Merge pull request #10 from ITachiLab/feature/#9-detect-admin

[GH-9] Warning message when running Hotkey Detective as a non-admin

CMakeLists.txt

@@ -5,11 +5,16 @@ add_subdirectory(dll)
 
 set(CMAKE_CXX_STANDARD 17)
 
+# This option will terminate all strings in the resources with proper null
+# characters.
+set(CMAKE_RC_FLAGS "/n")
+
 add_definitions(-DUNICODE)
 
 add_executable(HotkeyDetective WIN32
         src/MainWindow.cpp
         src/HotkeyTable.cpp
+        src/WindowsUtils.cpp
         src/Core.cpp
         src/main.cpp
         res/resources.rc)

README.adoc

@@ -80,6 +80,12 @@ system.
 
 == Changelog
 
+=== 1.1.0
+
+Added a warning message when trying to run Hotkey Detective as a non-admin user.
+This will greatly improve user experience, especially among users not reading
+readmes (I'm not reading them too, though).
+
 === 1.0.0
 
 The first major that brings up a basic but friendly UI in place of the scary

include/WindowsUtils.h

@@ -0,0 +1,30 @@
+#ifndef HOTKEY_DETECTIVE_INCLUDE_WINDOWSUTILS_H_
+#define HOTKEY_DETECTIVE_INCLUDE_WINDOWSUTILS_H_
+
+#include <windows.h>
+
+namespace WindowsUtils {
+/*!
+ * \brief Check if the running user has administrator privileges.
+ *
+ * @return If the running user has administrator privileges, the function
+ * returns true. Otherwise, when the user doesn't belong to the "Administrators"
+ * group, or there are errors while checking the affiliation, the result is
+ * false.
+ */
+BOOL isUserAdmin();
+
+/*!
+ * \brief Return a read-only pointer to a string resource.
+ *
+ * This function can be used to retrieve a read-only pointer to any string
+ * resource defined in this application.
+ *
+ * @param[in] strResource an ID of the string resource
+ * @return If the function succeeds, the return value is a read-only pointer to
+ * the desired string resource. Otherwise, the return value is a nullptr.
+ */
+const wchar_t *resStr(int strResource);
+}
+
+#endif //HOTKEY_DETECTIVE_INCLUDE_WINDOWSUTILS_H_

res/resource.h

@@ -2,6 +2,9 @@
 #define IDC_STATIC (-1)
 #endif
 
-#define ID_TABLE 101
+#define ID_TABLE_HOTKEYS 101
 
-#define IDI_MAIN_ICON 200
+#define ID_ICON_MAIN 200
+
+#define ID_STRING_APP_NAME      300
+#define ID_STRING_ADMIN_WARNING 301

res/resources.rc

@@ -1,3 +1,9 @@
 #include "resource.h"
 
-IDI_MAIN_ICON ICON "main.ico"
+ID_ICON_MAIN ICON "main.ico"
+
+STRINGTABLE
+BEGIN
+    ID_STRING_APP_NAME "Hotkey Detective"
+    ID_STRING_ADMIN_WARNING "You are trying to run Hotkey Detective without administrator privileges. If you proceed, Hotkey Detective won't be able to detect all hotkeys. Are you sure you want to continue?"
+END

src/HotkeyTable.cpp

@@ -67,7 +67,7 @@ void HotkeyTable::addToWindow(HWND parentWindow, HINSTANCE hInstance) {
                                 rcClient.right - rcClient.left,
                                 rcClient.bottom - rcClient.top,
                                 parentWindow,
-                                (HMENU) ID_TABLE,
+                                (HMENU) ID_TABLE_HOTKEYS,
                                 hInstance,
                                 NULL);
 

src/MainWindow.cpp

@@ -27,7 +27,7 @@ MainWindow::MainWindow(const HINSTANCE hInstance)
 
     RegisterClassW(&wc);
 
-    mainIcon = LoadIconW(hInstance, MAKEINTRESOURCE(IDI_MAIN_ICON));
+    mainIcon = LoadIconW(hInstance, MAKEINTRESOURCE(ID_ICON_MAIN));
 }
 
 LRESULT MainWindow::windowProc(HWND hwnd, UINT uMsg, WPARAM wParam,

src/WindowsUtils.cpp

@@ -0,0 +1,35 @@
+#include "WindowsUtils.h"
+
+#include <securitybaseapi.h>
+
+BOOL WindowsUtils::isUserAdmin() {
+    SID_IDENTIFIER_AUTHORITY authority = SECURITY_NT_AUTHORITY;
+    PSID administratorsGroup;
+
+    BOOL result = AllocateAndInitializeSid(&authority, 2,
+                                           SECURITY_BUILTIN_DOMAIN_RID,
+                                           DOMAIN_ALIAS_RID_ADMINS,
+                                           0, 0, 0, 0, 0, 0,
+                                           &administratorsGroup);
+
+    if (result) {
+        // If this call fails, that means an error, so we can as well assume
+        // the user has no admin rights.
+        if (!CheckTokenMembership(nullptr, administratorsGroup, &result)) {
+            result = FALSE;
+        }
+
+        FreeSid(administratorsGroup);
+    }
+
+    return result;
+}
+
+const wchar_t *WindowsUtils::resStr(int strResource) {
+    HINSTANCE hInstance = GetModuleHandleW(nullptr);
+
+    const wchar_t* strPtr = nullptr;
+    LoadStringW(hInstance, strResource, (LPWSTR) &strPtr, 0);
+
+    return strPtr;
+}

src/main.cpp

@@ -9,15 +9,28 @@
 
 #include <HotkeyTable.h>
 #include <MainWindow.h>
+#include <WindowsUtils.h>
+#include <resource.h>
 
 int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                     PWSTR cmdLine, int cmdShow) {
 
+    if (!WindowsUtils::isUserAdmin()) {
+        int userSelection = MessageBoxW(
+                nullptr, WindowsUtils::resStr(ID_STRING_ADMIN_WARNING),
+                WindowsUtils::resStr(ID_STRING_APP_NAME),
+                MB_YESNO | MB_ICONWARNING);
+
+        if (userSelection == IDNO) {
+            return 0;
+        }
+    }
+
     MainWindow *window = MainWindow::GetInstance(hInstance);
 
     ShowWindow(window->getHandle(), cmdShow);
 
-    MSG msg = { };
+    MSG msg = {};
 
     while (GetMessageW(&msg, NULL, 0, 0)) {
         TranslateMessage(&msg);