full error msg at one place

include/nana/gui/place.hpp

@@ -1,16 +1,16 @@
-/*
+/**
  *	An Implementation of Place for Layout
  *	Nana C++ Library(http://www.nanapro.org)
- *	Copyright(C) 2003-2018 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2019 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/place.cpp
+ *	@file nana/gui/place.cpp
  *
- *	@contributions:
- *	min/max and splitter bar initial weight by Ariel Vina-Rodriguez.
+ *	@contributions
+ *	error, width/height, min/max and splitter bar initial weight by Ariel Vina-Rodriguez.
  */
 
 #ifndef NANA_GUI_PLACE_HPP
@@ -104,23 +104,29 @@ namespace nana
 			virtual void _m_add_agent(const detail::place_agent&) = 0;
 		};
 	public:
-		class error :public ::std::invalid_argument
+		class error :public std::invalid_argument
 		{
 		public:
-			error(::std::string           what,
+			error( const std::string&     what,
 				   const place&           plc,
 				   std::string            field = "unknown",
 				   std::string::size_type pos = std::string::npos)
 
-				: std::invalid_argument(what),
-				owner_caption{ API::window_caption(plc.window_handle()).substr(0,80) },
-				field{ field },
-				div_text{ plc.div() },
-				pos{ pos }
+				: std::invalid_argument{ "Place error  " + what 
+				                        + " from widget " + API::window_caption(plc.window_handle()).substr(0,80)
+				                        + " in fleld " + field
+						                + ( pos == std::string::npos ? "" : "at  at position " + std::to_string(pos)  )
+						                + "in div_text:\n" + plc.div()},
+				  base_what    { what }, 
+				  owner_caption{ API::window_caption(plc.window_handle()).substr(0,80) },
+				  field        { field },
+				  div_text     { plc.div() },
+				  pos          { pos }
 			{}
-			std::string owner_caption; ///< truncate caption (title) of the "placed" widget
-			std::string div_text;
-			std::string field;   ///< posible field where the error ocurred.  
+			std::string base_what;
+			std::string owner_caption;  ///< truncate caption (title) of the "placed" widget
+			std::string div_text;       ///< involved div_text
+			std::string field;          ///< posible field where the error ocurred.  
 			std::string::size_type pos; ///< posible position in the div_text where the error ocurred. npos if unknown
 		};
         ///  reference to a field manipulator which refers to a field object created by place 
@@ -139,8 +145,8 @@ namespace nana
 
 		void splitter_renderer(std::function<void(window, paint::graphics&, mouse_action)> fn);
         
-		void div(std::string div_text);			///< Divides the attached widget into fields.
-		const std::string& div() const noexcept;	///< Returns div-text that depends on fields status.
+		void div(std::string div_text);			  ///< Divides the attached widget into fields. May throw placa::error
+		const std::string& div() const noexcept;  ///< Returns div-text that depends on fields status.
 		static bool valid_field_name(const char* name)  ///< must begin with _a-zA-Z
 		{
 			return name && (*name == '_' || (('a' <= *name && *name <= 'z') || ('A' <= *name && *name <= 'Z')));

source/gui/place.cpp

@@ -59,8 +59,7 @@ namespace nana
 				error(std::string           what,
 					  const tokenizer&      tok)
 
-					: std::invalid_argument{ what + " from tokenizer at position " 
-					                        + std::to_string(static_cast<unsigned>(tok.sp_ - tok.divstr_)) },
+					: std::invalid_argument{ what + " from tokenizer "  },
 					  pos{static_cast<std::string::size_type>(tok.sp_ - tok.divstr_)}
 				{}	
 				std::string::size_type pos;