[idd] helper: implement basic config class

idd/LGIddHelper/CConfigWindow.h

@@ -0,0 +1,20 @@
+#pragma once
+#include "CWindow.h"
+#include <functional>
+
+class CConfigWindow : public CWindow
+{
+  static ATOM s_atom;
+
+  std::function<void()> m_onDestroy;
+
+  virtual LRESULT handleMessage(UINT uMsg, WPARAM wParam, LPARAM lParam) override;
+  virtual LRESULT onCreate() override;
+  virtual LRESULT onFinal() override;
+
+public:
+  CConfigWindow();
+  static bool registerClass();
+
+  void onDestroy(std::function<void()> func) { m_onDestroy = std::move(func); }
+};