Refactor.

83 files changed, 755 insertions, 649 deletions

diff --git a/art/project_structure.png b/art/project_structure.png
new file mode 100644
index 00000000..51e15d95
--- /dev/null
+++ b/art/project_structure.png
diff --git a/include/cru/platform/debug.hpp b/include/cru/platform/debug.hpp
index 21c2b646..18472201 100644
--- a/include/cru/platform/debug.hpp
+++ b/include/cru/platform/debug.hpp
@@ -3,6 +3,6 @@
 
 #include <string_view>
 
-namespace cru::platform::debug {
+namespace cru::platform {
 void DebugMessage(const std::wstring_view& message);
 }
diff --git a/include/cru/platform/exception.hpp b/include/cru/platform/exception.hpp
new file mode 100644
index 00000000..6dae08c5
--- /dev/null
+++ b/include/cru/platform/exception.hpp
@@ -0,0 +1,11 @@
+#pragma once
+#include "cru/common/pre_config.hpp"
+
+#include <stdexcept>
+
+namespace cru::platform {
+class PlatformException : public std::runtime_error {
+ public:
+  using runtime_error::runtime_error; // inherent constructors
+};
+}  // namespace cru::platform
diff --git a/include/cru/platform/brush.hpp b/include/cru/platform/graph/brush.hpp
index 713d302d..8ffbfc97 100644
--- a/include/cru/platform/brush.hpp
+++ b/include/cru/platform/graph/brush.hpp
@@ -3,7 +3,7 @@
 
 #include "cru/common/ui_base.hpp"
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Brush : public virtual Interface {};
 
 struct SolidColorBrush : public virtual Brush {
diff --git a/include/cru/platform/font.hpp b/include/cru/platform/graph/font.hpp
index 750aaae1..5af369e5 100644
--- a/include/cru/platform/font.hpp
+++ b/include/cru/platform/graph/font.hpp
@@ -1,7 +1,7 @@
 #pragma once
 #include "cru/common/base.hpp"
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct FontDescriptor : virtual Interface {
 
 };
diff --git a/include/cru/platform/geometry.hpp b/include/cru/platform/graph/geometry.hpp
index aa93fe37..7a7ad8b2 100644
--- a/include/cru/platform/geometry.hpp
+++ b/include/cru/platform/graph/geometry.hpp
@@ -1,10 +1,9 @@
 #pragma once
 #include "cru/common/base.hpp"
 
-#include "basic_types.hpp"
 #include "cru/common/ui_base.hpp"
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Geometry : virtual Interface {
   virtual bool FillContains(const ui::Point& point) = 0;
 };
diff --git a/include/cru/platform/graph_factory.hpp b/include/cru/platform/graph/graph_factory.hpp
index f6122241..51cf6f15 100644
--- a/include/cru/platform/graph_factory.hpp
+++ b/include/cru/platform/graph/graph_factory.hpp
@@ -7,13 +7,15 @@
 #include <string>
 #include <string_view>
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct SolidColorBrush;
 struct GeometryBuilder;
 struct FontDescriptor;
 struct TextLayout;
 
 struct GraphFactory : virtual Interface {
+  static GraphFactory* GetInstance();
+
   virtual SolidColorBrush* CreateSolidColorBrush(const ui::Color& color) = 0;
   virtual GeometryBuilder* CreateGeometryBuilder() = 0;
   virtual FontDescriptor* CreateFontDescriptor(
diff --git a/include/cru/platform/painter.hpp b/include/cru/platform/graph/painter.hpp
index b7b89fc9..199ebbad 100644
--- a/include/cru/platform/painter.hpp
+++ b/include/cru/platform/graph/painter.hpp
@@ -2,9 +2,9 @@
 #include "cru/common/base.hpp"
 
 #include "cru/common/ui_base.hpp"
-#include "matrix.hpp"
+#include "../matrix.hpp"
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Brush;
 struct Geometry;
 struct TextLayout;
diff --git a/include/cru/platform/painter_util.hpp b/include/cru/platform/graph/painter_util.hpp
index 5711d099..c137e8cb 100644
--- a/include/cru/platform/painter_util.hpp
+++ b/include/cru/platform/graph/painter_util.hpp
@@ -4,7 +4,7 @@
 #include <functional>
 #include <type_traits>
 
-namespace cru::platform::util {
+namespace cru::platform::graph::util {
 template <typename Fn>
 inline void WithTransform(Painter* painter, const Matrix& matrix,
                           const Fn& action) {
diff --git a/include/cru/platform/text_layout.hpp b/include/cru/platform/graph/text_layout.hpp
index e43adfde..eb13c115 100644
--- a/include/cru/platform/text_layout.hpp
+++ b/include/cru/platform/graph/text_layout.hpp
@@ -7,7 +7,7 @@
 #include <string>
 #include <vector>
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct FontDescriptor;
 
 struct TextLayout : virtual Interface {
diff --git a/include/cru/platform/basic_types.hpp b/include/cru/platform/native/basic_types.hpp
index e6ab4b59..573a9e76 100644
--- a/include/cru/platform/basic_types.hpp
+++ b/include/cru/platform/native/basic_types.hpp
@@ -1,7 +1,7 @@
 #pragma once
 #include "cru/common/pre_config.hpp"
 
-namespace cru::platform {
+namespace cru::platform::native {
 struct Dpi {
   float x;
   float y;
diff --git a/include/cru/platform/native_window.hpp b/include/cru/platform/native/native_window.hpp
index f68fd3a4..a82e7a23 100644
--- a/include/cru/platform/native_window.hpp
+++ b/include/cru/platform/native/native_window.hpp
@@ -5,9 +5,11 @@
 #include "cru/common/event.hpp"
 #include "cru/common/ui_base.hpp"
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Painter;
+}
 
+namespace cru::platform::native {
 struct NativeWindow : public virtual Interface {
   // Return if the window is still valid, that is, hasn't been closed or
   // destroyed.
@@ -32,7 +34,7 @@ struct NativeWindow : public virtual Interface {
   // The lefttop of the rect is relative to screen lefttop.
   virtual void SetWindowRect(const ui::Rect& rect) = 0;
 
-  virtual Painter* BeginPaint() = 0;
+  virtual graph::Painter* BeginPaint() = 0;
 
   virtual Event<>* DestroyEvent() = 0;
   virtual Event<const ui::Size&>* ResizeEvent() = 0;
@@ -45,4 +47,4 @@ struct NativeWindow : public virtual Interface {
   virtual Event<int>* KeyDownEvent() = 0;
   virtual Event<int>* KeyUpEvent() = 0;
 };
-}  // namespace cru::platform
+}  // namespace cru::platform::ui
diff --git a/include/cru/platform/ui_applicaition.hpp b/include/cru/platform/native/ui_applicaition.hpp
index 16739f9d..8d42d813 100644
--- a/include/cru/platform/ui_applicaition.hpp
+++ b/include/cru/platform/native/ui_applicaition.hpp
@@ -1,15 +1,16 @@
 #pragma once
 #include "cru/common/base.hpp"
 
-#include "basic_types.hpp"
-
 #include <chrono>
 #include <functional>
 #include <vector>
 
-namespace cru::platform {
-struct NativeWindow;
+namespace cru::platform::graph {
 struct GraphFactory;
+}
+
+namespace cru::platform::native {
+struct NativeWindow;
 
 struct UiApplication : public virtual Interface {
   static UiApplication* GetInstance();
@@ -26,7 +27,5 @@ struct UiApplication : public virtual Interface {
 
   virtual std::vector<NativeWindow*> GetAllWindow() = 0;
   virtual NativeWindow* CreateWindow(NativeWindow* parent) = 0;
-
-  virtual GraphFactory* GetGraphFactory() = 0;
 };
-}  // namespace cru::platform
+}  // namespace cru::platform::ui
diff --git a/include/cru/platform/string_util.hpp b/include/cru/platform/string_util.hpp
index c3b9f93b..822c0c95 100644
--- a/include/cru/platform/string_util.hpp
+++ b/include/cru/platform/string_util.hpp
@@ -4,6 +4,6 @@
 #include <string>
 #include <string_view>
 
-namespace cru::platform::util {
+namespace cru::platform {
 std::string ToUtf8String(const std::wstring_view& string);
 }
diff --git a/include/cru/platform/win/win_graph_factory.hpp b/include/cru/platform/win/win_graph_factory.hpp
deleted file mode 100644
index ca83be86..00000000
--- a/include/cru/platform/win/win_graph_factory.hpp
+++ /dev/null
@@ -1,28 +0,0 @@
-#pragma once
-#include "win_pre_config.hpp"
-
-#include "../graph_factory.hpp"
-
-namespace cru::platform::win {
-class GraphManager;
-
-class WinGraphFactory : public Object, public virtual GraphFactory {
- public:
-  explicit WinGraphFactory(GraphManager* graph_manager);
-  WinGraphFactory(const WinGraphFactory& other) = delete;
-  WinGraphFactory(WinGraphFactory&& other) = delete;
-  WinGraphFactory& operator=(const WinGraphFactory& other) = delete;
-  WinGraphFactory& operator=(WinGraphFactory&& other) = delete;
-  ~WinGraphFactory() override = default;
-
-  SolidColorBrush* CreateSolidColorBrush(const ui::Color& color) override;
-  GeometryBuilder* CreateGeometryBuilder() override;
-  FontDescriptor* CreateFontDescriptor(const std::wstring_view& font_family,
-                                       float font_size);
-  TextLayout* CreateTextLayout(std::shared_ptr<FontDescriptor> font,
-                               std::wstring text);
-
- private:
-  GraphManager* graph_manager_;
-};
-}  // namespace cru::platform::win
diff --git a/include/cru/platform/win/win_painter.hpp b/include/cru/platform/win/win_painter.hpp
deleted file mode 100644
index 3c37ccb2..00000000
--- a/include/cru/platform/win/win_painter.hpp
+++ /dev/null
@@ -1,42 +0,0 @@
-#pragma once
-#include "win_pre_config.hpp"
-
-#include "../painter.hpp"
-
-namespace cru::platform::win {
-class WinNativeWindow;
-
-class WinPainter : public Object, public virtual Painter {
- public:
-  explicit WinPainter(WinNativeWindow* window);
-  WinPainter(const WinPainter& other) = delete;
-  WinPainter(WinPainter&& other) = delete;
-  WinPainter& operator=(const WinPainter& other) = delete;
-  WinPainter& operator=(WinPainter&& other) = delete;
-  ~WinPainter() override;
-
-  Matrix GetTransform() override;
-  void SetTransform(const Matrix& matrix) override;
-  void Clear(const ui::Color& color) override;
-  void StrokeRectangle(const ui::Rect& rectangle, Brush* brush,
-                               float width) override;
-  void FillRectangle(const ui::Rect& rectangle, Brush* brush) override;
-  void StrokeGeometry(Geometry* geometry, Brush* brush, float width) override;
-  void FillGeometry(Geometry* geometry, Brush* brush) override;
-  void DrawText(const ui::Point& offset, TextLayout* text_layout,
-                Brush* brush) override;
-  void EndDraw() override;
-  bool IsDisposed() override { return is_disposed; }
-
-  void EndDrawAndDeleteThis() {
-    EndDraw();
-    delete this;
-  }
-
- private:
-  WinNativeWindow* window_;
-  ID2D1RenderTarget* render_target_;
-
-  bool is_disposed = false;
-};
-}  // namespace cru::platform::win
diff --git a/include/cru/ui/control.hpp b/include/cru/ui/control.hpp
index 684af2f0..652efe89 100644
--- a/include/cru/ui/control.hpp
+++ b/include/cru/ui/control.hpp
@@ -1,7 +1,7 @@
 #pragma once
 #include "cru/common/base.hpp"
 
-#include "cru/platform/basic_types.hpp"
+#include "cru/platform/native/basic_types.hpp"
 #include "event/ui_event.hpp"
 
 #include <string_view>
@@ -127,8 +127,8 @@ class Control : public Object {
 
   //*************** region: additional mouse event ***************
  protected:
-  virtual void OnMouseClickBegin(platform::MouseButton button);
-  virtual void OnMouseClickEnd(platform::MouseButton button);
+  virtual void OnMouseClickBegin(platform::native::MouseButton button);
+  virtual void OnMouseClickEnd(platform::native::MouseButton button);
 
  private:
   Window* window_ = nullptr;
diff --git a/include/cru/ui/event/ui_event.hpp b/include/cru/ui/event/ui_event.hpp
index ba8940cb..c84116b9 100644
--- a/include/cru/ui/event/ui_event.hpp
+++ b/include/cru/ui/event/ui_event.hpp
@@ -3,11 +3,11 @@
 
 #include "cru/common/event.hpp"
 #include "cru/common/ui_base.hpp"
-#include "cru/platform/basic_types.hpp"
+#include "cru/platform/native/basic_types.hpp"
 
 #include <optional>
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Painter;
 }
 
@@ -19,9 +19,7 @@ namespace cru::ui::event {
 class UiEventArgs : public Object {
  public:
   UiEventArgs(Object* sender, Object* original_sender)
-      : sender_(sender),
-        original_sender_(original_sender),
-        handled_(false) {}
+      : sender_(sender), original_sender_(original_sender), handled_(false) {}
 
   UiEventArgs(const UiEventArgs& other) = default;
   UiEventArgs(UiEventArgs&& other) = default;
@@ -80,7 +78,8 @@ class MouseEventArgs : public UiEventArgs {
 class MouseButtonEventArgs : public MouseEventArgs {
  public:
   MouseButtonEventArgs(Object* sender, Object* original_sender,
-                       const Point& point, const platform::MouseButton button)
+                       const Point& point,
+                       const platform::native::MouseButton button)
       : MouseEventArgs(sender, original_sender, point), button_(button) {}
   MouseButtonEventArgs(const MouseButtonEventArgs& other) = default;
   MouseButtonEventArgs(MouseButtonEventArgs&& other) = default;
@@ -88,10 +87,10 @@ class MouseButtonEventArgs : public MouseEventArgs {
   MouseButtonEventArgs& operator=(MouseButtonEventArgs&& other) = default;
   ~MouseButtonEventArgs() override = default;
 
-  platform::MouseButton GetMouseButton() const { return button_; }
+  platform::native::MouseButton GetMouseButton() const { return button_; }
 
  private:
-  platform::MouseButton button_;
+  platform::native::MouseButton button_;
 };
 
 class MouseWheelEventArgs : public MouseEventArgs {
@@ -114,7 +113,7 @@ class MouseWheelEventArgs : public MouseEventArgs {
 class PaintEventArgs : public UiEventArgs {
  public:
   PaintEventArgs(Object* sender, Object* original_sender,
-                platform::Painter* painter)
+                 platform::graph::Painter* painter)
       : UiEventArgs(sender, original_sender), painter_(painter) {}
   PaintEventArgs(const PaintEventArgs& other) = default;
   PaintEventArgs(PaintEventArgs&& other) = default;
@@ -122,10 +121,10 @@ class PaintEventArgs : public UiEventArgs {
   PaintEventArgs& operator=(PaintEventArgs&& other) = default;
   ~PaintEventArgs() = default;
 
-  platform::Painter* GetPainter() const { return painter_; }
+  platform::graph::Painter* GetPainter() const { return painter_; }
 
  private:
-  platform::Painter* painter_;
+  platform::graph::Painter* painter_;
 };
 
 class FocusChangeEventArgs : public UiEventArgs {
@@ -197,4 +196,4 @@ class CharEventArgs : public UiEventArgs {
   wchar_t c_;
 };
 */
-}  // namespace cru::ui::events
+}  // namespace cru::ui::event
diff --git a/include/cru/ui/render/border_render_object.hpp b/include/cru/ui/render/border_render_object.hpp
index 35b98948..44382c63 100644
--- a/include/cru/ui/render/border_render_object.hpp
+++ b/include/cru/ui/render/border_render_object.hpp
@@ -3,7 +3,7 @@
 
 #include <memory>
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Brush;
 struct Geometry;
 }  // namespace cru::platform
@@ -32,7 +32,7 @@ struct CornerRadius {
 
 class BorderRenderObject : public RenderObject {
  public:
-  explicit BorderRenderObject(std::shared_ptr<platform::Brush> brush);
+  explicit BorderRenderObject(std::shared_ptr<platform::graph::Brush> brush);
   BorderRenderObject(const BorderRenderObject& other) = delete;
   BorderRenderObject(BorderRenderObject&& other) = delete;
   BorderRenderObject& operator=(const BorderRenderObject& other) = delete;
@@ -42,8 +42,8 @@ class BorderRenderObject : public RenderObject {
   bool IsEnabled() const { return is_enabled_; }
   void SetEnabled(bool enabled) { is_enabled_ = enabled; }
 
-  std::shared_ptr<platform::Brush> GetBrush() const { return border_brush_; }
-  void SetBrush(std::shared_ptr<platform::Brush> new_brush) {
+  std::shared_ptr<platform::graph::Brush> GetBrush() const { return border_brush_; }
+  void SetBrush(std::shared_ptr<platform::graph::Brush> new_brush) {
     border_brush_ = std::move(new_brush);
   }
 
@@ -59,7 +59,7 @@ class BorderRenderObject : public RenderObject {
 
   void Refresh() { RecreateGeometry(); }
 
-  void Draw(platform::Painter* painter) override;
+  void Draw(platform::graph::Painter* painter) override;
 
   RenderObject* HitTest(const Point& point) override;
 
@@ -83,11 +83,11 @@ class BorderRenderObject : public RenderObject {
  private:
   bool is_enabled_ = false;
 
-  std::shared_ptr<platform::Brush> border_brush_ = nullptr;
+  std::shared_ptr<platform::graph::Brush> border_brush_ = nullptr;
   Thickness border_thickness_{};
   CornerRadius corner_radius_{};
 
-  std::shared_ptr<platform::Geometry> geometry_ = nullptr;
-  std::shared_ptr<platform::Geometry> border_outer_geometry_ = nullptr;
+  std::shared_ptr<platform::graph::Geometry> geometry_ = nullptr;
+  std::shared_ptr<platform::graph::Geometry> border_outer_geometry_ = nullptr;
 };
 }  // namespace cru::ui::render
diff --git a/include/cru/ui/render/flex_layout_render_object.hpp b/include/cru/ui/render/flex_layout_render_object.hpp
index 278bf8c2..d225e679 100644
--- a/include/cru/ui/render/flex_layout_render_object.hpp
+++ b/include/cru/ui/render/flex_layout_render_object.hpp
@@ -38,7 +38,7 @@ class FlexLayoutRenderObject : public RenderObject {
 
   FlexChildLayoutData* GetChildLayoutData(int position);
 
-  void Draw(platform::Painter* painter) override;
+  void Draw(platform::graph::Painter* painter) override;
 
   RenderObject* HitTest(const Point& point) override;
 
diff --git a/include/cru/ui/render/render_object.hpp b/include/cru/ui/render/render_object.hpp
index 3cd14a6a..7f5f7ac6 100644
--- a/include/cru/ui/render/render_object.hpp
+++ b/include/cru/ui/render/render_object.hpp
@@ -10,7 +10,7 @@ namespace cru::ui {
 class Control;
 }
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Painter;
 }
 
@@ -58,7 +58,7 @@ class RenderObject : public Object {
   void Measure(const Size& available_size);
   void Layout(const Rect& rect);
 
-  virtual void Draw(platform::Painter* render_target) = 0;
+  virtual void Draw(platform::graph::Painter* painter) = 0;
 
   virtual RenderObject* HitTest(const Point& point) = 0;
 
diff --git a/include/cru/ui/render/text_render_object.hpp b/include/cru/ui/render/text_render_object.hpp
index 527fcd71..9f03551d 100644
--- a/include/cru/ui/render/text_render_object.hpp
+++ b/include/cru/ui/render/text_render_object.hpp
@@ -5,18 +5,18 @@
 #include <string>
 
 // forward declarations
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Brush;
 struct FontDescriptor;
 struct TextLayout;
-}  // namespace cru::platform
+}  // namespace cru::platform::graph
 
 namespace cru::ui::render {
 class TextRenderObject : public RenderObject {
  public:
-  TextRenderObject(std::shared_ptr<platform::Brush> brush,
-                   std::shared_ptr<platform::FontDescriptor> font,
-                   std::shared_ptr<platform::Brush> selection_brush);
+  TextRenderObject(std::shared_ptr<platform::graph::Brush> brush,
+                   std::shared_ptr<platform::graph::FontDescriptor> font,
+                   std::shared_ptr<platform::graph::Brush> selection_brush);
   TextRenderObject(const TextRenderObject& other) = delete;
   TextRenderObject(TextRenderObject&& other) = delete;
   TextRenderObject& operator=(const TextRenderObject& other) = delete;
@@ -26,13 +26,13 @@ class TextRenderObject : public RenderObject {
   std::wstring GetText() const;
   void SetText(std::wstring new_text);
 
-  std::shared_ptr<platform::Brush> GetBrush() const { return brush_; }
-  void SetBrush(std::shared_ptr<platform::Brush> new_brush) {
+  std::shared_ptr<platform::graph::Brush> GetBrush() const { return brush_; }
+  void SetBrush(std::shared_ptr<platform::graph::Brush> new_brush) {
     new_brush.swap(brush_);
   }
 
-  std::shared_ptr<platform::FontDescriptor> GetFont() const;
-  void SetFont(std::shared_ptr<platform::FontDescriptor> font);
+  std::shared_ptr<platform::graph::FontDescriptor> GetFont() const;
+  void SetFont(std::shared_ptr<platform::graph::FontDescriptor> font);
 
   std::optional<TextRange> GetSelectionRange() const {
     return selection_range_;
@@ -41,14 +41,14 @@ class TextRenderObject : public RenderObject {
     selection_range_ = std::move(new_range);
   }
 
-  std::shared_ptr<platform::Brush> GetSelectionBrush() const {
+  std::shared_ptr<platform::graph::Brush> GetSelectionBrush() const {
     return selection_brush_;
   }
-  void SetSelectionBrush(std::shared_ptr<platform::Brush> new_brush) {
+  void SetSelectionBrush(std::shared_ptr<platform::graph::Brush> new_brush) {
     new_brush.swap(selection_brush_);
   }
 
-  void Draw(platform::Painter* painter) override;
+  void Draw(platform::graph::Painter* painter) override;
 
   RenderObject* HitTest(const Point& point) override;
 
@@ -59,11 +59,11 @@ class TextRenderObject : public RenderObject {
   void OnLayoutContent(const Rect& content_rect) override;
 
  private:
-  std::shared_ptr<platform::Brush> brush_;
-  std::shared_ptr<platform::FontDescriptor> font_;
-  std::shared_ptr<platform::TextLayout> text_layout_;
+  std::shared_ptr<platform::graph::Brush> brush_;
+  std::shared_ptr<platform::graph::FontDescriptor> font_;
+  std::shared_ptr<platform::graph::TextLayout> text_layout_;
 
   std::optional<TextRange> selection_range_ = std::nullopt;
-  std::shared_ptr<platform::Brush>  selection_brush_;
+  std::shared_ptr<platform::graph::Brush> selection_brush_;
 };
 }  // namespace cru::ui::render
diff --git a/include/cru/ui/render/window_render_object.hpp b/include/cru/ui/render/window_render_object.hpp
index e0a7c74e..dfeae487 100644
--- a/include/cru/ui/render/window_render_object.hpp
+++ b/include/cru/ui/render/window_render_object.hpp
@@ -17,7 +17,7 @@ class WindowRenderObject : public RenderObject {
 
   void MeasureAndLayout();
 
-  void Draw(platform::Painter* painter) override;
+  void Draw(platform::graph::Painter* painter) override;
 
   RenderObject* HitTest(const Point& point) override;
 
diff --git a/include/cru/ui/ui_manager.hpp b/include/cru/ui/ui_manager.hpp
index 6f4a3bc0..5317f579 100644
--- a/include/cru/ui/ui_manager.hpp
+++ b/include/cru/ui/ui_manager.hpp
@@ -3,7 +3,7 @@
 
 #include <memory>
 
-namespace cru::platform {
+namespace cru::platform::graph {
 struct Brush;
 struct FontDescriptor;
 }  // namespace cru::platform
@@ -19,12 +19,12 @@ class PredefineResources : public Object {
   ~PredefineResources() override = default;
 
   // region Button
-  std::shared_ptr<platform::Brush> button_normal_border_brush;
+  std::shared_ptr<platform::graph::Brush> button_normal_border_brush;
 
   // region TextBlock
-  std::shared_ptr<platform::Brush> text_block_selection_brush;
-  std::shared_ptr<platform::Brush> text_block_text_brush;
-  std::shared_ptr<platform::FontDescriptor> text_block_font;
+  std::shared_ptr<platform::graph::Brush> text_block_selection_brush;
+  std::shared_ptr<platform::graph::Brush> text_block_text_brush;
+  std::shared_ptr<platform::graph::FontDescriptor> text_block_font;
 };
 
 class UiManager : public Object {
diff --git a/include/cru/ui/window.hpp b/include/cru/ui/window.hpp
index 9a76f30f..0a81e2e1 100644
--- a/include/cru/ui/window.hpp
+++ b/include/cru/ui/window.hpp
@@ -5,7 +5,7 @@
 
 #include <memory>
 
-namespace cru::platform {
+namespace cru::platform::native {
 struct NativeWindow;
 }
 
@@ -38,7 +38,7 @@ class Window final : public ContentControl {
 
   render::RenderObject* GetRenderObject() const override;
 
-  platform::NativeWindow* GetNativeWindow() const { return native_window_; }
+  platform::native::NativeWindow* GetNativeWindow() const { return native_window_; }
 
   Control* GetMouseHoverControl() const { return mouse_hover_control_; }
 
@@ -66,13 +66,14 @@ class Window final : public ContentControl {
 
   void OnNativeMouseEnterLeave(bool enter);
   void OnNativeMouseMove(const Point& point);
-  void OnNativeMouseDown(platform::MouseButton button, const Point& point);
-  void OnNativeMouseUp(platform::MouseButton button, const Point& point);
+  void OnNativeMouseDown(platform::native::MouseButton button,
+                         const Point& point);
+  void OnNativeMouseUp(platform::native::MouseButton button,
+                       const Point& point);
 
   void OnNativeKeyDown(int virtual_code);
   void OnNativeKeyUp(int virtual_code);
 
-
   //*************** region: event dispatcher helper ***************
 
   void DispatchMouseHoverControlChangeEvent(Control* old_control,
@@ -80,7 +81,7 @@ class Window final : public ContentControl {
                                             const Point& point);
 
  private:
-  platform::NativeWindow* native_window_;
+  platform::native::NativeWindow* native_window_;
   EventRevokerGuard event_revoker_guard_;
 
   std::shared_ptr<render::WindowRenderObject> render_object_;
diff --git a/include/cru/platform/win/exception.hpp b/include/cru/win/exception.hpp
index 01b139b4..39c52c45 100644
--- a/include/cru/platform/win/exception.hpp
+++ b/include/cru/win/exception.hpp
@@ -1,11 +1,13 @@
 #pragma once
 #include "win_pre_config.hpp"
 
+#include "cru/platform/exception.hpp"
+
 #include <stdexcept>
 #include <string_view>
 
-namespace cru::platform::win {
-class HResultError : public std::runtime_error {
+namespace cru::win {
+class HResultError : public platform::PlatformException {
  public:
   explicit HResultError(HRESULT h_result);
   explicit HResultError(HRESULT h_result,
@@ -31,7 +33,7 @@ inline void ThrowIfFailed(const HRESULT h_result,
   if (FAILED(h_result)) throw HResultError(h_result, message);
 }
 
-class Win32Error : public std::runtime_error {
+class Win32Error : public platform::PlatformException {
  public:
   explicit Win32Error(DWORD error_code);
   Win32Error(DWORD error_code, const std::string_view& additional_message);
@@ -46,4 +48,4 @@ class Win32Error : public std::runtime_error {
  private:
   DWORD error_code_;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win
diff --git a/include/cru/platform/win/d2d_util.hpp b/include/cru/win/graph/d2d_util.hpp
index 51aea4f8..7a2da91f 100644
--- a/include/cru/platform/win/d2d_util.hpp
+++ b/include/cru/win/graph/d2d_util.hpp
@@ -1,11 +1,11 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
-#include "../matrix.hpp"
 #include "cru/common/ui_base.hpp"
+#include "cru/platform/matrix.hpp"
 
-namespace cru::platform::win::util {
-inline D2D1_MATRIX_3X2_F Convert(const Matrix& matrix) {
+namespace cru::win::graph::util {
+inline D2D1_MATRIX_3X2_F Convert(const platform::Matrix& matrix) {
   D2D1_MATRIX_3X2_F m;
   m._11 = matrix.m11;
   m._12 = matrix.m12;
@@ -40,9 +40,9 @@ inline D2D1_ELLIPSE Convert(const ui::Ellipse& ellipse) {
                        ellipse.radius_y);
 }
 
-inline Matrix Convert(const D2D1_MATRIX_3X2_F& matrix) {
-  return Matrix{matrix._11, matrix._12, matrix._21,
-                matrix._22, matrix._31, matrix._32};
+inline platform::Matrix Convert(const D2D1_MATRIX_3X2_F& matrix) {
+  return platform::Matrix{matrix._11, matrix._12, matrix._21,
+                          matrix._22, matrix._31, matrix._32};
 }
 
 inline ui::Color Convert(const D2D1_COLOR_F& color) {
@@ -105,4 +105,4 @@ inline bool operator==(const D2D1_ELLIPSE& left, const D2D1_ELLIPSE& right) {
 inline bool operator!=(const D2D1_ELLIPSE& left, const D2D1_ELLIPSE& right) {
   return !(left == right);
 }
-}  // namespace cru::platform::win::util
+}  // namespace cru::win::graph::util
diff --git a/include/cru/platform/win/graph_manager.hpp b/include/cru/win/graph/graph_manager.hpp
index f2e29c22..bf14b802 100644
--- a/include/cru/platform/win/graph_manager.hpp
+++ b/include/cru/win/graph/graph_manager.hpp
@@ -1,14 +1,17 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
-#include "../basic_types.hpp"
 #include "cru/common/base.hpp"
+#include "cru/win/graph/win_graph_factory.hpp"
 
-namespace cru::platform::win {
-class WindowRenderTarget;
+#include <memory>
 
+namespace cru::win::graph {
 class GraphManager final : public Object {
  public:
+  static GraphManager* GetInstance();
+
+ public:
   GraphManager();
   GraphManager(const GraphManager& other) = delete;
   GraphManager(GraphManager&& other) = delete;
@@ -33,6 +36,8 @@ class GraphManager final : public Object {
     return dwrite_system_font_collection_.Get();
   }
 
+  WinGraphFactory* GetGraphFactory() const { return graph_factory_.get(); }
+
  private:
   Microsoft::WRL::ComPtr<ID3D11Device> d3d11_device_;
   Microsoft::WRL::ComPtr<ID2D1Factory1> d2d1_factory_;
@@ -40,5 +45,7 @@ class GraphManager final : public Object {
   Microsoft::WRL::ComPtr<IDXGIFactory2> dxgi_factory_;
   Microsoft::WRL::ComPtr<IDWriteFactory> dwrite_factory_;
   Microsoft::WRL::ComPtr<IDWriteFontCollection> dwrite_system_font_collection_;
+
+  std::unique_ptr<WinGraphFactory> graph_factory_;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win::graph
diff --git a/include/cru/platform/win/win_brush.hpp b/include/cru/win/graph/win_brush.hpp
index d32f6bbc..69cd952d 100644
--- a/include/cru/platform/win/win_brush.hpp
+++ b/include/cru/win/graph/win_brush.hpp
@@ -1,19 +1,21 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
-#include "../brush.hpp"
+#include "cru/platform/graph/brush.hpp"
 
-namespace cru::platform::win {
-struct WinBrush : virtual Brush {
+namespace cru::win::graph {
+class GraphManager;
+
+struct WinBrush : virtual platform::graph::Brush {
   virtual ID2D1Brush* GetD2DBrush() = 0;
 };
 
 class WinSolidColorBrush : public Object,
-                           public virtual SolidColorBrush,
+                           public virtual platform::graph::SolidColorBrush,
                            public virtual WinBrush {
  public:
-  explicit WinSolidColorBrush(
-      Microsoft::WRL::ComPtr<ID2D1SolidColorBrush> brush);
+  explicit WinSolidColorBrush(GraphManager* graph_manager,
+                              const ui::Color& color);
   WinSolidColorBrush(const WinSolidColorBrush& other) = delete;
   WinSolidColorBrush(WinSolidColorBrush&& other) = delete;
   WinSolidColorBrush& operator=(const WinSolidColorBrush& other) = delete;
@@ -28,4 +30,4 @@ class WinSolidColorBrush : public Object,
  private:
   Microsoft::WRL::ComPtr<ID2D1SolidColorBrush> brush_;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win::graph
diff --git a/include/cru/platform/win/win_font.hpp b/include/cru/win/graph/win_font.hpp
index f03ff3c8..3301e8da 100644
--- a/include/cru/platform/win/win_font.hpp
+++ b/include/cru/win/graph/win_font.hpp
@@ -1,17 +1,19 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
-#include "../font.hpp"
+#include "cru/platform/graph/font.hpp"
 
 #include <string_view>
 
-namespace cru::platform::win {
+namespace cru::win::graph {
 class GraphManager;
 
-class WinFontDescriptor : public Object, public virtual FontDescriptor {
+class WinFontDescriptor : public Object,
+                          public virtual platform::graph::FontDescriptor {
  public:
   explicit WinFontDescriptor(GraphManager* graph_manager,
-                             const std::wstring_view& font_family, float font_size);
+                             const std::wstring_view& font_family,
+                             float font_size);
   WinFontDescriptor(const WinFontDescriptor& other) = delete;
   WinFontDescriptor(WinFontDescriptor&& other) = delete;
   WinFontDescriptor& operator=(const WinFontDescriptor& other) = delete;
@@ -23,4 +25,4 @@ class WinFontDescriptor : public Object, public virtual FontDescriptor {
  private:
   Microsoft::WRL::ComPtr<IDWriteTextFormat> text_format_;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win::graph
diff --git a/include/cru/platform/win/win_geometry.hpp b/include/cru/win/graph/win_geometry.hpp
index e8ab7796..005a4384 100644
--- a/include/cru/platform/win/win_geometry.hpp
+++ b/include/cru/win/graph/win_geometry.hpp
@@ -1,12 +1,15 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
-#include "../geometry.hpp"
+#include "cru/platform/graph/geometry.hpp"
 
-namespace cru::platform::win {
-class WinGeometryBuilder : public Object, public virtual GeometryBuilder {
+namespace cru::win::graph {
+class GraphManager;
+
+class WinGeometryBuilder : public Object,
+                           public virtual platform::graph::GeometryBuilder {
  public:
-  explicit WinGeometryBuilder(Microsoft::WRL::ComPtr<ID2D1PathGeometry> geometry);
+  explicit WinGeometryBuilder(GraphManager* graph_manger);
   WinGeometryBuilder(const WinGeometryBuilder& other) = delete;
   WinGeometryBuilder(WinGeometryBuilder&& other) = delete;
   WinGeometryBuilder& operator=(const WinGeometryBuilder& other) = delete;
@@ -19,14 +22,14 @@ class WinGeometryBuilder : public Object, public virtual GeometryBuilder {
   void QuadraticBezierTo(const ui::Point& control_point,
                          const ui::Point& end_point) override;
   void CloseFigure(bool close) override;
-  Geometry* Build() override;
+  platform::graph::Geometry* Build() override;
 
  private:
   Microsoft::WRL::ComPtr<ID2D1PathGeometry> geometry_;
   Microsoft::WRL::ComPtr<ID2D1GeometrySink> geometry_sink_;
 };
 
-class WinGeometry : public Object, public virtual Geometry {
+class WinGeometry : public Object, public virtual platform::graph::Geometry {
  public:
   explicit WinGeometry(Microsoft::WRL::ComPtr<ID2D1PathGeometry> geometry);
   WinGeometry(const WinGeometry& other) = delete;
@@ -42,4 +45,4 @@ class WinGeometry : public Object, public virtual Geometry {
  private:
   Microsoft::WRL::ComPtr<ID2D1PathGeometry> geometry_;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win::graph
diff --git a/include/cru/win/graph/win_graph_factory.hpp b/include/cru/win/graph/win_graph_factory.hpp
new file mode 100644
index 00000000..f8a07819
--- /dev/null
+++ b/include/cru/win/graph/win_graph_factory.hpp
@@ -0,0 +1,30 @@
+#pragma once
+#include "../win_pre_config.hpp"
+
+#include "cru/platform/graph/graph_factory.hpp"
+
+namespace cru::win::graph {
+class GraphManager;
+
+class WinGraphFactory : public Object,
+                        public virtual platform::graph::GraphFactory {
+ public:
+  explicit WinGraphFactory(GraphManager* graph_manager);
+  WinGraphFactory(const WinGraphFactory& other) = delete;
+  WinGraphFactory(WinGraphFactory&& other) = delete;
+  WinGraphFactory& operator=(const WinGraphFactory& other) = delete;
+  WinGraphFactory& operator=(WinGraphFactory&& other) = delete;
+  ~WinGraphFactory() override = default;
+
+  platform::graph::SolidColorBrush* CreateSolidColorBrush(
+      const ui::Color& color) override;
+  platform::graph::GeometryBuilder* CreateGeometryBuilder() override;
+  platform::graph::FontDescriptor* CreateFontDescriptor(
+      const std::wstring_view& font_family, float font_size);
+  platform::graph::TextLayout* CreateTextLayout(
+      std::shared_ptr<platform::graph::FontDescriptor> font, std::wstring text);
+
+ private:
+  GraphManager* graph_manager_;
+};
+}  // namespace cru::win::graph
diff --git a/include/cru/win/graph/win_painter.hpp b/include/cru/win/graph/win_painter.hpp
new file mode 100644
index 00000000..8351cb7b
--- /dev/null
+++ b/include/cru/win/graph/win_painter.hpp
@@ -0,0 +1,48 @@
+#pragma once
+#include "../win_pre_config.hpp"
+
+#include "cru/platform/graph/painter.hpp"
+
+namespace cru::win::graph {
+class GraphManager;
+
+class WinPainter : public Object, public virtual platform::graph::Painter {
+ public:
+  explicit WinPainter(ID2D1RenderTarget* render_target);
+  WinPainter(const WinPainter& other) = delete;
+  WinPainter(WinPainter&& other) = delete;
+  WinPainter& operator=(const WinPainter& other) = delete;
+  WinPainter& operator=(WinPainter&& other) = delete;
+  ~WinPainter() override;
+
+  platform::Matrix GetTransform() override;
+  void SetTransform(const platform::Matrix& matrix) override;
+  void Clear(const ui::Color& color) override;
+  void StrokeRectangle(const ui::Rect& rectangle, platform::graph::Brush* brush,
+                       float width) override;
+  void FillRectangle(const ui::Rect& rectangle,
+                     platform::graph::Brush* brush) override;
+  void StrokeGeometry(platform::graph::Geometry* geometry,
+                      platform::graph::Brush* brush, float width) override;
+  void FillGeometry(platform::graph::Geometry* geometry,
+                    platform::graph::Brush* brush) override;
+  void DrawText(const ui::Point& offset,
+                platform::graph::TextLayout* text_layout,
+                platform::graph::Brush* brush) override;
+  void EndDraw() override;
+  bool IsDisposed() override { return is_disposed_; }
+
+  void EndDrawAndDeleteThis() {
+    EndDraw();
+    delete this;
+  }
+
+ protected:
+  virtual void DoEndDraw();
+
+ private:
+  ID2D1RenderTarget* render_target_;
+
+  bool is_disposed_ = false;
+};
+}  // namespace cru::win::graph
diff --git a/include/cru/platform/win/win_text_layout.hpp b/include/cru/win/graph/win_text_layout.hpp
index dfb54264..b861fda7 100644
--- a/include/cru/platform/win/win_text_layout.hpp
+++ b/include/cru/win/graph/win_text_layout.hpp
@@ -1,15 +1,15 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
-#include "../text_layout.hpp"
-#include "win_font.hpp"
+#include "cru/platform/graph/text_layout.hpp"
 
 #include <memory>
 
-namespace cru::platform::win {
+namespace cru::win::graph {
 class GraphManager;
+class WinFontDescriptor;
 
-class WinTextLayout : public Object, public virtual TextLayout {
+class WinTextLayout : public Object, public virtual platform::graph::TextLayout {
  public:
   explicit WinTextLayout(GraphManager* graph_manager,
                          std::shared_ptr<WinFontDescriptor> font, std::wstring text);
@@ -21,8 +21,8 @@ class WinTextLayout : public Object, public virtual TextLayout {
 
   std::wstring GetText() override;
   void SetText(std::wstring new_text) override;
-  std::shared_ptr<FontDescriptor> GetFont();
-  void SetFont(std::shared_ptr<FontDescriptor> font);
+  std::shared_ptr<platform::graph::FontDescriptor> GetFont();
+  void SetFont(std::shared_ptr<platform::graph::FontDescriptor> font);
   void SetMaxWidth(float max_width) override;
   void SetMaxHeight(float max_height) override;
   ui::Rect GetTextBounds() override;
diff --git a/include/cru/platform/win/god_window.hpp b/include/cru/win/native/god_window.hpp
index 95a253e9..9ac49858 100644
--- a/include/cru/platform/win/god_window.hpp
+++ b/include/cru/win/native/god_window.hpp
@@ -1,11 +1,11 @@
 #pragma once
-#include "win_pre_config.hpp"
-
-#include <memory>
+#include "../win_pre_config.hpp"
 
 #include "cru/common/base.hpp"
 
-namespace cru::platform::win {
+#include <memory>
+
+namespace cru::win::native {
 class WinApplication;
 class WindowClass;
 
@@ -29,4 +29,4 @@ class GodWindow : public Object {
   std::shared_ptr<WindowClass> god_window_class_;
   HWND hwnd_;
 };
-}  // namespace cru::platform::win
\ No newline at end of file
+}  // namespace cru::win::native
\ No newline at end of file
diff --git a/include/cru/platform/win/win_application.hpp b/include/cru/win/native/win_application.hpp
index f8150aed..458b10ae 100644
--- a/include/cru/platform/win/win_application.hpp
+++ b/include/cru/win/native/win_application.hpp
@@ -1,19 +1,17 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
-#include "../ui_applicaition.hpp"
-#include "cru/common/base.hpp"
+#include "cru/platform/native/ui_applicaition.hpp"
 
 #include <memory>
 
-namespace cru::platform::win {
+namespace cru::win::native {
 class GodWindow;
 class TimerManager;
 class WindowManager;
-class GraphManager;
-class WinGraphFactory;
 
-class WinApplication : public Object, public virtual UiApplication {
+class WinApplication : public Object,
+                       public virtual platform::native::UiApplication {
  public:
   static WinApplication* GetInstance();
 
@@ -41,19 +39,15 @@ class WinApplication : public Object, public virtual UiApplication {
                             const std::function<void()>& action) override;
   void CancelTimer(unsigned long id) override;
 
-  std::vector<NativeWindow*> GetAllWindow() override;
-  NativeWindow* CreateWindow(NativeWindow* parent) override;
-
-  GraphFactory* GetGraphFactory() override;
-
+  std::vector<platform::native::NativeWindow*> GetAllWindow() override;
+  platform::native::NativeWindow* CreateWindow(
+      platform::native::NativeWindow* parent) override;
 
   HINSTANCE GetInstanceHandle() const { return h_instance_; }
 
   GodWindow* GetGodWindow() const { return god_window_.get(); }
   TimerManager* GetTimerManager() const { return timer_manager_.get(); }
   WindowManager* GetWindowManager() const { return window_manager_.get(); }
-  GraphManager* GetGraphManager() const { return graph_manager_.get(); }
-  WinGraphFactory* GetWinGraphFactory() const { return graph_factory_.get(); }
 
  private:
   HINSTANCE h_instance_;
@@ -61,7 +55,5 @@ class WinApplication : public Object, public virtual UiApplication {
   std::shared_ptr<GodWindow> god_window_;
   std::shared_ptr<TimerManager> timer_manager_;
   std::shared_ptr<WindowManager> window_manager_;
-  std::shared_ptr<GraphManager> graph_manager_;
-  std::shared_ptr<WinGraphFactory> graph_factory_;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/include/cru/platform/win/win_native_window.hpp b/include/cru/win/native/win_native_window.hpp
index 7b93fd5c..2b9be25d 100644
--- a/include/cru/platform/win/win_native_window.hpp
+++ b/include/cru/win/native/win_native_window.hpp
@@ -1,18 +1,19 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
-#include "../native_window.hpp"
+#include "cru/platform/native/native_window.hpp"
 #include "window_native_message_event_args.hpp"
 
 #include <memory>
 
-namespace cru::platform::win {
+namespace cru::win::native {
 class WinApplication;
 class WindowClass;
 class WindowManager;
 class WindowRenderTarget;
 
-class WinNativeWindow : public Object, public virtual NativeWindow {
+class WinNativeWindow : public Object,
+                        public virtual platform::native::NativeWindow {
  public:
   WinNativeWindow(WinApplication* application,
                   std::shared_ptr<WindowClass> window_class, DWORD window_style,
@@ -44,7 +45,7 @@ class WinNativeWindow : public Object, public virtual NativeWindow {
   // The lefttop of the rect is relative to screen lefttop.
   void SetWindowRect(const ui::Rect& rect) override;
 
-  Painter* BeginPaint() override;
+  platform::graph::Painter* BeginPaint() override;
 
   Event<>* DestroyEvent() override { return &destroy_event_; }
   Event<const ui::Size&>* ResizeEvent() override { return &resize_event_; }
@@ -53,11 +54,15 @@ class WinNativeWindow : public Object, public virtual NativeWindow {
   Event<bool>* MouseEnterLeaveEvent() override {
     return &mouse_enter_leave_event_;
   }
-  Event<const ui::Point&>* MouseMoveEvent() override { return &mouse_move_event_; }
-  Event<MouseButton, const ui::Point&>* MouseDownEvent() override {
+  Event<const ui::Point&>* MouseMoveEvent() override {
+    return &mouse_move_event_;
+  }
+  Event<platform::native::MouseButton, const ui::Point&>* MouseDownEvent()
+      override {
     return &mouse_down_event_;
   }
-  Event<MouseButton, const ui::Point&>* MouseUpEvent() override {
+  Event<platform::native::MouseButton, const ui::Point&>* MouseUpEvent()
+      override {
     return &mouse_up_event_;
   }
   Event<int>* KeyDownEvent() override { return &key_down_event_; }
@@ -92,8 +97,8 @@ class WinNativeWindow : public Object, public virtual NativeWindow {
 
   void OnMouseMoveInternal(POINT point);
   void OnMouseLeaveInternal();
-  void OnMouseDownInternal(MouseButton button, POINT point);
-  void OnMouseUpInternal(MouseButton button, POINT point);
+  void OnMouseDownInternal(platform::native::MouseButton button, POINT point);
+  void OnMouseUpInternal(platform::native::MouseButton button, POINT point);
 
   void OnMouseWheelInternal(short delta, POINT point);
   void OnKeyDownInternal(int virtual_code);
@@ -122,11 +127,11 @@ class WinNativeWindow : public Object, public virtual NativeWindow {
   Event<bool> focus_event_;
   Event<bool> mouse_enter_leave_event_;
   Event<const ui::Point&> mouse_move_event_;
-  Event<MouseButton, const ui::Point&> mouse_down_event_;
-  Event<MouseButton, const ui::Point&> mouse_up_event_;
+  Event<platform::native::MouseButton, const ui::Point&> mouse_down_event_;
+  Event<platform::native::MouseButton, const ui::Point&> mouse_up_event_;
   Event<int> key_down_event_;
   Event<int> key_up_event_;
 
   Event<WindowNativeMessageEventArgs&> native_message_event_;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/include/cru/platform/win/window_class.hpp b/include/cru/win/native/window_class.hpp
index be79af13..17712958 100644
--- a/include/cru/platform/win/window_class.hpp
+++ b/include/cru/win/native/window_class.hpp
@@ -1,14 +1,15 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
 #include "cru/common/base.hpp"
 
 #include <string>
 
-namespace cru::platform::win {
+namespace cru::win::native {
 class WindowClass : public Object {
  public:
-  WindowClass(const std::wstring& name, WNDPROC window_proc, HINSTANCE h_instance);
+  WindowClass(const std::wstring& name, WNDPROC window_proc,
+              HINSTANCE h_instance);
   WindowClass(const WindowClass& other) = delete;
   WindowClass(WindowClass&& other) = delete;
   WindowClass& operator=(const WindowClass& other) = delete;
@@ -23,4 +24,4 @@ class WindowClass : public Object {
   std::wstring name_;
   ATOM atom_;
 };
-}  // namespace cru::ui
+}  // namespace cru::win::native
diff --git a/include/cru/platform/win/window_native_message_event_args.hpp b/include/cru/win/native/window_native_message_event_args.hpp
index b3419c24..37149f36 100644
--- a/include/cru/platform/win/window_native_message_event_args.hpp
+++ b/include/cru/win/native/window_native_message_event_args.hpp
@@ -1,9 +1,9 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
 #include "cru/common/base.hpp"
 
-namespace cru::platform::win {
+namespace cru::win::native {
 struct WindowNativeMessage {
   HWND hwnd;
   UINT msg;
@@ -42,4 +42,4 @@ class WindowNativeMessageEventArgs : public Object {
   LRESULT result_;
   bool handled_ = false;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/include/cru/platform/win/window_render_target.hpp b/include/cru/win/native/window_render_target.hpp
index f328a84a..c55055c6 100644
--- a/include/cru/platform/win/window_render_target.hpp
+++ b/include/cru/win/native/window_render_target.hpp
@@ -1,16 +1,17 @@
 #pragma once
-#include "win_pre_config.hpp"
+#include "../win_pre_config.hpp"
 
 #include "cru/common/base.hpp"
 
-
-namespace cru::platform::win {
+namespace cru::win::graph {
 class GraphManager;
+}
 
+namespace cru::win::native {
 // Represents a window render target.
 class WindowRenderTarget : public Object {
  public:
-  WindowRenderTarget(GraphManager* graph_manager, HWND hwnd);
+  WindowRenderTarget(graph::GraphManager* graph_manager, HWND hwnd);
   WindowRenderTarget(const WindowRenderTarget& other) = delete;
   WindowRenderTarget(WindowRenderTarget&& other) = delete;
   WindowRenderTarget& operator=(const WindowRenderTarget& other) = delete;
@@ -19,7 +20,7 @@ class WindowRenderTarget : public Object {
 
  public:
   // Get the graph manager that created the render target.
-  GraphManager* GetGraphManager() const { return graph_manager_; }
+  graph::GraphManager* GetGraphManager() const { return graph_manager_; }
 
   // Get the target bitmap which can be set as the ID2D1DeviceContext's target.
   ID2D1Bitmap1* GetTargetBitmap() const { return target_bitmap_.Get(); }
@@ -37,8 +38,8 @@ class WindowRenderTarget : public Object {
   void CreateTargetBitmap();
 
  private:
-  GraphManager* graph_manager_;
+  graph::GraphManager* graph_manager_;
   Microsoft::WRL::ComPtr<IDXGISwapChain1> dxgi_swap_chain_;
   Microsoft::WRL::ComPtr<ID2D1Bitmap1> target_bitmap_;
 };
-}  // namespace cru::graph
+}  // namespace cru::win::native
diff --git a/include/cru/platform/win/win_pre_config.hpp b/include/cru/win/win_pre_config.hpp
index 6962eb7b..6962eb7b 100644
--- a/include/cru/platform/win/win_pre_config.hpp
+++ b/include/cru/win/win_pre_config.hpp
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 8f29ddc9..b2209bb3 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,27 +1,9 @@
-add_library(cru_ui STATIC
-    ui/content_control.cpp
-    ui/control.cpp
-    ui/layout_control.cpp
-    ui/no_child_control.cpp
-    ui/ui_manager.cpp
-    ui/window.cpp
-    ui/controls/button.cpp
-    ui/controls/flex_layout.cpp
-    ui/controls/text_block.cpp
-    ui/render/border_render_object.cpp
-    ui/render/flex_layout_render_object.cpp
-    ui/render/render_object.cpp
-    ui/render/text_render_object.cpp
-    ui/render/window_render_object.cpp)
-
-target_include_directories(cru_ui PUBLIC ${PROJECT_SOURCE_DIR}/include .)
+add_subdirectory(ui)
 
 if(WIN32)
-add_subdirectory(platform_win)
-target_link_libraries(cru_ui PUBLIC cru_platform_win)
+add_subdirectory(win)
 endif()
 
-
 add_executable(demo main.cpp)
 
 target_link_libraries(demo PRIVATE cru_ui)
diff --git a/src/main.cpp b/src/main.cpp
index c0c90002..ecaebda5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,11 +1,11 @@
-#include "cru/platform/native_window.hpp"
-#include "cru/platform/ui_applicaition.hpp"
+#include "cru/platform/native/native_window.hpp"
+#include "cru/platform/native/ui_applicaition.hpp"
 #include "cru/ui/controls/button.hpp"
 #include "cru/ui/controls/flex_layout.hpp"
 #include "cru/ui/controls/text_block.hpp"
 #include "cru/ui/window.hpp"
 
-using cru::platform::UiApplication;
+using cru::platform::native::UiApplication;
 using cru::ui::Rect;
 using cru::ui::Thickness;
 using cru::ui::Window;
diff --git a/src/platform_win/CMakeLists.txt b/src/platform_win/CMakeLists.txt
deleted file mode 100644
index 27e93091..00000000
--- a/src/platform_win/CMakeLists.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-add_library(cru_platform_win STATIC
-	debug.cpp
-	exception.cpp
-	god_window.cpp
-	graph_manager.cpp
-	string_util.cpp
-	timer.cpp
-	win_application.cpp
-	win_brush.cpp
-	win_font.cpp
-	win_geometry.cpp
-	win_graph_factory.cpp
-	win_native_window.cpp
-	win_painter.cpp
-	win_text_layout.cpp
-	window_class.cpp
-	window_manager.cpp
-	window_render_target.cpp)
-target_include_directories(cru_platform_win PUBLIC ${PROJECT_SOURCE_DIR}/include .)
-target_link_libraries(cru_platform_win PRIVATE D3D11 D2d1 DWrite)
-target_compile_definitions(cru_platform_win PUBLIC UNICODE _UNICODE) # use unicode
diff --git a/src/platform_win/god_window_message.hpp b/src/platform_win/god_window_message.hpp
deleted file mode 100644
index a906a3b7..00000000
--- a/src/platform_win/god_window_message.hpp
+++ /dev/null
@@ -1,6 +0,0 @@
-#pragma once
-#include "cru/platform/win/win_pre_config.hpp"
-
-namespace cru::platform::win {
-constexpr int invoke_later_message_id = WM_USER + 2000;
-}
diff --git a/src/platform_win/win_brush.cpp b/src/platform_win/win_brush.cpp
deleted file mode 100644
index 189dfd57..00000000
--- a/src/platform_win/win_brush.cpp
+++ /dev/null
@@ -1,21 +0,0 @@
-#include "cru/platform/win/win_brush.hpp"
-
-#include "cru/platform/win/d2d_util.hpp"
-#include "cru/platform/win/exception.hpp"
-
-#include <cassert>
-
-namespace cru::platform::win {
-WinSolidColorBrush::WinSolidColorBrush(
-    Microsoft::WRL::ComPtr<ID2D1SolidColorBrush> brush) {
-  assert(brush);
-  brush_ = std::move(brush);
-}
-
-ui::Color cru::platform::win::WinSolidColorBrush::GetColor() {
-  return util::Convert(brush_->GetColor());
-}
-void WinSolidColorBrush::SetColor(const ui::Color& color) {
-  brush_->SetColor(util::Convert(color));
-}
-}  // namespace cru::platform::win
diff --git a/src/platform_win/win_graph_factory.cpp b/src/platform_win/win_graph_factory.cpp
deleted file mode 100644
index 03031b32..00000000
--- a/src/platform_win/win_graph_factory.cpp
+++ /dev/null
@@ -1,46 +0,0 @@
-#include "cru/platform/win/win_graph_factory.hpp"
-
-#include "cru/platform/win/d2d_util.hpp"
-#include "cru/platform/win/exception.hpp"
-#include "cru/platform/win/graph_manager.hpp"
-#include "cru/platform/win/win_brush.hpp"
-#include "cru/platform/win/win_font.hpp"
-#include "cru/platform/win/win_geometry.hpp"
-#include "cru/platform/win/win_text_layout.hpp"
-
-#include <cassert>
-#include <utility>
-
-namespace cru::platform::win {
-WinGraphFactory::WinGraphFactory(GraphManager* graph_manager) {
-  assert(graph_manager);
-  graph_manager_ = graph_manager;
-}
-
-SolidColorBrush* WinGraphFactory::CreateSolidColorBrush(
-    const ui::Color& color) {
-  Microsoft::WRL::ComPtr<ID2D1SolidColorBrush> brush;
-  ThrowIfFailed(graph_manager_->GetD2D1DeviceContext()->CreateSolidColorBrush(
-      util::Convert(color), &brush));
-  return new WinSolidColorBrush(std::move(brush));
-}
-
-GeometryBuilder* WinGraphFactory::CreateGeometryBuilder() {
-  Microsoft::WRL::ComPtr<ID2D1PathGeometry> geometry;
-  ThrowIfFailed(
-      graph_manager_->GetD2D1Factory()->CreatePathGeometry(&geometry));
-  return new WinGeometryBuilder(std::move(geometry));
-}
-
-FontDescriptor* WinGraphFactory::CreateFontDescriptor(
-    const std::wstring_view& font_family, float font_size) {
-  return new WinFontDescriptor(graph_manager_, font_family, font_size);
-}
-
-TextLayout* WinGraphFactory::CreateTextLayout(
-    std::shared_ptr<FontDescriptor> font, std::wstring text) {
-  const auto f = std::dynamic_pointer_cast<WinFontDescriptor>(font);
-  assert(f);
-  return new WinTextLayout(graph_manager_, std::move(f), std::move(text));
-}
-}  // namespace cru::platform::win
diff --git a/src/platform_win/win_painter.cpp b/src/platform_win/win_painter.cpp
deleted file mode 100644
index 7c99146a..00000000
--- a/src/platform_win/win_painter.cpp
+++ /dev/null
@@ -1,104 +0,0 @@
-#include "cru/platform/win/win_painter.hpp"
-
-#include "cru/platform/win/d2d_util.hpp"
-#include "cru/platform/win/exception.hpp"
-#include "cru/platform/win/graph_manager.hpp"
-#include "cru/platform/win/win_brush.hpp"
-#include "cru/platform/win/win_geometry.hpp"
-#include "cru/platform/win/win_native_window.hpp"
-#include "cru/platform/win/win_text_layout.hpp"
-#include "cru/platform/win/window_render_target.hpp"
-
-#include <cassert>
-
-namespace cru::platform::win {
-WinPainter::WinPainter(WinNativeWindow* window) {
-  assert(window);
-  window_ = window;
-  const auto window_render_target = window_->GetWindowRenderTarget();
-  render_target_ =
-      window_render_target->GetGraphManager()->GetD2D1DeviceContext();
-  window_render_target->SetAsTarget();
-  render_target_->BeginDraw();
-}
-
-WinPainter::~WinPainter() {
-  if (!IsDisposed()) {
-    ThrowIfFailed(render_target_->EndDraw());
-  }
-}
-
-Matrix WinPainter::GetTransform() {
-  assert(!IsDisposed());
-  D2D1_MATRIX_3X2_F m;
-  render_target_->GetTransform(&m);
-  return util::Convert(m);
-}
-
-void WinPainter::SetTransform(const Matrix& matrix) {
-  assert(!IsDisposed());
-  render_target_->SetTransform(util::Convert(matrix));
-}
-
-void WinPainter::Clear(const ui::Color& color) {
-  assert(!IsDisposed());
-  render_target_->Clear(util::Convert(color));
-}
-
-void WinPainter::StrokeRectangle(const ui::Rect& rectangle, Brush* brush,
-                                 float width) {
-  assert(!IsDisposed());
-  const auto b = dynamic_cast<WinBrush*>(brush);
-  assert(b);
-  render_target_->DrawRectangle(util::Convert(rectangle), b->GetD2DBrush(),
-                                width);
-}
-
-void WinPainter::FillRectangle(const ui::Rect& rectangle, Brush* brush) {
-  assert(!IsDisposed());
-  const auto b = dynamic_cast<WinBrush*>(brush);
-  assert(b);
-  render_target_->FillRectangle(util::Convert(rectangle), b->GetD2DBrush());
-}
-
-void WinPainter::StrokeGeometry(Geometry* geometry, Brush* brush, float width) {
-  assert(!IsDisposed());
-  const auto g = dynamic_cast<WinGeometry*>(geometry);
-  assert(g);
-  const auto b = dynamic_cast<WinBrush*>(brush);
-  assert(b);
-
-  render_target_->DrawGeometry(g->GetNative(), b->GetD2DBrush(), width);
-}
-
-void WinPainter::FillGeometry(Geometry* geometry, Brush* brush) {
-  assert(!IsDisposed());
-  const auto g = dynamic_cast<WinGeometry*>(geometry);
-  assert(g);
-  const auto b = dynamic_cast<WinBrush*>(brush);
-  assert(b);
-
-  render_target_->FillGeometry(g->GetNative(), b->GetD2DBrush());
-}
-
-void WinPainter::DrawText(const ui::Point& offset, TextLayout* text_layout,
-                          Brush* brush) {
-  assert(!IsDisposed());
-  const auto t = dynamic_cast<WinTextLayout*>(text_layout);
-  assert(t);
-  const auto b = dynamic_cast<WinBrush*>(brush);
-  assert(b);
-
-  render_target_->DrawTextLayout(util::Convert(offset),
-                                 t->GetDWriteTextLayout(), b->GetD2DBrush());
-}
-
-void WinPainter::EndDraw() {
-  if (!IsDisposed()) {
-    ThrowIfFailed(render_target_->EndDraw());
-    render_target_ = nullptr;
-    window_->GetWindowRenderTarget()->Present();
-    is_disposed = true;
-  }
-}
-}  // namespace cru::platform::win
diff --git a/src/ui/CMakeLists.txt b/src/ui/CMakeLists.txt
new file mode 100644
index 00000000..900948ca
--- /dev/null
+++ b/src/ui/CMakeLists.txt
@@ -0,0 +1,22 @@
+add_library(cru_ui STATIC
+    content_control.cpp
+    control.cpp
+    layout_control.cpp
+    no_child_control.cpp
+    ui_manager.cpp
+    window.cpp
+    controls/button.cpp
+    controls/flex_layout.cpp
+    controls/text_block.cpp
+    render/border_render_object.cpp
+    render/flex_layout_render_object.cpp
+    render/render_object.cpp
+    render/text_render_object.cpp
+    render/window_render_object.cpp)
+
+target_include_directories(cru_ui PUBLIC ${PROJECT_SOURCE_DIR}/include .)
+
+if(WIN32)
+target_link_libraries(cru_ui PUBLIC cru_win_native)
+endif()
+
diff --git a/src/ui/control.cpp b/src/ui/control.cpp
index f915af07..7563dc91 100644
--- a/src/ui/control.cpp
+++ b/src/ui/control.cpp
@@ -63,7 +63,7 @@ void Control::OnAttachToWindow(Window* window) {}
 
 void Control::OnDetachToWindow(Window* window) {}
 
-void Control::OnMouseClickBegin(platform::MouseButton button) {}
+void Control::OnMouseClickBegin(platform::native::MouseButton button) {}
 
-void Control::OnMouseClickEnd(platform::MouseButton button) {}
+void Control::OnMouseClickEnd(platform::native::MouseButton button) {}
 }  // namespace cru::ui
diff --git a/src/ui/render/border_render_object.cpp b/src/ui/render/border_render_object.cpp
index 97e386dd..541be473 100644
--- a/src/ui/render/border_render_object.cpp
+++ b/src/ui/render/border_render_object.cpp
@@ -1,26 +1,26 @@
- #include "cru/ui/render/border_render_object.hpp"
+#include "cru/ui/render/border_render_object.hpp"
 
 #include "cru/platform/debug.hpp"
-#include "cru/platform/geometry.hpp"
-#include "cru/platform/graph_factory.hpp"
-#include "cru/platform/painter_util.hpp"
-#include "cru/platform/ui_applicaition.hpp"
+#include "cru/platform/graph/geometry.hpp"
+#include "cru/platform/graph/graph_factory.hpp"
+#include "cru/platform/graph/painter_util.hpp"
 
 #include <algorithm>
 #include <cassert>
 
 namespace cru::ui::render {
-BorderRenderObject::BorderRenderObject(std::shared_ptr<platform::Brush> brush) {
+BorderRenderObject::BorderRenderObject(
+    std::shared_ptr<platform::graph::Brush> brush) {
   assert(brush);
   this->border_brush_ = std::move(brush);
   RecreateGeometry();
 }
 
-void BorderRenderObject::Draw(platform::Painter* painter) {
+void BorderRenderObject::Draw(platform::graph::Painter* painter) {
   painter->FillGeometry(geometry_.get(), border_brush_.get());
   if (const auto child = GetChild()) {
     auto offset = child->GetOffset();
-    platform::util::WithTransform(
+    platform::graph::util::WithTransform(
         painter, platform::Matrix::Translation(offset.x, offset.y),
         [child](auto p) { child->Draw(p); });
   }
@@ -75,13 +75,13 @@ void BorderRenderObject::OnMeasureCore(const Size& available_size) {
 
   auto coerced_margin_border_padding_size = margin_border_padding_size;
   if (coerced_margin_border_padding_size.width > available_size.width) {
-    platform::debug::DebugMessage(
+    platform::DebugMessage(
         L"Measure: horizontal length of padding, border and margin is bigger "
         L"than available length.");
     coerced_margin_border_padding_size.width = available_size.width;
   }
   if (coerced_margin_border_padding_size.height > available_size.height) {
-    platform::debug::DebugMessage(
+    platform::DebugMessage(
         L"Measure: vertical length of padding, border and margin is bigger "
         L"than available length.");
     coerced_margin_border_padding_size.height = available_size.height;
@@ -113,13 +113,13 @@ void BorderRenderObject::OnLayoutCore(const Rect& rect) {
   auto coerced_content_available_size = content_available_size;
 
   if (coerced_content_available_size.width < 0) {
-    platform::debug::DebugMessage(
+    platform::DebugMessage(
         L"Layout: horizontal length of padding, border and margin is bigger "
         L"than available length.");
     coerced_content_available_size.width = 0;
   }
   if (coerced_content_available_size.height < 0) {
-    platform::debug::DebugMessage(
+    platform::DebugMessage(
         L"Layout: vertical length of padding, border and margin is bigger "
         L"than "
         L"available length.");
@@ -154,7 +154,7 @@ void BorderRenderObject::RecreateGeometry() {
   geometry_.reset();
   border_outer_geometry_.reset();
 
-  auto f = [](platform::GeometryBuilder* builder, const Rect& rect,
+  auto f = [](platform::graph::GeometryBuilder* builder, const Rect& rect,
               const CornerRadius& corner) {
     builder->BeginFigure(Point(rect.left + corner.left_top.x, rect.top));
     builder->LineTo(Point(rect.GetRight() - corner.right_top.x, rect.top));
@@ -181,9 +181,9 @@ void BorderRenderObject::RecreateGeometry() {
   const Rect outer_rect{margin.left, margin.top,
                         size.width - margin.GetHorizontalTotal(),
                         size.height - margin.GetVerticalTotal()};
-  const auto graph_factory =
-      platform::UiApplication::GetInstance()->GetGraphFactory();
-  std::unique_ptr<platform::GeometryBuilder> builder{graph_factory->CreateGeometryBuilder()};
+  const auto graph_factory = platform::graph::GraphFactory::GetInstance();
+  std::unique_ptr<platform::graph::GeometryBuilder> builder{
+      graph_factory->CreateGeometryBuilder()};
   f(builder.get(), outer_rect, corner_radius_);
   border_outer_geometry_.reset(builder->Build());
   builder.reset();
diff --git a/src/ui/render/flex_layout_render_object.cpp b/src/ui/render/flex_layout_render_object.cpp
index e7840b7e..7528439f 100644
--- a/src/ui/render/flex_layout_render_object.cpp
+++ b/src/ui/render/flex_layout_render_object.cpp
@@ -1,15 +1,13 @@
 #include "cru/ui/render/flex_layout_render_object.hpp"
 
 #include "cru/platform/debug.hpp"
-#include "cru/platform/painter_util.hpp"
+#include "cru/platform/graph/painter_util.hpp"
 
 #include <algorithm>
 #include <cassert>
 #include <functional>
 
 namespace cru::ui::render {
-using namespace platform;
-
 FlexChildLayoutData* FlexLayoutRenderObject::GetChildLayoutData(int position) {
   assert(position >= 0 &&
          position < child_layout_data_.size());  // Position out of bound.
@@ -17,11 +15,12 @@ FlexChildLayoutData* FlexLayoutRenderObject::GetChildLayoutData(int position) {
   return &child_layout_data_[position];
 }
 
-void FlexLayoutRenderObject::Draw(platform::Painter* painter) {
+void FlexLayoutRenderObject::Draw(platform::graph::Painter* painter) {
   for (const auto child : GetChildren()) {
     auto offset = child->GetOffset();
-    util::WithTransform(painter, Matrix::Translation(offset.x, offset.y),
-                        [child](auto p) { child->Draw(p); });
+    platform::graph::util::WithTransform(
+        painter, platform::Matrix::Translation(offset.x, offset.y),
+        [child](auto p) { child->Draw(p); });
   }
 }
 
diff --git a/src/ui/render/render_object.cpp b/src/ui/render/render_object.cpp
index 111128b2..3cb7e4df 100644
--- a/src/ui/render/render_object.cpp
+++ b/src/ui/render/render_object.cpp
@@ -54,13 +54,13 @@ void RenderObject::OnMeasureCore(const Size& available_size) {
 
   auto coerced_margin_padding_size = margin_padding_size;
   if (coerced_margin_padding_size.width > available_size.width) {
-    platform::debug::DebugMessage(
+    platform::DebugMessage(
         L"Measure: horizontal length of padding and margin is bigger than "
         L"available length.");
     coerced_margin_padding_size.width = available_size.width;
   }
   if (coerced_margin_padding_size.height > available_size.height) {
-    platform::debug::DebugMessage(
+    platform::DebugMessage(
         L"Measure: vertical length of padding and margin is bigger than "
         L"available length.");
     coerced_margin_padding_size.height = available_size.height;
@@ -82,13 +82,13 @@ void RenderObject::OnLayoutCore(const Rect& rect) {
   auto coerced_content_available_size = content_available_size;
 
   if (coerced_content_available_size.width < 0) {
-    platform::debug::DebugMessage(
+    platform::DebugMessage(
         L"Layout: horizontal length of padding and margin is bigger than "
         L"available length.");
     coerced_content_available_size.width = 0;
   }
   if (coerced_content_available_size.height < 0) {
-    platform::debug::DebugMessage(
+    platform::DebugMessage(
         L"Layout: vertical length of padding and margin is bigger than "
         L"available length.");
     coerced_content_available_size.height = 0;
diff --git a/src/ui/render/text_render_object.cpp b/src/ui/render/text_render_object.cpp
index bdf48c9a..c886ee7a 100644
--- a/src/ui/render/text_render_object.cpp
+++ b/src/ui/render/text_render_object.cpp
@@ -1,18 +1,17 @@
 #include "cru/ui/render/text_render_object.hpp"
 
-#include "cru/platform/graph_factory.hpp"
-#include "cru/platform/painter_util.hpp"
-#include "cru/platform/text_layout.hpp"
-#include "cru/platform/ui_applicaition.hpp"
+#include "cru/platform/graph/graph_factory.hpp"
+#include "cru/platform/graph/painter_util.hpp"
+#include "cru/platform/graph/text_layout.hpp"
 
 #include <algorithm>
 #include <cassert>
 
 namespace cru::ui::render {
 TextRenderObject::TextRenderObject(
-    std::shared_ptr<platform::Brush> brush,
-    std::shared_ptr<platform::FontDescriptor> font,
-    std::shared_ptr<platform::Brush> selection_brush) {
+    std::shared_ptr<platform::graph::Brush> brush,
+    std::shared_ptr<platform::graph::FontDescriptor> font,
+    std::shared_ptr<platform::graph::Brush> selection_brush) {
   assert(brush);
   assert(font);
   assert(selection_brush);
@@ -21,8 +20,7 @@ TextRenderObject::TextRenderObject(
   font.swap(font_);
   selection_brush.swap(selection_brush_);
 
-  const auto graph_factory =
-      platform::UiApplication::GetInstance()->GetGraphFactory();
+  const auto graph_factory = platform::graph::GraphFactory::GetInstance();
 
   text_layout_.reset(graph_factory->CreateTextLayout(font_, L""));
 }
@@ -35,20 +33,22 @@ void TextRenderObject::SetText(std::wstring new_text) {
   text_layout_->SetText(std::move(new_text));
 }
 
-std::shared_ptr<platform::FontDescriptor> TextRenderObject::GetFont() const {
+std::shared_ptr<platform::graph::FontDescriptor> TextRenderObject::GetFont()
+    const {
   return text_layout_->GetFont();
 }
 
-void TextRenderObject::SetFont(std::shared_ptr<platform::FontDescriptor> font) {
+void TextRenderObject::SetFont(
+    std::shared_ptr<platform::graph::FontDescriptor> font) {
   text_layout_->SetFont(std::move(font));
 }
 
-void TextRenderObject::Draw(platform::Painter* painter) {
-  platform::util::WithTransform(
+void TextRenderObject::Draw(platform::graph::Painter* painter) {
+  platform::graph::util::WithTransform(
       painter,
       platform::Matrix::Translation(GetMargin().left + GetPadding().left,
                                     GetMargin().top + GetPadding().top),
-      [this](platform::Painter* p) {
+      [this](platform::graph::Painter* p) {
         if (this->selection_range_.has_value()) {
           const auto&& rects =
               text_layout_->TextRangeRect(this->selection_range_.value());
diff --git a/src/ui/render/window_render_object.cpp b/src/ui/render/window_render_object.cpp
index 781087aa..4fc57ad1 100644
--- a/src/ui/render/window_render_object.cpp
+++ b/src/ui/render/window_render_object.cpp
@@ -1,7 +1,7 @@
 #include "cru/ui/render/window_render_object.hpp"
 
-#include "cru/platform/native_window.hpp"
-#include "cru/platform/painter_util.hpp"
+#include "cru/platform/graph/painter_util.hpp"
+#include "cru/platform/native/native_window.hpp"
 #include "cru/ui/window.hpp"
 
 #include <cassert>
@@ -13,11 +13,11 @@ void WindowRenderObject::MeasureAndLayout() {
   Layout(Rect{Point{}, client_size});
 }
 
-void WindowRenderObject::Draw(platform::Painter* painter) {
+void WindowRenderObject::Draw(platform::graph::Painter* painter) {
   painter->Clear(colors::white);
   if (const auto child = GetChild()) {
     auto offset = child->GetOffset();
-    platform::util::WithTransform(
+    platform::graph::util::WithTransform(
         painter, platform::Matrix::Translation(offset.x, offset.y),
         [child](auto rt) { child->Draw(rt); });
   }
diff --git a/src/ui/ui_manager.cpp b/src/ui/ui_manager.cpp
index b1132ea8..2ac1c8e7 100644
--- a/src/ui/ui_manager.cpp
+++ b/src/ui/ui_manager.cpp
@@ -1,20 +1,19 @@
 #include "cru/ui/ui_manager.hpp"
 
-#include "cru/platform/brush.hpp"
-#include "cru/platform/font.hpp"
-#include "cru/platform/graph_factory.hpp"
-#include "cru/platform/ui_applicaition.hpp"
+#include "cru/platform/graph/brush.hpp"
+#include "cru/platform/graph/font.hpp"
+#include "cru/platform/graph/graph_factory.hpp"
+#include "cru/platform/native/ui_applicaition.hpp"
 
 namespace cru::ui {
 PredefineResources::PredefineResources() {
-  const auto graph_factory =
-      platform::UiApplication::GetInstance()->GetGraphFactory();
+  const auto graph_factory = platform::graph::GraphFactory::GetInstance();
 
-  button_normal_border_brush.reset(static_cast<platform::Brush*>(
+  button_normal_border_brush.reset(static_cast<platform::graph::Brush*>(
       graph_factory->CreateSolidColorBrush(colors::black)));
-  text_block_selection_brush.reset(static_cast<platform::Brush*>(
+  text_block_selection_brush.reset(static_cast<platform::graph::Brush*>(
       graph_factory->CreateSolidColorBrush(colors::skyblue)));
-  text_block_text_brush.reset(static_cast<platform::Brush*>(
+  text_block_text_brush.reset(static_cast<platform::graph::Brush*>(
       graph_factory->CreateSolidColorBrush(colors::black)));
   text_block_font.reset(graph_factory->CreateFontDescriptor(L"等线", 24.0f));
 }
diff --git a/src/ui/window.cpp b/src/ui/window.cpp
index f909e0f9..347a7a49 100644
--- a/src/ui/window.cpp
+++ b/src/ui/window.cpp
@@ -1,8 +1,8 @@
 #include "cru/ui/window.hpp"
 
-#include "cru/platform/native_window.hpp"
-#include "cru/platform/painter.hpp"
-#include "cru/platform/ui_applicaition.hpp"
+#include "cru/platform/graph/painter.hpp"
+#include "cru/platform/native/native_window.hpp"
+#include "cru/platform/native/ui_applicaition.hpp"
 #include "cru/ui/render/window_render_object.hpp"
 
 #include <cassert>
@@ -102,7 +102,7 @@ Window::Window(tag_overlapped_constructor) {
   using namespace std::placeholders;
 
   native_window_ =
-      platform::UiApplication::GetInstance()->CreateWindow(nullptr);
+      platform::native::UiApplication::GetInstance()->CreateWindow(nullptr);
   render_object_.reset(new render::WindowRenderObject(this));
 
   event_revoker_guard_.Add(native_window_->DestroyEvent()->AddHandler(
@@ -124,7 +124,7 @@ Window::Window(tag_overlapped_constructor) {
   event_revoker_guard_.Add(native_window_->KeyDownEvent()->AddHandler(
       std::bind(&Window::OnNativeKeyDown, this, _1)));
   event_revoker_guard_.Add(native_window_->KeyUpEvent()->AddHandler(
-      std::bind(&Window::OnNativeKeyUp, this, _1)));  
+      std::bind(&Window::OnNativeKeyUp, this, _1)));
 }
 
 Window::~Window() {
@@ -168,7 +168,7 @@ void Window::OnNativeDestroy() { delete this; }
 
 void Window::OnNativePaint() {
   const auto painter =
-      std::unique_ptr<platform::Painter>(native_window_->BeginPaint());
+      std::unique_ptr<platform::graph::Painter>(native_window_->BeginPaint());
   render_object_->Draw(painter.get());
   painter->EndDraw();
 }
@@ -202,13 +202,13 @@ void Window::OnNativeMouseMove(const Point& point) {
                 point);
 }
 
-void Window::OnNativeMouseDown(platform::MouseButton button,
+void Window::OnNativeMouseDown(platform::native::MouseButton button,
                                const Point& point) {
   Control* control = HitTest(point);
   DispatchEvent(control, &Control::MouseDownEvent, nullptr, point, button);
 }
 
-void Window::OnNativeMouseUp(platform::MouseButton button, const Point& point) {
+void Window::OnNativeMouseUp(platform::native::MouseButton button, const Point& point) {
   Control* control = HitTest(point);
   DispatchEvent(control, &Control::MouseUpEvent, nullptr, point, button);
 }
diff --git a/src/win/CMakeLists.txt b/src/win/CMakeLists.txt
new file mode 100644
index 00000000..1ca1f544
--- /dev/null
+++ b/src/win/CMakeLists.txt
@@ -0,0 +1,10 @@
+add_library(cru_win_base STATIC
+	debug.cpp
+	exception.cpp
+	string_util.cpp
+)
+target_compile_definitions(cru_win_base PUBLIC UNICODE _UNICODE) # use unicode
+target_include_directories(cru_win_base PUBLIC ${PROJECT_SOURCE_DIR}/include .)
+
+add_subdirectory(graph)
+add_subdirectory(native)
diff --git a/src/platform_win/debug.cpp b/src/win/debug.cpp
index f52d41bd..e15b1f6c 100644
--- a/src/platform_win/debug.cpp
+++ b/src/win/debug.cpp
@@ -1,10 +1,9 @@
-#include "cru/platform/win/win_pre_config.hpp"
+#include "cru/win/win_pre_config.hpp"
 
 #include "cru/platform/debug.hpp"
 
-
-namespace cru::platform::debug {
+namespace cru::platform {
 void DebugMessage(const std::wstring_view& message) {
   ::OutputDebugStringW(message.data());
 }
-}  // namespace cru::debug
+}  // namespace cru::platform
diff --git a/src/platform_win/exception.cpp b/src/win/exception.cpp
index 3db88b8b..62305329 100644
--- a/src/platform_win/exception.cpp
+++ b/src/win/exception.cpp
@@ -1,8 +1,8 @@
-#include "cru/platform/win/exception.hpp"
+#include "cru/win/exception.hpp"
 
 #include "cru/common/format.hpp"
 
-namespace cru::platform::win {
+namespace cru::win {
 using util::Format;
 
 inline std::string HResultMakeMessage(HRESULT h_result,
@@ -19,12 +19,12 @@ inline std::string HResultMakeMessage(HRESULT h_result,
 }
 
 HResultError::HResultError(HRESULT h_result)
-    : runtime_error(HResultMakeMessage(h_result, nullptr)),
+    : PlatformException(HResultMakeMessage(h_result, nullptr)),
       h_result_(h_result) {}
 
 HResultError::HResultError(HRESULT h_result,
                            const std::string_view& additional_message)
-    : runtime_error(HResultMakeMessage(h_result, &additional_message)),
+    : PlatformException(HResultMakeMessage(h_result, &additional_message)),
       h_result_(h_result) {}
 
 inline std::string Win32MakeMessage(DWORD error_code,
@@ -40,11 +40,11 @@ inline std::string Win32MakeMessage(DWORD error_code,
 }
 
 Win32Error::Win32Error(DWORD error_code)
-    : runtime_error(Win32MakeMessage(error_code, nullptr)),
+    : PlatformException(Win32MakeMessage(error_code, nullptr)),
       error_code_(error_code) {}
 
 Win32Error::Win32Error(DWORD error_code,
                        const std::string_view& additional_message)
-    : runtime_error(Win32MakeMessage(error_code, &additional_message)),
+    : PlatformException(Win32MakeMessage(error_code, &additional_message)),
       error_code_(error_code) {}
-}  // namespace cru::platform::win
+}  // namespace cru::win
diff --git a/src/win/graph/CMakeLists.txt b/src/win/graph/CMakeLists.txt
new file mode 100644
index 00000000..7781e09a
--- /dev/null
+++ b/src/win/graph/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_library(cru_win_graph STATIC
+	graph_manager.cpp
+	win_brush.cpp
+	win_font.cpp
+	win_geometry.cpp
+	win_graph_factory.cpp
+	win_painter.cpp
+	win_text_layout.cpp)
+target_link_libraries(cru_win_graph PUBLIC D3D11 D2d1 DWrite cru_win_base)
diff --git a/src/platform_win/graph_manager.cpp b/src/win/graph/graph_manager.cpp
index 4961867b..a4306b1b 100644
--- a/src/platform_win/graph_manager.cpp
+++ b/src/win/graph/graph_manager.cpp
@@ -1,8 +1,13 @@
-#include "cru/platform/win/graph_manager.hpp"
+#include "cru/win/graph/graph_manager.hpp"
 
-#include "cru/platform/win/exception.hpp"
+#include "cru/win/exception.hpp"
+
+namespace cru::win::graph {
+GraphManager* GraphManager::GetInstance() {
+  static GraphManager instance;
+  return &instance;
+}
 
-namespace cru::platform::win {
 GraphManager::GraphManager() {
   UINT creation_flags = D3D11_CREATE_DEVICE_BGRA_SUPPORT;
 
@@ -42,10 +47,13 @@ GraphManager::GraphManager() {
   // Get the factory object that created the DXGI device.
   ThrowIfFailed(dxgi_adapter->GetParent(IID_PPV_ARGS(&dxgi_factory_)));
 
-  ThrowIfFailed(
-      DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED, __uuidof(IDWriteFactory),
-                          reinterpret_cast<IUnknown**>(dwrite_factory_.GetAddressOf())));
+  ThrowIfFailed(DWriteCreateFactory(
+      DWRITE_FACTORY_TYPE_SHARED, __uuidof(IDWriteFactory),
+      reinterpret_cast<IUnknown**>(dwrite_factory_.GetAddressOf())));
+
+  ThrowIfFailed(dwrite_factory_->GetSystemFontCollection(
+      &dwrite_system_font_collection_));
 
-  ThrowIfFailed(dwrite_factory_->GetSystemFontCollection(&dwrite_system_font_collection_));
+  graph_factory_.reset(new WinGraphFactory(this));
 }
-}  // namespace cru::graph
+}  // namespace cru::win::graph
diff --git a/src/win/graph/win_brush.cpp b/src/win/graph/win_brush.cpp
new file mode 100644
index 00000000..262c3302
--- /dev/null
+++ b/src/win/graph/win_brush.cpp
@@ -0,0 +1,23 @@
+#include "cru/win/graph/win_brush.hpp"
+
+#include "cru/win/exception.hpp"
+#include "cru/win/graph/d2d_util.hpp"
+#include "cru/win/graph/graph_manager.hpp"
+
+#include <cassert>
+
+namespace cru::win::graph {
+WinSolidColorBrush::WinSolidColorBrush(GraphManager* graph_manager,
+                                       const ui::Color& color) {
+  assert(graph_manager);
+  ThrowIfFailed(graph_manager->GetD2D1DeviceContext()->CreateSolidColorBrush(
+      util::Convert(color), &brush_));
+}
+
+ui::Color WinSolidColorBrush::GetColor() {
+  return util::Convert(brush_->GetColor());
+}
+void WinSolidColorBrush::SetColor(const ui::Color& color) {
+  brush_->SetColor(util::Convert(color));
+}
+}  // namespace cru::win::graph
diff --git a/src/platform_win/win_font.cpp b/src/win/graph/win_font.cpp
index bca70b9f..0eb5e6b2 100644
--- a/src/platform_win/win_font.cpp
+++ b/src/win/graph/win_font.cpp
@@ -1,15 +1,17 @@
-#include "cru/platform/win/win_font.hpp"
+#include "cru/win/graph/win_font.hpp"
 
-#include "cru/platform/win/exception.hpp"
-#include "cru/platform/win/graph_manager.hpp"
+#include "cru/win/exception.hpp"
+#include "cru/win/graph/graph_manager.hpp"
 
 #include <array>
+#include <cassert>
 #include <utility>
 
-namespace cru::platform::win {
+namespace cru::win::graph {
 WinFontDescriptor::WinFontDescriptor(GraphManager* graph_manager,
                                      const std::wstring_view& font_family,
                                      float font_size) {
+  assert(graph_manager);
   std::array<wchar_t, LOCALE_NAME_MAX_LENGTH> buffer;
   if (!::GetUserDefaultLocaleName(buffer.data(), buffer.size()))
     throw Win32Error(::GetLastError(), "Failed to get locale.");
@@ -20,6 +22,7 @@ WinFontDescriptor::WinFontDescriptor(GraphManager* graph_manager,
       buffer.data(), &text_format_));
 
   ThrowIfFailed(text_format_->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_CENTER));
-  ThrowIfFailed(text_format_->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_CENTER));
+  ThrowIfFailed(
+      text_format_->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_CENTER));
 }
-}  // namespace cru::platform::win
+}  // namespace cru::win::graph
diff --git a/src/platform_win/win_geometry.cpp b/src/win/graph/win_geometry.cpp
index 1078700b..22c4b8a7 100644
--- a/src/platform_win/win_geometry.cpp
+++ b/src/win/graph/win_geometry.cpp
@@ -1,16 +1,17 @@
-#include "cru/platform/win/win_geometry.hpp"
+#include "cru/win/graph/win_geometry.hpp"
 
-#include "cru/platform/win/d2d_util.hpp"
-#include "cru/platform/win/exception.hpp"
+#include "cru/win/exception.hpp"
+#include "cru/win/graph/d2d_util.hpp"
+#include "cru/win/graph/graph_manager.hpp"
 
 #include <cassert>
 
-namespace cru::platform::win {
-WinGeometryBuilder::WinGeometryBuilder(
-    Microsoft::WRL::ComPtr<ID2D1PathGeometry> geometry) {
-  assert(geometry);
-  ThrowIfFailed(geometry->Open(&geometry_sink_));
-  geometry_ = std::move(geometry);
+namespace cru::win::graph {
+WinGeometryBuilder::WinGeometryBuilder(GraphManager* graph_manager) {
+  assert(graph_manager);
+  ThrowIfFailed(
+      graph_manager->GetD2D1Factory()->CreatePathGeometry(&geometry_));
+  ThrowIfFailed(geometry_->Open(&geometry_sink_));
 }
 
 WinGeometryBuilder::~WinGeometryBuilder() {
@@ -42,7 +43,7 @@ void WinGeometryBuilder::CloseFigure(bool close) {
                                   : D2D1_FIGURE_END_OPEN);
 }
 
-Geometry* WinGeometryBuilder::Build() {
+platform::graph::Geometry* WinGeometryBuilder::Build() {
   assert(IsValid());
   ThrowIfFailed(geometry_sink_->Close());
   geometry_sink_ = nullptr;
@@ -62,4 +63,4 @@ bool WinGeometry::FillContains(const ui::Point& point) {
       util::Convert(point), D2D1::Matrix3x2F::Identity(), &result));
   return result != 0;
 }
-}  // namespace cru::platform::win
+}  // namespace cru::win::graph
diff --git a/src/win/graph/win_graph_factory.cpp b/src/win/graph/win_graph_factory.cpp
new file mode 100644
index 00000000..5ab905b6
--- /dev/null
+++ b/src/win/graph/win_graph_factory.cpp
@@ -0,0 +1,46 @@
+#include "cru/win/graph/win_graph_factory.hpp"
+
+#include "cru/win/exception.hpp"
+#include "cru/win/graph/d2d_util.hpp"
+#include "cru/win/graph/graph_manager.hpp"
+#include "cru/win/graph/win_brush.hpp"
+#include "cru/win/graph/win_font.hpp"
+#include "cru/win/graph/win_geometry.hpp"
+#include "cru/win/graph/win_text_layout.hpp"
+
+#include <cassert>
+#include <utility>
+
+namespace cru::platform::graph {
+GraphFactory* GraphFactory::GetInstance() {
+  return win::graph::GraphManager::GetInstance()->GetGraphFactory();
+}
+}
+
+namespace cru::win::graph {
+WinGraphFactory::WinGraphFactory(GraphManager* graph_manager) {
+  assert(graph_manager);
+  graph_manager_ = graph_manager;
+}
+
+platform::graph::SolidColorBrush* WinGraphFactory::CreateSolidColorBrush(
+    const ui::Color& color) {
+  return new WinSolidColorBrush(graph_manager_, color);
+}
+
+platform::graph::GeometryBuilder* WinGraphFactory::CreateGeometryBuilder() {
+  return new WinGeometryBuilder(graph_manager_);
+}
+
+platform::graph::FontDescriptor* WinGraphFactory::CreateFontDescriptor(
+    const std::wstring_view& font_family, float font_size) {
+  return new WinFontDescriptor(graph_manager_, font_family, font_size);
+}
+
+platform::graph::TextLayout* WinGraphFactory::CreateTextLayout(
+    std::shared_ptr<platform::graph::FontDescriptor> font, std::wstring text) {
+  const auto f = std::dynamic_pointer_cast<WinFontDescriptor>(font);
+  assert(f);
+  return new WinTextLayout(graph_manager_, std::move(f), std::move(text));
+}
+}  // namespace cru::win::graph
diff --git a/src/win/graph/win_painter.cpp b/src/win/graph/win_painter.cpp
new file mode 100644
index 00000000..69ce1141
--- /dev/null
+++ b/src/win/graph/win_painter.cpp
@@ -0,0 +1,99 @@
+#include "cru/win/graph/win_painter.hpp"
+
+#include "cru/win/exception.hpp"
+#include "cru/win/graph/d2d_util.hpp"
+#include "cru/win/graph/graph_manager.hpp"
+#include "cru/win/graph/win_brush.hpp"
+#include "cru/win/graph/win_geometry.hpp"
+#include "cru/win/graph/win_text_layout.hpp"
+
+#include <cassert>
+
+namespace cru::win::graph {
+WinPainter::WinPainter(ID2D1RenderTarget* render_target) {
+  assert(render_target);
+  render_target_ = render_target;
+}
+
+WinPainter::~WinPainter() { EndDraw(); }
+
+platform::Matrix WinPainter::GetTransform() {
+  assert(!IsDisposed());
+  D2D1_MATRIX_3X2_F m;
+  render_target_->GetTransform(&m);
+  return util::Convert(m);
+}
+
+void WinPainter::SetTransform(const platform::Matrix& matrix) {
+  assert(!IsDisposed());
+  render_target_->SetTransform(util::Convert(matrix));
+}
+
+void WinPainter::Clear(const ui::Color& color) {
+  assert(!IsDisposed());
+  render_target_->Clear(util::Convert(color));
+}
+
+void WinPainter::StrokeRectangle(const ui::Rect& rectangle,
+                                 platform::graph::Brush* brush, float width) {
+  assert(!IsDisposed());
+  const auto b = dynamic_cast<WinBrush*>(brush);
+  assert(b);
+  render_target_->DrawRectangle(util::Convert(rectangle), b->GetD2DBrush(),
+                                width);
+}
+
+void WinPainter::FillRectangle(const ui::Rect& rectangle,
+                               platform::graph::Brush* brush) {
+  assert(!IsDisposed());
+  const auto b = dynamic_cast<WinBrush*>(brush);
+  assert(b);
+  render_target_->FillRectangle(util::Convert(rectangle), b->GetD2DBrush());
+}
+
+void WinPainter::StrokeGeometry(platform::graph::Geometry* geometry,
+                                platform::graph::Brush* brush, float width) {
+  assert(!IsDisposed());
+  const auto g = dynamic_cast<WinGeometry*>(geometry);
+  assert(g);
+  const auto b = dynamic_cast<WinBrush*>(brush);
+  assert(b);
+
+  render_target_->DrawGeometry(g->GetNative(), b->GetD2DBrush(), width);
+}
+
+void WinPainter::FillGeometry(platform::graph::Geometry* geometry,
+                              platform::graph::Brush* brush) {
+  assert(!IsDisposed());
+  const auto g = dynamic_cast<WinGeometry*>(geometry);
+  assert(g);
+  const auto b = dynamic_cast<WinBrush*>(brush);
+  assert(b);
+
+  render_target_->FillGeometry(g->GetNative(), b->GetD2DBrush());
+}
+
+void WinPainter::DrawText(const ui::Point& offset,
+                          platform::graph::TextLayout* text_layout,
+                          platform::graph::Brush* brush) {
+  assert(!IsDisposed());
+  const auto t = dynamic_cast<WinTextLayout*>(text_layout);
+  assert(t);
+  const auto b = dynamic_cast<WinBrush*>(brush);
+  assert(b);
+
+  render_target_->DrawTextLayout(util::Convert(offset),
+                                 t->GetDWriteTextLayout(), b->GetD2DBrush());
+}
+
+void WinPainter::EndDraw() {
+  if (!IsDisposed()) {
+    DoEndDraw();
+  }
+}
+
+void WinPainter::DoEndDraw() {
+  ThrowIfFailed(render_target_->EndDraw());
+  is_disposed_ = true;
+}
+}  // namespace cru::win::graph
diff --git a/src/platform_win/win_text_layout.cpp b/src/win/graph/win_text_layout.cpp
index 04b5e928..0506320a 100644
--- a/src/platform_win/win_text_layout.cpp
+++ b/src/win/graph/win_text_layout.cpp
@@ -1,12 +1,13 @@
-#include "cru/platform/win/win_text_layout.hpp"
+#include "cru/win/graph/win_text_layout.hpp"
 
-#include "cru/platform/win/exception.hpp"
-#include "cru/platform/win/graph_manager.hpp"
+#include "cru/win/exception.hpp"
+#include "cru/win/graph/graph_manager.hpp"
+#include "cru/win/graph/win_font.hpp"
 
 #include <cassert>
 #include <utility>
 
-namespace cru::platform::win {
+namespace cru::win::graph {
 WinTextLayout::WinTextLayout(GraphManager* graph_manager,
                              std::shared_ptr<WinFontDescriptor> font,
                              std::wstring text) {
@@ -32,11 +33,12 @@ void WinTextLayout::SetText(std::wstring new_text) {
       &text_layout_));
 }
 
-std::shared_ptr<FontDescriptor> WinTextLayout::GetFont() {
+std::shared_ptr<platform::graph::FontDescriptor> WinTextLayout::GetFont() {
   return font_descriptor_;
 }
 
-void WinTextLayout::SetFont(std::shared_ptr<FontDescriptor> font) {
+void WinTextLayout::SetFont(
+    std::shared_ptr<platform::graph::FontDescriptor> font) {
   auto f = std::dynamic_pointer_cast<WinFontDescriptor>(font);
   assert(f);
   f.swap(font_descriptor_);
@@ -89,4 +91,4 @@ std::vector<ui::Rect> WinTextLayout::TextRangeRect(
 
   return result;
 }
-}  // namespace cru::platform::win
+}  // namespace cru::win::graph
diff --git a/src/win/native/CMakeLists.txt b/src/win/native/CMakeLists.txt
new file mode 100644
index 00000000..421f7515
--- /dev/null
+++ b/src/win/native/CMakeLists.txt
@@ -0,0 +1,10 @@
+add_library(cru_win_native STATIC
+	god_window.cpp
+	timer.cpp
+	win_application.cpp
+	win_native_window.cpp
+	window_class.cpp
+	window_manager.cpp
+	window_painter.cpp
+	window_render_target.cpp)
+target_link_libraries(cru_win_native PUBLIC cru_win_graph)
diff --git a/src/platform_win/dpi_util.hpp b/src/win/native/dpi_util.hpp
index 92819e0f..d459e8c6 100644
--- a/src/platform_win/dpi_util.hpp
+++ b/src/win/native/dpi_util.hpp
@@ -1,10 +1,14 @@
 #pragma once
 
+#include "cru/platform/native/basic_types.hpp"
+
 // The dpi awareness needs to be implemented in the future. Currently we use 96
 // as default.
 
-namespace cru::platform {
-inline Dpi GetDpi() { return Dpi{96.0f, 96.0f}; }
+namespace cru::win::native {
+inline platform::native::Dpi GetDpi() {
+  return platform::native::Dpi{96.0f, 96.0f};
+}
 
 inline int DipToPixelInternal(const float dip, const float dpi) {
   return static_cast<int>(dip * dpi / 96.0f);
@@ -29,4 +33,4 @@ inline float PixelToDipX(const int pixel_x) {
 inline float PixelToDipY(const int pixel_y) {
   return DipToPixelInternal(pixel_y, GetDpi().y);
 }
-}  // namespace cru::platform
+}  // namespace cru::win::native
diff --git a/src/platform_win/god_window.cpp b/src/win/native/god_window.cpp
index 0cb1a0e4..58fb663c 100644
--- a/src/platform_win/god_window.cpp
+++ b/src/win/native/god_window.cpp
@@ -1,12 +1,12 @@
-#include "cru/platform/win/god_window.hpp"
+#include "cru/win/native/god_window.hpp"
 
-#include "cru/platform/win/exception.hpp"
-#include "cru/platform/win/win_application.hpp"
-#include "cru/platform/win/window_class.hpp"
+#include "cru/win/exception.hpp"
+#include "cru/win/native/win_application.hpp"
+#include "cru/win/native/window_class.hpp"
 #include "god_window_message.hpp"
 #include "timer.hpp"
 
-namespace cru::platform::win {
+namespace cru::win::native {
 constexpr auto god_window_class_name = L"GodWindowClass";
 
 LRESULT CALLBACK GodWndProc(HWND hWnd, UINT uMsg, WPARAM wParam,
@@ -15,8 +15,8 @@ LRESULT CALLBACK GodWndProc(HWND hWnd, UINT uMsg, WPARAM wParam,
 
   if (app) {
     LRESULT result;
-    const auto handled =
-        app->GetGodWindow()->HandleGodWindowMessage(hWnd, uMsg, wParam, lParam, &result);
+    const auto handled = app->GetGodWindow()->HandleGodWindowMessage(
+        hWnd, uMsg, wParam, lParam, &result);
     if (handled)
       return result;
     else
@@ -37,7 +37,8 @@ GodWindow::GodWindow(WinApplication* application) {
                          CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
                          HWND_MESSAGE, nullptr, h_instance, nullptr);
 
-  if (hwnd_ == nullptr) throw Win32Error(::GetLastError(), "Failed to create god window.");
+  if (hwnd_ == nullptr)
+    throw Win32Error(::GetLastError(), "Failed to create god window.");
 }
 
 GodWindow::~GodWindow() { ::DestroyWindow(hwnd_); }
@@ -69,4 +70,4 @@ bool GodWindow::HandleGodWindowMessage(HWND hwnd, UINT msg, WPARAM w_param,
   }
   return false;
 }
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/src/win/native/god_window_message.hpp b/src/win/native/god_window_message.hpp
new file mode 100644
index 00000000..10268625
--- /dev/null
+++ b/src/win/native/god_window_message.hpp
@@ -0,0 +1,6 @@
+#pragma once
+#include "cru/win/win_pre_config.hpp"
+
+namespace cru::win::native {
+constexpr int invoke_later_message_id = WM_USER + 2000;
+}
diff --git a/src/platform_win/timer.cpp b/src/win/native/timer.cpp
index 280d1aed..9e3bbde6 100644
--- a/src/platform_win/timer.cpp
+++ b/src/win/native/timer.cpp
@@ -1,6 +1,6 @@
 #include "timer.hpp"
 
-namespace cru::platform::win {
+namespace cru::win::native {
 TimerManager::TimerManager(GodWindow* god_window) { god_window_ = god_window; }
 
 UINT_PTR TimerManager::CreateTimer(const UINT milliseconds, const bool loop,
@@ -25,4 +25,4 @@ std::optional<std::pair<bool, TimerAction>> TimerManager::GetAction(
   if (find_result == map_.cend()) return std::nullopt;
   return find_result->second;
 }
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/src/platform_win/timer.hpp b/src/win/native/timer.hpp
index 95468b8d..f30d9b91 100644
--- a/src/platform_win/timer.hpp
+++ b/src/win/native/timer.hpp
@@ -1,15 +1,15 @@
 #pragma once
-#include "cru/platform/win/win_pre_config.hpp"
+#include "cru/win/win_pre_config.hpp"
+
+#include "cru/common/base.hpp"
+#include "cru/win/native/god_window.hpp"
 
 #include <chrono>
 #include <functional>
 #include <map>
 #include <optional>
 
-#include "cru/common/base.hpp"
-#include "cru/platform/win/god_window.hpp"
-
-namespace cru::platform::win {
+namespace cru::win::native {
 using TimerAction = std::function<void()>;
 
 class TimerManager : public Object {
@@ -31,4 +31,4 @@ class TimerManager : public Object {
   std::map<UINT_PTR, std::pair<bool, TimerAction>> map_{};
   UINT_PTR current_count_ = 0;
 };
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/src/platform_win/win_application.cpp b/src/win/native/win_application.cpp
index ce187136..72e12fa0 100644
--- a/src/platform_win/win_application.cpp
+++ b/src/win/native/win_application.cpp
@@ -1,10 +1,8 @@
-#include "cru/platform/win/win_application.hpp"
+#include "cru/win/native/win_application.hpp"
 
-#include "cru/platform/win/exception.hpp"
-#include "cru/platform/win/god_window.hpp"
-#include "cru/platform/win/graph_manager.hpp"
-#include "cru/platform/win/win_graph_factory.hpp"
-#include "cru/platform/win/win_native_window.hpp"
+#include "cru/win/exception.hpp"
+#include "cru/win/native/god_window.hpp"
+#include "cru/win/native/win_native_window.hpp"
 #include "god_window_message.hpp"
 #include "timer.hpp"
 #include "window_manager.hpp"
@@ -12,13 +10,13 @@
 #include <VersionHelpers.h>
 #include <cassert>
 
-namespace cru::platform {
+namespace cru::platform::native {
 UiApplication* UiApplication::GetInstance() {
-  return win::WinApplication::GetInstance();
+  return win::native::WinApplication::GetInstance();
 }
-}  // namespace cru::platform
+}  // namespace cru::platform::native
 
-namespace cru::platform::win {
+namespace cru::win::native {
 WinApplication* WinApplication::instance_ = nullptr;
 
 WinApplication* WinApplication::GetInstance() {
@@ -39,8 +37,6 @@ WinApplication::WinApplication(HINSTANCE h_instance) : h_instance_(h_instance) {
   god_window_ = std::make_shared<GodWindow>(this);
   timer_manager_ = std::make_shared<TimerManager>(god_window_.get());
   window_manager_ = std::make_shared<WindowManager>(this);
-  graph_manager_ = std::make_shared<GraphManager>();
-  graph_factory_ = std::make_shared<WinGraphFactory>(graph_manager_.get());
 }
 
 WinApplication::~WinApplication() { instance_ = nullptr; }
@@ -82,16 +78,17 @@ void WinApplication::CancelTimer(unsigned long id) {
   timer_manager_->KillTimer(static_cast<UINT_PTR>(id));
 }
 
-std::vector<NativeWindow*> WinApplication::GetAllWindow() {
+std::vector<platform::native::NativeWindow*> WinApplication::GetAllWindow() {
   const auto&& windows = window_manager_->GetAllWindows();
-  std::vector<NativeWindow*> result;
+  std::vector<platform::native::NativeWindow*> result;
   for (const auto w : windows) {
-    result.push_back(static_cast<NativeWindow*>(w));
+    result.push_back(static_cast<platform::native::NativeWindow*>(w));
   }
   return result;
 }
 
-NativeWindow* WinApplication::CreateWindow(NativeWindow* parent) {
+platform::native::NativeWindow* WinApplication::CreateWindow(
+    platform::native::NativeWindow* parent) {
   WinNativeWindow* p = nullptr;
   if (parent != nullptr) {
     p = dynamic_cast<WinNativeWindow*>(parent);
@@ -100,6 +97,4 @@ NativeWindow* WinApplication::CreateWindow(NativeWindow* parent) {
   return new WinNativeWindow(this, window_manager_->GetGeneralWindowClass(),
                              WS_OVERLAPPEDWINDOW, p);
 }
-
-GraphFactory* WinApplication::GetGraphFactory() { return graph_factory_.get(); }
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/src/platform_win/win_native_window.cpp b/src/win/native/win_native_window.cpp
index 3f34717f..0afad4e6 100644
--- a/src/platform_win/win_native_window.cpp
+++ b/src/win/native/win_native_window.cpp
@@ -1,17 +1,18 @@
-#include "cru/platform/win/win_native_window.hpp"
+#include "cru/win/native/win_native_window.hpp"
 
-#include "cru/platform/win/exception.hpp"
-#include "cru/platform/win/win_application.hpp"
-#include "cru/platform/win/win_painter.hpp"
-#include "cru/platform/win/window_class.hpp"
-#include "cru/platform/win/window_render_target.hpp"
+#include "cru/win/exception.hpp"
+#include "cru/win/graph/graph_manager.hpp"
+#include "cru/win/native/win_application.hpp"
+#include "cru/win/native/window_class.hpp"
+#include "cru/win/native/window_render_target.hpp"
 #include "dpi_util.hpp"
 #include "window_manager.hpp"
+#include "window_painter.hpp"
 
 #include <assert.h>
 #include <windowsx.h>
 
-namespace cru::platform::win {
+namespace cru::win::native {
 WinNativeWindow::WinNativeWindow(WinApplication* application,
                                  std::shared_ptr<WindowClass> window_class,
                                  DWORD window_style, WinNativeWindow* parent) {
@@ -36,7 +37,7 @@ WinNativeWindow::WinNativeWindow(WinApplication* application,
   window_manager->RegisterWindow(hwnd_, this);
 
   window_render_target_.reset(
-      new WindowRenderTarget(application->GetGraphManager(), hwnd_));
+      new WindowRenderTarget(graph::GraphManager::GetInstance(), hwnd_));
 }
 
 WinNativeWindow::~WinNativeWindow() {
@@ -116,8 +117,9 @@ void WinNativeWindow::SetWindowRect(const ui::Rect& rect) {
   }
 }
 
-Painter* WinNativeWindow::BeginPaint() { 
-  return new WinPainter(this); }
+platform::graph::Painter* WinNativeWindow::BeginPaint() {
+  return new WindowPainter(this);
+}
 
 bool WinNativeWindow::HandleNativeWindowMessage(HWND hwnd, UINT msg,
                                                 WPARAM w_param, LPARAM l_param,
@@ -158,7 +160,7 @@ bool WinNativeWindow::HandleNativeWindowMessage(HWND hwnd, UINT msg,
       POINT point;
       point.x = GET_X_LPARAM(l_param);
       point.y = GET_Y_LPARAM(l_param);
-      OnMouseDownInternal(MouseButton::Left, point);
+      OnMouseDownInternal(platform::native::MouseButton::Left, point);
       *result = 0;
       return true;
     }
@@ -166,7 +168,7 @@ bool WinNativeWindow::HandleNativeWindowMessage(HWND hwnd, UINT msg,
       POINT point;
       point.x = GET_X_LPARAM(l_param);
       point.y = GET_Y_LPARAM(l_param);
-      OnMouseUpInternal(MouseButton::Left, point);
+      OnMouseUpInternal(platform::native::MouseButton::Left, point);
       *result = 0;
       return true;
     }
@@ -174,7 +176,7 @@ bool WinNativeWindow::HandleNativeWindowMessage(HWND hwnd, UINT msg,
       POINT point;
       point.x = GET_X_LPARAM(l_param);
       point.y = GET_Y_LPARAM(l_param);
-      OnMouseDownInternal(MouseButton::Right, point);
+      OnMouseDownInternal(platform::native::MouseButton::Right, point);
       *result = 0;
       return true;
     }
@@ -182,7 +184,7 @@ bool WinNativeWindow::HandleNativeWindowMessage(HWND hwnd, UINT msg,
       POINT point;
       point.x = GET_X_LPARAM(l_param);
       point.y = GET_Y_LPARAM(l_param);
-      OnMouseUpInternal(MouseButton::Right, point);
+      OnMouseUpInternal(platform::native::MouseButton::Right, point);
       *result = 0;
       return true;
     }
@@ -190,7 +192,7 @@ bool WinNativeWindow::HandleNativeWindowMessage(HWND hwnd, UINT msg,
       POINT point;
       point.x = GET_X_LPARAM(l_param);
       point.y = GET_Y_LPARAM(l_param);
-      OnMouseDownInternal(MouseButton::Middle, point);
+      OnMouseDownInternal(platform::native::MouseButton::Middle, point);
       *result = 0;
       return true;
     }
@@ -198,7 +200,7 @@ bool WinNativeWindow::HandleNativeWindowMessage(HWND hwnd, UINT msg,
       POINT point;
       point.x = GET_X_LPARAM(l_param);
       point.y = GET_Y_LPARAM(l_param);
-      OnMouseUpInternal(MouseButton::Middle, point);
+      OnMouseUpInternal(platform::native::MouseButton::Middle, point);
       *result = 0;
       return true;
     }
@@ -308,12 +310,14 @@ void WinNativeWindow::OnMouseLeaveInternal() {
   mouse_enter_leave_event_.Raise(false);
 }
 
-void WinNativeWindow::OnMouseDownInternal(MouseButton button, POINT point) {
+void WinNativeWindow::OnMouseDownInternal(platform::native::MouseButton button,
+                                          POINT point) {
   const auto dip_point = PiToDip(point);
   mouse_down_event_.Raise(button, dip_point);
 }
 
-void WinNativeWindow::OnMouseUpInternal(MouseButton button, POINT point) {
+void WinNativeWindow::OnMouseUpInternal(platform::native::MouseButton button,
+                                        POINT point) {
   const auto dip_point = PiToDip(point);
   mouse_up_event_.Raise(button, dip_point);
 }
@@ -333,4 +337,4 @@ void WinNativeWindow::OnCharInternal(wchar_t c) {}
 void WinNativeWindow::OnActivatedInternal() {}
 
 void WinNativeWindow::OnDeactivatedInternal() {}
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/src/platform_win/window_class.cpp b/src/win/native/window_class.cpp
index b58f53b2..6c7d0d3d 100644
--- a/src/platform_win/window_class.cpp
+++ b/src/win/native/window_class.cpp
@@ -1,13 +1,13 @@
-#include "cru/platform/win/window_class.hpp"
+#include "cru/win/native/window_class.hpp"
 
-#include "cru/platform/win/exception.hpp"
+#include "cru/win/exception.hpp"
 
-namespace cru::platform::win {
+namespace cru::win::native {
 WindowClass::WindowClass(const std::wstring& name, WNDPROC window_proc,
                          HINSTANCE h_instance)
     : name_(name) {
-  WNDCLASSEX window_class;
-  window_class.cbSize = sizeof(WNDCLASSEX);
+  WNDCLASSEXW window_class;
+  window_class.cbSize = sizeof(WNDCLASSEXW);
 
   window_class.style = CS_HREDRAW | CS_VREDRAW;
   window_class.lpfnWndProc = window_proc;
@@ -25,4 +25,4 @@ WindowClass::WindowClass(const std::wstring& name, WNDPROC window_proc,
   if (atom_ == 0)
     throw Win32Error(::GetLastError(), "Failed to create window class.");
 }
-}  // namespace cru::ui
+}  // namespace cru::win::native
diff --git a/src/platform_win/window_manager.cpp b/src/win/native/window_manager.cpp
index e6c255c3..a2fcdb54 100644
--- a/src/platform_win/window_manager.cpp
+++ b/src/win/native/window_manager.cpp
@@ -1,12 +1,12 @@
 #include "window_manager.hpp"
 
-#include "cru/platform/win/win_application.hpp"
-#include "cru/platform/win/win_native_window.hpp"
-#include "cru/platform/win/window_class.hpp"
+#include "cru/win/native/win_application.hpp"
+#include "cru/win/native/win_native_window.hpp"
+#include "cru/win/native/window_class.hpp"
 
 #include <assert.h>
 
-namespace cru::platform::win {
+namespace cru::win::native {
 LRESULT __stdcall GeneralWndProc(HWND hWnd, UINT Msg, WPARAM wParam,
                                  LPARAM lParam) {
   auto window =
@@ -51,4 +51,4 @@ std::vector<WinNativeWindow*> WindowManager::GetAllWindows() const {
   for (auto [key, value] : window_map_) windows.push_back(value);
   return windows;
 }
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/src/platform_win/window_manager.hpp b/src/win/native/window_manager.hpp
index 6e36ead1..fa5bbe9d 100644
--- a/src/platform_win/window_manager.hpp
+++ b/src/win/native/window_manager.hpp
@@ -1,5 +1,5 @@
 #pragma once
-#include "cru/platform/win/win_pre_config.hpp"
+#include "cru/win/win_pre_config.hpp"
 
 #include "cru/common/base.hpp"
 
@@ -7,7 +7,7 @@
 #include <memory>
 #include <vector>
 
-namespace cru::platform::win {
+namespace cru::win::native {
 class WinApplication;
 class WinNativeWindow;
 class WindowClass;
@@ -49,4 +49,4 @@ class WindowManager : public Object {
   std::map<HWND, WinNativeWindow*> window_map_;
 };
 
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/src/win/native/window_painter.cpp b/src/win/native/window_painter.cpp
new file mode 100644
index 00000000..46364cdd
--- /dev/null
+++ b/src/win/native/window_painter.cpp
@@ -0,0 +1,24 @@
+#include "window_painter.hpp"
+
+#include "cru/win/graph/graph_manager.hpp"
+#include "cru/win/native/window_render_target.hpp"
+
+#include <cassert>
+
+namespace cru::win::native {
+WindowPainter::WindowPainter(WinNativeWindow* window)
+    : WinPainter(window->GetWindowRenderTarget()
+                     ->GetGraphManager()
+                     ->GetD2D1DeviceContext()),
+      window_(window) {
+  window->GetWindowRenderTarget()->SetAsTarget();
+  window->GetWindowRenderTarget()
+      ->GetGraphManager()
+      ->GetD2D1DeviceContext()
+      ->BeginDraw();
+}
+
+void WindowPainter::DoEndDraw() {
+  WinPainter::DoEndDraw();
+  window_->GetWindowRenderTarget()->Present(); }
+}  // namespace cru::win::native
diff --git a/src/win/native/window_painter.hpp b/src/win/native/window_painter.hpp
new file mode 100644
index 00000000..0e6ab2cb
--- /dev/null
+++ b/src/win/native/window_painter.hpp
@@ -0,0 +1,21 @@
+#pragma once
+#include "cru/win/graph/win_painter.hpp"
+#include "cru/win/native/win_native_window.hpp"
+
+namespace cru::win::native {
+class WindowPainter : public graph::WinPainter {
+ public:
+  explicit WindowPainter(WinNativeWindow* window);
+  WindowPainter(const WindowPainter& other) = delete;
+  WindowPainter& operator=(const WindowPainter& other) = delete;
+  WindowPainter(WindowPainter&& other) = delete;
+  WindowPainter& operator=(WindowPainter&& other) = delete;
+  ~WindowPainter() override = default;
+
+ protected:
+  void DoEndDraw() override;
+
+ private:
+  WinNativeWindow* window_;
+};
+}  // namespace cru::win::native
diff --git a/src/platform_win/window_render_target.cpp b/src/win/native/window_render_target.cpp
index f4836d17..c49a920e 100644
--- a/src/platform_win/window_render_target.cpp
+++ b/src/win/native/window_render_target.cpp
@@ -1,13 +1,14 @@
-#include "cru/platform/win/window_render_target.hpp"
+#include "cru/win/native/window_render_target.hpp"
 
-#include "cru/platform/win/exception.hpp"
-#include "cru/platform/win/graph_manager.hpp"
+#include "cru/win/exception.hpp"
+#include "cru/win/graph/graph_manager.hpp"
 #include "dpi_util.hpp"
 
 #include <cassert>
 
-namespace cru::platform::win {
-WindowRenderTarget::WindowRenderTarget(GraphManager* graph_manager, HWND hwnd) {
+namespace cru::win::native {
+WindowRenderTarget::WindowRenderTarget(graph::GraphManager* graph_manager,
+                                       HWND hwnd) {
   this->graph_manager_ = graph_manager;
 
   const auto d3d11_device = graph_manager->GetD3D11Device();
@@ -86,4 +87,4 @@ void WindowRenderTarget::CreateTargetBitmap() {
       graph_manager_->GetD2D1DeviceContext()->CreateBitmapFromDxgiSurface(
           dxgi_back_buffer.Get(), &bitmap_properties, &target_bitmap_));
 }
-}  // namespace cru::platform::win
+}  // namespace cru::win::native
diff --git a/src/platform_win/string_util.cpp b/src/win/string_util.cpp
index 8ae069c0..dd513b12 100644
--- a/src/platform_win/string_util.cpp
+++ b/src/win/string_util.cpp
@@ -1,8 +1,8 @@
 #include "cru/platform/string_util.hpp"
 
-#include "cru/platform/win/exception.hpp"
+#include "cru/win/exception.hpp"
 
-namespace cru::platform::util {
+namespace cru::platform {
 std::string ToUtf8String(const std::wstring_view& string) {
   if (string.empty()) return std::string();
 
@@ -17,4 +17,4 @@ std::string ToUtf8String(const std::wstring_view& string) {
                           "Failed to convert wide string to UTF-8.");
   return result;
 }
-}  // namespace cru::platform::util
+}  // namespace cru::platform