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_INPUTLANGCHANGE => handle_input_language_changed(lparam, state_ptr),
  97        WM_GPUI_CURSOR_STYLE_CHANGED => handle_cursor_changed(lparam, state_ptr),
  98        _ => None,
  99    };
 100    if let Some(n) = handled {
 101        LRESULT(n)
 102    } else {
 103        unsafe { DefWindowProcW(handle, msg, wparam, lparam) }
 104    }
 105}
 106
 107fn handle_move_msg(
 108    handle: HWND,
 109    lparam: LPARAM,
 110    state_ptr: Rc<WindowsWindowStatePtr>,
 111) -> Option<isize> {
 112    let mut lock = state_ptr.state.borrow_mut();
 113    let origin = logical_point(
 114        lparam.signed_loword() as f32,
 115        lparam.signed_hiword() as f32,
 116        lock.scale_factor,
 117    );
 118    lock.origin = origin;
 119    let size = lock.logical_size;
 120    let center_x = origin.x.0 + size.width.0 / 2.;
 121    let center_y = origin.y.0 + size.height.0 / 2.;
 122    let monitor_bounds = lock.display.bounds();
 123    if center_x < monitor_bounds.left().0
 124        || center_x > monitor_bounds.right().0
 125        || center_y < monitor_bounds.top().0
 126        || center_y > monitor_bounds.bottom().0
 127    {
 128        // center of the window may have moved to another monitor
 129        let monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 130        // minimize the window can trigger this event too, in this case,
 131        // monitor is invalid, we do nothing.
 132        if !monitor.is_invalid() && lock.display.handle != monitor {
 133            // we will get the same monitor if we only have one
 134            lock.display = WindowsDisplay::new_with_handle(monitor);
 135        }
 136    }
 137    if let Some(mut callback) = lock.callbacks.moved.take() {
 138        drop(lock);
 139        callback();
 140        state_ptr.state.borrow_mut().callbacks.moved = Some(callback);
 141    }
 142    Some(0)
 143}
 144
 145fn handle_get_min_max_info_msg(
 146    lparam: LPARAM,
 147    state_ptr: Rc<WindowsWindowStatePtr>,
 148) -> Option<isize> {
 149    let lock = state_ptr.state.borrow();
 150    if let Some(min_size) = lock.min_size {
 151        let scale_factor = lock.scale_factor;
 152        let boarder_offset = lock.border_offset;
 153        drop(lock);
 154
 155        unsafe {
 156            let minmax_info = &mut *(lparam.0 as *mut MINMAXINFO);
 157            minmax_info.ptMinTrackSize.x =
 158                min_size.width.scale(scale_factor).0 as i32 + boarder_offset.width_offset;
 159            minmax_info.ptMinTrackSize.y =
 160                min_size.height.scale(scale_factor).0 as i32 + boarder_offset.height_offset;
 161        }
 162        Some(0)
 163    } else {
 164        None
 165    }
 166}
 167
 168fn handle_size_msg(
 169    wparam: WPARAM,
 170    lparam: LPARAM,
 171    state_ptr: Rc<WindowsWindowStatePtr>,
 172) -> Option<isize> {
 173    let mut lock = state_ptr.state.borrow_mut();
 174
 175    // Don't resize the renderer when the window is minimized, but record that it was minimized so
 176    // that on restore the swap chain can be recreated via `update_drawable_size_even_if_unchanged`.
 177    if wparam.0 == SIZE_MINIMIZED as usize {
 178        lock.restore_from_minimized = lock.callbacks.request_frame.take();
 179        return Some(0);
 180    }
 181
 182    let width = lparam.loword().max(1) as i32;
 183    let height = lparam.hiword().max(1) as i32;
 184    let new_size = size(DevicePixels(width), DevicePixels(height));
 185    let scale_factor = lock.scale_factor;
 186    if lock.restore_from_minimized.is_some() {
 187        lock.renderer
 188            .update_drawable_size_even_if_unchanged(new_size);
 189        lock.callbacks.request_frame = lock.restore_from_minimized.take();
 190    } else {
 191        lock.renderer.update_drawable_size(new_size);
 192    }
 193    let new_size = new_size.to_pixels(scale_factor);
 194    lock.logical_size = new_size;
 195    if let Some(mut callback) = lock.callbacks.resize.take() {
 196        drop(lock);
 197        callback(new_size, scale_factor);
 198        state_ptr.state.borrow_mut().callbacks.resize = Some(callback);
 199    }
 200    Some(0)
 201}
 202
 203fn handle_size_move_loop(handle: HWND) -> Option<isize> {
 204    unsafe {
 205        let ret = SetTimer(
 206            Some(handle),
 207            SIZE_MOVE_LOOP_TIMER_ID,
 208            USER_TIMER_MINIMUM,
 209            None,
 210        );
 211        if ret == 0 {
 212            log::error!(
 213                "unable to create timer: {}",
 214                std::io::Error::last_os_error()
 215            );
 216        }
 217    }
 218    None
 219}
 220
 221fn handle_size_move_loop_exit(handle: HWND) -> Option<isize> {
 222    unsafe {
 223        KillTimer(Some(handle), SIZE_MOVE_LOOP_TIMER_ID).log_err();
 224    }
 225    None
 226}
 227
 228fn handle_timer_msg(
 229    handle: HWND,
 230    wparam: WPARAM,
 231    state_ptr: Rc<WindowsWindowStatePtr>,
 232) -> Option<isize> {
 233    if wparam.0 == SIZE_MOVE_LOOP_TIMER_ID {
 234        for runnable in state_ptr.main_receiver.drain() {
 235            runnable.run();
 236        }
 237        handle_paint_msg(handle, state_ptr)
 238    } else {
 239        None
 240    }
 241}
 242
 243fn handle_paint_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 244    let mut lock = state_ptr.state.borrow_mut();
 245    if let Some(mut request_frame) = lock.callbacks.request_frame.take() {
 246        drop(lock);
 247        request_frame(Default::default());
 248        state_ptr.state.borrow_mut().callbacks.request_frame = Some(request_frame);
 249    }
 250    unsafe { ValidateRect(Some(handle), None).ok().log_err() };
 251    Some(0)
 252}
 253
 254fn handle_close_msg(state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 255    let mut lock = state_ptr.state.borrow_mut();
 256    if let Some(mut callback) = lock.callbacks.should_close.take() {
 257        drop(lock);
 258        let should_close = callback();
 259        state_ptr.state.borrow_mut().callbacks.should_close = Some(callback);
 260        if should_close { None } else { Some(0) }
 261    } else {
 262        None
 263    }
 264}
 265
 266fn handle_destroy_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 267    let callback = {
 268        let mut lock = state_ptr.state.borrow_mut();
 269        lock.callbacks.close.take()
 270    };
 271    if let Some(callback) = callback {
 272        callback();
 273    }
 274    unsafe {
 275        PostThreadMessageW(
 276            state_ptr.main_thread_id_win32,
 277            WM_GPUI_CLOSE_ONE_WINDOW,
 278            WPARAM(state_ptr.validation_number),
 279            LPARAM(handle.0 as isize),
 280        )
 281        .log_err();
 282    }
 283    Some(0)
 284}
 285
 286fn handle_mouse_move_msg(
 287    handle: HWND,
 288    lparam: LPARAM,
 289    wparam: WPARAM,
 290    state_ptr: Rc<WindowsWindowStatePtr>,
 291) -> Option<isize> {
 292    start_tracking_mouse(handle, &state_ptr, TME_LEAVE);
 293
 294    let mut lock = state_ptr.state.borrow_mut();
 295    if let Some(mut callback) = lock.callbacks.input.take() {
 296        let scale_factor = lock.scale_factor;
 297        drop(lock);
 298        let pressed_button = match MODIFIERKEYS_FLAGS(wparam.loword() as u32) {
 299            flags if flags.contains(MK_LBUTTON) => Some(MouseButton::Left),
 300            flags if flags.contains(MK_RBUTTON) => Some(MouseButton::Right),
 301            flags if flags.contains(MK_MBUTTON) => Some(MouseButton::Middle),
 302            flags if flags.contains(MK_XBUTTON1) => {
 303                Some(MouseButton::Navigate(NavigationDirection::Back))
 304            }
 305            flags if flags.contains(MK_XBUTTON2) => {
 306                Some(MouseButton::Navigate(NavigationDirection::Forward))
 307            }
 308            _ => None,
 309        };
 310        let x = lparam.signed_loword() as f32;
 311        let y = lparam.signed_hiword() as f32;
 312        let event = MouseMoveEvent {
 313            position: logical_point(x, y, scale_factor),
 314            pressed_button,
 315            modifiers: current_modifiers(),
 316        };
 317        let result = if callback(PlatformInput::MouseMove(event)).default_prevented {
 318            Some(0)
 319        } else {
 320            Some(1)
 321        };
 322        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 323        return result;
 324    }
 325    Some(1)
 326}
 327
 328fn handle_mouse_leave_msg(state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 329    let mut lock = state_ptr.state.borrow_mut();
 330    lock.hovered = false;
 331    if let Some(mut callback) = lock.callbacks.hovered_status_change.take() {
 332        drop(lock);
 333        callback(false);
 334        state_ptr.state.borrow_mut().callbacks.hovered_status_change = Some(callback);
 335    }
 336
 337    Some(0)
 338}
 339
 340fn handle_syskeydown_msg(
 341    wparam: WPARAM,
 342    lparam: LPARAM,
 343    state_ptr: Rc<WindowsWindowStatePtr>,
 344) -> Option<isize> {
 345    let mut lock = state_ptr.state.borrow_mut();
 346    let vkey = wparam.loword();
 347    let input = if is_modifier(VIRTUAL_KEY(vkey)) {
 348        let modifiers = current_modifiers();
 349        if let Some(prev_modifiers) = lock.last_reported_modifiers {
 350            if prev_modifiers == modifiers {
 351                return Some(0);
 352            }
 353        }
 354        lock.last_reported_modifiers = Some(modifiers);
 355        PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 356    } else {
 357        let keystroke = parse_syskeydown_msg_keystroke(wparam)?;
 358        PlatformInput::KeyDown(KeyDownEvent {
 359            keystroke,
 360            is_held: lparam.0 & (0x1 << 30) > 0,
 361        })
 362    };
 363    let mut func = lock.callbacks.input.take()?;
 364    drop(lock);
 365    let result = if !func(input).propagate {
 366        state_ptr.state.borrow_mut().system_key_handled = true;
 367        Some(0)
 368    } else {
 369        // we need to call `DefWindowProcW`, or we will lose the system-wide `Alt+F4`, `Alt+{other keys}`
 370        // shortcuts.
 371        None
 372    };
 373    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 374
 375    result
 376}
 377
 378fn handle_syskeyup_msg(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 379    let mut lock = state_ptr.state.borrow_mut();
 380    let vkey = wparam.loword();
 381    let input = if is_modifier(VIRTUAL_KEY(vkey)) {
 382        let modifiers = current_modifiers();
 383        if let Some(prev_modifiers) = lock.last_reported_modifiers {
 384            if prev_modifiers == modifiers {
 385                return Some(0);
 386            }
 387        }
 388        lock.last_reported_modifiers = Some(modifiers);
 389        PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 390    } else {
 391        let keystroke = parse_syskeydown_msg_keystroke(wparam)?;
 392        PlatformInput::KeyUp(KeyUpEvent { keystroke })
 393    };
 394    let mut func = lock.callbacks.input.take()?;
 395    drop(lock);
 396    let result = if !func(input).propagate {
 397        Some(0)
 398    } else {
 399        // we need to call `DefWindowProcW`, or we will lose the system-wide `Alt+F4`, `Alt+{other keys}`
 400        // shortcuts.
 401        None
 402    };
 403    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 404
 405    result
 406}
 407
 408fn handle_keydown_msg(
 409    wparam: WPARAM,
 410    lparam: LPARAM,
 411    state_ptr: Rc<WindowsWindowStatePtr>,
 412) -> Option<isize> {
 413    let Some(keystroke_or_modifier) = parse_keystroke_from_vkey(wparam, false) else {
 414        return Some(1);
 415    };
 416    let mut lock = state_ptr.state.borrow_mut();
 417
 418    let event = match keystroke_or_modifier {
 419        KeystrokeOrModifier::Keystroke(keystroke) => PlatformInput::KeyDown(KeyDownEvent {
 420            keystroke,
 421            is_held: lparam.0 & (0x1 << 30) > 0,
 422        }),
 423        KeystrokeOrModifier::Modifier(modifiers) => {
 424            if let Some(prev_modifiers) = lock.last_reported_modifiers {
 425                if prev_modifiers == modifiers {
 426                    return Some(0);
 427                }
 428            }
 429            lock.last_reported_modifiers = Some(modifiers);
 430            PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 431        }
 432    };
 433    let Some(mut func) = lock.callbacks.input.take() else {
 434        return Some(1);
 435    };
 436    drop(lock);
 437
 438    let result = if func(event).default_prevented {
 439        Some(0)
 440    } else {
 441        Some(1)
 442    };
 443    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 444
 445    result
 446}
 447
 448fn handle_keyup_msg(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 449    let Some(keystroke_or_modifier) = parse_keystroke_from_vkey(wparam, true) else {
 450        return Some(1);
 451    };
 452    let mut lock = state_ptr.state.borrow_mut();
 453
 454    let event = match keystroke_or_modifier {
 455        KeystrokeOrModifier::Keystroke(keystroke) => PlatformInput::KeyUp(KeyUpEvent { keystroke }),
 456        KeystrokeOrModifier::Modifier(modifiers) => {
 457            if let Some(prev_modifiers) = lock.last_reported_modifiers {
 458                if prev_modifiers == modifiers {
 459                    return Some(0);
 460                }
 461            }
 462            lock.last_reported_modifiers = Some(modifiers);
 463            PlatformInput::ModifiersChanged(ModifiersChangedEvent { modifiers })
 464        }
 465    };
 466    let Some(mut func) = lock.callbacks.input.take() else {
 467        return Some(1);
 468    };
 469    drop(lock);
 470
 471    let result = if func(event).default_prevented {
 472        Some(0)
 473    } else {
 474        Some(1)
 475    };
 476    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 477
 478    result
 479}
 480
 481fn handle_char_msg(
 482    wparam: WPARAM,
 483    lparam: LPARAM,
 484    state_ptr: Rc<WindowsWindowStatePtr>,
 485) -> Option<isize> {
 486    let Some(keystroke) = parse_char_msg_keystroke(wparam) else {
 487        return Some(1);
 488    };
 489    let mut lock = state_ptr.state.borrow_mut();
 490    let Some(mut func) = lock.callbacks.input.take() else {
 491        return Some(1);
 492    };
 493    drop(lock);
 494    let key_char = keystroke.key_char.clone();
 495    let event = KeyDownEvent {
 496        keystroke,
 497        is_held: lparam.0 & (0x1 << 30) > 0,
 498    };
 499    let dispatch_event_result = func(PlatformInput::KeyDown(event));
 500    state_ptr.state.borrow_mut().callbacks.input = Some(func);
 501
 502    if dispatch_event_result.default_prevented || !dispatch_event_result.propagate {
 503        return Some(0);
 504    }
 505    let Some(ime_char) = key_char else {
 506        return Some(1);
 507    };
 508    with_input_handler(&state_ptr, |input_handler| {
 509        input_handler.replace_text_in_range(None, &ime_char);
 510    });
 511
 512    Some(0)
 513}
 514
 515fn handle_mouse_down_msg(
 516    handle: HWND,
 517    button: MouseButton,
 518    lparam: LPARAM,
 519    state_ptr: Rc<WindowsWindowStatePtr>,
 520) -> Option<isize> {
 521    unsafe { SetCapture(handle) };
 522    let mut lock = state_ptr.state.borrow_mut();
 523    if let Some(mut callback) = lock.callbacks.input.take() {
 524        let x = lparam.signed_loword() as f32;
 525        let y = lparam.signed_hiword() as f32;
 526        let physical_point = point(DevicePixels(x as i32), DevicePixels(y as i32));
 527        let click_count = lock.click_state.update(button, physical_point);
 528        let scale_factor = lock.scale_factor;
 529        drop(lock);
 530
 531        let event = MouseDownEvent {
 532            button,
 533            position: logical_point(x, y, scale_factor),
 534            modifiers: current_modifiers(),
 535            click_count,
 536            first_mouse: false,
 537        };
 538        let result = if callback(PlatformInput::MouseDown(event)).default_prevented {
 539            Some(0)
 540        } else {
 541            Some(1)
 542        };
 543        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 544
 545        result
 546    } else {
 547        Some(1)
 548    }
 549}
 550
 551fn handle_mouse_up_msg(
 552    _handle: HWND,
 553    button: MouseButton,
 554    lparam: LPARAM,
 555    state_ptr: Rc<WindowsWindowStatePtr>,
 556) -> Option<isize> {
 557    unsafe { ReleaseCapture().log_err() };
 558    let mut lock = state_ptr.state.borrow_mut();
 559    if let Some(mut callback) = lock.callbacks.input.take() {
 560        let x = lparam.signed_loword() as f32;
 561        let y = lparam.signed_hiword() as f32;
 562        let click_count = lock.click_state.current_count;
 563        let scale_factor = lock.scale_factor;
 564        drop(lock);
 565
 566        let event = MouseUpEvent {
 567            button,
 568            position: logical_point(x, y, scale_factor),
 569            modifiers: current_modifiers(),
 570            click_count,
 571        };
 572        let result = if callback(PlatformInput::MouseUp(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 handle_xbutton_msg(
 586    handle: HWND,
 587    wparam: WPARAM,
 588    lparam: LPARAM,
 589    handler: impl Fn(HWND, MouseButton, LPARAM, Rc<WindowsWindowStatePtr>) -> Option<isize>,
 590    state_ptr: Rc<WindowsWindowStatePtr>,
 591) -> Option<isize> {
 592    let nav_dir = match wparam.hiword() {
 593        XBUTTON1 => NavigationDirection::Back,
 594        XBUTTON2 => NavigationDirection::Forward,
 595        _ => return Some(1),
 596    };
 597    handler(handle, MouseButton::Navigate(nav_dir), lparam, state_ptr)
 598}
 599
 600fn handle_mouse_wheel_msg(
 601    handle: HWND,
 602    wparam: WPARAM,
 603    lparam: LPARAM,
 604    state_ptr: Rc<WindowsWindowStatePtr>,
 605) -> Option<isize> {
 606    let modifiers = current_modifiers();
 607    let mut lock = state_ptr.state.borrow_mut();
 608    if let Some(mut callback) = lock.callbacks.input.take() {
 609        let scale_factor = lock.scale_factor;
 610        let wheel_scroll_amount = match modifiers.shift {
 611            true => lock.system_settings.mouse_wheel_settings.wheel_scroll_chars,
 612            false => lock.system_settings.mouse_wheel_settings.wheel_scroll_lines,
 613        };
 614        drop(lock);
 615        let wheel_distance =
 616            (wparam.signed_hiword() as f32 / WHEEL_DELTA as f32) * wheel_scroll_amount as f32;
 617        let mut cursor_point = POINT {
 618            x: lparam.signed_loword().into(),
 619            y: lparam.signed_hiword().into(),
 620        };
 621        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 622        let event = ScrollWheelEvent {
 623            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 624            delta: ScrollDelta::Lines(match modifiers.shift {
 625                true => Point {
 626                    x: wheel_distance,
 627                    y: 0.0,
 628                },
 629                false => Point {
 630                    y: wheel_distance,
 631                    x: 0.0,
 632                },
 633            }),
 634            modifiers: current_modifiers(),
 635            touch_phase: TouchPhase::Moved,
 636        };
 637        let result = if callback(PlatformInput::ScrollWheel(event)).default_prevented {
 638            Some(0)
 639        } else {
 640            Some(1)
 641        };
 642        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 643
 644        result
 645    } else {
 646        Some(1)
 647    }
 648}
 649
 650fn handle_mouse_horizontal_wheel_msg(
 651    handle: HWND,
 652    wparam: WPARAM,
 653    lparam: LPARAM,
 654    state_ptr: Rc<WindowsWindowStatePtr>,
 655) -> Option<isize> {
 656    let mut lock = state_ptr.state.borrow_mut();
 657    if let Some(mut callback) = lock.callbacks.input.take() {
 658        let scale_factor = lock.scale_factor;
 659        let wheel_scroll_chars = lock.system_settings.mouse_wheel_settings.wheel_scroll_chars;
 660        drop(lock);
 661        let wheel_distance =
 662            (-wparam.signed_hiword() as f32 / WHEEL_DELTA as f32) * wheel_scroll_chars as f32;
 663        let mut cursor_point = POINT {
 664            x: lparam.signed_loword().into(),
 665            y: lparam.signed_hiword().into(),
 666        };
 667        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 668        let event = ScrollWheelEvent {
 669            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
 670            delta: ScrollDelta::Lines(Point {
 671                x: wheel_distance,
 672                y: 0.0,
 673            }),
 674            modifiers: current_modifiers(),
 675            touch_phase: TouchPhase::Moved,
 676        };
 677        let result = if callback(PlatformInput::ScrollWheel(event)).default_prevented {
 678            Some(0)
 679        } else {
 680            Some(1)
 681        };
 682        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
 683
 684        result
 685    } else {
 686        Some(1)
 687    }
 688}
 689
 690fn retrieve_caret_position(state_ptr: &Rc<WindowsWindowStatePtr>) -> Option<POINT> {
 691    with_input_handler_and_scale_factor(state_ptr, |input_handler, scale_factor| {
 692        let caret_range = input_handler.selected_text_range(false)?;
 693        let caret_position = input_handler.bounds_for_range(caret_range.range)?;
 694        Some(POINT {
 695            // logical to physical
 696            x: (caret_position.origin.x.0 * scale_factor) as i32,
 697            y: (caret_position.origin.y.0 * scale_factor) as i32
 698                + ((caret_position.size.height.0 * scale_factor) as i32 / 2),
 699        })
 700    })
 701}
 702
 703fn handle_ime_position(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 704    unsafe {
 705        let ctx = ImmGetContext(handle);
 706
 707        let Some(caret_position) = retrieve_caret_position(&state_ptr) else {
 708            return Some(0);
 709        };
 710        {
 711            let config = COMPOSITIONFORM {
 712                dwStyle: CFS_POINT,
 713                ptCurrentPos: caret_position,
 714                ..Default::default()
 715            };
 716            ImmSetCompositionWindow(ctx, &config as _).ok().log_err();
 717        }
 718        {
 719            let config = CANDIDATEFORM {
 720                dwStyle: CFS_CANDIDATEPOS,
 721                ptCurrentPos: caret_position,
 722                ..Default::default()
 723            };
 724            ImmSetCandidateWindow(ctx, &config as _).ok().log_err();
 725        }
 726        ImmReleaseContext(handle, ctx).ok().log_err();
 727        Some(0)
 728    }
 729}
 730
 731fn handle_ime_composition(
 732    handle: HWND,
 733    lparam: LPARAM,
 734    state_ptr: Rc<WindowsWindowStatePtr>,
 735) -> Option<isize> {
 736    let ctx = unsafe { ImmGetContext(handle) };
 737    let result = handle_ime_composition_inner(ctx, lparam, state_ptr);
 738    unsafe { ImmReleaseContext(handle, ctx).ok().log_err() };
 739    result
 740}
 741
 742fn handle_ime_composition_inner(
 743    ctx: HIMC,
 744    lparam: LPARAM,
 745    state_ptr: Rc<WindowsWindowStatePtr>,
 746) -> Option<isize> {
 747    let mut ime_input = None;
 748    if lparam.0 as u32 & GCS_COMPSTR.0 > 0 {
 749        let (comp_string, string_len) = parse_ime_compostion_string(ctx)?;
 750        with_input_handler(&state_ptr, |input_handler| {
 751            input_handler.replace_and_mark_text_in_range(
 752                None,
 753                &comp_string,
 754                Some(string_len..string_len),
 755            );
 756        })?;
 757        ime_input = Some(comp_string);
 758    }
 759    if lparam.0 as u32 & GCS_CURSORPOS.0 > 0 {
 760        let comp_string = &ime_input?;
 761        let caret_pos = retrieve_composition_cursor_position(ctx);
 762        with_input_handler(&state_ptr, |input_handler| {
 763            input_handler.replace_and_mark_text_in_range(
 764                None,
 765                comp_string,
 766                Some(caret_pos..caret_pos),
 767            );
 768        })?;
 769    }
 770    if lparam.0 as u32 & GCS_RESULTSTR.0 > 0 {
 771        let comp_result = parse_ime_compostion_result(ctx)?;
 772        with_input_handler(&state_ptr, |input_handler| {
 773            input_handler.replace_text_in_range(None, &comp_result);
 774        })?;
 775        return Some(0);
 776    }
 777    // currently, we don't care other stuff
 778    None
 779}
 780
 781/// SEE: https://learn.microsoft.com/en-us/windows/win32/winmsg/wm-nccalcsize
 782fn handle_calc_client_size(
 783    handle: HWND,
 784    wparam: WPARAM,
 785    lparam: LPARAM,
 786    state_ptr: Rc<WindowsWindowStatePtr>,
 787) -> Option<isize> {
 788    if !state_ptr.hide_title_bar || state_ptr.state.borrow().is_fullscreen() || wparam.0 == 0 {
 789        return None;
 790    }
 791
 792    let is_maximized = state_ptr.state.borrow().is_maximized();
 793    let insets = get_client_area_insets(handle, is_maximized, state_ptr.windows_version);
 794    // wparam is TRUE so lparam points to an NCCALCSIZE_PARAMS structure
 795    let mut params = lparam.0 as *mut NCCALCSIZE_PARAMS;
 796    let mut requested_client_rect = unsafe { &mut ((*params).rgrc) };
 797
 798    requested_client_rect[0].left += insets.left;
 799    requested_client_rect[0].top += insets.top;
 800    requested_client_rect[0].right -= insets.right;
 801    requested_client_rect[0].bottom -= insets.bottom;
 802
 803    // Fix auto hide taskbar not showing. This solution is based on the approach
 804    // used by Chrome. However, it may result in one row of pixels being obscured
 805    // in our client area. But as Chrome says, "there seems to be no better solution."
 806    if is_maximized {
 807        if let Some(ref taskbar_position) = state_ptr
 808            .state
 809            .borrow()
 810            .system_settings
 811            .auto_hide_taskbar_position
 812        {
 813            // Fot the auto-hide taskbar, adjust in by 1 pixel on taskbar edge,
 814            // so the window isn't treated as a "fullscreen app", which would cause
 815            // the taskbar to disappear.
 816            match taskbar_position {
 817                AutoHideTaskbarPosition::Left => {
 818                    requested_client_rect[0].left += AUTO_HIDE_TASKBAR_THICKNESS_PX
 819                }
 820                AutoHideTaskbarPosition::Top => {
 821                    requested_client_rect[0].top += AUTO_HIDE_TASKBAR_THICKNESS_PX
 822                }
 823                AutoHideTaskbarPosition::Right => {
 824                    requested_client_rect[0].right -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 825                }
 826                AutoHideTaskbarPosition::Bottom => {
 827                    requested_client_rect[0].bottom -= AUTO_HIDE_TASKBAR_THICKNESS_PX
 828                }
 829            }
 830        }
 831    }
 832
 833    Some(0)
 834}
 835
 836fn handle_activate_msg(
 837    handle: HWND,
 838    wparam: WPARAM,
 839    state_ptr: Rc<WindowsWindowStatePtr>,
 840) -> Option<isize> {
 841    let activated = wparam.loword() > 0;
 842    if state_ptr.hide_title_bar {
 843        if let Some(titlebar_rect) = state_ptr.state.borrow().get_titlebar_rect().log_err() {
 844            unsafe {
 845                InvalidateRect(Some(handle), Some(&titlebar_rect), false)
 846                    .ok()
 847                    .log_err()
 848            };
 849        }
 850    }
 851    let this = state_ptr.clone();
 852    state_ptr
 853        .executor
 854        .spawn(async move {
 855            let mut lock = this.state.borrow_mut();
 856            if let Some(mut cb) = lock.callbacks.active_status_change.take() {
 857                drop(lock);
 858                cb(activated);
 859                this.state.borrow_mut().callbacks.active_status_change = Some(cb);
 860            }
 861        })
 862        .detach();
 863
 864    None
 865}
 866
 867fn handle_create_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 868    if state_ptr.hide_title_bar {
 869        notify_frame_changed(handle);
 870        Some(0)
 871    } else {
 872        None
 873    }
 874}
 875
 876fn handle_dpi_changed_msg(
 877    handle: HWND,
 878    wparam: WPARAM,
 879    lparam: LPARAM,
 880    state_ptr: Rc<WindowsWindowStatePtr>,
 881) -> Option<isize> {
 882    let new_dpi = wparam.loword() as f32;
 883    let mut lock = state_ptr.state.borrow_mut();
 884    lock.scale_factor = new_dpi / USER_DEFAULT_SCREEN_DPI as f32;
 885    lock.border_offset.update(handle).log_err();
 886    drop(lock);
 887
 888    let rect = unsafe { &*(lparam.0 as *const RECT) };
 889    let width = rect.right - rect.left;
 890    let height = rect.bottom - rect.top;
 891    // this will emit `WM_SIZE` and `WM_MOVE` right here
 892    // even before this function returns
 893    // the new size is handled in `WM_SIZE`
 894    unsafe {
 895        SetWindowPos(
 896            handle,
 897            None,
 898            rect.left,
 899            rect.top,
 900            width,
 901            height,
 902            SWP_NOZORDER | SWP_NOACTIVATE,
 903        )
 904        .context("unable to set window position after dpi has changed")
 905        .log_err();
 906    }
 907
 908    Some(0)
 909}
 910
 911/// The following conditions will trigger this event:
 912/// 1. The monitor on which the window is located goes offline or changes resolution.
 913/// 2. Another monitor goes offline, is plugged in, or changes resolution.
 914///
 915/// In either case, the window will only receive information from the monitor on which
 916/// it is located.
 917///
 918/// For example, in the case of condition 2, where the monitor on which the window is
 919/// located has actually changed nothing, it will still receive this event.
 920fn handle_display_change_msg(handle: HWND, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
 921    // NOTE:
 922    // Even the `lParam` holds the resolution of the screen, we just ignore it.
 923    // Because WM_DPICHANGED, WM_MOVE, WM_SIZE will come first, window reposition and resize
 924    // are handled there.
 925    // So we only care about if monitor is disconnected.
 926    let previous_monitor = state_ptr.as_ref().state.borrow().display;
 927    if WindowsDisplay::is_connected(previous_monitor.handle) {
 928        // we are fine, other display changed
 929        return None;
 930    }
 931    // display disconnected
 932    // in this case, the OS will move our window to another monitor, and minimize it.
 933    // we deminimize the window and query the monitor after moving
 934    unsafe {
 935        let _ = ShowWindow(handle, SW_SHOWNORMAL);
 936    };
 937    let new_monitor = unsafe { MonitorFromWindow(handle, MONITOR_DEFAULTTONULL) };
 938    // all monitors disconnected
 939    if new_monitor.is_invalid() {
 940        log::error!("No monitor detected!");
 941        return None;
 942    }
 943    let new_display = WindowsDisplay::new_with_handle(new_monitor);
 944    state_ptr.as_ref().state.borrow_mut().display = new_display;
 945    Some(0)
 946}
 947
 948fn handle_hit_test_msg(
 949    handle: HWND,
 950    msg: u32,
 951    wparam: WPARAM,
 952    lparam: LPARAM,
 953    state_ptr: Rc<WindowsWindowStatePtr>,
 954) -> Option<isize> {
 955    if !state_ptr.is_movable {
 956        return None;
 957    }
 958    if !state_ptr.hide_title_bar {
 959        return None;
 960    }
 961
 962    // default handler for resize areas
 963    let hit = unsafe { DefWindowProcW(handle, msg, wparam, lparam) };
 964    if matches!(
 965        hit.0 as u32,
 966        HTNOWHERE
 967            | HTRIGHT
 968            | HTLEFT
 969            | HTTOPLEFT
 970            | HTTOP
 971            | HTTOPRIGHT
 972            | HTBOTTOMRIGHT
 973            | HTBOTTOM
 974            | HTBOTTOMLEFT
 975    ) {
 976        return Some(hit.0);
 977    }
 978
 979    if state_ptr.state.borrow().is_fullscreen() {
 980        return Some(HTCLIENT as _);
 981    }
 982
 983    let dpi = unsafe { GetDpiForWindow(handle) };
 984    let frame_y = unsafe { GetSystemMetricsForDpi(SM_CYFRAME, dpi) };
 985
 986    let mut cursor_point = POINT {
 987        x: lparam.signed_loword().into(),
 988        y: lparam.signed_hiword().into(),
 989    };
 990    unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
 991    if !state_ptr.state.borrow().is_maximized() && cursor_point.y >= 0 && cursor_point.y <= frame_y
 992    {
 993        return Some(HTTOP as _);
 994    }
 995
 996    let titlebar_rect = state_ptr.state.borrow().get_titlebar_rect();
 997    if let Ok(titlebar_rect) = titlebar_rect {
 998        if cursor_point.y < titlebar_rect.bottom {
 999            let caption_btn_width = (state_ptr.state.borrow().caption_button_width().0
1000                * state_ptr.state.borrow().scale_factor) as i32;
1001            if cursor_point.x >= titlebar_rect.right - caption_btn_width {
1002                return Some(HTCLOSE as _);
1003            } else if cursor_point.x >= titlebar_rect.right - caption_btn_width * 2 {
1004                return Some(HTMAXBUTTON as _);
1005            } else if cursor_point.x >= titlebar_rect.right - caption_btn_width * 3 {
1006                return Some(HTMINBUTTON as _);
1007            }
1008
1009            return Some(HTCAPTION as _);
1010        }
1011    }
1012
1013    Some(HTCLIENT as _)
1014}
1015
1016fn handle_nc_mouse_move_msg(
1017    handle: HWND,
1018    lparam: LPARAM,
1019    state_ptr: Rc<WindowsWindowStatePtr>,
1020) -> Option<isize> {
1021    if !state_ptr.hide_title_bar {
1022        return None;
1023    }
1024
1025    start_tracking_mouse(handle, &state_ptr, TME_LEAVE | TME_NONCLIENT);
1026
1027    let mut lock = state_ptr.state.borrow_mut();
1028    if let Some(mut callback) = lock.callbacks.input.take() {
1029        let scale_factor = lock.scale_factor;
1030        drop(lock);
1031        let mut cursor_point = POINT {
1032            x: lparam.signed_loword().into(),
1033            y: lparam.signed_hiword().into(),
1034        };
1035        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
1036        let event = MouseMoveEvent {
1037            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
1038            pressed_button: None,
1039            modifiers: current_modifiers(),
1040        };
1041        let result = if callback(PlatformInput::MouseMove(event)).default_prevented {
1042            Some(0)
1043        } else {
1044            Some(1)
1045        };
1046        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
1047
1048        result
1049    } else {
1050        None
1051    }
1052}
1053
1054fn handle_nc_mouse_down_msg(
1055    handle: HWND,
1056    button: MouseButton,
1057    wparam: WPARAM,
1058    lparam: LPARAM,
1059    state_ptr: Rc<WindowsWindowStatePtr>,
1060) -> Option<isize> {
1061    if !state_ptr.hide_title_bar {
1062        return None;
1063    }
1064
1065    let mut lock = state_ptr.state.borrow_mut();
1066    if let Some(mut callback) = lock.callbacks.input.take() {
1067        let scale_factor = lock.scale_factor;
1068        let mut cursor_point = POINT {
1069            x: lparam.signed_loword().into(),
1070            y: lparam.signed_hiword().into(),
1071        };
1072        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
1073        let physical_point = point(DevicePixels(cursor_point.x), DevicePixels(cursor_point.y));
1074        let click_count = lock.click_state.update(button, physical_point);
1075        drop(lock);
1076        let event = MouseDownEvent {
1077            button,
1078            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
1079            modifiers: current_modifiers(),
1080            click_count,
1081            first_mouse: false,
1082        };
1083        let result = if callback(PlatformInput::MouseDown(event)).default_prevented {
1084            Some(0)
1085        } else {
1086            None
1087        };
1088        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
1089
1090        if result.is_some() {
1091            return result;
1092        }
1093    } else {
1094        drop(lock);
1095    };
1096
1097    // Since these are handled in handle_nc_mouse_up_msg we must prevent the default window proc
1098    if button == MouseButton::Left {
1099        match wparam.0 as u32 {
1100            HTMINBUTTON => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTMINBUTTON),
1101            HTMAXBUTTON => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTMAXBUTTON),
1102            HTCLOSE => state_ptr.state.borrow_mut().nc_button_pressed = Some(HTCLOSE),
1103            _ => return None,
1104        };
1105        Some(0)
1106    } else {
1107        None
1108    }
1109}
1110
1111fn handle_nc_mouse_up_msg(
1112    handle: HWND,
1113    button: MouseButton,
1114    wparam: WPARAM,
1115    lparam: LPARAM,
1116    state_ptr: Rc<WindowsWindowStatePtr>,
1117) -> Option<isize> {
1118    if !state_ptr.hide_title_bar {
1119        return None;
1120    }
1121
1122    let mut lock = state_ptr.state.borrow_mut();
1123    if let Some(mut callback) = lock.callbacks.input.take() {
1124        let scale_factor = lock.scale_factor;
1125        drop(lock);
1126        let mut cursor_point = POINT {
1127            x: lparam.signed_loword().into(),
1128            y: lparam.signed_hiword().into(),
1129        };
1130        unsafe { ScreenToClient(handle, &mut cursor_point).ok().log_err() };
1131        let event = MouseUpEvent {
1132            button,
1133            position: logical_point(cursor_point.x as f32, cursor_point.y as f32, scale_factor),
1134            modifiers: current_modifiers(),
1135            click_count: 1,
1136        };
1137        let result = if callback(PlatformInput::MouseUp(event)).default_prevented {
1138            Some(0)
1139        } else {
1140            None
1141        };
1142        state_ptr.state.borrow_mut().callbacks.input = Some(callback);
1143        if result.is_some() {
1144            return result;
1145        }
1146    } else {
1147        drop(lock);
1148    }
1149
1150    let last_pressed = state_ptr.state.borrow_mut().nc_button_pressed.take();
1151    if button == MouseButton::Left && last_pressed.is_some() {
1152        let last_button = last_pressed.unwrap();
1153        let mut handled = false;
1154        match wparam.0 as u32 {
1155            HTMINBUTTON => {
1156                if last_button == HTMINBUTTON {
1157                    unsafe { ShowWindowAsync(handle, SW_MINIMIZE).ok().log_err() };
1158                    handled = true;
1159                }
1160            }
1161            HTMAXBUTTON => {
1162                if last_button == HTMAXBUTTON {
1163                    if state_ptr.state.borrow().is_maximized() {
1164                        unsafe { ShowWindowAsync(handle, SW_NORMAL).ok().log_err() };
1165                    } else {
1166                        unsafe { ShowWindowAsync(handle, SW_MAXIMIZE).ok().log_err() };
1167                    }
1168                    handled = true;
1169                }
1170            }
1171            HTCLOSE => {
1172                if last_button == HTCLOSE {
1173                    unsafe {
1174                        PostMessageW(Some(handle), WM_CLOSE, WPARAM::default(), LPARAM::default())
1175                            .log_err()
1176                    };
1177                    handled = true;
1178                }
1179            }
1180            _ => {}
1181        };
1182        if handled {
1183            return Some(0);
1184        }
1185    }
1186
1187    None
1188}
1189
1190fn handle_cursor_changed(lparam: LPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1191    let mut state = state_ptr.state.borrow_mut();
1192    let had_cursor = state.current_cursor.is_some();
1193
1194    state.current_cursor = if lparam.0 == 0 {
1195        None
1196    } else {
1197        Some(HCURSOR(lparam.0 as _))
1198    };
1199
1200    if had_cursor != state.current_cursor.is_some() {
1201        unsafe { SetCursor(state.current_cursor) };
1202    }
1203
1204    Some(0)
1205}
1206
1207fn handle_set_cursor(lparam: LPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1208    if matches!(
1209        lparam.loword() as u32,
1210        HTLEFT | HTRIGHT | HTTOP | HTTOPLEFT | HTTOPRIGHT | HTBOTTOM | HTBOTTOMLEFT | HTBOTTOMRIGHT
1211    ) {
1212        return None;
1213    }
1214    unsafe {
1215        SetCursor(state_ptr.state.borrow().current_cursor);
1216    };
1217    Some(1)
1218}
1219
1220fn handle_system_settings_changed(
1221    handle: HWND,
1222    lparam: LPARAM,
1223    state_ptr: Rc<WindowsWindowStatePtr>,
1224) -> Option<isize> {
1225    let mut lock = state_ptr.state.borrow_mut();
1226    let display = lock.display;
1227    // system settings
1228    lock.system_settings.update(display);
1229    // mouse double click
1230    lock.click_state.system_update();
1231    // window border offset
1232    lock.border_offset.update(handle).log_err();
1233    drop(lock);
1234
1235    // lParam is a pointer to a string that indicates the area containing the system parameter
1236    // that was changed.
1237    let parameter = PCWSTR::from_raw(lparam.0 as _);
1238    if unsafe { !parameter.is_null() && !parameter.is_empty() } {
1239        if let Some(parameter_string) = unsafe { parameter.to_string() }.log_err() {
1240            log::info!("System settings changed: {}", parameter_string);
1241            match parameter_string.as_str() {
1242                "ImmersiveColorSet" => {
1243                    handle_system_theme_changed(handle, state_ptr);
1244                }
1245                _ => {}
1246            }
1247        }
1248    }
1249
1250    // Force to trigger WM_NCCALCSIZE event to ensure that we handle auto hide
1251    // taskbar correctly.
1252    notify_frame_changed(handle);
1253    Some(0)
1254}
1255
1256fn handle_system_command(wparam: WPARAM, state_ptr: Rc<WindowsWindowStatePtr>) -> Option<isize> {
1257    if wparam.0 == SC_KEYMENU as usize {
1258        let mut lock = state_ptr.state.borrow_mut();
1259        if lock.system_key_handled {
1260            lock.system_key_handled = false;
1261            return Some(0);
1262        }
1263    }
1264    None
1265}
1266
1267fn handle_system_theme_changed(
1268    handle: HWND,
1269    state_ptr: Rc<WindowsWindowStatePtr>,
1270) -> Option<isize> {
1271    let mut callback = state_ptr
1272        .state
1273        .borrow_mut()
1274        .callbacks
1275        .appearance_changed
1276        .take()?;
1277    callback();
1278    state_ptr.state.borrow_mut().callbacks.appearance_changed = Some(callback);
1279    configure_dwm_dark_mode(handle);
1280    Some(0)
1281}
1282
1283fn handle_input_language_changed(
1284    lparam: LPARAM,
1285    state_ptr: Rc<WindowsWindowStatePtr>,
1286) -> Option<isize> {
1287    let thread = state_ptr.main_thread_id_win32;
1288    let validation = state_ptr.validation_number;
1289    unsafe {
1290        PostThreadMessageW(thread, WM_INPUTLANGCHANGE, WPARAM(validation), lparam).log_err();
1291    }
1292    Some(0)
1293}
1294
1295fn parse_syskeydown_msg_keystroke(wparam: WPARAM) -> Option<Keystroke> {
1296    let modifiers = current_modifiers();
1297    let vk_code = wparam.loword();
1298
1299    // on Windows, F10 can trigger this event, not just the alt key,
1300    // so when F10 was pressed, handle only it
1301    if !modifiers.alt {
1302        if vk_code == VK_F10.0 {
1303            let offset = vk_code - VK_F1.0;
1304            return Some(Keystroke {
1305                modifiers,
1306                key: format!("f{}", offset + 1),
1307                key_char: None,
1308            });
1309        } else {
1310            return None;
1311        }
1312    }
1313
1314    let key = match VIRTUAL_KEY(vk_code) {
1315        VK_BACK => "backspace",
1316        VK_RETURN => "enter",
1317        VK_TAB => "tab",
1318        VK_UP => "up",
1319        VK_DOWN => "down",
1320        VK_RIGHT => "right",
1321        VK_LEFT => "left",
1322        VK_HOME => "home",
1323        VK_END => "end",
1324        VK_PRIOR => "pageup",
1325        VK_NEXT => "pagedown",
1326        VK_BROWSER_BACK => "back",
1327        VK_BROWSER_FORWARD => "forward",
1328        VK_ESCAPE => "escape",
1329        VK_INSERT => "insert",
1330        VK_DELETE => "delete",
1331        VK_APPS => "menu",
1332        _ => {
1333            let basic_key = basic_vkcode_to_string(vk_code, modifiers);
1334            if basic_key.is_some() {
1335                return basic_key;
1336            } else {
1337                if vk_code >= VK_F1.0 && vk_code <= VK_F24.0 {
1338                    let offset = vk_code - VK_F1.0;
1339                    return Some(Keystroke {
1340                        modifiers,
1341                        key: format!("f{}", offset + 1),
1342                        key_char: None,
1343                    });
1344                } else {
1345                    return None;
1346                }
1347            }
1348        }
1349    }
1350    .to_owned();
1351
1352    Some(Keystroke {
1353        modifiers,
1354        key,
1355        key_char: None,
1356    })
1357}
1358
1359enum KeystrokeOrModifier {
1360    Keystroke(Keystroke),
1361    Modifier(Modifiers),
1362}
1363
1364fn parse_keystroke_from_vkey(wparam: WPARAM, is_keyup: bool) -> Option<KeystrokeOrModifier> {
1365    let vk_code = wparam.loword();
1366
1367    let modifiers = current_modifiers();
1368
1369    let key = match VIRTUAL_KEY(vk_code) {
1370        VK_BACK => "backspace",
1371        VK_RETURN => "enter",
1372        VK_TAB => "tab",
1373        VK_UP => "up",
1374        VK_DOWN => "down",
1375        VK_RIGHT => "right",
1376        VK_LEFT => "left",
1377        VK_HOME => "home",
1378        VK_END => "end",
1379        VK_PRIOR => "pageup",
1380        VK_NEXT => "pagedown",
1381        VK_BROWSER_BACK => "back",
1382        VK_BROWSER_FORWARD => "forward",
1383        VK_ESCAPE => "escape",
1384        VK_INSERT => "insert",
1385        VK_DELETE => "delete",
1386        VK_APPS => "menu",
1387        _ => {
1388            if is_modifier(VIRTUAL_KEY(vk_code)) {
1389                return Some(KeystrokeOrModifier::Modifier(modifiers));
1390            }
1391
1392            if modifiers.control || modifiers.alt || is_keyup {
1393                let basic_key = basic_vkcode_to_string(vk_code, modifiers);
1394                if let Some(basic_key) = basic_key {
1395                    return Some(KeystrokeOrModifier::Keystroke(basic_key));
1396                }
1397            }
1398
1399            if vk_code >= VK_F1.0 && vk_code <= VK_F24.0 {
1400                let offset = vk_code - VK_F1.0;
1401                return Some(KeystrokeOrModifier::Keystroke(Keystroke {
1402                    modifiers,
1403                    key: format!("f{}", offset + 1),
1404                    key_char: None,
1405                }));
1406            };
1407            return None;
1408        }
1409    }
1410    .to_owned();
1411
1412    Some(KeystrokeOrModifier::Keystroke(Keystroke {
1413        modifiers,
1414        key,
1415        key_char: None,
1416    }))
1417}
1418
1419fn parse_char_msg_keystroke(wparam: WPARAM) -> Option<Keystroke> {
1420    let first_char = char::from_u32((wparam.0 as u16).into())?;
1421    if first_char.is_control() {
1422        None
1423    } else {
1424        let mut modifiers = current_modifiers();
1425        // for characters that use 'shift' to type it is expected that the
1426        // shift is not reported if the uppercase/lowercase are the same and instead only the key is reported
1427        if first_char.to_ascii_uppercase() == first_char.to_ascii_lowercase() {
1428            modifiers.shift = false;
1429        }
1430        let key = match first_char {
1431            ' ' => "space".to_string(),
1432            first_char => first_char.to_lowercase().to_string(),
1433        };
1434        Some(Keystroke {
1435            modifiers,
1436            key,
1437            key_char: Some(first_char.to_string()),
1438        })
1439    }
1440}
1441
1442fn parse_ime_compostion_string(ctx: HIMC) -> Option<(String, usize)> {
1443    unsafe {
1444        let string_len = ImmGetCompositionStringW(ctx, GCS_COMPSTR, None, 0);
1445        if string_len >= 0 {
1446            let mut buffer = vec![0u8; string_len as usize + 2];
1447            ImmGetCompositionStringW(
1448                ctx,
1449                GCS_COMPSTR,
1450                Some(buffer.as_mut_ptr() as _),
1451                string_len as _,
1452            );
1453            let wstring = std::slice::from_raw_parts::<u16>(
1454                buffer.as_mut_ptr().cast::<u16>(),
1455                string_len as usize / 2,
1456            );
1457            let string = String::from_utf16_lossy(wstring);
1458            Some((string, string_len as usize / 2))
1459        } else {
1460            None
1461        }
1462    }
1463}
1464
1465#[inline]
1466fn retrieve_composition_cursor_position(ctx: HIMC) -> usize {
1467    unsafe { ImmGetCompositionStringW(ctx, GCS_CURSORPOS, None, 0) as usize }
1468}
1469
1470fn parse_ime_compostion_result(ctx: HIMC) -> Option<String> {
1471    unsafe {
1472        let string_len = ImmGetCompositionStringW(ctx, GCS_RESULTSTR, None, 0);
1473        if string_len >= 0 {
1474            let mut buffer = vec![0u8; string_len as usize + 2];
1475            ImmGetCompositionStringW(
1476                ctx,
1477                GCS_RESULTSTR,
1478                Some(buffer.as_mut_ptr() as _),
1479                string_len as _,
1480            );
1481            let wstring = std::slice::from_raw_parts::<u16>(
1482                buffer.as_mut_ptr().cast::<u16>(),
1483                string_len as usize / 2,
1484            );
1485            let string = String::from_utf16_lossy(wstring);
1486            Some(string)
1487        } else {
1488            None
1489        }
1490    }
1491}
1492
1493fn basic_vkcode_to_string(code: u16, modifiers: Modifiers) -> Option<Keystroke> {
1494    let mapped_code = unsafe { MapVirtualKeyW(code as u32, MAPVK_VK_TO_CHAR) };
1495
1496    let key = match mapped_code {
1497        0 => None,
1498        raw_code => char::from_u32(raw_code),
1499    }?
1500    .to_ascii_lowercase();
1501
1502    let key = if matches!(code as u32, 112..=135) {
1503        format!("f{key}")
1504    } else {
1505        key.to_string()
1506    };
1507
1508    Some(Keystroke {
1509        modifiers,
1510        key,
1511        key_char: None,
1512    })
1513}
1514
1515#[inline]
1516fn is_virtual_key_pressed(vkey: VIRTUAL_KEY) -> bool {
1517    unsafe { GetKeyState(vkey.0 as i32) < 0 }
1518}
1519
1520fn is_modifier(virtual_key: VIRTUAL_KEY) -> bool {
1521    matches!(
1522        virtual_key,
1523        VK_CONTROL | VK_MENU | VK_SHIFT | VK_LWIN | VK_RWIN
1524    )
1525}
1526
1527#[inline]
1528pub(crate) fn current_modifiers() -> Modifiers {
1529    Modifiers {
1530        control: is_virtual_key_pressed(VK_CONTROL),
1531        alt: is_virtual_key_pressed(VK_MENU),
1532        shift: is_virtual_key_pressed(VK_SHIFT),
1533        platform: is_virtual_key_pressed(VK_LWIN) || is_virtual_key_pressed(VK_RWIN),
1534        function: false,
1535    }
1536}
1537
1538fn get_client_area_insets(
1539    handle: HWND,
1540    is_maximized: bool,
1541    windows_version: WindowsVersion,
1542) -> RECT {
1543    // For maximized windows, Windows outdents the window rect from the screen's client rect
1544    // by `frame_thickness` on each edge, meaning `insets` must contain `frame_thickness`
1545    // on all sides (including the top) to avoid the client area extending onto adjacent
1546    // monitors.
1547    //
1548    // For non-maximized windows, things become complicated:
1549    //
1550    // - On Windows 10
1551    // The top inset must be zero, since if there is any nonclient area, Windows will draw
1552    // a full native titlebar outside the client area. (This doesn't occur in the maximized
1553    // case.)
1554    //
1555    // - On Windows 11
1556    // The top inset is calculated using an empirical formula that I derived through various
1557    // tests. Without this, the top 1-2 rows of pixels in our window would be obscured.
1558    let dpi = unsafe { GetDpiForWindow(handle) };
1559    let frame_thickness = get_frame_thickness(dpi);
1560    let top_insets = if is_maximized {
1561        frame_thickness
1562    } else {
1563        match windows_version {
1564            WindowsVersion::Win10 => 0,
1565            WindowsVersion::Win11 => (dpi as f32 / USER_DEFAULT_SCREEN_DPI as f32).round() as i32,
1566        }
1567    };
1568    RECT {
1569        left: frame_thickness,
1570        top: top_insets,
1571        right: frame_thickness,
1572        bottom: frame_thickness,
1573    }
1574}
1575
1576// there is some additional non-visible space when talking about window
1577// borders on Windows:
1578// - SM_CXSIZEFRAME: The resize handle.
1579// - SM_CXPADDEDBORDER: Additional border space that isn't part of the resize handle.
1580fn get_frame_thickness(dpi: u32) -> i32 {
1581    let resize_frame_thickness = unsafe { GetSystemMetricsForDpi(SM_CXSIZEFRAME, dpi) };
1582    let padding_thickness = unsafe { GetSystemMetricsForDpi(SM_CXPADDEDBORDER, dpi) };
1583    resize_frame_thickness + padding_thickness
1584}
1585
1586fn notify_frame_changed(handle: HWND) {
1587    unsafe {
1588        SetWindowPos(
1589            handle,
1590            None,
1591            0,
1592            0,
1593            0,
1594            0,
1595            SWP_FRAMECHANGED
1596                | SWP_NOACTIVATE
1597                | SWP_NOCOPYBITS
1598                | SWP_NOMOVE
1599                | SWP_NOOWNERZORDER
1600                | SWP_NOREPOSITION
1601                | SWP_NOSENDCHANGING
1602                | SWP_NOSIZE
1603                | SWP_NOZORDER,
1604        )
1605        .log_err();
1606    }
1607}
1608
1609fn start_tracking_mouse(
1610    handle: HWND,
1611    state_ptr: &Rc<WindowsWindowStatePtr>,
1612    flags: TRACKMOUSEEVENT_FLAGS,
1613) {
1614    let mut lock = state_ptr.state.borrow_mut();
1615    if !lock.hovered {
1616        lock.hovered = true;
1617        unsafe {
1618            TrackMouseEvent(&mut TRACKMOUSEEVENT {
1619                cbSize: std::mem::size_of::<TRACKMOUSEEVENT>() as u32,
1620                dwFlags: flags,
1621                hwndTrack: handle,
1622                dwHoverTime: HOVER_DEFAULT,
1623            })
1624            .log_err()
1625        };
1626        if let Some(mut callback) = lock.callbacks.hovered_status_change.take() {
1627            drop(lock);
1628            callback(true);
1629            state_ptr.state.borrow_mut().callbacks.hovered_status_change = Some(callback);
1630        }
1631    }
1632}
1633
1634fn with_input_handler<F, R>(state_ptr: &Rc<WindowsWindowStatePtr>, f: F) -> Option<R>
1635where
1636    F: FnOnce(&mut PlatformInputHandler) -> R,
1637{
1638    let mut input_handler = state_ptr.state.borrow_mut().input_handler.take()?;
1639    let result = f(&mut input_handler);
1640    state_ptr.state.borrow_mut().input_handler = Some(input_handler);
1641    Some(result)
1642}
1643
1644fn with_input_handler_and_scale_factor<F, R>(
1645    state_ptr: &Rc<WindowsWindowStatePtr>,
1646    f: F,
1647) -> Option<R>
1648where
1649    F: FnOnce(&mut PlatformInputHandler, f32) -> Option<R>,
1650{
1651    let mut lock = state_ptr.state.borrow_mut();
1652    let mut input_handler = lock.input_handler.take()?;
1653    let scale_factor = lock.scale_factor;
1654    drop(lock);
1655    let result = f(&mut input_handler, scale_factor);
1656    state_ptr.state.borrow_mut().input_handler = Some(input_handler);
1657    result
1658}