4 files changed, 37 insertions, 5 deletions
diff --git a/include/cru/platform/Check.h b/include/cru/platform/Check.h
index 270150e8..202ee86e 100644
--- a/include/cru/platform/Check.h
+++ b/include/cru/platform/Check.h
@@ -35,4 +35,32 @@ std::shared_ptr<TTarget> CheckPlatform(const std::shared_ptr<TSource>& resource,
   }
   return result;
 }
+
+template <typename TTarget>
+TTarget* CheckPlatform(IPlatformResource* resource,
+                       std::string target_platform) {
+  if (resource == nullptr) return nullptr;
+  const auto result = dynamic_cast<TTarget*>(resource);
+  if (result == nullptr) {
+    throw PlatformNotMatchException(
+        resource->GetPlatformIdUtf8(), target_platform,
+        "Try to convert resource to target platform failed.");
+  }
+  return result;
+}
+
+template <typename TTarget, typename TSource>
+std::shared_ptr<TTarget> CheckPlatform(const std::shared_ptr<TSource>& resource,
+                                       std::string target_platform) {
+  if (resource == nullptr) return nullptr;
+  static_assert(std::is_base_of_v<IPlatformResource, TSource>,
+                "TSource must be a subclass of IPlatformResource.");
+  const auto result = std::dynamic_pointer_cast<TTarget>(resource);
+  if (result == nullptr) {
+    throw PlatformNotMatchException(
+        resource->GetPlatformIdUtf8(), target_platform,
+        "Try to convert resource to target platform failed.");
+  }
+  return result;
+}
 }  // namespace cru::platform
diff --git a/include/cru/platform/Exception.h b/include/cru/platform/Exception.h
index 25017869..f8ed5b0c 100644
--- a/include/cru/platform/Exception.h
+++ b/include/cru/platform/Exception.h
@@ -14,7 +14,7 @@ class CRU_PLATFORM_API PlatformNotMatchException : public PlatformException {
  public:
   PlatformNotMatchException(
       std::string resource_platform, std::string target_platform,
-      std::optional<std::string> additional_message = std::nullopt);
+      std::optional<std::string_view> additional_message = std::nullopt);
 
   PlatformNotMatchException(
       StringView resource_platform, StringView target_platform,
diff --git a/include/cru/platform/Resource.h b/include/cru/platform/Resource.h
index 69210348..a16a9dbd 100644
--- a/include/cru/platform/Resource.h
+++ b/include/cru/platform/Resource.h
@@ -11,5 +11,7 @@ struct CRU_PLATFORM_API IPlatformResource : virtual Interface {
   virtual String GetPlatformId() const = 0;
 
   virtual String GetDebugString() { return String(); }
+
+  virtual std::string GetPlatformIdUtf8() const;
 };
 }  // namespace cru::platform
diff --git a/include/cru/platform/gui/xcb/Window.h b/include/cru/platform/gui/xcb/Window.h
index e09fdbfb..f9fbf735 100644
--- a/include/cru/platform/gui/xcb/Window.h
+++ b/include/cru/platform/gui/xcb/Window.h
@@ -18,10 +18,10 @@ class XcbWindow : public XcbResource, public virtual INativeWindow {
   explicit XcbWindow(XcbUiApplication* application);
   ~XcbWindow() override;
 
-  virtual void Close() = 0;
+  void Close() override;
 
-  virtual INativeWindow* GetParent() = 0;
-  virtual void SetParent(INativeWindow* parent) = 0;
+  INativeWindow* GetParent() override;
+  void SetParent(INativeWindow* parent) override;
 
   virtual WindowStyleFlag GetStyleFlag() = 0;
   virtual void SetStyleFlag(WindowStyleFlag flag) = 0;
@@ -91,9 +91,11 @@ class XcbWindow : public XcbResource, public virtual INativeWindow {
  private:
   XcbUiApplication* application_;
   std::optional<xcb_window_t> xcb_window_;
-  cairo_surface_t *cairo_surface_;
+  cairo_surface_t* cairo_surface_;
   Size current_size_;
 
+  XcbWindow* parent_;
+
   Event<std::nullptr_t> create_event_;
   Event<std::nullptr_t> destroy_event_;
   Event<std::nullptr_t> paint_event_;