Split Win32 main window session state

src/platform_windows/windows_main_window_session.cpp

@@ -0,0 +1,47 @@
+#include "pch.h"
+
+#include "platform_windows/windows_main_window_session.h"
+
+namespace pp::platform::windows {
+namespace {
+
+struct RetainedMainWindowSessionState final {
+    HWND handle{};
+    wchar_t title[512]{};
+    bool sandboxed = false;
+};
+
+[[nodiscard]] RetainedMainWindowSessionState& retained_main_window_session_state() noexcept
+{
+    static RetainedMainWindowSessionState state;
+    return state;
+}
+
+}
+
+HWND& retained_main_window_handle_ref() noexcept
+{
+    return retained_main_window_session_state().handle;
+}
+
+wchar_t* retained_main_window_title_buffer() noexcept
+{
+    return retained_main_window_session_state().title;
+}
+
+const wchar_t* retained_main_window_title() noexcept
+{
+    return retained_main_window_session_state().title;
+}
+
+bool retained_main_window_sandboxed() noexcept
+{
+    return retained_main_window_session_state().sandboxed;
+}
+
+void set_retained_main_window_sandboxed(bool sandboxed) noexcept
+{
+    retained_main_window_session_state().sandboxed = sandboxed;
+}
+
+}