add reload

main.cpp

@@ -1,12 +1,13 @@
 #include <print>
 #include <thread>
 #include <chrono>
+#include <filesystem>
 #include <RmlUi/Core.h>
 #include <RmlUi/Debugger.h>
 #include <RmlUi_Backend.h>
 #include <RmlUi_Include_Windows.h>
 
-void LoadFonts()
+void load_fonts()
 {
     const Rml::String directory = "assets/";
 
@@ -48,17 +49,38 @@ int main()
         return -1;
     }
 
-    LoadFonts();
+    load_fonts();
 
-    if (Rml::ElementDocument* document = context->LoadDocument("assets/demo.rml"))
+    Rml::ElementDocument* document = context->LoadDocument("assets/demo.rml");
+    if (document)
     {
         document->Show();
     }
 
+    const std::wstring assets_path = std::filesystem::absolute(
+        std::filesystem::current_path() / "assets").wstring();
+
+    HANDLE hNotif = FindFirstChangeNotification(assets_path.c_str(),
+        TRUE, FILE_NOTIFY_CHANGE_LAST_WRITE);
+
     bool running = true;
     while (running)
     {
-        // Handle input and window events.
+        if (const DWORD wait_result = WaitForSingleObject(hNotif, 100);
+            wait_result == WAIT_OBJECT_0)
+        {
+            if (document)
+                context->UnloadDocument(document);
+            context->Update();
+            std::this_thread::sleep_for(std::chrono::milliseconds(100));
+            document = context->LoadDocument("assets/demo.rml");
+            if (document)
+            {
+                document->ReloadStyleSheet();
+                document->Show();
+            }
+            FindNextChangeNotification(hNotif);
+        }
         running = Backend::ProcessEvents(context);
         context->Update();
         Backend::BeginFrame();