events.rs

   1use std::rc::Rc;
   2
   3use ::util::ResultExt;
   4use anyhow::Context;
   5use windows::Win32::{
   6    Foundation::*,
   7    Graphics::Gdi::*,
   8    System::SystemServices::*,
   9    UI::{
  10        HiDpi::*,
  11        Input::{Ime::*, KeyboardAndMouse::*},
  12        WindowsAndMessaging::*,
  13    },
  14};
  15
  16use crate::*;
  17
  18pub(crate) const CURSOR_STYLE_CHANGED: u32 = WM_USER + 1;
  19pub(crate) const CLOSE_ONE_WINDOW: u32 = WM_USER + 2;
  20
  21const SIZE_MOVE_LOOP_TIMER_ID: usize = 1;
  22const AUTO_HIDE_TASKBAR_THICKNESS_PX: i32 = 1;
  23
  24pub(crate) fn handle_msg(
  25    handle: HWND,
  26    msg: u32,
  27    wparam: WPARAM,
  28    lparam: LPARAM,
  29    state_ptr: Rc<WindowsWindowStatePtr>,
  30) -> LRESULT {
  31    let handled = match msg {
  32        WM_ACTIVATE => handle_activate_msg(handle, wparam, state_ptr),
  33        WM_CREATE => handle_create_msg(handle, state_ptr),
  34        WM_MOVE => handle_move_msg(handle, lparam, state_ptr),
  35        WM_SIZE => handle_size_msg(lparam, state_ptr),
  36        WM_ENTERSIZEMOVE | WM_ENTERMENULOOP => handle_size_move_loop(handle),
  37        WM_EXITSIZEMOVE | WM_EXITMENULOOP => handle_size_move_loop_exit(handle),
  38        WM_TIMER => handle_timer_msg(handle, wparam, state_ptr),
  39        WM_NCCALCSIZE => handle_calc_client_size(handle, wparam, lparam, state_ptr),
  40        WM_DPICHANGED => handle_dpi_changed_msg(handle, wparam, lparam, state_ptr),
  41        WM_DISPLAYCHANGE => handle_display_change_msg(handle, state_ptr),
  42        WM_NCHITTEST => handle_hit_test_msg(handle, msg, wparam, lparam, state_ptr),
  43        WM_PAINT => handle_paint_msg(handle, state_ptr),
  44        WM_CLOSE => handle_close_msg(state_ptr),
  45        WM_DESTROY => handle_destroy_msg(handle, state_ptr),
  46        WM_MOUSEMOVE => handle_mouse_move_msg(lparam, wparam, state_ptr),
  47        WM_NCMOUSEMOVE => handle_nc_mouse_move_msg(handle, lparam, state_ptr),
  48        WM_NCLBUTTONDOWN => {
  49            handle_nc_mouse_down_msg(handle, MouseButton::Left, wparam, lparam, state_ptr)
  50        }
  51        WM_NCRBUTTONDOWN => {
  52            handle_nc_mouse_down_msg(handle, MouseButton::Right, wparam, lparam, state_ptr)
  53        }
  54        WM_NCMBUTTONDOWN => {
  55            handle_nc_mouse_down_msg(handle, MouseButton::Middle, wparam, lparam, state_ptr)
  56        }
  57        WM_NCLBUTTONUP => {
  58            handle_nc_mouse_up_msg(handle, MouseButton::Left, wparam, lparam, state_ptr)
  59        }
  60        WM_NCRBUTTONUP => {
  61            handle_nc_mouse_up_msg(handle, MouseButton::Right, wparam, lparam, state_ptr)
  62        }
  63        WM_NCMBUTTONUP => {
  64            handle_nc_mouse_up_msg(handle, MouseButton::Middle, wparam, lparam, state_ptr)
  65        }
  66        WM_LBUTTONDOWN => handle_mouse_down_msg(handle, MouseButton::Left, lparam, state_ptr),
  67        WM_RBUTTONDOWN => handle_mouse_down_msg(handle, MouseButton::Right, lparam, state_ptr),
  68        WM_MBUTTONDOWN => handle_mouse_down_msg(handle, MouseButton::Middle, lparam, state_ptr),
  69        WM_XBUTTONDOWN => {
  70            handle_xbutton_msg(handle, wparam, lparam, handle_mouse_down_msg, state_ptr)
  71        }
  72        WM_LBUTTONUP => handle_mouse_up_msg(handle, MouseButton::Left, lparam, state_ptr),
  73        WM_RBUTTONUP => handle_mouse_up_msg(handle, MouseButton::Right, lparam, state_ptr),
  74        WM_MBUTTONUP => handle_mouse_up_msg(handle, MouseButton::Middle, lparam, state_ptr),
  75        WM_XBUTTONUP => handle_xbutton_msg(handle, wparam, lparam, handle_mouse_up_msg, state_ptr),
  76        WM_MOUSEWHEEL => handle_mouse_wheel_msg(handle, wparam, lparam, state_ptr),
  77        WM_MOUSEHWHEEL => handle_mouse_horizontal_wheel_msg(handle, wparam, lparam, state_ptr),
  78        WM_SYSKEYDOWN => handle_syskeydown_msg(wparam, lparam, state_ptr),
  79        WM_SYSKEYUP => handle_syskeyup_msg(wparam, state_ptr),
  80        WM_SYSCOMMAND => handle_system_command(wparam, state_ptr),
  81        WM_KEYDOWN => handle_keydown_msg(wparam, lparam, state_ptr),
  82        WM_KEYUP => handle_keyup_msg(wparam, state_ptr),
  83        WM_CHAR => handle_char_msg(wparam, lparam, state_ptr),
  84        WM_IME_STARTCOMPOSITION => handle_ime_position(handle, state_ptr),
  85        WM_IME_COMPOSITION => handle_ime_composition(handle, lparam, state_ptr),
  86        WM_SETCURSOR => handle_set_cursor(lparam, state_ptr),
  87        WM_SETTINGCHANGE => handle_system_settings_changed(handle, state_ptr),
  88        WM_DWMCOLORIZATIONCOLORCHANGED => handle_system_theme_changed(state_ptr),
  89        CURSOR_STYLE_CHANGED => handle_cursor_changed(lparam, state_ptr),
  90        _ => None,
  91    };
  92    if let Some(n) = handled {
  93        LRESULT(n)
  94    } else {
  95        unsafe { DefWindowProcW(handle, msg, wparam, lparam) }
  96    }
  97}
  98
  99fn handle_move_msg(
 100    handle: HWND,
 101    lparam: LPARAM,
 102    state_ptr: Rc<WindowsWindowStatePtr>,
 103) -> Option<isize> {
 104    let mut lock = state_ptr.state.borrow_mut();
 105    let origin = logical_point(
 106        lparam.signed_loword() as f32,
 107        lparam.signed_hiword() as f32,
 108        lock.scale_factor,
 109    );
 110    lock.origin = origin;
 111    let size = lock.logical_size;
 112    let center_x = origin.x.0 + size.width.0 / 2.;
 113    let center_y = origin.y.0 + size.height.0 / 2.;
 114    let monitor_bounds = lock.display.bounds();
 115    if center_x < monitor_bounds.left().0
 116        || center_x > monitor_bounds.right().0
 117        || center_y < monitor_bounds.top().0
 118        || center_y > monitor_bounds.bottom().0
 119    {
 120        // center of the window may have moved to another monitor
 121        let monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 122        // minimize the window can trigger this event too, in this case,
 123        // monitor is invalid, we do nothing.
 124        if !monitor.is_invalid() && lock.display.handle != monitor {
 125            // we will get the same monitor if we only have one
 126            lock.display = WindowsDisplay::new_with_handle(monitor);
 127        }
 128    }
 129    if let Some(mut callback) = lock.callbacks.moved.take() {
 130        drop(lock);
 131        callback();
 132        state_ptr.state.borrow_mut().callbacks.moved = Some(callback);
 133    }
 134    Some(0)
 135}
 136
 137fn handle_size_msg(lparam: LPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 138    let width = lparam.loword().max(1) as i32;
 139    let height = lparam.hiword().max(1) as i32;
 140    let mut lock = state_ptr.state.borrow_mut();
 141    let new_size = size(DevicePixels(width), DevicePixels(height));
 142    let scale_factor = lock.scale_factor;
 143    lock.renderer.update_drawable_size(new_size);
 144    let new_size = new_size.to_pixels(scale_factor);
 145    lock.logical_size = new_size;
 146    if let Some(mut callback) = lock.callbacks.resize.take() {
 147        drop(lock);
 148        callback(new_size, scale_factor);
 149        state_ptr.state.borrow_mut().callbacks.resize = Some(callback);
 150    }
 151    Some(0)
 152}
 153
 154fn handle_size_move_loop(handle: HWND) -> Option<isize> {
 155    unsafe {
 156        let ret = SetTimer(handle, SIZE_MOVE_LOOP_TIMER_ID, USER_TIMER_MINIMUM, None);
 157        if ret == 0 {
 158            log::error!(
 159                "unable to create timer: {}",
 160                std::io::Error::last_os_error()
 161            );
 162        }
 163    }
 164    None
 165}
 166
 167fn handle_size_move_loop_exit(handle: HWND) -> Option<isize> {
 168    unsafe {
 169        KillTimer(handle, SIZE_MOVE_LOOP_TIMER_ID).log_err();
 170    }
 171    None
 172}
 173
 174fn handle_timer_msg(
 175    handle: HWND,
 176    wparam: WPARAM,
 177    state_ptr: Rc<WindowsWindowStatePtr>,
 178) -> Option<isize> {
 179    if wparam.0 == SIZE_MOVE_LOOP_TIMER_ID {
 180        for runnable in state_ptr.main_receiver.drain() {
 181            runnable.run();
 182        }
 183        handle_paint_msg(handle, state_ptr)
 184    } else {
 185        None
 186    }
 187}
 188
 189fn handle_paint_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 190    let mut lock = state_ptr.state.borrow_mut();
 191    if let Some(mut request_frame) = lock.callbacks.request_frame.take() {
 192        drop(lock);
 193        request_frame(Default::default());
 194        state_ptr.state.borrow_mut().callbacks.request_frame = Some(request_frame);
 195    }
 196    unsafe { ValidateRect(handle, None).ok().log_err() };
 197    Some(0)
 198}
 199
 200fn handle_close_msg(state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 201    let mut lock = state_ptr.state.borrow_mut();
 202    if let Some(mut callback) = lock.callbacks.should_close.take() {
 203        drop(lock);
 204        let should_close = callback();
 205        state_ptr.state.borrow_mut().callbacks.should_close = Some(callback);
 206        if should_close {
 207            None
 208        } else {
 209            Some(0)
 210        }
 211    } else {
 212        None
 213    }
 214}
 215
 216fn handle_destroy_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 217    let callback = {
 218        let mut lock = state_ptr.state.borrow_mut();
 219        lock.callbacks.close.take()
 220    };
 221    if let Some(callback) = callback {
 222        callback();
 223    }
 224    unsafe {
 225        PostMessageW(
 226            None,
 227            CLOSE_ONE_WINDOW,
 228            WPARAM(state_ptr.validation_number),
 229            LPARAM(handle.0 as isize),
 230        )
 231        .log_err();
 232    }
 233    Some(0)
 234}
 235
 236fn handle_mouse_move_msg(
 237    lparam: LPARAM,
 238    wparam: WPARAM,
 239    state_ptr: Rc<WindowsWindowStatePtr>,
 240) -> Option<isize> {
 241    let mut lock = state_ptr.state.borrow_mut();
 242    if let Some(mut callback) = lock.callbacks.input.take() {
 243        let scale_factor = lock.scale_factor;
 244        drop(lock);
 245        let pressed_button = match MODIFIERKEYS_FLAGS(wparam.loword() as u32) {
 246            flags if flags.contains(MK_LBUTTON) => Some(MouseButton::Left),
 247            flags if flags.contains(MK_RBUTTON) => Some(MouseButton::Right),
 248            flags if flags.contains(MK_MBUTTON) => Some(MouseButton::Middle),
 249            flags if flags.contains(MK_XBUTTON1) => {
 250                Some(MouseButton::Navigate(NavigationDirection::Back))
 251            }
 252            flags if flags.contains(MK_XBUTTON2) => {
 253                Some(MouseButton::Navigate(NavigationDirection::Forward))
 254            }
 255            _ => None,
 256        };
 257        let x = lparam.signed_loword() as f32;
 258        let y = lparam.signed_hiword() as f32;
 259        let event = MouseMoveEvent {
 260            position: logical_point(x, y, scale_factor),
 261            pressed_button,
 262            modifiers: current_modifiers(),
 263        };
 264        let result = if callback(PlatformInput::MouseMove(event)).default_prevented {
 265            Some(0)
 266        } else {
 267            Some(1)
 268        };
 269        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 270        return result;
 271    }
 272    Some(1)
 273}
 274
 275fn handle_syskeydown_msg(
 276    wparam: WPARAM,
 277    lparam: LPARAM,
 278    state_ptr: Rc<WindowsWindowStatePtr>,
 279) -> Option<isize> {
 280    // we need to call `DefWindowProcW`, or we will lose the system-wide `Alt+F4`, `Alt+{other keys}`
 281    // shortcuts.
 282    let keystroke = parse_syskeydown_msg_keystroke(wparam)?;
 283    let mut func = state_ptr.state.borrow_mut().callbacks.input.take()?;
 284    let event = KeyDownEvent {
 285        keystroke,
 286        is_held: lparam.0 & (0x1 << 30) > 0,
 287    };
 288    let result = if !func(PlatformInput::KeyDown(event)).propagate {
 289        state_ptr.state.borrow_mut().system_key_handled = true;
 290        Some(0)
 291    } else {
 292        None
 293    };
 294    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 295
 296    result
 297}
 298
 299fn handle_syskeyup_msg(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 300    // we need to call `DefWindowProcW`, or we will lose the system-wide `Alt+F4`, `Alt+{other keys}`
 301    // shortcuts.
 302    let keystroke = parse_syskeydown_msg_keystroke(wparam)?;
 303    let mut func = state_ptr.state.borrow_mut().callbacks.input.take()?;
 304    let event = KeyUpEvent { keystroke };
 305    let result = if func(PlatformInput::KeyUp(event)).default_prevented {
 306        Some(0)
 307    } else {
 308        Some(1)
 309    };
 310    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 311
 312    result
 313}
 314
 315fn handle_keydown_msg(
 316    wparam: WPARAM,
 317    lparam: LPARAM,
 318    state_ptr: Rc<WindowsWindowStatePtr>,
 319) -> Option<isize> {
 320    let Some(keystroke_or_modifier) = parse_keydown_msg_keystroke(wparam) else {
 321        return Some(1);
 322    };
 323    let mut lock = state_ptr.state.borrow_mut();
 324    let Some(mut func) = lock.callbacks.input.take() else {
 325        return Some(1);
 326    };
 327    drop(lock);
 328
 329    let event = match keystroke_or_modifier {
 330        KeystrokeOrModifier::Keystroke(keystroke) => PlatformInput::KeyDown(KeyDownEvent {
 331            keystroke,
 332            is_held: lparam.0 & (0x1 << 30) > 0,
 333        }),
 334        KeystrokeOrModifier::Modifier(modifiers) => {
 335            PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 336        }
 337    };
 338
 339    let result = if func(event).default_prevented {
 340        Some(0)
 341    } else {
 342        Some(1)
 343    };
 344    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 345
 346    result
 347}
 348
 349fn handle_keyup_msg(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 350    let Some(keystroke_or_modifier) = parse_keydown_msg_keystroke(wparam) else {
 351        return Some(1);
 352    };
 353    let mut lock = state_ptr.state.borrow_mut();
 354    let Some(mut func) = lock.callbacks.input.take() else {
 355        return Some(1);
 356    };
 357    drop(lock);
 358
 359    let event = match keystroke_or_modifier {
 360        KeystrokeOrModifier::Keystroke(keystroke) => PlatformInput::KeyUp(KeyUpEvent { keystroke }),
 361        KeystrokeOrModifier::Modifier(modifiers) => {
 362            PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 363        }
 364    };
 365
 366    let result = if func(event).default_prevented {
 367        Some(0)
 368    } else {
 369        Some(1)
 370    };
 371    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 372
 373    result
 374}
 375
 376fn handle_char_msg(
 377    wparam: WPARAM,
 378    lparam: LPARAM,
 379    state_ptr: Rc<WindowsWindowStatePtr>,
 380) -> Option<isize> {
 381    let Some(keystroke) = parse_char_msg_keystroke(wparam) else {
 382        return Some(1);
 383    };
 384    let mut lock = state_ptr.state.borrow_mut();
 385    let Some(mut func) = lock.callbacks.input.take() else {
 386        return Some(1);
 387    };
 388    drop(lock);
 389    let key_char = keystroke.key_char.clone();
 390    let event = KeyDownEvent {
 391        keystroke,
 392        is_held: lparam.0 & (0x1 << 30) > 0,
 393    };
 394    let dispatch_event_result = func(PlatformInput::KeyDown(event));
 395    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 396
 397    if dispatch_event_result.default_prevented || !dispatch_event_result.propagate {
 398        return Some(0);
 399    }
 400    let Some(ime_char) = key_char else {
 401        return Some(1);
 402    };
 403    with_input_handler(&state_ptr, |input_handler| {
 404        input_handler.replace_text_in_range(None, &ime_char);
 405    });
 406
 407    Some(0)
 408}
 409
 410fn handle_mouse_down_msg(
 411    handle: HWND,
 412    button: MouseButton,
 413    lparam: LPARAM,
 414    state_ptr: Rc<WindowsWindowStatePtr>,
 415) -> Option<isize> {
 416    unsafe { SetCapture(handle) };
 417    let mut lock = state_ptr.state.borrow_mut();
 418    if let Some(mut callback) = lock.callbacks.input.take() {
 419        let x = lparam.signed_loword() as f32;
 420        let y = lparam.signed_hiword() as f32;
 421        let physical_point = point(DevicePixels(x as i32), DevicePixels(y as i32));
 422        let click_count = lock.click_state.update(button, physical_point);
 423        let scale_factor = lock.scale_factor;
 424        drop(lock);
 425
 426        let event = MouseDownEvent {
 427            button,
 428            position: logical_point(x, y, scale_factor),
 429            modifiers: current_modifiers(),
 430            click_count,
 431            first_mouse: false,
 432        };
 433        let result = if callback(PlatformInput::MouseDown(event)).default_prevented {
 434            Some(0)
 435        } else {
 436            Some(1)
 437        };
 438        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 439
 440        result
 441    } else {
 442        Some(1)
 443    }
 444}
 445
 446fn handle_mouse_up_msg(
 447    _handle: HWND,
 448    button: MouseButton,
 449    lparam: LPARAM,
 450    state_ptr: Rc<WindowsWindowStatePtr>,
 451) -> Option<isize> {
 452    unsafe { ReleaseCapture().log_err() };
 453    let mut lock = state_ptr.state.borrow_mut();
 454    if let Some(mut callback) = lock.callbacks.input.take() {
 455        let x = lparam.signed_loword() as f32;
 456        let y = lparam.signed_hiword() as f32;
 457        let click_count = lock.click_state.current_count;
 458        let scale_factor = lock.scale_factor;
 459        drop(lock);
 460
 461        let event = MouseUpEvent {
 462            button,
 463            position: logical_point(x, y, scale_factor),
 464            modifiers: current_modifiers(),
 465            click_count,
 466        };
 467        let result = if callback(PlatformInput::MouseUp(event)).default_prevented {
 468            Some(0)
 469        } else {
 470            Some(1)
 471        };
 472        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 473
 474        result
 475    } else {
 476        Some(1)
 477    }
 478}
 479
 480fn handle_xbutton_msg(
 481    handle: HWND,
 482    wparam: WPARAM,
 483    lparam: LPARAM,
 484    handler: impl Fn(HWND, MouseButton, LPARAM, Rc<WindowsWindowStatePtr>) -> Option<isize>,
 485    state_ptr: Rc<WindowsWindowStatePtr>,
 486) -> Option<isize> {
 487    let nav_dir = match wparam.hiword() {
 488        XBUTTON1 => NavigationDirection::Back,
 489        XBUTTON2 => NavigationDirection::Forward,
 490        _ => return Some(1),
 491    };
 492    handler(handle, MouseButton::Navigate(nav_dir), lparam, state_ptr)
 493}
 494
 495fn handle_mouse_wheel_msg(
 496    handle: HWND,
 497    wparam: WPARAM,
 498    lparam: LPARAM,
 499    state_ptr: Rc<WindowsWindowStatePtr>,
 500) -> Option<isize> {
 501    let modifiers = current_modifiers();
 502    let mut lock = state_ptr.state.borrow_mut();
 503    if let Some(mut callback) = lock.callbacks.input.take() {
 504        let scale_factor = lock.scale_factor;
 505        let wheel_scroll_amount = match modifiers.shift {
 506            true => lock.system_settings.mouse_wheel_settings.wheel_scroll_chars,
 507            false => lock.system_settings.mouse_wheel_settings.wheel_scroll_lines,
 508        };
 509        drop(lock);
 510        let wheel_distance =
 511            (wparam.signed_hiword() as f32 / WHEEL_DELTA as f32) * wheel_scroll_amount as f32;
 512        let mut cursor_point = POINT {
 513            x: lparam.signed_loword().into(),
 514            y: lparam.signed_hiword().into(),
 515        };
 516        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 517        let event = ScrollWheelEvent {
 518            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 519            delta: ScrollDelta::Lines(match modifiers.shift {
 520                true => Point {
 521                    x: wheel_distance,
 522                    y: 0.0,
 523                },
 524                false => Point {
 525                    y: wheel_distance,
 526                    x: 0.0,
 527                },
 528            }),
 529            modifiers: current_modifiers(),
 530            touch_phase: TouchPhase::Moved,
 531        };
 532        let result = if callback(PlatformInput::ScrollWheel(event)).default_prevented {
 533            Some(0)
 534        } else {
 535            Some(1)
 536        };
 537        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 538
 539        result
 540    } else {
 541        Some(1)
 542    }
 543}
 544
 545fn handle_mouse_horizontal_wheel_msg(
 546    handle: HWND,
 547    wparam: WPARAM,
 548    lparam: LPARAM,
 549    state_ptr: Rc<WindowsWindowStatePtr>,
 550) -> Option<isize> {
 551    let mut lock = state_ptr.state.borrow_mut();
 552    if let Some(mut callback) = lock.callbacks.input.take() {
 553        let scale_factor = lock.scale_factor;
 554        let wheel_scroll_chars = lock.system_settings.mouse_wheel_settings.wheel_scroll_chars;
 555        drop(lock);
 556        let wheel_distance =
 557            (-wparam.signed_hiword() as f32 / WHEEL_DELTA as f32) * wheel_scroll_chars as f32;
 558        let mut cursor_point = POINT {
 559            x: lparam.signed_loword().into(),
 560            y: lparam.signed_hiword().into(),
 561        };
 562        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 563        let event = ScrollWheelEvent {
 564            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 565            delta: ScrollDelta::Lines(Point {
 566                x: wheel_distance,
 567                y: 0.0,
 568            }),
 569            modifiers: current_modifiers(),
 570            touch_phase: TouchPhase::Moved,
 571        };
 572        let result = if callback(PlatformInput::ScrollWheel(event)).default_prevented {
 573            Some(0)
 574        } else {
 575            Some(1)
 576        };
 577        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 578
 579        result
 580    } else {
 581        Some(1)
 582    }
 583}
 584
 585fn retrieve_caret_position(state_ptr: &Rc<WindowsWindowStatePtr>) -> Option<POINT> {
 586    with_input_handler_and_scale_factor(state_ptr, |input_handler, scale_factor| {
 587        let caret_range = input_handler.selected_text_range(false)?;
 588        let caret_position = input_handler.bounds_for_range(caret_range.range)?;
 589        Some(POINT {
 590            // logical to physical
 591            x: (caret_position.origin.x.0 * scale_factor) as i32,
 592            y: (caret_position.origin.y.0 * scale_factor) as i32
 593                + ((caret_position.size.height.0 * scale_factor) as i32 / 2),
 594        })
 595    })
 596}
 597
 598fn handle_ime_position(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 599    unsafe {
 600        let ctx = ImmGetContext(handle);
 601
 602        let Some(caret_position) = retrieve_caret_position(&state_ptr) else {
 603            return Some(0);
 604        };
 605        {
 606            let config = COMPOSITIONFORM {
 607                dwStyle: CFS_POINT,
 608                ptCurrentPos: caret_position,
 609                ..Default::default()
 610            };
 611            ImmSetCompositionWindow(ctx, &config as _).ok().log_err();
 612        }
 613        {
 614            let config = CANDIDATEFORM {
 615                dwStyle: CFS_CANDIDATEPOS,
 616                ptCurrentPos: caret_position,
 617                ..Default::default()
 618            };
 619            ImmSetCandidateWindow(ctx, &config as _).ok().log_err();
 620        }
 621        ImmReleaseContext(handle, ctx).ok().log_err();
 622        Some(0)
 623    }
 624}
 625
 626fn handle_ime_composition(
 627    handle: HWND,
 628    lparam: LPARAM,
 629    state_ptr: Rc<WindowsWindowStatePtr>,
 630) -> Option<isize> {
 631    let ctx = unsafe { ImmGetContext(handle) };
 632    let result = handle_ime_composition_inner(ctx, lparam, state_ptr);
 633    unsafe { ImmReleaseContext(handle, ctx).ok().log_err() };
 634    result
 635}
 636
 637fn handle_ime_composition_inner(
 638    ctx: HIMC,
 639    lparam: LPARAM,
 640    state_ptr: Rc<WindowsWindowStatePtr>,
 641) -> Option<isize> {
 642    let mut ime_input = None;
 643    if lparam.0 as u32 & GCS_COMPSTR.0 > 0 {
 644        let (comp_string, string_len) = parse_ime_compostion_string(ctx)?;
 645        with_input_handler(&state_ptr, |input_handler| {
 646            input_handler.replace_and_mark_text_in_range(
 647                None,
 648                &comp_string,
 649                Some(string_len..string_len),
 650            );
 651        })?;
 652        ime_input = Some(comp_string);
 653    }
 654    if lparam.0 as u32 & GCS_CURSORPOS.0 > 0 {
 655        let comp_string = &ime_input?;
 656        let caret_pos = retrieve_composition_cursor_position(ctx);
 657        with_input_handler(&state_ptr, |input_handler| {
 658            input_handler.replace_and_mark_text_in_range(
 659                None,
 660                comp_string,
 661                Some(caret_pos..caret_pos),
 662            );
 663        })?;
 664    }
 665    if lparam.0 as u32 & GCS_RESULTSTR.0 > 0 {
 666        let comp_result = parse_ime_compostion_result(ctx)?;
 667        with_input_handler(&state_ptr, |input_handler| {
 668            input_handler.replace_text_in_range(None, &comp_result);
 669        })?;
 670        return Some(0);
 671    }
 672    // currently, we don't care other stuff
 673    None
 674}
 675
 676/// SEE: https://learn.microsoft.com/en-us/windows/win32/winmsg/wm-nccalcsize
 677fn handle_calc_client_size(
 678    handle: HWND,
 679    wparam: WPARAM,
 680    lparam: LPARAM,
 681    state_ptr: Rc<WindowsWindowStatePtr>,
 682) -> Option<isize> {
 683    if !state_ptr.hide_title_bar || state_ptr.state.borrow().is_fullscreen() || wparam.0 == 0 {
 684        return None;
 685    }
 686
 687    let is_maximized = state_ptr.state.borrow().is_maximized();
 688    let insets = get_client_area_insets(handle, is_maximized, state_ptr.windows_version);
 689    // wparam is TRUE so lparam points to an NCCALCSIZE_PARAMS structure
 690    let mut params = lparam.0 as *mut NCCALCSIZE_PARAMS;
 691    let mut requested_client_rect = unsafe { &mut ((*params).rgrc) };
 692
 693    requested_client_rect[0].left += insets.left;
 694    requested_client_rect[0].top += insets.top;
 695    requested_client_rect[0].right -= insets.right;
 696    requested_client_rect[0].bottom -= insets.bottom;
 697
 698    // Fix auto hide taskbar not showing. This solution is based on the approach
 699    // used by Chrome. However, it may result in one row of pixels being obscured
 700    // in our client area. But as Chrome says, "there seems to be no better solution."
 701    if is_maximized {
 702        if let Some(ref taskbar_position) = state_ptr
 703            .state
 704            .borrow()
 705            .system_settings
 706            .auto_hide_taskbar_position
 707        {
 708            // Fot the auto-hide taskbar, adjust in by 1 pixel on taskbar edge,
 709            // so the window isn't treated as a "fullscreen app", which would cause
 710            // the taskbar to disappear.
 711            match taskbar_position {
 712                AutoHideTaskbarPosition::Left => {
 713                    requested_client_rect[0].left += AUTO_HIDE_TASKBAR_THICKNESS_PX
 714                }
 715                AutoHideTaskbarPosition::Top => {
 716                    requested_client_rect[0].top += AUTO_HIDE_TASKBAR_THICKNESS_PX
 717                }
 718                AutoHideTaskbarPosition::Right => {
 719                    requested_client_rect[0].right -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 720                }
 721                AutoHideTaskbarPosition::Bottom => {
 722                    requested_client_rect[0].bottom -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 723                }
 724            }
 725        }
 726    }
 727
 728    Some(0)
 729}
 730
 731fn handle_activate_msg(
 732    handle: HWND,
 733    wparam: WPARAM,
 734    state_ptr: Rc<WindowsWindowStatePtr>,
 735) -> Option<isize> {
 736    let activated = wparam.loword() > 0;
 737    if state_ptr.hide_title_bar {
 738        if let Some(titlebar_rect) = state_ptr.state.borrow().get_titlebar_rect().log_err() {
 739            unsafe {
 740                InvalidateRect(handle, Some(&titlebar_rect), FALSE)
 741                    .ok()
 742                    .log_err()
 743            };
 744        }
 745    }
 746    let this = state_ptr.clone();
 747    state_ptr
 748        .executor
 749        .spawn(async move {
 750            let mut lock = this.state.borrow_mut();
 751            if let Some(mut cb) = lock.callbacks.active_status_change.take() {
 752                drop(lock);
 753                cb(activated);
 754                this.state.borrow_mut().callbacks.active_status_change = Some(cb);
 755            }
 756        })
 757        .detach();
 758
 759    None
 760}
 761
 762fn handle_create_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 763    if state_ptr.hide_title_bar {
 764        notify_frame_changed(handle);
 765        Some(0)
 766    } else {
 767        None
 768    }
 769}
 770
 771fn handle_dpi_changed_msg(
 772    handle: HWND,
 773    wparam: WPARAM,
 774    lparam: LPARAM,
 775    state_ptr: Rc<WindowsWindowStatePtr>,
 776) -> Option<isize> {
 777    let new_dpi = wparam.loword() as f32;
 778    let mut lock = state_ptr.state.borrow_mut();
 779    lock.scale_factor = new_dpi / USER_DEFAULT_SCREEN_DPI as f32;
 780    lock.border_offset.update(handle).log_err();
 781    drop(lock);
 782
 783    let rect = unsafe { &*(lparam.0 as *const RECT) };
 784    let width = rect.right - rect.left;
 785    let height = rect.bottom - rect.top;
 786    // this will emit `WM_SIZE` and `WM_MOVE` right here
 787    // even before this function returns
 788    // the new size is handled in `WM_SIZE`
 789    unsafe {
 790        SetWindowPos(
 791            handle,
 792            None,
 793            rect.left,
 794            rect.top,
 795            width,
 796            height,
 797            SWP_NOZORDER | SWP_NOACTIVATE,
 798        )
 799        .context("unable to set window position after dpi has changed")
 800        .log_err();
 801    }
 802
 803    Some(0)
 804}
 805
 806/// The following conditions will trigger this event:
 807/// 1. The monitor on which the window is located goes offline or changes resolution.
 808/// 2. Another monitor goes offline, is plugged in, or changes resolution.
 809///
 810/// In either case, the window will only receive information from the monitor on which
 811/// it is located.
 812///
 813/// For example, in the case of condition 2, where the monitor on which the window is
 814/// located has actually changed nothing, it will still receive this event.
 815fn handle_display_change_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 816    // NOTE:
 817    // Even the `lParam` holds the resolution of the screen, we just ignore it.
 818    // Because WM_DPICHANGED, WM_MOVE, WM_SIZE will come first, window reposition and resize
 819    // are handled there.
 820    // So we only care about if monitor is disconnected.
 821    let previous_monitor = state_ptr.as_ref().state.borrow().display;
 822    if WindowsDisplay::is_connected(previous_monitor.handle) {
 823        // we are fine, other display changed
 824        return None;
 825    }
 826    // display disconnected
 827    // in this case, the OS will move our window to another monitor, and minimize it.
 828    // we deminimize the window and query the monitor after moving
 829    unsafe {
 830        let _ = ShowWindow(handle, SW_SHOWNORMAL);
 831    };
 832    let new_monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 833    // all monitors disconnected
 834    if new_monitor.is_invalid() {
 835        log::error!("No monitor detected!");
 836        return None;
 837    }
 838    let new_display = WindowsDisplay::new_with_handle(new_monitor);
 839    state_ptr.as_ref().state.borrow_mut().display = new_display;
 840    Some(0)
 841}
 842
 843fn handle_hit_test_msg(
 844    handle: HWND,
 845    msg: u32,
 846    wparam: WPARAM,
 847    lparam: LPARAM,
 848    state_ptr: Rc<WindowsWindowStatePtr>,
 849) -> Option<isize> {
 850    if !state_ptr.is_movable {
 851        return None;
 852    }
 853    if !state_ptr.hide_title_bar {
 854        return None;
 855    }
 856
 857    // default handler for resize areas
 858    let hit = unsafe { DefWindowProcW(handle, msg, wparam, lparam) };
 859    if matches!(
 860        hit.0 as u32,
 861        HTNOWHERE
 862            | HTRIGHT
 863            | HTLEFT
 864            | HTTOPLEFT
 865            | HTTOP
 866            | HTTOPRIGHT
 867            | HTBOTTOMRIGHT
 868            | HTBOTTOM
 869            | HTBOTTOMLEFT
 870    ) {
 871        return Some(hit.0);
 872    }
 873
 874    if state_ptr.state.borrow().is_fullscreen() {
 875        return Some(HTCLIENT as _);
 876    }
 877
 878    let dpi = unsafe { GetDpiForWindow(handle) };
 879    let frame_y = unsafe { GetSystemMetricsForDpi(SM_CYFRAME, dpi) };
 880
 881    let mut cursor_point = POINT {
 882        x: lparam.signed_loword().into(),
 883        y: lparam.signed_hiword().into(),
 884    };
 885    unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 886    if !state_ptr.state.borrow().is_maximized() && cursor_point.y >= 0 && cursor_point.y <= frame_y
 887    {
 888        return Some(HTTOP as _);
 889    }
 890
 891    let titlebar_rect = state_ptr.state.borrow().get_titlebar_rect();
 892    if let Ok(titlebar_rect) = titlebar_rect {
 893        if cursor_point.y < titlebar_rect.bottom {
 894            let caption_btn_width = (state_ptr.state.borrow().caption_button_width().0
 895                * state_ptr.state.borrow().scale_factor) as i32;
 896            if cursor_point.x >= titlebar_rect.right - caption_btn_width {
 897                return Some(HTCLOSE as _);
 898            } else if cursor_point.x >= titlebar_rect.right - caption_btn_width * 2 {
 899                return Some(HTMAXBUTTON as _);
 900            } else if cursor_point.x >= titlebar_rect.right - caption_btn_width * 3 {
 901                return Some(HTMINBUTTON as _);
 902            }
 903
 904            return Some(HTCAPTION as _);
 905        }
 906    }
 907
 908    Some(HTCLIENT as _)
 909}
 910
 911fn handle_nc_mouse_move_msg(
 912    handle: HWND,
 913    lparam: LPARAM,
 914    state_ptr: Rc<WindowsWindowStatePtr>,
 915) -> Option<isize> {
 916    if !state_ptr.hide_title_bar {
 917        return None;
 918    }
 919
 920    let mut lock = state_ptr.state.borrow_mut();
 921    if let Some(mut callback) = lock.callbacks.input.take() {
 922        let scale_factor = lock.scale_factor;
 923        drop(lock);
 924        let mut cursor_point = POINT {
 925            x: lparam.signed_loword().into(),
 926            y: lparam.signed_hiword().into(),
 927        };
 928        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 929        let event = MouseMoveEvent {
 930            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 931            pressed_button: None,
 932            modifiers: current_modifiers(),
 933        };
 934        let result = if callback(PlatformInput::MouseMove(event)).default_prevented {
 935            Some(0)
 936        } else {
 937            Some(1)
 938        };
 939        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 940
 941        result
 942    } else {
 943        None
 944    }
 945}
 946
 947fn handle_nc_mouse_down_msg(
 948    handle: HWND,
 949    button: MouseButton,
 950    wparam: WPARAM,
 951    lparam: LPARAM,
 952    state_ptr: Rc<WindowsWindowStatePtr>,
 953) -> Option<isize> {
 954    if !state_ptr.hide_title_bar {
 955        return None;
 956    }
 957
 958    let mut lock = state_ptr.state.borrow_mut();
 959    if let Some(mut callback) = lock.callbacks.input.take() {
 960        let scale_factor = lock.scale_factor;
 961        let mut cursor_point = POINT {
 962            x: lparam.signed_loword().into(),
 963            y: lparam.signed_hiword().into(),
 964        };
 965        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 966        let physical_point = point(DevicePixels(cursor_point.x), DevicePixels(cursor_point.y));
 967        let click_count = lock.click_state.update(button, physical_point);
 968        drop(lock);
 969        let event = MouseDownEvent {
 970            button,
 971            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 972            modifiers: current_modifiers(),
 973            click_count,
 974            first_mouse: false,
 975        };
 976        let result = if callback(PlatformInput::MouseDown(event)).default_prevented {
 977            Some(0)
 978        } else {
 979            None
 980        };
 981        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 982
 983        if result.is_some() {
 984            return result;
 985        }
 986    } else {
 987        drop(lock);
 988    };
 989
 990    // Since these are handled in handle_nc_mouse_up_msg we must prevent the default window proc
 991    if button == MouseButton::Left {
 992        match wparam.0 as u32 {
 993            HTMINBUTTON => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTMINBUTTON),
 994            HTMAXBUTTON => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTMAXBUTTON),
 995            HTCLOSE => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTCLOSE),
 996            _ => return None,
 997        };
 998        Some(0)
 999    } else {
1000        None
1001    }
1002}
1003
1004fn handle_nc_mouse_up_msg(
1005    handle: HWND,
1006    button: MouseButton,
1007    wparam: WPARAM,
1008    lparam: LPARAM,
1009    state_ptr: Rc<WindowsWindowStatePtr>,
1010) -> Option<isize> {
1011    if !state_ptr.hide_title_bar {
1012        return None;
1013    }
1014
1015    let mut lock = state_ptr.state.borrow_mut();
1016    if let Some(mut callback) = lock.callbacks.input.take() {
1017        let scale_factor = lock.scale_factor;
1018        drop(lock);
1019        let mut cursor_point = POINT {
1020            x: lparam.signed_loword().into(),
1021            y: lparam.signed_hiword().into(),
1022        };
1023        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
1024        let event = MouseUpEvent {
1025            button,
1026            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
1027            modifiers: current_modifiers(),
1028            click_count: 1,
1029        };
1030        let result = if callback(PlatformInput::MouseUp(event)).default_prevented {
1031            Some(0)
1032        } else {
1033            None
1034        };
1035        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
1036        if result.is_some() {
1037            return result;
1038        }
1039    } else {
1040        drop(lock);
1041    }
1042
1043    let last_pressed = state_ptr.state.borrow_mut().nc_button_pressed.take();
1044    if button == MouseButton::Left && last_pressed.is_some() {
1045        let last_button = last_pressed.unwrap();
1046        let mut handled = false;
1047        match wparam.0 as u32 {
1048            HTMINBUTTON => {
1049                if last_button == HTMINBUTTON {
1050                    unsafe { ShowWindowAsync(handle, SW_MINIMIZE).ok().log_err() };
1051                    handled = true;
1052                }
1053            }
1054            HTMAXBUTTON => {
1055                if last_button == HTMAXBUTTON {
1056                    if state_ptr.state.borrow().is_maximized() {
1057                        unsafe { ShowWindowAsync(handle, SW_NORMAL).ok().log_err() };
1058                    } else {
1059                        unsafe { ShowWindowAsync(handle, SW_MAXIMIZE).ok().log_err() };
1060                    }
1061                    handled = true;
1062                }
1063            }
1064            HTCLOSE => {
1065                if last_button == HTCLOSE {
1066                    unsafe {
1067                        PostMessageW(handle, WM_CLOSE, WPARAM::default(), LPARAM::default())
1068                            .log_err()
1069                    };
1070                    handled = true;
1071                }
1072            }
1073            _ => {}
1074        };
1075        if handled {
1076            return Some(0);
1077        }
1078    }
1079
1080    None
1081}
1082
1083fn handle_cursor_changed(lparam: LPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1084    state_ptr.state.borrow_mut().current_cursor = HCURSOR(lparam.0 as _);
1085    Some(0)
1086}
1087
1088fn handle_set_cursor(lparam: LPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1089    if matches!(
1090        lparam.loword() as u32,
1091        HTLEFT | HTRIGHT | HTTOP | HTTOPLEFT | HTTOPRIGHT | HTBOTTOM | HTBOTTOMLEFT | HTBOTTOMRIGHT
1092    ) {
1093        return None;
1094    }
1095    unsafe { SetCursor(state_ptr.state.borrow().current_cursor) };
1096    Some(1)
1097}
1098
1099fn handle_system_settings_changed(
1100    handle: HWND,
1101    state_ptr: Rc<WindowsWindowStatePtr>,
1102) -> Option<isize> {
1103    let mut lock = state_ptr.state.borrow_mut();
1104    let display = lock.display;
1105    // system settings
1106    lock.system_settings.update(display);
1107    // mouse double click
1108    lock.click_state.system_update();
1109    // window border offset
1110    lock.border_offset.update(handle).log_err();
1111    drop(lock);
1112    // Force to trigger WM_NCCALCSIZE event to ensure that we handle auto hide
1113    // taskbar correctly.
1114    notify_frame_changed(handle);
1115    Some(0)
1116}
1117
1118fn handle_system_command(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1119    if wparam.0 == SC_KEYMENU as usize {
1120        let mut lock = state_ptr.state.borrow_mut();
1121        if lock.system_key_handled {
1122            lock.system_key_handled = false;
1123            return Some(0);
1124        }
1125    }
1126    None
1127}
1128
1129fn handle_system_theme_changed(state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1130    let mut callback = state_ptr
1131        .state
1132        .borrow_mut()
1133        .callbacks
1134        .appearance_changed
1135        .take()?;
1136    callback();
1137    state_ptr.state.borrow_mut().callbacks.appearance_changed = Some(callback);
1138    Some(0)
1139}
1140
1141fn parse_syskeydown_msg_keystroke(wparam: WPARAM) -> Option<Keystroke> {
1142    let modifiers = current_modifiers();
1143    if !modifiers.alt {
1144        // on Windows, F10 can trigger this event, not just the alt key
1145        // and we just don't care about F10
1146        return None;
1147    }
1148
1149    let vk_code = wparam.loword();
1150
1151    let key = match VIRTUAL_KEY(vk_code) {
1152        VK_BACK => "backspace",
1153        VK_RETURN => "enter",
1154        VK_TAB => "tab",
1155        VK_UP => "up",
1156        VK_DOWN => "down",
1157        VK_RIGHT => "right",
1158        VK_LEFT => "left",
1159        VK_HOME => "home",
1160        VK_END => "end",
1161        VK_PRIOR => "pageup",
1162        VK_NEXT => "pagedown",
1163        VK_BROWSER_BACK => "back",
1164        VK_BROWSER_FORWARD => "forward",
1165        VK_ESCAPE => "escape",
1166        VK_INSERT => "insert",
1167        VK_DELETE => "delete",
1168        _ => return basic_vkcode_to_string(vk_code, modifiers),
1169    }
1170    .to_owned();
1171
1172    Some(Keystroke {
1173        modifiers,
1174        key,
1175        key_char: None,
1176    })
1177}
1178
1179enum KeystrokeOrModifier {
1180    Keystroke(Keystroke),
1181    Modifier(Modifiers),
1182}
1183
1184fn parse_keydown_msg_keystroke(wparam: WPARAM) -> Option<KeystrokeOrModifier> {
1185    let vk_code = wparam.loword();
1186
1187    let modifiers = current_modifiers();
1188
1189    let key = match VIRTUAL_KEY(vk_code) {
1190        VK_BACK => "backspace",
1191        VK_RETURN => "enter",
1192        VK_TAB => "tab",
1193        VK_UP => "up",
1194        VK_DOWN => "down",
1195        VK_RIGHT => "right",
1196        VK_LEFT => "left",
1197        VK_HOME => "home",
1198        VK_END => "end",
1199        VK_PRIOR => "pageup",
1200        VK_NEXT => "pagedown",
1201        VK_BROWSER_BACK => "back",
1202        VK_BROWSER_FORWARD => "forward",
1203        VK_ESCAPE => "escape",
1204        VK_INSERT => "insert",
1205        VK_DELETE => "delete",
1206        _ => {
1207            if is_modifier(VIRTUAL_KEY(vk_code)) {
1208                return Some(KeystrokeOrModifier::Modifier(modifiers));
1209            }
1210
1211            if modifiers.control || modifiers.alt {
1212                let basic_key = basic_vkcode_to_string(vk_code, modifiers);
1213                if let Some(basic_key) = basic_key {
1214                    return Some(KeystrokeOrModifier::Keystroke(basic_key));
1215                }
1216            }
1217
1218            if vk_code >= VK_F1.0 && vk_code <= VK_F24.0 {
1219                let offset = vk_code - VK_F1.0;
1220                return Some(KeystrokeOrModifier::Keystroke(Keystroke {
1221                    modifiers,
1222                    key: format!("f{}", offset + 1),
1223                    key_char: None,
1224                }));
1225            };
1226            return None;
1227        }
1228    }
1229    .to_owned();
1230
1231    Some(KeystrokeOrModifier::Keystroke(Keystroke {
1232        modifiers,
1233        key,
1234        key_char: None,
1235    }))
1236}
1237
1238fn parse_char_msg_keystroke(wparam: WPARAM) -> Option<Keystroke> {
1239    let first_char = char::from_u32((wparam.0 as u16).into())?;
1240    if first_char.is_control() {
1241        None
1242    } else {
1243        let mut modifiers = current_modifiers();
1244        // for characters that use 'shift' to type it is expected that the
1245        // shift is not reported if the uppercase/lowercase are the same and instead only the key is reported
1246        if first_char.to_ascii_uppercase() == first_char.to_ascii_lowercase() {
1247            modifiers.shift = false;
1248        }
1249        let key = match first_char {
1250            ' ' => "space".to_string(),
1251            first_char => first_char.to_lowercase().to_string(),
1252        };
1253        Some(Keystroke {
1254            modifiers,
1255            key,
1256            key_char: Some(first_char.to_string()),
1257        })
1258    }
1259}
1260
1261fn parse_ime_compostion_string(ctx: HIMC) -> Option<(String, usize)> {
1262    unsafe {
1263        let string_len = ImmGetCompositionStringW(ctx, GCS_COMPSTR, None, 0);
1264        if string_len >= 0 {
1265            let mut buffer = vec![0u8; string_len as usize + 2];
1266            ImmGetCompositionStringW(
1267                ctx,
1268                GCS_COMPSTR,
1269                Some(buffer.as_mut_ptr() as _),
1270                string_len as _,
1271            );
1272            let wstring = std::slice::from_raw_parts::<u16>(
1273                buffer.as_mut_ptr().cast::<u16>(),
1274                string_len as usize / 2,
1275            );
1276            let string = String::from_utf16_lossy(wstring);
1277            Some((string, string_len as usize / 2))
1278        } else {
1279            None
1280        }
1281    }
1282}
1283
1284#[inline]
1285fn retrieve_composition_cursor_position(ctx: HIMC) -> usize {
1286    unsafe { ImmGetCompositionStringW(ctx, GCS_CURSORPOS, None, 0) as usize }
1287}
1288
1289fn parse_ime_compostion_result(ctx: HIMC) -> Option<String> {
1290    unsafe {
1291        let string_len = ImmGetCompositionStringW(ctx, GCS_RESULTSTR, None, 0);
1292        if string_len >= 0 {
1293            let mut buffer = vec![0u8; string_len as usize + 2];
1294            ImmGetCompositionStringW(
1295                ctx,
1296                GCS_RESULTSTR,
1297                Some(buffer.as_mut_ptr() as _),
1298                string_len as _,
1299            );
1300            let wstring = std::slice::from_raw_parts::<u16>(
1301                buffer.as_mut_ptr().cast::<u16>(),
1302                string_len as usize / 2,
1303            );
1304            let string = String::from_utf16_lossy(wstring);
1305            Some(string)
1306        } else {
1307            None
1308        }
1309    }
1310}
1311
1312fn basic_vkcode_to_string(code: u16, modifiers: Modifiers) -> Option<Keystroke> {
1313    let mapped_code = unsafe { MapVirtualKeyW(code as u32, MAPVK_VK_TO_CHAR) };
1314
1315    let key = match mapped_code {
1316        0 => None,
1317        raw_code => char::from_u32(raw_code),
1318    }?
1319    .to_ascii_lowercase();
1320
1321    let key = if matches!(code as u32, 112..=135) {
1322        format!("f{key}")
1323    } else {
1324        key.to_string()
1325    };
1326
1327    Some(Keystroke {
1328        modifiers,
1329        key,
1330        key_char: None,
1331    })
1332}
1333
1334#[inline]
1335fn is_virtual_key_pressed(vkey: VIRTUAL_KEY) -> bool {
1336    unsafe { GetKeyState(vkey.0 as i32) < 0 }
1337}
1338
1339fn is_modifier(virtual_key: VIRTUAL_KEY) -> bool {
1340    matches!(
1341        virtual_key,
1342        VK_CONTROL | VK_MENU | VK_SHIFT | VK_LWIN | VK_RWIN
1343    )
1344}
1345
1346#[inline]
1347pub(crate) fn current_modifiers() -> Modifiers {
1348    Modifiers {
1349        control: is_virtual_key_pressed(VK_CONTROL),
1350        alt: is_virtual_key_pressed(VK_MENU),
1351        shift: is_virtual_key_pressed(VK_SHIFT),
1352        platform: is_virtual_key_pressed(VK_LWIN) || is_virtual_key_pressed(VK_RWIN),
1353        function: false,
1354    }
1355}
1356
1357fn get_client_area_insets(
1358    handle: HWND,
1359    is_maximized: bool,
1360    windows_version: WindowsVersion,
1361) -> RECT {
1362    // For maximized windows, Windows outdents the window rect from the screen's client rect
1363    // by `frame_thickness` on each edge, meaning `insets` must contain `frame_thickness`
1364    // on all sides (including the top) to avoid the client area extending onto adjacent
1365    // monitors.
1366    //
1367    // For non-maximized windows, things become complicated:
1368    //
1369    // - On Windows 10
1370    // The top inset must be zero, since if there is any nonclient area, Windows will draw
1371    // a full native titlebar outside the client area. (This doesn't occur in the maximized
1372    // case.)
1373    //
1374    // - On Windows 11
1375    // The top inset is calculated using an empirical formula that I derived through various
1376    // tests. Without this, the top 1-2 rows of pixels in our window would be obscured.
1377    let dpi = unsafe { GetDpiForWindow(handle) };
1378    let frame_thickness = get_frame_thickness(dpi);
1379    let top_insets = if is_maximized {
1380        frame_thickness
1381    } else {
1382        match windows_version {
1383            WindowsVersion::Win10 => 0,
1384            WindowsVersion::Win11 => (dpi as f32 / USER_DEFAULT_SCREEN_DPI as f32).round() as i32,
1385        }
1386    };
1387    RECT {
1388        left: frame_thickness,
1389        top: top_insets,
1390        right: frame_thickness,
1391        bottom: frame_thickness,
1392    }
1393}
1394
1395// there is some additional non-visible space when talking about window
1396// borders on Windows:
1397// - SM_CXSIZEFRAME: The resize handle.
1398// - SM_CXPADDEDBORDER: Additional border space that isn't part of the resize handle.
1399fn get_frame_thickness(dpi: u32) -> i32 {
1400    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CXSIZEFRAME, dpi) };
1401    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1402    resize_frame_thickness + padding_thickness
1403}
1404
1405fn notify_frame_changed(handle: HWND) {
1406    unsafe {
1407        SetWindowPos(
1408            handle,
1409            None,
1410            0,
1411            0,
1412            0,
1413            0,
1414            SWP_FRAMECHANGED
1415                | SWP_NOACTIVATE
1416                | SWP_NOCOPYBITS
1417                | SWP_NOMOVE
1418                | SWP_NOOWNERZORDER
1419                | SWP_NOREPOSITION
1420                | SWP_NOSENDCHANGING
1421                | SWP_NOSIZE
1422                | SWP_NOZORDER,
1423        )
1424        .log_err();
1425    }
1426}
1427
1428fn with_input_handler<F, R>(state_ptr: &Rc<WindowsWindowStatePtr>, f: F) -> Option<R>
1429where
1430    F: FnOnce(&mut PlatformInputHandler) -> R,
1431{
1432    let mut input_handler = state_ptr.state.borrow_mut().input_handler.take()?;
1433    let result = f(&mut input_handler);
1434    state_ptr.state.borrow_mut().input_handler = Some(input_handler);
1435    Some(result)
1436}
1437
1438fn with_input_handler_and_scale_factor<F, R>(
1439    state_ptr: &Rc<WindowsWindowStatePtr>,
1440    f: F,
1441) -> Option<R>
1442where
1443    F: FnOnce(&mut PlatformInputHandler, f32) -> Option<R>,
1444{
1445    let mut lock = state_ptr.state.borrow_mut();
1446    let mut input_handler = lock.input_handler.take()?;
1447    let scale_factor = lock.scale_factor;
1448    drop(lock);
1449    let result = f(&mut input_handler, scale_factor);
1450    state_ptr.state.borrow_mut().input_handler = Some(input_handler);
1451    result
1452}