diff --git a/.travis.yml b/.travis.yml
index 6a47d771..20ef6e32 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -46,8 +46,6 @@ before_install:
   - cd ..
   - git clone --depth=1 --branch=hotfix https://github.com/qPCR4vir/nana-demo.git nana-demo
   - export PATH="$HOME/bin:$PATH"
-
-  #- mkdir ~/bin #it seemd that a bin already exists from 20170901 
   - wget --no-check-certificate --no-clobber -O /tmp/tools/cmake https://cmake.org/files/v3.12/cmake-3.12.0-rc3-Linux-x86_64.sh || true
   - chmod -R +x /tmp/tools
 
diff --git a/build/vc2017/nana.vcxproj b/build/vc2017/nana.vcxproj
index 911548d5..24f5ef80 100644
--- a/build/vc2017/nana.vcxproj
+++ b/build/vc2017/nana.vcxproj
@@ -256,6 +256,7 @@
     <ClInclude Include="..\..\include\nana\gui.hpp" />
     <ClInclude Include="..\..\include\nana\gui\animation.hpp" />
     <ClInclude Include="..\..\include\nana\gui\basis.hpp" />
+    <ClInclude Include="..\..\include\nana\gui\dragdrop.hpp" />
     <ClInclude Include="..\..\include\nana\gui\dragger.hpp" />
     <ClInclude Include="..\..\include\nana\gui\drawing.hpp" />
     <ClInclude Include="..\..\include\nana\gui\effects.hpp" />
diff --git a/build/vc2017/nana.vcxproj.filters b/build/vc2017/nana.vcxproj.filters
index e88f7ed3..4923833d 100644
--- a/build/vc2017/nana.vcxproj.filters
+++ b/build/vc2017/nana.vcxproj.filters
@@ -474,6 +474,9 @@
     <ClInclude Include="..\..\include\nana\verbose_preprocessor.hpp">
       <Filter>Include</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\include\nana\gui\dragdrop.hpp">
+      <Filter>Include\gui</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\..\include\nana\pop_ignore_diagnostic">
diff --git a/include/nana/gui/dragdrop.hpp b/include/nana/gui/dragdrop.hpp
index 1eeb9541..70c91013 100644
--- a/include/nana/gui/dragdrop.hpp
+++ b/include/nana/gui/dragdrop.hpp
@@ -40,7 +40,16 @@ namespace nana
 		simple_dragdrop(simple_dragdrop&&) = delete;
 		simple_dragdrop& operator=(simple_dragdrop&&) = delete;
 	public:
-		simple_dragdrop(window source);
+		explicit simple_dragdrop(window source);
+		simple_dragdrop(window                drag_origin,
+						std::function<bool()> when,
+						window                drop_target,
+						std::function<void()> how)
+		: simple_dragdrop{drag_origin}
+		{
+			condition(when);
+			make_drop(drop_target, how);
+		}
 		~simple_dragdrop();
 
 		/// Condition checker
diff --git a/include/nana/gui/widgets/group.hpp b/include/nana/gui/widgets/group.hpp
index d62a7abf..43dd5e85 100644
--- a/include/nana/gui/widgets/group.hpp
+++ b/include/nana/gui/widgets/group.hpp
@@ -59,9 +59,8 @@ namespace nana{
 		group(window parent, const rectangle& = {}, bool visible = true);
 
 		///  The construction that creates the widget and set the title or caption
-
-		group(window			parent,		///< a handle to the parent
-			  ::std::string		title,		///< caption of the group
+		group(window			parent,		        ///< a handle to the parent
+			  ::std::string	    title,		        ///< caption of the group
 			  bool				formatted = false,  ///< Enable/disable the formatted text for the title
 			  unsigned			gap = 2,			///< between the content and the external limit
 			  const rectangle&	r = {} ,
diff --git a/include/nana/gui/widgets/listbox.hpp b/include/nana/gui/widgets/listbox.hpp
index 52680582..9a9b6206 100644
--- a/include/nana/gui/widgets/listbox.hpp
+++ b/include/nana/gui/widgets/listbox.hpp
@@ -1465,7 +1465,7 @@ the nana::detail::basic_window member pointer scheme
 		size_type column_size() const;
 
 		/// Move column to view_position
-		void move_column(size_type abs_pos, size_type view_pos);
+        void move_column(size_type abs_pos, size_type view_pos);
 
         /// Sort columns in range first_col to last_col inclusive using the values from a row
         void reorder_columns(size_type first_col,
diff --git a/include/nana/gui/widgets/treebox.hpp b/include/nana/gui/widgets/treebox.hpp
index 4d832c27..c1edbadf 100644
--- a/include/nana/gui/widgets/treebox.hpp
+++ b/include/nana/gui/widgets/treebox.hpp
@@ -350,9 +350,9 @@ namespace nana
     /// \brief  Displays a hierarchical list of items, such as the files and directories on a disk.
     /// See also in [documentation](http://nanapro.org/en-us/documentation/widgets/treebox.htm)
     class treebox
-		:public widget_object < category::widget_tag,
+		:public widget_object <category::widget_tag,
 		                        drawerbase::treebox::trigger,
-		                        drawerbase::treebox::treebox_events>
+		                        drawerbase::treebox::treebox_events, drawerbase::treebox::scheme>
 	{
 	public:
         /// A type refers to the item and is also used to iterate through the nodes.
diff --git a/source/gui/widgets/listbox.cpp b/source/gui/widgets/listbox.cpp
index 00e2052a..91ce34d8 100644
--- a/source/gui/widgets/listbox.cpp
+++ b/source/gui/widgets/listbox.cpp
@@ -549,9 +549,9 @@ namespace nana
 					if (!front) view++;
 					if (view >= cont_.size() )		return;
 
-					auto i = std::find_if( cont_.begin(),
-							               cont_.end(),
-							               [&](const column& c){return col==c.index;});
+					auto i = std::find_if(   cont_.begin(),
+							              cont_.end(),
+							              [&](const column& c){return col==c.index;});
 
 					if (i==cont_.end()) return;
 
@@ -4474,7 +4474,7 @@ namespace nana
 						essence_->stop_mouse_selection();
 						need_refresh = true;
 					}
-					
+
 					if (operation_states::msup_deselect == essence_->operation.state)
 					{
 						essence_->operation.state = operation_states::none;
@@ -6193,7 +6193,7 @@ namespace nana
 			
 			std::vector<size_type> new_idx;
 			for(size_type i=first_col; i<=last_col; ++i) new_idx.push_back(i);
-			
+
 			internal_scope_guard lock;
 			auto ip_row = this->at(row);
 			auto pnany=_m_ess().lister.anyobj(row,false);