Updated Dark mode title bar changed for Windows

Added dynamical change of the title bar if main dark/light theme changed

src/api/api.c

@@ -20,3 +20,23 @@ void api_load_libs(lua_State *L) {
     luaL_requiref(L, libs[i].name, libs[i].func, 1);
   }
 }
+
+#ifdef _WIN32
+int api_windows_dark_theme_activated()
+ {
+     DWORD   type;
+     DWORD   value;
+     DWORD   count = 4;
+     LSTATUS st = RegGetValue(
+         HKEY_CURRENT_USER,
+         TEXT("Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize"),
+         TEXT("AppsUseLightTheme"),
+         RRF_RT_REG_DWORD,
+         &type,
+         &value,
+         &count );
+     if ( st == ERROR_SUCCESS && type == REG_DWORD )
+         return value == 0? 1 : 0;
+     return 0;
+ }
+ #endif

src/api/api.h

@@ -11,4 +11,11 @@
 
 void api_load_libs(lua_State *L);
 
+#ifdef _WIN32
+  #define WINDOWS_DARK_MODE_BEFORE_20H1 19
+  #define WINDOWS_DARK_MODE 20
+  #include <windows.h>
+  int api_windows_dark_theme_activated();
+#endif
+
 #endif

src/api/system.c

@@ -11,6 +11,8 @@
   #include <direct.h>
   #include <windows.h>
   #include <fileapi.h>
+  #include "SDL_syswm.h"
+  #include <dwmapi.h>
 #endif
 
 extern SDL_Window *window;
@@ -107,7 +109,30 @@ top:
     case SDL_QUIT:
       lua_pushstring(L, "quit");
       return 1;
+      
+#ifdef _WIN32
+     case SDL_SYSWMEVENT:      
+       if (e.syswm.msg->msg.win.msg == WM_SETTINGCHANGE) {
+         HWND hwnd = e.syswm.msg->msg.win.hwnd;
+         LPARAM lParam = e.syswm.msg->msg.win.lParam;
+         if (lParam) {
+           int current_immersive_mode = 0;
+           if(DwmGetWindowAttribute(hwnd, WINDOWS_DARK_MODE_BEFORE_20H1, &current_immersive_mode, 4) != FACILITY_NULL)
+             DwmGetWindowAttribute(hwnd, WINDOWS_DARK_MODE, &current_immersive_mode, 4);
 
+           int current_dark_mode = api_windows_dark_theme_activated();
+
+           if (current_dark_mode != current_immersive_mode) {
+             if (DwmSetWindowAttribute(hwnd, WINDOWS_DARK_MODE_BEFORE_20H1, &current_dark_mode, 4) != 0)
+               DwmSetWindowAttribute(hwnd, WINDOWS_DARK_MODE, &current_dark_mode, 4);
+
+           }
+
+         }
+       }
+       return 0;
+
+ #endif
     case SDL_WINDOWEVENT:
       if (e.window.event == SDL_WINDOWEVENT_RESIZED) {
         ren_resize_window();

src/main.c

@@ -30,7 +30,7 @@ static double get_scale(void) {
 #endif
 }
 
-#if _WIN32
+#ifdef _WIN32
 static HWND GetWindowHandle(SDL_Window* window){
     SDL_SysWMinfo sysInfo;
 
@@ -38,39 +38,6 @@ static HWND GetWindowHandle(SDL_Window* window){
     SDL_GetWindowWMInfo(window, &sysInfo);
     return sysInfo.info.win.window;
 }
-
-static int GetWinDarkMode() {
-  
-     LPCSTR subKey = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize";
-     LPCSTR pValue = "AppsUseLightTheme";
-     DWORD options = 0;
-     REGSAM samDesired = KEY_READ;
-     HKEY OpenResult;
-     DWORD flags = RRF_RT_ANY;
-
-     //Allocationg memory for a DWORD value.
-     DWORD dataType;
-
-     WCHAR value[255];
-     PVOID pvData = value;
-
-     DWORD size = sizeof(value);
-
-     LONG err = RegOpenKeyEx(HKEY_CURRENT_USER, subKey, options, samDesired, &OpenResult);
-
-     if (err == ERROR_SUCCESS) {
-      err = RegGetValueA(OpenResult, NULL, pValue, flags, &dataType, pvData, &size);
-      if (err == ERROR_SUCCESS) {
-        return *(DWORD*)pvData;
-      }
-      else
-        err = 1;
-      RegCloseKey(OpenResult);
-     }
-     else
-      err = 1;
-     return err;
-}
 #endif
 
 
@@ -117,8 +84,6 @@ static void init_window_icon(void) {
 #define LITE_OS_HOME "USERPROFILE"
 #define LITE_PATHSEP_PATTERN "\\\\"
 #define LITE_NONPATHSEP_PATTERN "[^\\\\]+"
-#define USE_IMMERSIVE_DARK_MODE_BEFORE_20H1 19
-#define USE_IMMERSIVE_DARK_MODE 20
 #else
 #define LITE_OS_HOME "HOME"
 #define LITE_PATHSEP_PATTERN "/"
@@ -159,12 +124,13 @@ int main(int argc, char **argv) {
   window = SDL_CreateWindow(
     "", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, dm.w * 0.8, dm.h * 0.8,
     SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI | SDL_WINDOW_HIDDEN);
-  #if _WIN32
-    HWND handle = GetWindowHandle(window);
-    int mode = GetWinDarkMode()? 0 : 1;
-    if (DwmSetWindowAttribute(handle, USE_IMMERSIVE_DARK_MODE_BEFORE_20H1, &mode, 4) != 0)
-      DwmSetWindowAttribute(handle, USE_IMMERSIVE_DARK_MODE, &mode, 4);
-  #endif
+#ifdef _WIN32
+   HWND handle = GetWindowHandle(window);
+   int mode = api_windows_dark_theme_activated();
+
+   if (DwmSetWindowAttribute(handle, WINDOWS_DARK_MODE_BEFORE_20H1, &mode, 4) != 0)
+     DwmSetWindowAttribute(handle, WINDOWS_DARK_MODE, &mode, 4);
+#endif
   init_window_icon();
   ren_init(window);