------------------------------------------------------------------------------
--                                                                          --
--                           GNAT ncurses Binding                           --
--                                                                          --
--               Terminal_Interface.Curses.Forms.Field_Types.User           --
--                                                                          --
--                                 S P E C                                  --
--                                                                          --
------------------------------------------------------------------------------
-- Copyright (c) 1998 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: 1.11 $
--  Binding Version 01.00
------------------------------------------------------------------------------
with Interfaces.C;

package Terminal_Interface.Curses.Forms.Field_Types.User is
   pragma Preelaborate (Terminal_Interface.Curses.Forms.Field_Types.User);
   use type Interfaces.C.int;
   subtype C_Int is Interfaces.C.int;

   type User_Defined_Field_Type is abstract new Field_Type with null record;
   --  This is the root of the mechanism we use to create field types in
   --  Ada95. You should your own type derive from this one and implement
   --  the Field_Check and Character_Check functions for your own type.

   type User_Defined_Field_Type_Access is access all
     User_Defined_Field_Type'Class;

   function Field_Check
     (Fld : Field;
      Typ : User_Defined_Field_Type) return Boolean
      is abstract;
   --  If True is returned, the field is considered valid, otherwise it is
   --  invalid.

   function Character_Check
     (Ch  : Character;
      Typ : User_Defined_Field_Type) return Boolean
      is abstract;
   --  If True is returned, the character is considered as valid for the
   --  field, otherwise as invalid.

   procedure Set_Field_Type (Fld : in Field;
                             Typ : in User_Defined_Field_Type);
   --  This should work for all types derived from User_Defined_Field_Type.
   --  No need to reimplement it for your derived type.

   --  +----------------------------------------------------------------------
   --  | Private Part.
   --  | Used by the Choice child package.
private
   use type Interfaces.C.int;

   function C_Generic_Type   return C_Field_Type;

   function Generic_Field_Check (Fld : Field;
                                 Usr : System.Address) return C_Int;
   pragma Convention (C, Generic_Field_Check);
   --  This is the generic Field_Check_Function for the low-level fieldtype
   --  representing all the User_Defined_Field_Type derivates. It routes
   --  the call to the Field_Check implementation for the type.

   function Generic_Char_Check (Ch  : C_Int;
                                Usr : System.Address) return C_Int;
   pragma Convention (C, Generic_Char_Check);
   --  This is the generic Char_Check_Function for the low-level fieldtype
   --  representing all the User_Defined_Field_Type derivates. It routes
   --  the call to the Character_Check implementation for the type.

end Terminal_Interface.Curses.Forms.Field_Types.User;
