Make wrapper for forcing existing instance on top

Also renamed constant 'DEFAULT_WINDOW_CLASS_NAME' to 'GAME_WINDOW_CLASS_NAME'.

r5dev/sdklauncher/CMakeLists.txt

@@ -25,6 +25,11 @@ add_sources( SOURCE_GROUP "Resource"
     "${ENGINE_SOURCE_DIR}/resource/sdklauncher.rc"
 )
 
+add_sources( SOURCE_GROUP "Windows"
+    "${ENGINE_SOURCE_DIR}/windows/window.cpp"
+    "${ENGINE_SOURCE_DIR}/windows/window.h"
+)
+
 end_sources()
 
 set_target_properties( ${PROJECT_NAME} PROPERTIES OUTPUT_NAME

r5dev/sdklauncher/sdklauncher.cpp

@@ -7,6 +7,7 @@
 #include "base_surface.h"
 #include "advanced_surface.h"
 #include "sdklauncher.h"
+#include "sdklauncher_utils.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 // Purpose: initializes and runs the user interface
@@ -345,7 +346,7 @@ BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
         return FALSE;
     }
 
-    if (strcmp(szClassName, DEFAULT_WINDOW_CLASS_NAME) == 0)
+    if (strcmp(szClassName, GAME_WINDOW_CLASS_NAME) == 0)
     {
         pHandles->push_back(hwnd);
     }
@@ -390,24 +391,12 @@ void LauncherLoggerSink(LogType_t logType, LogLevel_t logLevel, eDLL_T context,
 ///////////////////////////////////////////////////////////////////////////////
 int main(int argc, char* argv[]/*, char* envp[]*/)
 {
-    HANDLE singleInstanceMutex = CreateMutexW(NULL, TRUE, L"SDKLauncher_Mutex");
-
-    if (singleInstanceMutex == NULL || GetLastError() == ERROR_ALREADY_EXISTS)
+    // Only 1 instance at a time.
+    if (SDKLauncher_ForceExistingInstanceOnTop())
     {
-        HWND existingApp = FindWindowW(0, L"SDKLauncher001");
-        if (existingApp) SetForegroundWindow(existingApp);
         return EXIT_SUCCESS;
     }
 
-    WNDCLASSEXW wcex = { sizeof(wcex) };
-    wcex.lpszClassName = L"SDKLauncher001";
-
-    if (!RegisterClassExW(&wcex))
-    {
-        DWORD dwError = GetLastError();
-        return dwError;
-    }
-
     g_pLauncher->InitLogger();
     if (argc < 2)
     {

r5dev/sdklauncher/sdklauncher_const.h

@@ -7,7 +7,8 @@
 //#define DEDI_LAUNCHER
 
 #define GAME_CFG_PATH "platform\\cfg\\system\\"
-#define DEFAULT_WINDOW_CLASS_NAME "Respawn001"
+#define GAME_WINDOW_CLASS_NAME "Respawn001"
+
 #define LAUNCHER_SETTING_FILE "launcher.vdf"
 
 // Gigabytes.

r5dev/sdklauncher/sdklauncher_utils.cpp

@@ -1,4 +1,5 @@
 #include "sdklauncher_utils.h"
+#include "windows/window.h"
 #include "tier1/xorstr.h"
 #include "tier1/utlmap.h"
 #include "tier2/curlutils.h"
@@ -528,3 +529,19 @@ bool SDKLauncher_CheckForUpdate(const bool bPreRelease)
 	// This evaluates to '0' if the version tags are equal.
 	return !(localManifest["version"] == remoteManifest["tag_name"]);
 }
+
+//----------------------------------------------------------------------------
+// Purpose: 
+//----------------------------------------------------------------------------
+bool SDKLauncher_ForceExistingInstanceOnTop()
+{
+	HWND existingApp = FindWindowA(FORM_DEFAULT_CLASS_NAME, NULL);
+
+	if (existingApp)
+	{
+		ForceForegroundWindow(existingApp);
+		return true;
+	}
+
+	return false;
+}

r5dev/sdklauncher/sdklauncher_utils.h

@@ -19,3 +19,5 @@ bool SDKLauncher_InstallAssetList(const bool bOptionalAssets,
 
 bool SDKLauncher_CheckDiskSpace(const int minRequiredSpace, int* const availableSize = nullptr);
 bool SDKLauncher_CheckForUpdate(const bool bPreRelease);
+
+bool SDKLauncher_ForceExistingInstanceOnTop();