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| 1 | +use std::{ |
| 2 | + collections::HashSet, |
| 3 | + ffi::c_int, |
| 4 | + ptr, |
| 5 | + sync::{LazyLock, RwLock}, |
| 6 | +}; |
| 7 | + |
| 8 | +use winapi::{ |
| 9 | + shared::{ |
| 10 | + minwindef::{LPARAM, WPARAM}, |
| 11 | + windef::{HHOOK, HWND, POINT}, |
| 12 | + }, |
| 13 | + um::{ |
| 14 | + libloaderapi::GetModuleHandleW, |
| 15 | + processthreadsapi::GetCurrentThreadId, |
| 16 | + winuser::{ |
| 17 | + CallNextHookEx, SetWindowsHookExW, UnhookWindowsHookEx, HC_ACTION, MSG, PM_REMOVE, |
| 18 | + WH_GETMESSAGE, WM_CHAR, WM_KEYDOWN, WM_KEYUP, WM_SYSCHAR, WM_SYSKEYDOWN, WM_SYSKEYUP, |
| 19 | + WM_USER, |
| 20 | + }, |
| 21 | + }, |
| 22 | +}; |
| 23 | + |
| 24 | +use crate::win::wnd_proc; |
| 25 | + |
| 26 | +// track all windows opened by this instance of baseview |
| 27 | +// we use an RwLock here since the vast majority of uses (event interceptions) |
| 28 | +// will only need to read from the HashSet |
| 29 | +static HOOK_STATE: LazyLock<RwLock<KeyboardHookState>> = LazyLock::new(|| RwLock::default()); |
| 30 | + |
| 31 | +pub(crate) struct KeyboardHookHandle(HWNDWrapper); |
| 32 | + |
| 33 | +#[derive(Default)] |
| 34 | +struct KeyboardHookState { |
| 35 | + hook: Option<HHOOK>, |
| 36 | + open_windows: HashSet<HWNDWrapper>, |
| 37 | +} |
| 38 | + |
| 39 | +#[derive(Hash, PartialEq, Eq, Clone, Copy)] |
| 40 | +struct HWNDWrapper(HWND); |
| 41 | + |
| 42 | +// SAFETY: it's a pointer behind an RwLock. we'll live |
| 43 | +unsafe impl Send for KeyboardHookState {} |
| 44 | +unsafe impl Sync for KeyboardHookState {} |
| 45 | + |
| 46 | +// SAFETY: we never access the underlying HWND ourselves, just use it as a HashSet entry |
| 47 | +unsafe impl Send for HWNDWrapper {} |
| 48 | +unsafe impl Sync for HWNDWrapper {} |
| 49 | + |
| 50 | +impl Drop for KeyboardHookHandle { |
| 51 | + fn drop(&mut self) { |
| 52 | + deinit_keyboard_hook(self.0); |
| 53 | + } |
| 54 | +} |
| 55 | + |
| 56 | +// initialize keyboard hook |
| 57 | +// some DAWs (particularly Ableton) intercept incoming keyboard messages, |
| 58 | +// but we're naughty so we intercept them right back |
| 59 | +pub(crate) fn init_keyboard_hook(hwnd: HWND) -> KeyboardHookHandle { |
| 60 | + let state = &mut *HOOK_STATE.write().unwrap(); |
| 61 | + |
| 62 | + // register hwnd to global window set |
| 63 | + state.open_windows.insert(HWNDWrapper(hwnd)); |
| 64 | + |
| 65 | + if state.hook.is_some() { |
| 66 | + // keyboard hook already exists, just return handle |
| 67 | + KeyboardHookHandle(HWNDWrapper(hwnd)) |
| 68 | + } else { |
| 69 | + // keyboard hook doesn't exist (no windows open before this), create it |
| 70 | + let new_hook = unsafe { |
| 71 | + SetWindowsHookExW( |
| 72 | + WH_GETMESSAGE, |
| 73 | + Some(keyboard_hook_callback), |
| 74 | + GetModuleHandleW(ptr::null()), |
| 75 | + GetCurrentThreadId(), |
| 76 | + ) |
| 77 | + }; |
| 78 | + |
| 79 | + state.hook = Some(new_hook); |
| 80 | + |
| 81 | + KeyboardHookHandle(HWNDWrapper(hwnd)) |
| 82 | + } |
| 83 | +} |
| 84 | + |
| 85 | +fn deinit_keyboard_hook(hwnd: HWNDWrapper) { |
| 86 | + let state = &mut *HOOK_STATE.write().unwrap(); |
| 87 | + |
| 88 | + state.open_windows.remove(&hwnd); |
| 89 | + |
| 90 | + if state.open_windows.is_empty() { |
| 91 | + if let Some(hhook) = state.hook { |
| 92 | + unsafe { |
| 93 | + UnhookWindowsHookEx(hhook); |
| 94 | + } |
| 95 | + |
| 96 | + state.hook = None; |
| 97 | + } |
| 98 | + } |
| 99 | +} |
| 100 | + |
| 101 | +unsafe extern "system" fn keyboard_hook_callback( |
| 102 | + n_code: c_int, wparam: WPARAM, lparam: LPARAM, |
| 103 | +) -> isize { |
| 104 | + let msg = lparam as *mut MSG; |
| 105 | + |
| 106 | + if n_code == HC_ACTION && wparam == PM_REMOVE as usize && offer_message_to_baseview(msg) { |
| 107 | + *msg = MSG { |
| 108 | + hwnd: ptr::null_mut(), |
| 109 | + message: WM_USER, |
| 110 | + wParam: 0, |
| 111 | + lParam: 0, |
| 112 | + time: 0, |
| 113 | + pt: POINT { x: 0, y: 0 }, |
| 114 | + }; |
| 115 | + |
| 116 | + 0 |
| 117 | + } else { |
| 118 | + CallNextHookEx(ptr::null_mut(), n_code, wparam, lparam) |
| 119 | + } |
| 120 | +} |
| 121 | + |
| 122 | +// check if `msg` is a keyboard message addressed to a window |
| 123 | +// in KeyboardHookState::open_windows, and intercept it if so |
| 124 | +unsafe fn offer_message_to_baseview(msg: *mut MSG) -> bool { |
| 125 | + let msg = &*msg; |
| 126 | + |
| 127 | + // if this isn't a keyboard message, ignore it |
| 128 | + match msg.message { |
| 129 | + WM_KEYDOWN | WM_SYSKEYDOWN | WM_KEYUP | WM_SYSKEYUP | WM_CHAR | WM_SYSCHAR => {} |
| 130 | + |
| 131 | + _ => return false, |
| 132 | + } |
| 133 | + |
| 134 | + // check if this is one of our windows. if so, intercept it |
| 135 | + if HOOK_STATE.read().unwrap().open_windows.contains(&HWNDWrapper(msg.hwnd)) { |
| 136 | + let _ = wnd_proc(msg.hwnd, msg.message, msg.wParam, msg.lParam); |
| 137 | + |
| 138 | + return true; |
| 139 | + } |
| 140 | + |
| 141 | + false |
| 142 | +} |
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