[Settings/Run] LowLevel Keyboard hooking for Hotkeys (#3825)

* [Launcher/Settings] Low Level Keyboard Hooks

* [Run] LowLevel Keyboard Hook for Hotkeys

* Prevent shortcuts from auto repeating when keeping the keys pressed down

src/common/interop/KeyboardHook.cpp

@@ -0,0 +1,96 @@
+#include "pch.h"
+#include "KeyboardHook.h"
+#include <exception>
+#include <msclr\marshal.h>
+#include <msclr\marshal_cppstd.h>
+
+using namespace interop;
+using namespace System::Runtime::InteropServices;
+using namespace System;
+using namespace System::Diagnostics;
+
+KeyboardHook::KeyboardHook(
+    KeyboardEventCallback ^ keyboardEventCallback,
+    IsActiveCallback ^ isActiveCallback,
+    FilterKeyboardEvent ^ filterKeyboardEvent)
+{
+    kbEventDispatch = gcnew Thread(gcnew ThreadStart(this, &KeyboardHook::DispatchProc));
+    queue = gcnew Queue<KeyboardEvent ^>();
+    this->keyboardEventCallback = keyboardEventCallback;
+    this->isActiveCallback = isActiveCallback;
+    this->filterKeyboardEvent = filterKeyboardEvent;
+}
+
+KeyboardHook::~KeyboardHook()
+{
+    quit = true;
+    kbEventDispatch->Join();
+
+    // Unregister low level hook procedure
+    UnhookWindowsHookEx(hookHandle);
+}
+
+void KeyboardHook::DispatchProc()
+{
+    Monitor::Enter(queue);
+    quit = false;
+    while (!quit)
+    {
+        if (queue->Count == 0)
+        {
+            Monitor::Wait(queue);
+            continue;
+        }
+        auto nextEv = queue->Dequeue();
+
+        // Release lock while callback is being invoked
+        Monitor::Exit(queue);
+        
+        keyboardEventCallback->Invoke(nextEv);
+        
+        // Re-aquire lock
+        Monitor::Enter(queue);
+    }
+
+    Monitor::Exit(queue);
+}
+
+void KeyboardHook::Start()
+{
+    hookProc = gcnew HookProcDelegate(this, &KeyboardHook::HookProc);
+    Process ^ curProcess = Process::GetCurrentProcess();
+    ProcessModule ^ curModule = curProcess->MainModule;
+    // register low level hook procedure
+    hookHandle = SetWindowsHookEx(
+        WH_KEYBOARD_LL, 
+        (HOOKPROC)(void*)Marshal::GetFunctionPointerForDelegate(hookProc), 
+        0,
+        0);
+    if (hookHandle == nullptr)
+    {
+        throw std::exception("SetWindowsHookEx failed.");
+    }
+
+    kbEventDispatch->Start();
+}
+
+LRESULT CALLBACK KeyboardHook::HookProc(int nCode, WPARAM wParam, LPARAM lParam)
+{
+    if (nCode == HC_ACTION && isActiveCallback->Invoke())
+    {
+        KeyboardEvent ^ ev = gcnew KeyboardEvent();
+        ev->message = wParam;
+        ev->key = reinterpret_cast<KBDLLHOOKSTRUCT*>(lParam)->vkCode;
+        if (filterKeyboardEvent != nullptr && !filterKeyboardEvent->Invoke(ev))
+        {
+            return CallNextHookEx(hookHandle, nCode, wParam, lParam);
+        }
+
+        Monitor::Enter(queue);
+        queue->Enqueue(ev);
+        Monitor::Pulse(queue);
+        Monitor::Exit(queue);
+        return 1;
+    }
+    return CallNextHookEx(hookHandle, nCode, wParam, lParam);
+}