3 files changed, 22 insertions, 0 deletions
diff --git a/include/cru/platform/native/native_window.hpp b/include/cru/platform/native/native_window.hpp
index 22a2dce0..b557a0dd 100644
--- a/include/cru/platform/native/native_window.hpp
+++ b/include/cru/platform/native/native_window.hpp
@@ -56,6 +56,12 @@ class NativeWindow : public NativeResource {
   // The lefttop of the rect is relative to screen lefttop.
   virtual void SetWindowRect(const Rect& rect) = 0;
 
+  // Relative to client lefttop.
+  virtual Point GetMousePosition() = 0;
+
+  virtual bool CaptureMouse() = 0;
+  virtual bool ReleaseMouse() = 0;
+
   virtual graph::Painter* BeginPaint() = 0;
 
   virtual IEvent<std::nullptr_t>* DestroyEvent() = 0;
diff --git a/include/cru/ui/window.hpp b/include/cru/ui/window.hpp
index 197198d2..ee6d2176 100644
--- a/include/cru/ui/window.hpp
+++ b/include/cru/ui/window.hpp
@@ -60,6 +60,14 @@ class Window final : public ContentControl, public SelfResolvable<Window> {
   // Get the control that has focus.
   Control* GetFocusControl();
 
+  //*************** region: focus ***************
+
+  // Pass nullptr to release capture.
+  bool CaptureMouseFor(Control* control);
+
+  // Return null if not captured.
+  Control* GetMouseCaptureControl();
+
  protected:
   void OnChildChanged(Control* old_child, Control* new_child) override;
 
@@ -86,6 +94,7 @@ class Window final : public ContentControl, public SelfResolvable<Window> {
 
   //*************** region: event dispatcher helper ***************
 
+  // dispatch enter is useful when mouse is captured.
   void DispatchMouseHoverControlChangeEvent(Control* old_control,
                                             Control* new_control,
                                             const Point& point);
@@ -100,6 +109,8 @@ class Window final : public ContentControl, public SelfResolvable<Window> {
 
   Control* focus_control_;  // "focus_control_" can't be nullptr
 
+  Control* mouse_captured_control_;
+
   bool need_layout_ = false;
 };
 }  // namespace cru::ui
diff --git a/include/cru/win/native/native_window.hpp b/include/cru/win/native/native_window.hpp
index ed678591..b044aef8 100644
--- a/include/cru/win/native/native_window.hpp
+++ b/include/cru/win/native/native_window.hpp
@@ -48,6 +48,11 @@ class WinNativeWindow : public NativeWindow {
   // The lefttop of the rect is relative to screen lefttop.
   void SetWindowRect(const Rect& rect) override;
 
+  Point GetMousePosition() override;
+
+  bool CaptureMouse() override;
+  bool ReleaseMouse() override;
+
   graph::Painter* BeginPaint() override;
 
   IEvent<std::nullptr_t>* DestroyEvent() override { return &destroy_event_; }