Merge branch 'RustAudio:master' into x11-gl-context-leak

Author: Quant1um

src/win/drop_target.rs

@@ -27,19 +27,22 @@ use super::WindowState;
 // These function pointers have to be stored in a (const) variable before they can be transmuted
 // Transmuting is needed because winapi has a bug where the pt parameter has an incorrect
 // type `*const POINTL`
+#[allow(non_snake_case)]
 const DRAG_ENTER_PTR: unsafe extern "system" fn(
     this: *mut IDropTarget,
     pDataObj: *const IDataObject,
     grfKeyState: DWORD,
     pt: POINTL,
     pdwEffect: *mut DWORD,
 ) -> HRESULT = DropTarget::drag_enter;
+#[allow(non_snake_case)]
 const DRAG_OVER_PTR: unsafe extern "system" fn(
     this: *mut IDropTarget,
     grfKeyState: DWORD,
     pt: POINTL,
     pdwEffect: *mut DWORD,
 ) -> HRESULT = DropTarget::drag_over;
+#[allow(non_snake_case)]
 const DROP_PTR: unsafe extern "system" fn(
     this: *mut IDropTarget,
     pDataObj: *const IDataObject,

src/win/hook.rs

@@ -0,0 +1,142 @@
+use std::{
+    collections::HashSet,
+    ffi::c_int,
+    ptr,
+    sync::{LazyLock, RwLock},
+};
+
+use winapi::{
+    shared::{
+        minwindef::{LPARAM, WPARAM},
+        windef::{HHOOK, HWND, POINT},
+    },
+    um::{
+        libloaderapi::GetModuleHandleW,
+        processthreadsapi::GetCurrentThreadId,
+        winuser::{
+            CallNextHookEx, SetWindowsHookExW, UnhookWindowsHookEx, HC_ACTION, MSG, PM_REMOVE,
+            WH_GETMESSAGE, WM_CHAR, WM_KEYDOWN, WM_KEYUP, WM_SYSCHAR, WM_SYSKEYDOWN, WM_SYSKEYUP,
+            WM_USER,
+        },
+    },
+};
+
+use crate::win::wnd_proc;
+
+// track all windows opened by this instance of baseview
+// we use an RwLock here since the vast majority of uses (event interceptions)
+// will only need to read from the HashSet
+static HOOK_STATE: LazyLock<RwLock<KeyboardHookState>> = LazyLock::new(|| RwLock::default());
+
+pub(crate) struct KeyboardHookHandle(HWNDWrapper);
+
+#[derive(Default)]
+struct KeyboardHookState {
+    hook: Option<HHOOK>,
+    open_windows: HashSet<HWNDWrapper>,
+}
+
+#[derive(Hash, PartialEq, Eq, Clone, Copy)]
+struct HWNDWrapper(HWND);
+
+// SAFETY: it's a pointer behind an RwLock. we'll live
+unsafe impl Send for KeyboardHookState {}
+unsafe impl Sync for KeyboardHookState {}
+
+// SAFETY: we never access the underlying HWND ourselves, just use it as a HashSet entry
+unsafe impl Send for HWNDWrapper {}
+unsafe impl Sync for HWNDWrapper {}
+
+impl Drop for KeyboardHookHandle {
+    fn drop(&mut self) {
+        deinit_keyboard_hook(self.0);
+    }
+}
+
+// initialize keyboard hook
+// some DAWs (particularly Ableton) intercept incoming keyboard messages,
+// but we're naughty so we intercept them right back
+pub(crate) fn init_keyboard_hook(hwnd: HWND) -> KeyboardHookHandle {
+    let state = &mut *HOOK_STATE.write().unwrap();
+
+    // register hwnd to global window set
+    state.open_windows.insert(HWNDWrapper(hwnd));
+
+    if state.hook.is_some() {
+        // keyboard hook already exists, just return handle
+        KeyboardHookHandle(HWNDWrapper(hwnd))
+    } else {
+        // keyboard hook doesn't exist (no windows open before this), create it
+        let new_hook = unsafe {
+            SetWindowsHookExW(
+                WH_GETMESSAGE,
+                Some(keyboard_hook_callback),
+                GetModuleHandleW(ptr::null()),
+                GetCurrentThreadId(),
+            )
+        };
+
+        state.hook = Some(new_hook);
+
+        KeyboardHookHandle(HWNDWrapper(hwnd))
+    }
+}
+
+fn deinit_keyboard_hook(hwnd: HWNDWrapper) {
+    let state = &mut *HOOK_STATE.write().unwrap();
+
+    state.open_windows.remove(&hwnd);
+
+    if state.open_windows.is_empty() {
+        if let Some(hhook) = state.hook {
+            unsafe {
+                UnhookWindowsHookEx(hhook);
+            }
+
+            state.hook = None;
+        }
+    }
+}
+
+unsafe extern "system" fn keyboard_hook_callback(
+    n_code: c_int, wparam: WPARAM, lparam: LPARAM,
+) -> isize {
+    let msg = lparam as *mut MSG;
+
+    if n_code == HC_ACTION && wparam == PM_REMOVE as usize && offer_message_to_baseview(msg) {
+        *msg = MSG {
+            hwnd: ptr::null_mut(),
+            message: WM_USER,
+            wParam: 0,
+            lParam: 0,
+            time: 0,
+            pt: POINT { x: 0, y: 0 },
+        };
+
+        0
+    } else {
+        CallNextHookEx(ptr::null_mut(), n_code, wparam, lparam)
+    }
+}
+
+// check if `msg` is a keyboard message addressed to a window
+// in KeyboardHookState::open_windows, and intercept it if so
+unsafe fn offer_message_to_baseview(msg: *mut MSG) -> bool {
+    let msg = &*msg;
+
+    // if this isn't a keyboard message, ignore it
+    match msg.message {
+        WM_KEYDOWN | WM_SYSKEYDOWN | WM_KEYUP | WM_SYSKEYUP | WM_CHAR | WM_SYSCHAR => {}
+
+        _ => return false,
+    }
+
+    // check if this is one of our windows. if so, intercept it
+    if HOOK_STATE.read().unwrap().open_windows.contains(&HWNDWrapper(msg.hwnd)) {
+        let _ = wnd_proc(msg.hwnd, msg.message, msg.wParam, msg.lParam);
+
+        return true;
+    }
+
+    false
+}

src/win/mod.rs

@@ -1,5 +1,6 @@
 mod cursor;
 mod drop_target;
+mod hook;
 mod keyboard;
 mod window;
 

src/win/window.rs

@@ -33,6 +33,7 @@ use raw_window_handle::{
 
 const BV_WINDOW_MUST_CLOSE: UINT = WM_USER + 1;
 
+use crate::win::hook::{self, KeyboardHookHandle};
 use crate::{
     Event, MouseButton, MouseCursor, MouseEvent, PhyPoint, PhySize, ScrollDelta, Size, WindowEvent,
     WindowHandler, WindowInfo, WindowOpenOptions, WindowScalePolicy,
@@ -118,7 +119,7 @@ impl Drop for ParentHandle {
     }
 }
 
-unsafe extern "system" fn wnd_proc(
+pub(crate) unsafe extern "system" fn wnd_proc(
     hwnd: HWND, msg: UINT, wparam: WPARAM, lparam: LPARAM,
 ) -> LRESULT {
     if msg == WM_CREATE {
@@ -507,6 +508,11 @@ pub(super) struct WindowState {
     scale_policy: WindowScalePolicy,
     dw_style: u32,
 
+    // handle to the win32 keyboard hook
+    // we don't need to read from this, just carry it around so the Drop impl can run
+    #[allow(dead_code)]
+    kb_hook: KeyboardHookHandle,
+
     /// Tasks that should be executed at the end of `wnd_proc`. This is needed to avoid mutably
     /// borrowing the fields from `WindowState` more than once. For instance, when the window
     /// handler requests a resize in response to a keyboard event, the window state will already be
@@ -519,19 +525,19 @@ pub(super) struct WindowState {
 }
 
 impl WindowState {
-    pub(super) fn create_window(&self) -> Window {
+    pub(super) fn create_window(&self) -> Window<'_> {
         Window { state: self }
     }
 
-    pub(super) fn window_info(&self) -> Ref<WindowInfo> {
+    pub(super) fn window_info(&self) -> Ref<'_, WindowInfo> {
         self.window_info.borrow()
     }
 
-    pub(super) fn keyboard_state(&self) -> Ref<KeyboardState> {
+    pub(super) fn keyboard_state(&self) -> Ref<'_, KeyboardState> {
         self.keyboard_state.borrow()
     }
 
-    pub(super) fn handler_mut(&self) -> RefMut<Option<Box<dyn WindowHandler>>> {
+    pub(super) fn handler_mut(&self) -> RefMut<'_, Option<Box<dyn WindowHandler>>> {
         self.handler.borrow_mut()
     }
 
@@ -686,6 +692,8 @@ impl Window<'_> {
             );
             // todo: manage error ^
 
+            let kb_hook = hook::init_keyboard_hook(hwnd);
+
             #[cfg(feature = "opengl")]
             let gl_context: Option<GlContext> = options.gl_config.map(|gl_config| {
                 let mut handle = Win32WindowHandle::empty();
@@ -716,6 +724,8 @@ impl Window<'_> {
 
                 deferred_tasks: RefCell::new(VecDeque::with_capacity(4)),
 
+                kb_hook,
+
                 #[cfg(feature = "opengl")]
                 gl_context,
             });