diff --git a/include/nana/gui/programming_interface.hpp b/include/nana/gui/programming_interface.hpp
index 09bb1c84..c2430ccd 100644
--- a/include/nana/gui/programming_interface.hpp
+++ b/include/nana/gui/programming_interface.hpp
@@ -239,7 +239,7 @@ namespace API
 	cursor window_cursor(window);
 
 	void activate_window(window);
-	bool is_focus_window(window);
+	bool is_focus_ready(window);
 	window focus_window();
 	void focus_window(window);
 
diff --git a/source/gui/programming_interface.cpp b/source/gui/programming_interface.cpp
index c2db60b8..f9409904 100644
--- a/source/gui/programming_interface.cpp
+++ b/source/gui/programming_interface.cpp
@@ -796,7 +796,7 @@ namespace API
 		return cursor::arrow;
 	}
 
-	bool is_focus_window(window wd)
+	bool is_focus_ready(window wd)
 	{
 		auto iwd = reinterpret_cast<restrict::core_window_t*>(wd);
 		internal_scope_guard lock;
diff --git a/source/gui/widgets/skeletons/text_editor.cpp b/source/gui/widgets/skeletons/text_editor.cpp
index eceda23e..0a2f9261 100644
--- a/source/gui/widgets/skeletons/text_editor.cpp
+++ b/source/gui/widgets/skeletons/text_editor.cpp
@@ -18,6 +18,7 @@
 #include <numeric>
 #include <cwctype>
 #include <set>
+#include <algorithm>
 
 namespace nana{	namespace widgets
 {
@@ -688,7 +689,7 @@ namespace nana{	namespace widgets
 					}
 				}
 				else
-					editor_.render(API::is_focus_window(editor_.window_));
+					editor_.render(API::is_focus_ready(editor_.window_));
 			}
 
 			void render(const ::nana::color& fgcolor) override
@@ -1447,7 +1448,7 @@ namespace nana{	namespace widgets
 				move_caret(upoint{});
 
 				_m_scrollbar();
-				render(API::is_focus_window(window_));
+				render(API::is_focus_ready(window_));
 				return true;
 			}
 			return false;
@@ -1465,7 +1466,7 @@ namespace nana{	namespace widgets
 
 			_m_reset();
 			behavior_->pre_calc_lines(width_pixels());
-			render(API::is_focus_window(window_));
+			render(API::is_focus_ready(window_));
 			_m_scrollbar();
 			return true;
 		}
@@ -1716,7 +1717,7 @@ namespace nana{	namespace widgets
 		//Set caret position through text coordinate
 		void text_editor::move_caret(const upoint& crtpos)
 		{
-			if (!API::is_focus_window(window_))
+			if (!API::is_focus_ready(window_))
 				return;
 			
 			const unsigned line_pixels = line_height();
@@ -1758,7 +1759,7 @@ namespace nana{	namespace widgets
 
 		void text_editor::show_caret(bool isshow)
 		{
-			if(isshow == false || API::is_focus_window(window_))
+			if(isshow == false || API::is_focus_ready(window_))
 				API::caret_visible(window_, isshow);
 		}
 
@@ -1923,7 +1924,7 @@ namespace nana{	namespace widgets
 			{
 				behavior_->adjust_caret_into_screen();
 				reset_caret();
-				render(API::is_focus_window(window_));
+				render(API::is_focus_ready(window_));
 				_m_scrollbar();
 
 				points_.xpos = points_.caret.x;
diff --git a/source/gui/widgets/spinbox.cpp b/source/gui/widgets/spinbox.cpp
index ebbf006e..6be8deb2 100644
--- a/source/gui/widgets/spinbox.cpp
+++ b/source/gui/widgets/spinbox.cpp
@@ -14,6 +14,7 @@
 #include <nana/gui/widgets/skeletons/text_editor.hpp>
 #include <nana/gui/element.hpp>
 #include <nana/gui/timer.hpp>
+#include <algorithm>
 
 namespace nana
 {
@@ -328,7 +329,7 @@ namespace nana
 
 				void render()
 				{
-					editor_->render(API::is_focus_window(editor_->window_handle()));
+					editor_->render(API::is_focus_ready(editor_->window_handle()));
 					_m_draw_spins(spin_stated_);
 				}
 
@@ -420,7 +421,7 @@ namespace nana
 					if (!editor_)
 						return;
 
-					if (API::is_focus_window(editor_->window_handle()))
+					if (API::is_focus_ready(editor_->window_handle()))
 						editor_->text(range_->value());
 					else
 						editor_->text(modifier_.prefix + range_->value() + modifier_.suffix);
diff --git a/source/gui/widgets/textbox.cpp b/source/gui/widgets/textbox.cpp
index 840a1762..4bb6a670 100644
--- a/source/gui/widgets/textbox.cpp
+++ b/source/gui/widgets/textbox.cpp
@@ -83,7 +83,7 @@ namespace drawerbase {
 
 		void drawer::refresh(graph_reference graph)
 		{
-			editor_->render(API::is_focus_window(*widget_));
+			editor_->render(API::is_focus_ready(*widget_));
 		}
 
 		void drawer::focus(graph_reference graph, const arg_focus& arg)
diff --git a/source/gui/widgets/widget.cpp b/source/gui/widgets/widget.cpp
index f573c6b6..07e81946 100644
--- a/source/gui/widgets/widget.cpp
+++ b/source/gui/widgets/widget.cpp
@@ -101,7 +101,7 @@ namespace nana
 
 		bool widget::focused() const
 		{
-			return API::is_focus_window(handle());
+			return (API::focus_window() == handle());
 		}
 
 		void widget::show()