5 files changed, 19 insertions, 16 deletions
diff --git a/include/cru/ui/Base.hpp b/include/cru/ui/Base.hpp
index 36d0eb78..39fbb035 100644
--- a/include/cru/ui/Base.hpp
+++ b/include/cru/ui/Base.hpp
@@ -29,7 +29,10 @@ namespace colors = cru::platform::colors;
 class Window;
 class Control;
 class ClickDetector;
+
+namespace host {
 class WindowHost;
+}
 
 namespace render {
 class RenderObject;
diff --git a/include/cru/ui/Control.hpp b/include/cru/ui/Control.hpp
index 5f381965..fe50624a 100644
--- a/include/cru/ui/Control.hpp
+++ b/include/cru/ui/Control.hpp
@@ -9,7 +9,7 @@
 
 namespace cru::ui {
 class Control : public Object {
-  friend WindowHost;
+  friend host::WindowHost;
 
  protected:
   Control();
@@ -26,7 +26,7 @@ class Control : public Object {
 
   //*************** region: tree ***************
  public:
-  WindowHost* GetWindowHost() const;
+  host::WindowHost* GetWindowHost() const;
 
   Control* GetParent() const { return parent_; }
 
@@ -131,8 +131,8 @@ class Control : public Object {
   virtual void OnAddChild(Control* child, Index position);
   virtual void OnRemoveChild(Control* child, Index position);
   virtual void OnParentChanged(Control* old_parent, Control* new_parent);
-  virtual void OnAttachToHost(WindowHost* host);
-  virtual void OnDetachFromHost(WindowHost* host);
+  virtual void OnAttachToHost(host::WindowHost* host);
+  virtual void OnDetachFromHost(host::WindowHost* host);
 
  protected:
   virtual void OnMouseHoverChange(bool newHover) { CRU_UNUSED(newHover) }
@@ -141,7 +141,7 @@ class Control : public Object {
   Control* parent_ = nullptr;
   std::vector<Control*> children_;
 
-  WindowHost* window_host_ = nullptr;
+  host::WindowHost* window_host_ = nullptr;
 
  private:
   bool is_mouse_over_ = false;
diff --git a/include/cru/ui/Window.hpp b/include/cru/ui/Window.hpp
index 0739e3dc..70423a14 100644
--- a/include/cru/ui/Window.hpp
+++ b/include/cru/ui/Window.hpp
@@ -29,7 +29,7 @@ class Window final : public LayoutControl {
   void OnRemoveChild(Control* child, Index position) override;
 
  private:
-  std::unique_ptr<WindowHost> window_host_;
+  std::unique_ptr<host::WindowHost> window_host_;
 
   std::unique_ptr<render::StackLayoutRenderObject> render_object_;
 };
diff --git a/include/cru/ui/WindowHost.hpp b/include/cru/ui/host/WindowHost.hpp
index 7f7d62f0..77ed937f 100644
--- a/include/cru/ui/WindowHost.hpp
+++ b/include/cru/ui/host/WindowHost.hpp
@@ -1,19 +1,19 @@
 #pragma once
-#include "Base.hpp"
+#include "../Base.hpp"
 
 #include "cru/common/Event.hpp"
 #include "cru/platform/gui/UiApplication.hpp"
 #include "cru/platform/gui/Window.hpp"
-#include "render/Base.hpp"
+#include "../render/Base.hpp"
 
 #include <functional>
 
-namespace cru::ui {
+namespace cru::ui::host {
 struct AfterLayoutEventArgs {};
 
 // The bridge between control tree and native window.
 class WindowHost : public Object {
-  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::WindowHost")
+  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::host::WindowHost")
 
  public:
   WindowHost(Control* root_control);
diff --git a/include/cru/ui/render/RenderObject.hpp b/include/cru/ui/render/RenderObject.hpp
index 436cf6b2..635a541e 100644
--- a/include/cru/ui/render/RenderObject.hpp
+++ b/include/cru/ui/render/RenderObject.hpp
@@ -39,7 +39,7 @@ namespace cru::ui::render {
 //  Size OnMeasureContent(const MeasureRequirement& requirement) override;
 //  void OnLayoutContent(const Rect& content_rect) override;
 class RenderObject : public Object {
-  friend WindowHost;
+  friend host::WindowHost;
 
   CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render::RenderObject")
 
@@ -65,7 +65,7 @@ class RenderObject : public Object {
   Control* GetAttachedControl() const { return control_; }
   void SetAttachedControl(Control* new_control) { control_ = new_control; }
 
-  WindowHost* GetWindowHost() const { return window_host_; }
+  host::WindowHost* GetWindowHost() const { return window_host_; }
 
   RenderObject* GetParent() const { return parent_; }
 
@@ -135,7 +135,7 @@ class RenderObject : public Object {
   // Add offset before pass point to children.
   virtual RenderObject* HitTest(const Point& point) = 0;
 
-  IEvent<WindowHost*>* AttachToHostEvent() { return &attach_to_host_event_; }
+  IEvent<host::WindowHost*>* AttachToHostEvent() { return &attach_to_host_event_; }
   IEvent<std::nullptr_t>* DetachFromHostEvent() {
     return &detach_from_host_event_;
   }
@@ -205,11 +205,11 @@ class RenderObject : public Object {
  private:
   void SetParent(RenderObject* new_parent);
 
-  void SetWindowHostRecursive(WindowHost* host);
+  void SetWindowHostRecursive(host::WindowHost* host);
 
  private:
   Control* control_ = nullptr;
-  WindowHost* window_host_ = nullptr;
+  host::WindowHost* window_host_ = nullptr;
 
   RenderObject* parent_ = nullptr;
   std::vector<RenderObject*> children_{};
@@ -225,7 +225,7 @@ class RenderObject : public Object {
   Thickness margin_{};
   Thickness padding_{};
 
-  Event<WindowHost*> attach_to_host_event_;
+  Event<host::WindowHost*> attach_to_host_event_;
   Event<std::nullptr_t> detach_from_host_event_;
 };
 }  // namespace cru::ui::render