Game window respects Windows theme setting

1 files changed, 25 insertions, 1 deletions

diff --git a/source/application/StarMainApplication_sdl.cpp b/source/application/StarMainApplication_sdl.cpp
index 2130968..7b1601f 100644
--- a/source/application/StarMainApplication_sdl.cpp
+++ b/source/application/StarMainApplication_sdl.cpp
@@ -10,6 +10,11 @@
 #include "SDL2/SDL.h"
 #include "StarPlatformServices_pc.hpp"
 
+#ifdef STAR_SYSTEM_WINDOWS
+#include "SDL2/SDL_syswm.h"
+#include <dwmapi.h>
+#endif
+
 namespace Star {
 
 Maybe<Key> keyFromSdlKeyCode(SDL_Keycode sym) {
@@ -268,11 +273,30 @@ public:
     m_sdlWindow = SDL_CreateWindow(m_windowTitle.utf8Ptr(), SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
         m_windowSize[0], m_windowSize[1], SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
     if (!m_sdlWindow)
-      throw ApplicationException::format("Application: Could not create SDL window: {}", SDL_GetError());
+      throw ApplicationException::format("Application: Could not create SDL Window: {}", SDL_GetError());
 
     SDL_ShowWindow(m_sdlWindow);
     SDL_RaiseWindow(m_sdlWindow);
 
+// Makes the window border black. From https://github.com/libsdl-org/SDL/commit/89948787#diff-f2ae5c36a8afc0a9a343a6664ab306da2963213e180af8cd97b12397dcbb9ae7R1478
+#ifdef STAR_SYSTEM_WINDOWS
+    if (void* handle = SDL_LoadObject("dwmapi.dll")) {
+      if (auto DwmSetWindowAttributeFunc = (decltype(&DwmSetWindowAttribute))SDL_LoadFunction(handle, "DwmSetWindowAttribute")) {
+        SDL_SysWMinfo wmInfo{};
+        SDL_VERSION(&wmInfo.version);
+        SDL_GetWindowWMInfo(m_sdlWindow, &wmInfo);
+        DWORD type{}, value{}, count = sizeof(value);
+        LSTATUS status = RegGetValue(HKEY_CURRENT_USER,
+                             TEXT("Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize"),
+                             TEXT("AppsUseLightTheme"),
+                             RRF_RT_REG_DWORD, &type, &value, &count);
+        BOOL enabled = status == ERROR_SUCCESS && type == REG_DWORD && value == 0;
+        DwmSetWindowAttributeFunc(wmInfo.info.win.window, DWMWA_USE_IMMERSIVE_DARK_MODE, &enabled, sizeof(enabled));
+      }
+      SDL_UnloadObject(handle);
+    }
+#endif
+
     int width;
     int height;
     SDL_GetWindowSize(m_sdlWindow, &width, &height);