SysKey hook filter:

. Also suppress ALT+SPACE
. PostMessage to AppleWin message-pump for WM_KEYDOWN, WM_KEYUP for these special key combos
. Add special any-key-down (AKD) handling for these special key combos

HookFilter/HookFilter.cpp

@@ -2,40 +2,65 @@
 
 // https://stackoverflow.com/questions/2490577/suppress-task-switch-keys-winkey-alt-tab-alt-esc-ctrl-esc-using-low-level-k
 
+static HWND g_hFrameWindow = (HWND)0;
+
 // NB. __stdcall (or WINAPI) and extern "C":
 // . symbol is decorated as _<symbol>@bytes
 // . so use the #pragma to create an undecorated alias for our symbol
 extern "C" __declspec(dllexport) LRESULT CALLBACK LowLevelKeyboardProc(
   _In_ int    nCode,
   _In_ WPARAM wParam,
-  _In_ LPARAM lParam
+  _In_ LPARAM lParam)
-)
 {
 	#pragma comment(linker, "/EXPORT:" __FUNCTION__ "=" __FUNCDNAME__)
 
-	if (nCode >= 0)
+	if (nCode == HC_ACTION)
 	{
 		bool suppress = false;
 
 		PKBDLLHOOKSTRUCT pKbdLlHookStruct = (PKBDLLHOOKSTRUCT) lParam;
+		UINT newMsg = pKbdLlHookStruct->flags & LLKHF_UP ? WM_KEYUP : WM_KEYDOWN;
+		LPARAM newlParam = newMsg == WM_KEYUP ? 3<<30 : 0;	// b31:transition state, b30:previous key state
 
-		// Suppress alt-tab.
+		// Note about PostMessage() and use of VkKeyScan():
-		if (pKbdLlHookStruct->vkCode == VK_TAB && (pKbdLlHookStruct->flags & LLKHF_ALTDOWN)) 
+		// . Convert the ascii code to virtual key code, so that the message pump can do TranslateMessage()
+		// . NB. From MSDN for "WM_KEYDOWN" && "WM_KEYUP" : "Applications must pass wParam to TranslateMessage without altering it at all."
+
+		// Suppress alt-tab
+		if (pKbdLlHookStruct->vkCode == VK_TAB && (pKbdLlHookStruct->flags & LLKHF_ALTDOWN))
+		{
+			PostMessage(g_hFrameWindow, newMsg, LOBYTE(VkKeyScan(0x09)), newlParam);
 			suppress = true;
+		}
 
-		// Suppress alt-escape.
+		// Suppress alt-escape
-		if (pKbdLlHookStruct->vkCode == VK_ESCAPE && (pKbdLlHookStruct->flags & LLKHF_ALTDOWN)) 
+		if (pKbdLlHookStruct->vkCode == VK_ESCAPE && (pKbdLlHookStruct->flags & LLKHF_ALTDOWN))
+		{
+			PostMessage(g_hFrameWindow, newMsg, LOBYTE(VkKeyScan(0x1B)), newlParam);
 			suppress = true;
+		}
 
-		// Suppress ctrl-escape.
+		// Suppress alt-space
+		if (pKbdLlHookStruct->vkCode == VK_SPACE && (pKbdLlHookStruct->flags & LLKHF_ALTDOWN))
+		{
+			PostMessage(g_hFrameWindow, newMsg, LOBYTE(VkKeyScan(0x20)), newlParam);
+			suppress = true;
+		}
+
+		// Suppress ctrl-escape
 		bool ControlDown = (GetKeyState(VK_CONTROL) & 0x8000) != 0;
 		if (pKbdLlHookStruct->vkCode == VK_ESCAPE && ControlDown)
 			suppress = true;
 
-		// Suppress keys by returning 1.
+		// Suppress keys by returning 1
 		if (suppress)
 			return 1;
 	}
 
 	return CallNextHookEx(0/*parameter is ignored*/, nCode, wParam, lParam);
 }
+
+extern "C" __declspec(dllexport) void __cdecl RegisterHWND(HWND hWnd)
+{
+	g_hFrameWindow = hWnd;
+}

HookFilter/HookFilter.vcproj

@@ -2,7 +2,7 @@
 <VisualStudioProject
 	ProjectType="Visual C++"
 	Version="9.00"
-	Name="AppleWinHookFilter"
+	Name="HookFilter"
 	ProjectGUID="{AA5854AD-2BC7-4EFD-9790-349ADB35E35A}"
 	RootNamespace="HookFilter"
 	Keyword="Win32Proj"

source/Applewin.cpp

@@ -821,7 +821,7 @@ void RegisterExtensions(void)
 //===========================================================================
 
 // NB. On a restart, it's OK to call RegisterHotKey() again since the old g_hFrameWindow has been destroyed
-static void AppleWin_RegisterHotKeys(void)
+static void RegisterHotKeys(void)
 {
 	BOOL bStatus[3] = {0,0,0};
 
@@ -865,6 +865,49 @@ static void AppleWin_RegisterHotKeys(void)
 	}
 }
 
+//---------------------------------------------------------------------------
+
+static HINSTANCE g_hinstDLL = 0;
+static HHOOK g_hhook = 0;
+
+// Pre: g_hFrameWindow must be valid
+void HookFilterForKeyboard()
+{
+	g_hinstDLL = LoadLibrary(TEXT("HookFilter.dll"));
+
+	_ASSERT(g_hFrameWindow);
+
+	typedef void (*RegisterHWNDProc)(HWND);
+	RegisterHWNDProc RegisterHWND = (RegisterHWNDProc) GetProcAddress(g_hinstDLL, "RegisterHWND");
+	if (RegisterHWND)
+		RegisterHWND(g_hFrameWindow);
+
+	HOOKPROC hkprcLowLevelKeyboardProc = (HOOKPROC) GetProcAddress(g_hinstDLL, "LowLevelKeyboardProc");
+
+	g_hhook = SetWindowsHookEx(
+						WH_KEYBOARD_LL,
+						hkprcLowLevelKeyboardProc,
+						g_hinstDLL,
+						0);
+
+	if (g_hhook == 0 || g_hFrameWindow == 0)
+	{
+		std::string msg("Failed to install hook filter for system keys");
+
+		DWORD dwErr = GetLastError();
+		MessageBox(GetDesktopWindow(), msg.c_str(), "Warning", MB_ICONASTERISK | MB_OK);
+
+		msg += "\n";
+		LogFileOutput(msg.c_str());
+	}
+}
+
+void UnhookFilterForKeyboard()
+{
+	UnhookWindowsHookEx(g_hhook);
+	FreeLibrary(g_hinstDLL);
+}
+
 //===========================================================================
 
 LPSTR GetCurrArg(LPSTR lpCmdLine)
@@ -1012,40 +1055,6 @@ static void InsertHardDisks(LPSTR szImageName_harddisk[NUM_HARDDISKS], bool& bBo
 
 //---------------------------------------------------------------------------
 
-static HINSTANCE g_hinstDLL = 0;
-static HHOOK g_hhook = 0;
-
-void HookFilterForKeyboard()
-{
-	g_hinstDLL = LoadLibrary(TEXT("AppleWinHookFilter.dll"));
-	HOOKPROC hkprcLowLevelKeyboardProc = (HOOKPROC) GetProcAddress(g_hinstDLL, "LowLevelKeyboardProc");
-
-	g_hhook = SetWindowsHookEx(
-						WH_KEYBOARD_LL,
-						hkprcLowLevelKeyboardProc,
-						g_hinstDLL,
-						0);
-
-	if (g_hhook == NULL)
-	{
-		std::string msg("Failed to install hook filter for system keys");
-
-		DWORD dwErr = GetLastError();
-		MessageBox(GetDesktopWindow(), msg.c_str(), "Warning", MB_ICONASTERISK | MB_OK);	// NB. g_hFrameWindow is not yet valid
-
-		msg += "\n";
-		LogFileOutput(msg.c_str());
-	}
-}
-
-void UnhookFilterForKeyboard()
-{
-	UnhookWindowsHookEx(g_hhook);
-	FreeLibrary(g_hinstDLL);
-}
-
-//---------------------------------------------------------------------------
-
 int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 {
 	bool bShutdown = false;
@@ -1344,8 +1353,6 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 	DiskInitialize();
 	LogFileOutput("Init: DiskInitialize()\n");
 
-	HookFilterForKeyboard();
-
 	//
 
 	do
@@ -1398,10 +1405,13 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 				RegSaveString(TEXT(REG_CONFIG), TEXT(REGVALUE_VERSION), 1, VERSIONSTRING);	// Only save version after user accepts license
 		}
 
-		// PrintScrn support
 		if (g_bCapturePrintScreenKey)
-			AppleWin_RegisterHotKeys(); // needs valid g_hFrameWindow
+		{
-		LogFileOutput("Main: AppleWin_RegisterHotKeys()\n");
+			RegisterHotKeys();		// needs valid g_hFrameWindow
+			LogFileOutput("Main: RegisterHotKeys()\n");
+		}
+
+		HookFilterForKeyboard();	// needs valid g_hFrameWindow (for message pump)
 
 		// Need to test if it's safe to call ResetMachineState(). In the meantime, just call DiskReset():
 		DiskReset();	// Switch from a booting A][+ to a non-autostart A][, so need to turn off floppy motor
@@ -1508,11 +1518,11 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 
 		DSUninit();
 		LogFileOutput("Main: DSUninit()\n");
+
+		UnhookFilterForKeyboard();
 	}
 	while (g_bRestart);
 
-	UnhookFilterForKeyboard();
-
 	if (bChangedDisplayResolution)
 		ChangeDisplaySettings(NULL, 0);	// restore default
 

source/Frame.cpp

@@ -1260,6 +1260,7 @@ LRESULT CALLBACK FrameWndProc (
 
 	case WM_KEYDOWN:
 		KeybUpdateCtrlShiftStatus();
+		KeybSpecialKeydown(wparam);
 
 		// Process is done in WM_KEYUP: VK_F1 VK_F2 VK_F3 VK_F4 VK_F5 VK_F6 VK_F7 VK_F8
 		if ((wparam >= VK_F1) && (wparam <= VK_F8) && (buttondown == -1))
@@ -1399,6 +1400,8 @@ LRESULT CALLBACK FrameWndProc (
 		break;
 
 	case WM_KEYUP:
+		KeybSpecialKeyup(wparam);
+
 		// Process is done in WM_KEYUP: VK_F1 VK_F2 VK_F3 VK_F4 VK_F5 VK_F6 VK_F7 VK_F8
 		if ((wparam >= VK_F1) && (wparam <= VK_F8) && (buttondown == (int)wparam-VK_F1))
 		{

source/Keyboard.cpp

@@ -389,6 +389,58 @@ static char ClipboardCurrChar(bool bIncPtr)
 
 //===========================================================================
 
+// For AKD (Any Key Down), need special handling for the hooked key combos(*), as GetKeyState() doesn't detect the keys as being down.
+// (*) ALT+TAB, ALT+ESCAPE, ALT+SPACE
+
+static enum {AKD_TAB=0, AKD_ESCAPE, AKD_SPACE};
+static bool g_specialAKD[3] = {false,false,false};
+
+void KeybSpecialKeydown(DWORD wparam)
+{
+	switch (wparam)
+	{
+	case VK_TAB:
+		g_specialAKD[AKD_TAB] = true;
+		break;
+	case VK_ESCAPE:
+		g_specialAKD[AKD_ESCAPE] = true;
+		break;
+	case VK_SPACE:
+		g_specialAKD[AKD_SPACE] = true;
+		break;
+	};
+}
+
+void KeybSpecialKeyup(DWORD wparam)
+{
+	switch (wparam)
+	{
+	case VK_TAB:
+		g_specialAKD[AKD_TAB] = false;
+		break;
+	case VK_ESCAPE:
+		g_specialAKD[AKD_ESCAPE] = false;
+		break;
+	case VK_SPACE:
+		g_specialAKD[AKD_SPACE] = false;
+		break;
+	};
+}
+
+static bool IsSpecialAKD(int lastvirtkey)
+{
+	if (VK_TAB == lastvirtkey)
+		return g_specialAKD[AKD_TAB];
+	else if (VK_ESCAPE == lastvirtkey)
+		return g_specialAKD[AKD_ESCAPE];
+	else if (VK_SPACE == lastvirtkey)
+		return g_specialAKD[AKD_SPACE];
+
+	return false;
+}
+
+//===========================================================================
+
 BYTE __stdcall KeybReadData (WORD, WORD, BYTE, BYTE, ULONG)
 {
 	LogFileTimeUntilFirstKeyRead();
@@ -428,6 +480,9 @@ BYTE __stdcall KeybReadFlag (WORD, WORD, BYTE, BYTE, ULONG)
 
 	keywaiting = 0;
 
+	if (IsSpecialAKD(lastvirtkey))
+		return keycode | 0x80;
+
 	return keycode | ((GetKeyState(lastvirtkey) < 0) ? 0x80 : 0);
 }
 

source/Keyboard.h

@@ -14,6 +14,8 @@ BYTE    KeybGetKeycode ();
 void    KeybQueueKeypress (int,BOOL);
 void    KeybToggleCapsLock ();
 void    KeybToggleP8ACapsLock ();
+void    KeybSpecialKeydown(DWORD wparam);
+void    KeybSpecialKeyup(DWORD wparam);
 void    KeybSetSnapshot_v1(const BYTE LastKey);
 void    KeybSaveSnapshot(class YamlSaveHelper& yamlSaveHelper);
 void    KeybLoadSnapshot(class YamlLoadHelper& yamlLoadHelper);