Added the ability to disable Switchy

* Added the ability to disable Switchy
* Added debug messages
* Fixed bugs

Switchy/main.c

@@ -1,4 +1,7 @@
 #include <Windows.h>
+#if _DEBUG
+#include <stdio.h>
+#endif // _DEBUG
 
 typedef NTSTATUS(WINAPI* RtlGetVersionPtr)(PRTL_OSVERSIONINFOW);
 
@@ -9,12 +12,14 @@ typedef struct {
 
 void ShowError(LPCSTR message);
 DWORD GetOSVersion();
+void ToggleCapsLockState();
 LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam);
 
 
 HHOOK hHook;
 BOOL modifier;
-BOOL processed = FALSE;
+BOOL enabled = TRUE;
+BOOL capsLockPressed = FALSE;
 BOOL winPressed = FALSE;
 
 Settings settings = {
@@ -24,11 +29,14 @@ Settings settings = {
 
 
 int main(int argc, char** argv) {
-	if (argc > 1 && argv[1] == "nopopup") {
+	if (argc > 1 && strcmp(argv[1], "nopopup") == 0) {
 		settings.popup = FALSE;
 	} else {
 		settings.popup = GetOSVersion() >= 10;
 	}
+#if _DEBUG
+	printf("Pop-up %s\n", settings.popup ? "enabled" : "disabled");
+#endif
 
 	HANDLE hMutex = CreateMutex(0, 0, "Switchy");
 	if (GetLastError() == ERROR_ALREADY_EXISTS) {
@@ -38,7 +46,7 @@ int main(int argc, char** argv) {
 
 	hHook = SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, 0, 0);
 	if (hHook == NULL) {
-		ShowError("Error with \"SetWindowsHookEx\"");
+		ShowError("Error calling \"SetWindowsHookEx(...)\"");
 		return 1;
 	}
 
@@ -74,26 +82,48 @@ DWORD GetOSVersion() {
 }
 
 
-LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam) {
-	if (nCode == HC_ACTION) {
-		KBDLLHOOKSTRUCT* key = (KBDLLHOOKSTRUCT*)lParam;
+void ToggleCapsLockState() {
+	UnhookWindowsHookEx(hHook);
+	keybd_event(VK_CAPITAL, 0x3A, 0, 0);
+	keybd_event(VK_CAPITAL, 0x3A, KEYEVENTF_KEYUP, 0);
+	hHook = SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, 0, 0);
+#if _DEBUG
+	printf("Caps Lock state has been toggled\n");
+#endif // _DEBUG
+}
 
+
+LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam) {
+	KBDLLHOOKSTRUCT* key = (KBDLLHOOKSTRUCT*)lParam;
+	if (nCode == HC_ACTION && !(key->flags & LLKHF_INJECTED)) {
+#if _DEBUG
+		const char* keyStatus = (wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN) ? "pressed" : "released";
+		printf("Key %d has been %s\n", key->vkCode, keyStatus);
+#endif // _DEBUG
 		if (key->vkCode == VK_CAPITAL) {
-			if (wParam == WM_KEYDOWN) {
-				if (GetKeyState(settings.modifier)) {
-					UnhookWindowsHookEx(hHook);
-					keybd_event(VK_CAPITAL, 0x3a, 0, 0);
-					keybd_event(VK_CAPITAL, 0x3a, KEYEVENTF_KEYUP, 0);
-					hHook = SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, 0, 0);
-					return 1;
-				}
-				else if (!processed) {
-					processed = TRUE;
+			if (wParam == WM_SYSKEYDOWN) {
+				enabled = !enabled;
+#if _DEBUG
+				printf("Switchy has been %s\n", enabled ? "enabled" : "disabled");
+#endif // _DEBUG
+				return 1;
+			}
 
+			if (!enabled) {
+				return CallNextHookEx(NULL, nCode, wParam, lParam);
+			}
+
+			if (wParam == WM_KEYDOWN && !capsLockPressed) {
+				capsLockPressed = TRUE;
+
+				if (GetKeyState(settings.modifier) & 0x8000) {
+					ToggleCapsLockState();
+					return 1;
+				} else {
 					if (settings.popup) {
-						keybd_event(VK_LWIN, 0x3a, 0, 0);
-						keybd_event(VK_SPACE, 0x3a, 0, 0);
-						keybd_event(VK_SPACE, 0x3a, KEYEVENTF_KEYUP, 0);
+						keybd_event(VK_LWIN, 0x3A, 0, 0);
+						keybd_event(VK_SPACE, 0x3A, 0, 0);
+						keybd_event(VK_SPACE, 0x3A, KEYEVENTF_KEYUP, 0);
 						winPressed = TRUE;
 					}
 					else {
@@ -103,19 +133,17 @@ LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam) {
 							PostMessage(hWnd, WM_INPUTLANGCHANGEREQUEST, 0, (LPARAM)HKL_NEXT);
 						}
 					}
-
-					return 1;
 				}
 			}
 			else if (wParam == WM_KEYUP) {
-				processed = FALSE;
+				capsLockPressed = FALSE;
 
 				if (winPressed) {
-					keybd_event(VK_LWIN, 0x3a, KEYEVENTF_KEYUP, 0);
+					keybd_event(VK_LWIN, 0x3A, KEYEVENTF_KEYUP, 0);
 				}
-
-				return 1;
 			}
+
+			return 1;
 		}
 	}