terminal_interface-curses-forms-field_types-user-choice.adb

ncurses 库 可能有用酒用 没用就算了 我觉得还可以用

------------------------------------------------------------------------------
--                                                                          --
--                           GNAT ncurses Binding                           --
--                                                                          --
--          Terminal_Interface.Curses.Forms.Field_Types.User.Choice         --
--                                                                          --
--                                 B O D Y                                  --
--                                                                          --
------------------------------------------------------------------------------
-- Copyright (c) 1998,2004 Free Software Foundation, Inc.                   --
--                                                                          --
-- Permission is hereby granted, free of charge, to any person obtaining a  --
-- copy of this software and associated documentation files (the            --
-- "Software"), to deal in the Software without restriction, including      --
-- without limitation the rights to use, copy, modify, merge, publish,      --
-- distribute, distribute with modifications, sublicense, and/or sell       --
-- copies of the Software, and to permit persons to whom the Software is    --
-- furnished to do so, subject to the following conditions:                 --
--                                                                          --
-- The above copyright notice and this permission notice shall be included  --
-- in all copies or substantial portions of the Software.                   --
--                                                                          --
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  --
-- OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               --
-- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   --
-- IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   --
-- DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    --
-- OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    --
-- THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               --
--                                                                          --
-- Except as contained in this notice, the name(s) of the above copyright   --
-- holders shall not be used in advertising or otherwise to promote the     --
-- sale, use or other dealings in this Software without prior written       --
-- authorization.                                                           --
------------------------------------------------------------------------------
--  Author:  Juergen Pfeifer, 1996
--  Version Control:
--  $Revision: 1.13 $
--  $Date: 2004/08/21 21:37:00 $
--  Binding Version 01.00
------------------------------------------------------------------------------
with Ada.Unchecked_Conversion;
with Interfaces.C;
with Terminal_Interface.Curses.Aux; use Terminal_Interface.Curses.Aux;

package body Terminal_Interface.Curses.Forms.Field_Types.User.Choice is

   use type Interfaces.C.int;

   function To_Argument_Access is new Ada.Unchecked_Conversion
     (System.Address, Argument_Access);

   function Generic_Next (Fld : Field;
                          Usr : System.Address) return C_Int
   is
      Result : Boolean;
      Udf    : constant User_Defined_Field_Type_With_Choice_Access :=
        User_Defined_Field_Type_With_Choice_Access
        (To_Argument_Access (Usr).Typ);
   begin
      Result := Next (Fld, Udf.all);
      return C_Int (Boolean'Pos (Result));
   end Generic_Next;

   function Generic_Prev (Fld : Field;
                          Usr : System.Address) return C_Int
   is
      Result : Boolean;
      Udf    : constant User_Defined_Field_Type_With_Choice_Access :=
        User_Defined_Field_Type_With_Choice_Access
        (To_Argument_Access (Usr).Typ);
   begin
      Result := Previous (Fld, Udf.all);
      return C_Int (Boolean'Pos (Result));
   end Generic_Prev;

   --  -----------------------------------------------------------------------
   --
   function C_Generic_Choice return C_Field_Type
   is
      Res : Eti_Error;
      T   : C_Field_Type;
   begin
      if M_Generic_Choice = Null_Field_Type then
         T := New_Fieldtype (Generic_Field_Check'Access,
                             Generic_Char_Check'Access);
         if T = Null_Field_Type then
            raise Form_Exception;
         else
            Res := Set_Fieldtype_Arg (T,
                                      Make_Arg'Access,
                                      Copy_Arg'Access,
                                      Free_Arg'Access);
            if Res /= E_Ok then
               Eti_Exception (Res);
            end if;

            Res := Set_Fieldtype_Choice (T,
                                         Generic_Next'Access,
                                         Generic_Prev'Access);
            if Res /= E_Ok then
               Eti_Exception (Res);
            end if;
         end if;
         M_Generic_Choice := T;
      end if;
      pragma Assert (M_Generic_Choice /= Null_Field_Type);
      return M_Generic_Choice;
   end C_Generic_Choice;

end Terminal_Interface.Curses.Forms.Field_Types.User.Choice;