Re: Interrupt Calls

[jerry@jvdsys.nextjk.stuyts.nl (Jerry van Dijk)]

In article <3467a0ef.0@silver.truman.edu> v025@academic.truman.edu writes:

>I am trying to write a package similar to your conio package.  So there would
>be a text screen manipulation package for the NT complier.  I figured since NT
>supports text-base dos programs all I would need to do is call the dos
>interrupt, but all I really need is a move cursor cursor function for my text
>graphics routines.

Unfortunately, there is no such thing as a 'dos interrupt' in a Win95/NT
program. To do this you need to use the Win32 API.

I will release AdaConio (a console package simular to conio for DOS) for
Win95/NT after the next upgrade of AdaGraph.

In the meantime, if you just need cursor control, the following might be
of some help:


-- ****************************************
-- * cursor.ads - Win95/NT cursor control *
-- ****************************************

package Cursor is

   procedure Console_Size (X, Y: out Integer);

   function Where_X return Integer;
   function Where_Y return Integer;

   procedure Goto_XY (X, Y: Integer);

end Cursor;


-- ****************************************
-- * cursor.adb - Win95/NT cursor control *
-- ****************************************

pragma C_Pass_By_Copy (128);

package body Cursor is

   -----------------
   -- WIN32 stuff --
   -----------------

   type SHORT is mod 2 ** 16;
   for SHORT'Size use 16;

   subtype WORD   is SHORT;
   subtype BOOL   is Integer;
   subtype DWORD  is Integer;
   subtype HANDLE is Integer;

   type COORD is
      record
         X : SHORT;
         Y : SHORT;
      end record;
   pragma Convention (C, COORD);

   type SMALL_RECT is
      record
         Left   : SHORT;
         Top    : SHORT;
         Right  : SHORT;
         Bottom : SHORT;
      end record;
   pragma Convention (C, SMALL_RECT);

   type CONSOLE_SCREEN_BUFFER_INFO is
      record
         Size       : COORD;
         Cursor_Pos : COORD;
         Attrib     : WORD;
         Window     : SMALL_RECT;
         Max_Size   : COORD;
      end record;
   pragma Convention (C, CONSOLE_SCREEN_BUFFER_INFO);

   type PCONSOLE_SCREEN_BUFFER_INFO is access all CONSOLE_SCREEN_BUFFER_INFO;
   pragma Convention (C, PCONSOLE_SCREEN_BUFFER_INFO);

   function GetStdHandle (Value : DWORD) return HANDLE;
   pragma Import (StdCall, GetStdHandle, "GetStdHandle");

   function SetConsoleCursorPosition (Buffer : HANDLE;
                                      Pos    : COORD)
                                      return BOOL;
   pragma Import (StdCall, SetConsoleCursorPosition,
                          "SetConsoleCursorPosition");

   function GetConsoleScreenBufferInfo (Buffer : HANDLE;
                                        Info   : PCONSOLE_SCREEN_BUFFER_INFO)
                                        return BOOL;
   pragma Import (StdCall, GetConsoleScreenBufferInfo,
                          "GetConsoleScreenBufferInfo");

   FALSE                : constant BOOL   := 0;
   STD_OUTPUT_HANDLE    : constant DWORD  := -11;
   INVALID_HANDLE_VALUE : constant HANDLE := -1;

   Output_Buffer   : HANDLE;
   Buffer_Info_Rec : aliased CONSOLE_SCREEN_BUFFER_INFO;
   Buffer_Info     : PCONSOLE_SCREEN_BUFFER_INFO := Buffer_Info_Rec'Access;

   Cursor_Pos_Error     : Exception;
   Buffer_Info_Error    : Exception;
   Invalid_Handle_Error : Exception;

   ----------------------
   -- Supporting stuff --
   ----------------------

   procedure Get_Buffer_Info is
   begin
      if GetConsoleScreenBufferInfo (Output_Buffer, Buffer_Info) = FALSE then
         raise Buffer_Info_Error;
      end if;
   end Get_Buffer_Info;

   ---------------------
   -- Implementations --
   ---------------------

   procedure Console_Size (X, Y: out Integer) is
   begin
      Get_Buffer_Info;
      X := Integer (Buffer_Info_Rec.Size.X);
      Y := Integer (Buffer_Info_Rec.Size.Y);
   end Console_Size;

   function Where_X return Integer is
   begin
      Get_Buffer_Info;
      return Integer (Buffer_Info_Rec.Cursor_Pos.X);
   end Where_X;

   function Where_Y return Integer is
   begin
      Get_Buffer_Info;
      return Integer (Buffer_Info_Rec.Cursor_Pos.Y);
   end Where_Y;

   procedure Goto_XY (X, Y: in Integer) is
      New_Pos : COORD := (SHORT (X), SHORT (Y));
   begin
      Get_Buffer_Info;

      if New_Pos.X > Buffer_Info_Rec.Size.X then
         New_Pos.X := Buffer_Info_Rec.Size.X;
      end if;

      if New_Pos.Y > Buffer_Info_Rec.Size.Y then
         New_Pos.Y := Buffer_Info_Rec.Size.Y;
      end if;

      if SetConsoleCursorPosition (Output_Buffer, New_Pos) = FALSE then
         raise Cursor_Pos_Error;
      end if;

   end Goto_XY;

--------------------
-- Initialization --
--------------------
begin
   Output_Buffer := GetStdHandle (STD_OUTPUT_HANDLE);
   if Output_Buffer = INVALID_HANDLE_VALUE then
      raise Invalid_Handle_Error;
   end if;
end Cursor;

--

-- Jerry van Dijk | Leiden, Holland
-- Consultant     | Team Ada
-- Ordina Finance | jdijk@acm.org