };
1555    RECT {
1556        left: frame_thickness,
1557        top: top_insets,
1558        right: frame_thickness,
1559        bottom: frame_thickness,
1560    }
1561}
1562
1563// there is some additional non-visible space when talking about window
1564// borders on Windows:
1565// - SM_CXSIZEFRAME: The resize handle.
1566// - SM_CXPADDEDBORDER: Additional border space that isn't part of the resize handle.
1567fn get_frame_thickness(dpi: u32) -> i32 {
1568    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CXSIZEFRAME, dpi) };
1569    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1570    resize_frame_thickness + padding_thickness
1571}
1572
1573fn notify_frame_changed(handle: HWND) {
1574    unsafe {
1575        SetWindowPos(
1576            handle,
1577            None,
1578            0,
1579            0,
1580            0,
1581            0,
1582            SWP_FRAMECHANGED
1583                | SWP_NOACTIVATE
1584                | SWP_NOCOPYBITS
1585                | SWP_NOMOVE
1586                | SWP_NOOWNERZORDER
1587                | SWP_NOREPOSITION
1588                | SWP_NOSENDCHANGING
1589                | SWP_NOSIZE
1590                | SWP_NOZORDER,
1591        )
1592        .log_err();
1593    }
1594}
1595
1596fn start_tracking_mouse(
1597    handle: HWND,
1598    state_ptr: &Rc<WindowsWindowStatePtr>,
1599    flags: TRACKMOUSEEVENT_FLAGS,
1600) {
1601    let mut lock = state_ptr.state.borrow_mut();
1602    if !lock.hovered {
1603        lock.hovered = true;
1604        unsafe {
1605            TrackMouseEvent(&mut TRACKMOUSEEVENT {
1606                cbSize: std::mem::size_of::<TRACKMOUSEEVENT>() as u32,
1607                dwFlags: flags,
1608                hwndTrack: handle,
1609                dwHoverTime: HOVER_DEFAULT,
1610            })
1611            .log_err()
1612        };
1613        if let Some(mut callback) = lock.callbacks.hovered_status_change.take() {
1614            drop(lock);
1615            callback(true);
1616            state_ptr.state.borrow_mut().callbacks.hovered_status_change = Some(callback);
1617        }
1618    }
1619}
1620
1621fn with_input_handler<F, R>(state_ptr: &Rc<WindowsWindowStatePtr>, f: F) -> Option<R>
1622where
1623    F: FnOnce(&mut PlatformInputHandler) -> R,
1624{
1625    let mut input_handler = state_ptr.state.borrow_mut().input_handler.take()?;
1626    let result = f(&mut input_handler);
1627    state_ptr.state.borrow_mut().input_handler = Some(input_handler);
1628    Some(result)
1629}
1630
1631fn with_input_handler_and_scale_factor<F, R>(
1632    state_ptr: &Rc<WindowsWindowStatePtr>,
1633    f: F,
1634) -> Option<R>
1635where
1636    F: FnOnce(&mut PlatformInputHandler, f32) -> Option<R>,
1637{
1638    let mut lock = state_ptr.state.borrow_mut();
1639    let mut input_handler = lock.input_handler.take()?;
1640    let scale_factor = lock.scale_factor;
1641    drop(lock);
1642    let result = f(&mut input_handler, scale_factor);
1643    state_ptr.state.borrow_mut().input_handler = Some(input_handler);
1644    result
1645}