diff --git a/include/nana/deploy.hpp b/include/nana/deploy.hpp
index 35659972..19163c82 100644
--- a/include/nana/deploy.hpp
+++ b/include/nana/deploy.hpp
@@ -95,9 +95,9 @@ namespace std
 namespace nana
 {
 	/// Checks whether a specified text is utf8 encoding
-	bool is_utf8(const char* str, unsigned len);
+	bool is_utf8(const char* str, std::size_t len);
 	void throw_not_utf8(const std::string& text);
-	void throw_not_utf8(const char*, unsigned len);
+	void throw_not_utf8(const char*, std::size_t len);
 	void throw_not_utf8(const char*);
 
 	const std::string& to_utf8(const std::string&);
diff --git a/include/nana/gui/detail/bedrock.hpp b/include/nana/gui/detail/bedrock.hpp
index e4872711..e29c1758 100644
--- a/include/nana/gui/detail/bedrock.hpp
+++ b/include/nana/gui/detail/bedrock.hpp
@@ -1,7 +1,7 @@
 /*
  *	A Bedrock Implementation
  *	Nana C++ Library(http://www.nanapro.org)
- *	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0.
  *	(See accompanying file LICENSE_1_0.txt or copy at
@@ -78,8 +78,8 @@ namespace detail
 		void define_state_cursor(core_window_t*, nana::cursor, thread_context*);
 		void undefine_state_cursor(core_window_t*, thread_context*);
 
-		widget_colors& get_scheme_template(scheme_factory_base&&);
-		widget_colors* make_scheme(scheme_factory_base&&);
+		widget_colors& get_scheme_template(scheme_factory_interface&&);
+		widget_colors* make_scheme(scheme_factory_interface&&);
 
 		events_operation&	evt_operation();
 		window_manager&		wd_manager();
diff --git a/include/nana/gui/detail/color_schemes.hpp b/include/nana/gui/detail/color_schemes.hpp
index 9482f084..2d177c17 100644
--- a/include/nana/gui/detail/color_schemes.hpp
+++ b/include/nana/gui/detail/color_schemes.hpp
@@ -1,7 +1,7 @@
 /*
 *	Color Schemes
 *	Nana C++ Library(http://www.nanapro.org)
-*	Copyright(C) 2003-2014 Jinhao(cnjinhao@hotmail.com)
+*	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
 *
 *	Distributed under the Boost Software License, Version 1.0.
 *	(See accompanying file LICENSE_1_0.txt or copy at
@@ -19,20 +19,21 @@ namespace nana
 {
 	namespace detail
 	{
-		class scheme_factory_base
+		class scheme_factory_interface
 		{
 		public:
 			struct factory_identifier{};
-			virtual ~scheme_factory_base() = default;
+			virtual ~scheme_factory_interface() = default;
 
 			virtual factory_identifier* get_id() const = 0;
 			virtual	widget_colors* create() = 0;
 			virtual widget_colors* create(widget_colors&) = 0;
 		};
+		
 
 		template<typename Scheme>
 		class scheme_factory
-			: public scheme_factory_base
+			: public scheme_factory_interface
 		{
 		private:
 			factory_identifier* get_id() const override
@@ -54,7 +55,7 @@ namespace nana
 		};
 
 		template<typename Scheme>
-		scheme_factory_base::factory_identifier scheme_factory<Scheme>::fid_;
+		scheme_factory_interface::factory_identifier scheme_factory<Scheme>::fid_;
 
 		class color_schemes
 		{
@@ -69,8 +70,8 @@ namespace nana
 			color_schemes();
 			~color_schemes();
 
-			scheme&	scheme_template(scheme_factory_base&&);
-			scheme* create(scheme_factory_base&&);
+			scheme&	scheme_template(scheme_factory_interface&&);
+			scheme* create(scheme_factory_interface&&);
 		private:
 			implement * impl_;
 		};
diff --git a/include/nana/gui/detail/events_operation.hpp b/include/nana/gui/detail/events_operation.hpp
index 78f5c432..025ef5b1 100644
--- a/include/nana/gui/detail/events_operation.hpp
+++ b/include/nana/gui/detail/events_operation.hpp
@@ -4,6 +4,7 @@
 #include <nana/gui/detail/general_events.hpp>
 #include <unordered_set>
 #include <unordered_map>
+#include <memory>
 
 #if defined(STD_THREAD_NOT_SUPPORTED)
 #include <nana/std_mutex.hpp>
diff --git a/include/nana/gui/detail/general_events.hpp b/include/nana/gui/detail/general_events.hpp
index 446664fa..e801dba5 100644
--- a/include/nana/gui/detail/general_events.hpp
+++ b/include/nana/gui/detail/general_events.hpp
@@ -17,7 +17,6 @@
 #include "internal_scope_guard.hpp"
 #include <type_traits>
 #include <functional>
-#include <memory>
 #include <vector>
 
 namespace nana
@@ -67,7 +66,7 @@ namespace nana
 		protected:
 			//class emit_counter is a RAII helper for emitting count
 			//It is used for avoiding a try{}catch block which is required for some finial works when
-			//event handlers throw exceptions.
+			//event handlers throw exceptions. Precondition event_base.dockers_ != nullptr.
 			class emit_counter
 			{
 			public:
@@ -77,12 +76,10 @@ namespace nana
 				event_base * const evt_;
 			};
 			
-			//event_handle _m_emplace(::std::unique_ptr<detail::docker_interface>& docker_ptr, bool in_front);
 			event_handle _m_emplace(detail::docker_interface*, bool in_front);
 		protected:
 			unsigned emitting_count_{ 0 };
 			bool deleted_flags_{ false };
-			//std::unique_ptr<std::vector<std::unique_ptr<detail::docker_interface>>> dockers_;
 			std::vector<detail::docker_interface*> * dockers_{ nullptr };
 		};
 	}//end namespace detail
@@ -172,27 +169,26 @@ namespace nana
 
 			emit_counter ec(this);
 
-			auto& dockers = *dockers_;
-			const auto dockers_len = dockers_->size();
-
 			//The dockers may resize when a new event handler is created by a calling handler.
 			//Traverses with position can avaid crash error which caused by a iterator which becomes invalid.
-			for (std::size_t pos = 0; pos < dockers_len; ++pos)
+
+			auto i = dockers_->data();
+			auto const end = i + dockers_->size();
+
+			for (; i != end; ++i)
 			{
-				auto docker_ptr = static_cast<docker*>(dockers[pos]);
-				if (docker_ptr->flag_deleted)
+				if (static_cast<docker*>(*i)->flag_deleted)
 					continue;
 
-				docker_ptr->invoke(arg);
+				static_cast<docker*>(*i)->invoke(arg);
 				if (arg.propagation_stopped())
 				{
-					for (++pos; pos < dockers_len; ++pos)
+					for (++i; i != end; ++i)
 					{
-						auto docker_ptr = static_cast<docker*>(dockers[pos]);
-						if (!docker_ptr->unignorable || docker_ptr->flag_deleted)
+						if (!static_cast<docker*>(*i)->unignorable || static_cast<docker*>(*i)->flag_deleted)
 							continue;
 
-						docker_ptr->invoke(arg);
+						static_cast<docker*>(*i)->invoke(arg);
 					}
 					break;
 				}
@@ -274,7 +270,7 @@ namespace nana
 				};
 			}
 		};
-
+		
 		template<typename Ret, typename Arg2>
 		struct factory < std::function<Ret(Arg2)>, false>
 		{
diff --git a/include/nana/gui/element.hpp b/include/nana/gui/element.hpp
index 599aa87a..7f0a891c 100644
--- a/include/nana/gui/element.hpp
+++ b/include/nana/gui/element.hpp
@@ -1,7 +1,7 @@
 /*
  *	Elements of GUI Gadgets
  *	Nana C++ Library(http://www.nanapro.org)
- *	Copyright(C) 2003-2014 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0. 
  *	(See accompanying file LICENSE_1_0.txt or copy at 
@@ -88,7 +88,6 @@ namespace nana
 			struct factory_interface
 				: public detail::factory_abstract
 			{
-				virtual ~factory_interface(){}
 				virtual ElementInterface* create() const = 0;
 			};
 
diff --git a/include/nana/gui/programming_interface.hpp b/include/nana/gui/programming_interface.hpp
index 8adfd2eb..c50f8f2e 100644
--- a/include/nana/gui/programming_interface.hpp
+++ b/include/nana/gui/programming_interface.hpp
@@ -46,7 +46,7 @@ namespace API
 {
 	namespace detail
 	{
-		::nana::widget_colors* make_scheme(::nana::detail::scheme_factory_base&&);
+		::nana::widget_colors* make_scheme(::nana::detail::scheme_factory_interface&&);
 	}
 
 	void effects_edge_nimbus(window, effects::edge_nimbus);
diff --git a/include/nana/gui/widgets/widget.hpp b/include/nana/gui/widgets/widget.hpp
index 1fdb48fa..cfc174f7 100644
--- a/include/nana/gui/widgets/widget.hpp
+++ b/include/nana/gui/widgets/widget.hpp
@@ -1,7 +1,7 @@
 /**
  *	The fundamental widget class implementation
  *	Nana C++ Library(http://www.nanapro.org)
- *	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0. 
  *	(See accompanying file LICENSE_1_0.txt or copy at 
@@ -132,9 +132,25 @@ namespace nana
 		virtual nana::color _m_bgcolor() const;
 	};
 
+	namespace detail
+	{
+		class widget_base
+			: public widget
+		{
+		public:
+			~widget_base();
+
+			window handle() const override;
+		private:
+			void _m_notify_destroy() override final;
+		protected:
+			window handle_{ nullptr };
+		};
+	}
+
             /// Base class of all the classes defined as a widget window. Defaultly a widget_tag
 	template<typename Category, typename DrawerTrigger, typename Events = ::nana::general_events, typename Scheme = ::nana::widget_colors>
-	class widget_object: public widget
+	class widget_object: public detail::widget_base
 	{
 	protected:
 		typedef DrawerTrigger drawer_trigger_t;
@@ -147,12 +163,6 @@ namespace nana
 				scheme_{ API::dev::make_scheme<Scheme>() }
 		{}
 
-		~widget_object()
-		{
-			if(handle_)
-				API::close_window(handle_);
-		}
-
 		event_type& events() const
 		{
 			return *events_;
@@ -179,11 +189,6 @@ namespace nana
 			return (this->empty() == false);
 		}
 
-		window handle() const override
-		{
-			return handle_;
-		}
-
 		widget_object& borderless(bool enable)
 		{
 			API::widget_borderless(handle_, enable);
@@ -214,13 +219,7 @@ namespace nana
 		{
 			return *events_;
 		}
-
-		void _m_notify_destroy() override final
-		{
-			handle_ = nullptr;
-		}
 	private:
-		window handle_{nullptr};
 		DrawerTrigger trigger_;
 		std::shared_ptr<Events> events_;
 		std::unique_ptr<scheme_type> scheme_;
@@ -228,7 +227,7 @@ namespace nana
 
 	        /// Base class of all the classes defined as a non-graphics-buffer widget window. The second template parameter DrawerTrigger is always ignored.\see nana::panel
 	template<typename DrawerTrigger, typename Events, typename Scheme>
-	class widget_object<category::lite_widget_tag, DrawerTrigger, Events, Scheme>: public widget
+	class widget_object<category::lite_widget_tag, DrawerTrigger, Events, Scheme>: public detail::widget_base
 	{
 	protected:
 		typedef DrawerTrigger drawer_trigger_t;
@@ -240,12 +239,6 @@ namespace nana
 			: events_{ std::make_shared<Events>() }, scheme_{ API::dev::make_scheme<scheme_type>() }
 		{}
 
-		~widget_object()
-		{
-			if(handle_)
-				API::close_window(handle_);
-		}
-
 		event_type& events() const
 		{
 			return *events_;
@@ -269,12 +262,7 @@ namespace nana
 			}
 			return (this->empty() == false);
 		}
-
-		window handle() const override
-		{
-			return handle_;
-		}
-
+		
 		scheme_type& scheme() const
 		{
 			return *scheme_;
@@ -284,13 +272,7 @@ namespace nana
 		{
 			return *events_;
 		}
-
-		void _m_notify_destroy() override final
-		{
-			handle_ = nullptr;
-		}
 	private:
-		window handle_{nullptr};
 		std::shared_ptr<Events> events_;
 		std::unique_ptr<scheme_type> scheme_;
 	};//end class widget_object
@@ -298,7 +280,7 @@ namespace nana
 
 	        /// Base class of all the classes defined as a root window. \see nana::form
 	template<typename DrawerTrigger, typename Events, typename Scheme>
-	class widget_object<category::root_tag, DrawerTrigger, Events, Scheme>: public widget
+	class widget_object<category::root_tag, DrawerTrigger, Events, Scheme>: public detail::widget_base
 	{
 	protected:
 		typedef DrawerTrigger drawer_trigger_t;
@@ -324,12 +306,6 @@ namespace nana
 			_m_bind_and_attach();
 		}
 
-		~widget_object()
-		{
-			if(handle_)
-				API::close_window(handle_);
-		}
-
 		event_type& events() const
 		{
 			return *events_;
@@ -340,11 +316,6 @@ namespace nana
 			API::activate_window(handle_);
 		}
 
-		window handle() const override
-		{
-			return handle_;
-		}
-
 		native_window_type native_handle() const
 		{
 			return API::root(handle_);
@@ -435,13 +406,7 @@ namespace nana
 		{
 			return *events_;
 		}
-
-		void _m_notify_destroy() override final
-		{
-			handle_ = nullptr;
-		}
 	private:
-		window handle_;
 		DrawerTrigger trigger_;
 		std::shared_ptr<Events> events_;
 		std::unique_ptr<scheme_type> scheme_;
@@ -453,7 +418,7 @@ namespace nana
 
 	           /// Especialization. Base class of all the classes defined as a frame window. \see nana::frame
 	template<typename Events, typename Scheme>
-	class widget_object<category::frame_tag, int, Events, Scheme>: public widget
+	class widget_object<category::frame_tag, int, Events, Scheme>: public detail::widget_base
 	{
 	protected:
 		typedef int drawer_trigger_t;
@@ -465,12 +430,6 @@ namespace nana
 			: events_{ std::make_shared<Events>() }, scheme_{ API::dev::make_scheme<scheme_type>() }
 		{}
 
-		~widget_object()
-		{
-			if(handle_)
-				API::close_window(handle_);
-		}
-
 		event_type& events() const
 		{
 			return *events_;
@@ -494,11 +453,6 @@ namespace nana
 			return (this->empty() == false);
 		}
 
-		window handle() const override
-		{
-			return handle_;
-		}
-
 		scheme_type& scheme() const
 		{
 			return *scheme_;
@@ -513,13 +467,7 @@ namespace nana
 		{
 			return *events_;
 		}
-
-		void _m_notify_destroy() override final
-		{
-			handle_ = nullptr;
-		}
 	private:
-		window handle_{nullptr};
 		std::shared_ptr<Events> events_;
 		std::unique_ptr<scheme_type> scheme_;
 	};//end class widget_object<category::frame_tag>
diff --git a/source/deploy.cpp b/source/deploy.cpp
index 3592a3bf..6971d563 100644
--- a/source/deploy.cpp
+++ b/source/deploy.cpp
@@ -438,7 +438,7 @@ namespace std
 
 namespace nana
 {
-	bool is_utf8(const char* str, unsigned len)
+	bool is_utf8(const char* str, std::size_t len)
 	{
 		auto ustr = reinterpret_cast<const unsigned char*>(str);
 		auto end = ustr + len;
@@ -474,7 +474,7 @@ namespace nana
 			throw std::invalid_argument("The text is not encoded in UTF8");
 	}
 
-	void throw_not_utf8(const char* text, unsigned len)
+	void throw_not_utf8(const char* text, std::size_t len)
 	{
 		if (!is_utf8(text, len))
 			throw std::invalid_argument("The text is not encoded in UTF8");
diff --git a/source/gui/detail/bedrock_pi.cpp b/source/gui/detail/bedrock_pi.cpp
index 830887ea..7c7472bb 100644
--- a/source/gui/detail/bedrock_pi.cpp
+++ b/source/gui/detail/bedrock_pi.cpp
@@ -1,7 +1,7 @@
 /*
 *	A Bedrock Platform-Independent Implementation
 *	Nana C++ Library(http://www.nanapro.org)
-*	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
+*	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
 *
 *	Distributed under the Boost Software License, Version 1.0.
 *	(See accompanying file LICENSE_1_0.txt or copy at
@@ -198,12 +198,12 @@ namespace nana
 			}
 		}
 
-		widget_colors& bedrock::get_scheme_template(scheme_factory_base&& factory)
+		widget_colors& bedrock::get_scheme_template(scheme_factory_interface&& factory)
 		{
 			return pi_data_->scheme.scheme_template(std::move(factory));
 		}
 
-		widget_colors* bedrock::make_scheme(scheme_factory_base&& factory)
+		widget_colors* bedrock::make_scheme(scheme_factory_interface&& factory)
 		{
 			return pi_data_->scheme.create(std::move(factory));
 		}
diff --git a/source/gui/detail/color_schemes.cpp b/source/gui/detail/color_schemes.cpp
index c7fcd530..6cfa41d4 100644
--- a/source/gui/detail/color_schemes.cpp
+++ b/source/gui/detail/color_schemes.cpp
@@ -1,3 +1,15 @@
+/*
+*	Color Schemes
+*	Nana C++ Library(http://www.nanapro.org)
+*	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
+*
+*	Distributed under the Boost Software License, Version 1.0.
+*	(See accompanying file LICENSE_1_0.txt or copy at
+*	http://www.boost.org/LICENSE_1_0.txt)
+*
+*	@file: nana/gui/color_schemes.cpp
+*/
+
 #include <nana/gui/detail/color_schemes.hpp>
 #include <map>
 
@@ -57,7 +69,7 @@ namespace nana
 		//class color_schemes
 			struct color_schemes::implement
 			{
-				std::map<scheme_factory_base::factory_identifier*, std::unique_ptr<scheme>> scheme_template;
+				std::map<scheme_factory_interface::factory_identifier*, std::unique_ptr<scheme>> scheme_template;
 			};
 
 			color_schemes::color_schemes()
@@ -70,7 +82,7 @@ namespace nana
 				delete impl_;
 			}
 
-			auto color_schemes::scheme_template(scheme_factory_base&& factory) -> scheme&
+			auto color_schemes::scheme_template(scheme_factory_interface&& factory) -> scheme&
 			{
 				auto & tmpl_scheme = impl_->scheme_template[factory.get_id()];
 
@@ -81,7 +93,7 @@ namespace nana
 				return *tmpl_scheme.get();
 			}
 
-			widget_colors* color_schemes::create(scheme_factory_base&& factory)
+			widget_colors* color_schemes::create(scheme_factory_interface&& factory)
 			{
 				return factory.create(scheme_template(std::move(factory)));
 			}
diff --git a/source/gui/place.cpp b/source/gui/place.cpp
index d6adb5d0..b7fadf7f 100644
--- a/source/gui/place.cpp
+++ b/source/gui/place.cpp
@@ -1346,74 +1346,77 @@ namespace nana
 				splitter_.cursor(splitter_cursor_);
 
 				dragger_.trigger(splitter_);
-				splitter_.events().mouse_down.connect_unignorable([this](const arg_mouse& arg)
+
+				auto grab_fn = [this](const arg_mouse& arg)
 				{
 					if (false == arg.left_button)
 						return;
 
-					begin_point_ = splitter_.pos();
-
-					auto px_ptr = &nana::rectangle::width;
-
-					//Use field_area of leaf, not margin_area. Otherwise splitter would be at wrong position
-					auto area_left = _m_leaf_left()->field_area;
-					auto area_right = _m_leaf_right()->field_area;
-
-					if (nana::cursor::size_we != splitter_cursor_)
+					if (event_code::mouse_down == arg.evt_code)
 					{
-						left_pos_ = area_left.y;
-						right_pos_ = area_right.bottom();
-						px_ptr = &nana::rectangle::height;
+						begin_point_ = splitter_.pos();
+
+						auto px_ptr = &nana::rectangle::width;
+
+						//Use field_area of leaf, not margin_area. Otherwise splitter would be at wrong position
+						auto area_left = _m_leaf_left()->field_area;
+						auto area_right = _m_leaf_right()->field_area;
+
+						if (nana::cursor::size_we != splitter_cursor_)
+						{
+							left_pos_ = area_left.y;
+							right_pos_ = area_right.bottom();
+							px_ptr = &nana::rectangle::height;
+						}
+						else
+						{
+							left_pos_ = area_left.x;
+							right_pos_ = area_right.right();
+						}
+
+						left_pixels_ = area_left.*px_ptr;
+						right_pixels_ = area_right.*px_ptr;
 					}
-					else
+					else if (event_code::mouse_move == arg.evt_code)
 					{
-						left_pos_ = area_left.x;
-						right_pos_ = area_right.right();
+						const bool vert = (::nana::cursor::size_we != splitter_cursor_);
+						auto area_px = rectangle_rotator(vert, div_owner->margin_area()).w();
+						int delta = (vert ? splitter_.pos().y - begin_point_.y : splitter_.pos().x - begin_point_.x);
+
+						int total_pixels = static_cast<int>(left_pixels_ + right_pixels_);
+
+						auto left_px = static_cast<int>(left_pixels_) + delta;
+						if (left_px > total_pixels)
+							left_px = total_pixels;
+						else if (left_px < 0)
+							left_px = 0;
+
+						double imd_rate = 100.0 / area_px;
+						left_px = static_cast<int>(limit_px(_m_leaf_left(), left_px, area_px));
+						_m_leaf_left()->weight.assign_percent(imd_rate * left_px);
+
+						auto right_px = static_cast<int>(right_pixels_) - delta;
+						if (right_px > total_pixels)
+							right_px = total_pixels;
+						else if (right_px < 0)
+							right_px = 0;
+
+						right_px = static_cast<int>(limit_px(_m_leaf_right(), right_px, area_px));
+						_m_leaf_right()->weight.assign_percent(imd_rate * right_px);
+
+						pause_move_collocate_ = true;
+						div_owner->collocate(splitter_.parent());
+
+						//After the collocating, the splitter keeps the calculated weight of left division,
+						//and clear the weight of right division.
+						_m_leaf_right()->weight.reset();
+
+						pause_move_collocate_ = false;
 					}
+				};
 
-					left_pixels_ = area_left.*px_ptr;
-					right_pixels_ = area_right.*px_ptr;
-				});
-
-				splitter_.events().mouse_move.connect_unignorable([this](const arg_mouse& arg)
-				{
-					if (false == arg.left_button)
-						return;
-
-					const bool vert = (::nana::cursor::size_we != splitter_cursor_);
-					auto area_px = rectangle_rotator(vert, div_owner->margin_area()).w();
-					int delta = (vert ? splitter_.pos().y - begin_point_.y : splitter_.pos().x - begin_point_.x);
-
-					int total_pixels = static_cast<int>(left_pixels_ + right_pixels_);
-
-					auto left_px = static_cast<int>(left_pixels_)+delta;
-					if (left_px > total_pixels)
-						left_px = total_pixels;
-					else if (left_px < 0)
-						left_px = 0;
-
-					double imd_rate = 100.0 / area_px;
-					left_px = static_cast<int>(limit_px(_m_leaf_left(), left_px, area_px));
-					_m_leaf_left()->weight.assign_percent(imd_rate * left_px);
-
-					auto right_px = static_cast<int>(right_pixels_)-delta;
-					if (right_px > total_pixels)
-						right_px = total_pixels;
-					else if (right_px < 0)
-						right_px = 0;
-
-					right_px = static_cast<int>(limit_px(_m_leaf_right(), right_px, area_px));
-					_m_leaf_right()->weight.assign_percent(imd_rate * right_px);
-
-					pause_move_collocate_ = true;
-					div_owner->collocate(splitter_.parent());
-
-					//After the collocating, the splitter keeps the calculated weight of left division,
-					//and clear the weight of right division.
-					_m_leaf_right()->weight.reset();
-
-					pause_move_collocate_ = false;
-				});
+				splitter_.events().mouse_down.connect_unignorable(grab_fn);
+				splitter_.events().mouse_move.connect_unignorable(grab_fn);
 			}
 
 			auto limited_range = _m_update_splitter_range();
@@ -1621,7 +1624,7 @@ namespace nana
 				indicator_.docker->z_order(nullptr, ::nana::z_order_action::topmost);
 				indicator_.docker->show();
 
-				indicator_.docker->events().destroy([this]
+				indicator_.docker->events().destroy([this](const arg_destroy&)
 				{
 					if (indicator_.dock_area)
 					{
@@ -1764,81 +1767,86 @@ namespace nana
 				this->bgcolor(colors::alice_blue);
 				this->cursor(_m_is_vert(dir_) ? ::nana::cursor::size_ns : ::nana::cursor::size_we);
 
-				this->events().mouse_down([this](const arg_mouse& arg)
+
+				auto grab_fn = [this, wd](const arg_mouse& arg)
 				{
-					if (arg.button != ::nana::mouse::left_button)
-						return;
-
-					bool is_vert = _m_is_vert(dir_);
-
-					API::capture_window(this->handle(), true);
-					auto basepos = API::cursor_position();
-					base_pos_.x = (is_vert ? basepos.y : basepos.x);
-
-					basepos = this->pos();
-					base_pos_.y = (is_vert ? basepos.y : basepos.x);
-
-					base_px_ = (is_vert ? pane_dv_->field_area.height : pane_dv_->field_area.width);
-				});
-
-				this->events().mouse_up([this]
-				{
-					API::capture_window(this->handle(), false);
-				});
-
-				this->events().mouse_move([this, wd](const arg_mouse& arg)
-				{
-					if (!arg.is_left_button())
-						return;
-
-					auto now_pos = API::cursor_position();
-					int delta = (_m_is_vert(dir_) ? now_pos.y : now_pos.x) - base_pos_.x;
-					int new_pos = base_pos_.y + delta;
-					if (new_pos < range_.x)
+					if (event_code::mouse_down == arg.evt_code)	//press mouse button
 					{
-						new_pos = range_.x;
-						delta = new_pos - base_pos_.y;
-					}
-					else if (new_pos >= range_.y)
-					{
-						new_pos = range_.y - 1;
-						delta = new_pos - base_pos_.y;
-					}
+						if (arg.button != ::nana::mouse::left_button)
+							return;
 
-					now_pos = this->pos();
-					if (_m_is_vert(dir_))
-						now_pos.y = new_pos;
+						bool is_vert = _m_is_vert(dir_);
+
+						API::capture_window(this->handle(), true);
+						auto basepos = API::cursor_position();
+						base_pos_.x = (is_vert ? basepos.y : basepos.x);
+
+						basepos = this->pos();
+						base_pos_.y = (is_vert ? basepos.y : basepos.x);
+
+						base_px_ = (is_vert ? pane_dv_->field_area.height : pane_dv_->field_area.width);
+					}
+					else if (event_code::mouse_move == arg.evt_code)	//hover
+					{
+						if (!arg.is_left_button())
+							return;
+
+						auto now_pos = API::cursor_position();
+						int delta = (_m_is_vert(dir_) ? now_pos.y : now_pos.x) - base_pos_.x;
+						int new_pos = base_pos_.y + delta;
+						if (new_pos < range_.x)
+						{
+							new_pos = range_.x;
+							delta = new_pos - base_pos_.y;
+						}
+						else if (new_pos >= range_.y)
+						{
+							new_pos = range_.y - 1;
+							delta = new_pos - base_pos_.y;
+						}
+
+						now_pos = this->pos();
+						if (_m_is_vert(dir_))
+							now_pos.y = new_pos;
+						else
+							now_pos.x = new_pos;
+						this->move(now_pos);
+
+						auto px = base_px_;
+						switch (dir_)
+						{
+						case ::nana::direction::west:
+						case ::nana::direction::north:
+							if (delta < 0)
+								px -= static_cast<unsigned>(-delta);
+							else
+								px += static_cast<unsigned>(delta);
+							break;
+						case ::nana::direction::east:
+						case ::nana::direction::south:
+							if (delta < 0)
+								px += static_cast<unsigned>(-delta);
+							else
+								px -= static_cast<unsigned>(delta);
+							break;
+						default:
+							break;
+						}
+
+						auto dock_px = (_m_is_vert(dir_) ? dock_dv_->field_area.height : dock_dv_->field_area.width);
+
+						pane_dv_->weight.assign_percent(double(px) / double(dock_px) * 100);
+
+						dock_dv_->collocate(wd);
+					}
 					else
-						now_pos.x = new_pos;
-					this->move(now_pos);
+						API::capture_window(this->handle(), false);	//release mouse button
+				};
 
-					auto px = base_px_;
-					switch (dir_)
-					{
-					case ::nana::direction::west:
-					case ::nana::direction::north:
-						if (delta < 0)
-							px -= static_cast<unsigned>(-delta);
-						else
-							px += static_cast<unsigned>(delta);
-						break;
-					case ::nana::direction::east:
-					case ::nana::direction::south:
-						if (delta < 0)
-							px += static_cast<unsigned>(-delta);
-						else
-							px -= static_cast<unsigned>(delta);
-						break;
-                    default:
-                        break;
-					}
-
-					auto dock_px = (_m_is_vert(dir_) ? dock_dv_->field_area.height : dock_dv_->field_area.width);
-
-					pane_dv_->weight.assign_percent(double(px) / double(dock_px) * 100);
-
-					dock_dv_->collocate(wd);
-				});
+				auto & evt = this->events();
+				evt.mouse_down(grab_fn);
+				evt.mouse_up(grab_fn);
+				evt.mouse_move(grab_fn);
 			}
 
 			void range(int begin, int end)
@@ -1867,6 +1875,7 @@ namespace nana
 				if (i->get()->display)
 					return i->get();
 			}
+
 			return nullptr;
 		}
 
diff --git a/source/gui/place_parts.hpp b/source/gui/place_parts.hpp
index 25708b93..1832d74a 100644
--- a/source/gui/place_parts.hpp
+++ b/source/gui/place_parts.hpp
@@ -1,7 +1,7 @@
 /*
  *	Parts of Class Place
  *	Nana C++ Library(http://www.nanapro.org)
- *	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0.
  *	(See accompanying file LICENSE_1_0.txt or copy at
@@ -233,45 +233,50 @@ namespace nana
 					}
 				});
 
-				caption_.events().mouse_down([this](const arg_mouse& arg)
+				auto grab_fn = [this](const arg_mouse& arg)
 				{
-					if (::nana::mouse::left_button == arg.button)
+					if (event_code::mouse_down == arg.evt_code)
 					{
-						moves_.started = true;
-						moves_.start_pos = API::cursor_position();
-						moves_.start_container_pos = (floating() ? container_->pos() : this->pos());
-						API::capture_window(caption_, true);
-					}
-				});
-
-				caption_.events().mouse_move([this](const arg_mouse& arg)
-				{
-					if (arg.left_button && moves_.started)
-					{
-						auto move_pos = API::cursor_position() - moves_.start_pos;
-						if (!floating())
+						if (::nana::mouse::left_button == arg.button)
 						{
-							if (std::abs(move_pos.x) > 4 || std::abs(move_pos.y) > 4)
-								float_away(move_pos);
-						}
-						else
-						{
-							move_pos += moves_.start_container_pos;
-							API::move_window(container_->handle(), move_pos);
-							notifier_->notify_move();
+							moves_.started = true;
+							moves_.start_pos = API::cursor_position();
+							moves_.start_container_pos = (floating() ? container_->pos() : this->pos());
+							API::capture_window(caption_, true);
 						}
 					}
-				});
-
-				caption_.events().mouse_up([this](const arg_mouse& arg)
-				{
-					if ((::nana::mouse::left_button == arg.button) && moves_.started)
+					else if (event_code::mouse_move == arg.evt_code)
 					{
-						moves_.started = false;
-						API::capture_window(caption_, false);
-						notifier_->notify_move_stopped();
+						if (arg.left_button && moves_.started)
+						{
+							auto move_pos = API::cursor_position() - moves_.start_pos;
+							if (!floating())
+							{
+								if (std::abs(move_pos.x) > 4 || std::abs(move_pos.y) > 4)
+									float_away(move_pos);
+							}
+							else
+							{
+								move_pos += moves_.start_container_pos;
+								API::move_window(container_->handle(), move_pos);
+								notifier_->notify_move();
+							}
+						}
 					}
-				});
+					else if (event_code::mouse_up == arg.evt_code)
+					{
+						if ((::nana::mouse::left_button == arg.button) && moves_.started)
+						{
+							moves_.started = false;
+							API::capture_window(caption_, false);
+							notifier_->notify_move_stopped();
+						}
+					}
+				};
+
+				caption_.events().mouse_down(grab_fn);
+				caption_.events().mouse_move(grab_fn);
+				caption_.events().mouse_up(grab_fn);
 
 			}
 
@@ -293,13 +298,13 @@ namespace nana
 						tabbar_.reset(new tabbar_lite(*this));
 
 						tabbar_->events().selected.clear();
-						tabbar_->events().selected([this]
+						tabbar_->events().selected([this](const event_arg&)
 						{
 							auto handle = tabbar_->attach(tabbar_->selected());
-							if (handle)
-								caption_.caption(API::window_caption(handle));
-							else
-								caption_.caption(::std::string());
+
+							//Set caption through a caption of window specified by handle
+							//Empty if handle is null
+							caption_.caption(API::window_caption(handle));
 						});
 
 						tabbar_->move({ 0, r.bottom() - 20, r.width, 20 });
@@ -320,7 +325,7 @@ namespace nana
 
 				if (tabbar_)
 				{
-					tabbar_->push_back(::nana::charset(wdg->caption()));
+					tabbar_->push_back(wdg->caption());
 					tabbar_->attach(panels_.size(), wdg->handle());
 				}
 
diff --git a/source/gui/programming_interface.cpp b/source/gui/programming_interface.cpp
index a5f96e98..f653069c 100644
--- a/source/gui/programming_interface.cpp
+++ b/source/gui/programming_interface.cpp
@@ -55,9 +55,9 @@ namespace API
 
 	namespace detail
 	{
-		::nana::widget_colors* make_scheme(::nana::detail::scheme_factory_base&& factory)
+		::nana::widget_colors* make_scheme(::nana::detail::scheme_factory_interface&& factory)
 		{
-			return restrict::bedrock.make_scheme(static_cast<::nana::detail::scheme_factory_base&&>(factory));
+			return restrict::bedrock.make_scheme(static_cast<::nana::detail::scheme_factory_interface&&>(factory));
 		}
 
 		bool emit_event(event_code evt_code, window wd, const ::nana::event_arg& arg)
diff --git a/source/gui/widgets/widget.cpp b/source/gui/widgets/widget.cpp
index 5982ea71..1169e59e 100644
--- a/source/gui/widgets/widget.cpp
+++ b/source/gui/widgets/widget.cpp
@@ -1,6 +1,6 @@
 /*
  *	The fundamental widget class implementation
- *	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2016 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0.
  *	(See accompanying file LICENSE_1_0.txt or copy at
@@ -370,6 +370,24 @@ namespace nana
 		{
 			return std::unique_ptr<widget_notifier_interface>(new widget::inner_widget_notifier(*wdg));
 		}
+
+		//class widget_base
+			widget_base::~widget_base()
+			{
+				if (handle_)
+					API::close_window(handle_);
+			}
+
+			window widget_base::handle() const
+			{
+				return handle_;
+			}
+
+			void widget_base::_m_notify_destroy()
+			{
+				handle_ = nullptr;
+			}
+		//end class widget_base
 	}
 }//end namespace nana