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303 | ------------------------------------------------------------------
-- Tokeneer ID Station Core Software
--
-- Copyright (2003) United States Government, as represented
-- by the Director, National Security Agency. All rights reserved.
--
-- This material was originally developed by Praxis High Integrity
-- Systems Ltd. under contract to the National Security Agency.
------------------------------------------------------------------
------------------------------------------------------------------
-- Keyboard.Interfac
--
-- Implementation Notes:
-- Not SPARK as it uses a task to allow polling.
--
------------------------------------------------------------------
with Interfaces.C;
with Ada.Characters.Latin_1;
with Ada.Characters.Handling;
with System;
package body Keyboard.Interfac
with SPARK_Mode => Off
is
--PromptCoord : constant Win32.WinCon.Coord := (2, 4);
----------------------------------------------------------------------
-- KeyedDataStore Protected Object
--
-- Description:
-- This protected object provides a shared data repository for
-- the Keyboard reader Task and the remainder of the system.
-- The Reader Task Sets the value of KeyedData, the remainder
-- of the system can then read the values.
--
---------------------------------------------------------------------
protected KeyedDataStore is
----------------------------------------------------------------------
-- SetData
--
-- Description:
-- Adds Keyed Data to the Store.
--
---------------------------------------------------------------------
procedure SetData (KeyedData : in Keyboard.DataTextT;
Length : in Natural);
----------------------------------------------------------------------
-- GetData
--
-- Description:
-- Reads Keyed Data from the Store and clears the currently
-- held Keyed Data so it is not read twice.
--
---------------------------------------------------------------------
procedure GetData (KeyedData : out Keyboard.DataTextT;
Length : out Keyboard.DataLengthT;
Presence : out CommonTypes.PresenceT);
----------------------------------------------------------------------
-- Refresh
--
-- Description:
-- Refreshes the data if it becomes too old.
--
---------------------------------------------------------------------
procedure Refresh;
private
TheData : Keyboard.DataTextT := (others => ' ');
TheLength : Keyboard.DataLengthT := 0;
ThePresence : CommonTypes.PresenceT := CommonTypes.Absent;
IsFresh : Boolean := False;
end KeyedDataStore;
----------------------------------------------------------------------
-- KeyedDataStore Protected Object
--
-- Implementation Notes:
-- None.
--
---------------------------------------------------------------------
protected body KeyedDataStore is
----------------------------------------------------------------------
-- SetData
--
-- Implementation Notes:
-- Removes the CR and LF from the end of the read data.
-- A blank line with no characters other than <Return>
-- will not count at present data.
---------------------------------------------------------------------
procedure SetData (KeyedData : in Keyboard.DataTextT;
Length : in Natural)
is
begin
TheData := KeyedData;
if Length <= Keyboard.DataLengthT'Last then
TheLength := Length;
else
TheLength := Keyboard.DataLengthT'Last;
end if;
-- Remove the CR & LF. A blank line does not count as present data.
if TheLength > 2 then
ThePresence := CommonTypes.Present;
TheLength := TheLength - 2;
IsFresh := True;
else
ThePresence := CommonTypes.Absent;
TheLength := 0;
end if;
end SetData;
----------------------------------------------------------------------
-- GetData
--
-- Implementation Notes:
-- None.
--
---------------------------------------------------------------------
procedure GetData (KeyedData : out Keyboard.DataTextT;
Length : out Keyboard.DataLengthT;
Presence : out CommonTypes.PresenceT) is
begin
KeyedData := TheData;
Length := TheLength;
Presence := ThePresence;
ThePresence := CommonTypes.Absent;
TheLength := 0;
end GetData;
----------------------------------------------------------------------
-- Refresh
--
-- Implementation Notes:
-- None.
--
---------------------------------------------------------------------
procedure Refresh is
begin
if not IsFresh then
TheData := (others => ' ');
ThePresence := CommonTypes.Absent;
TheLength := 0;
else
IsFresh := False;
end if;
end Refresh;
end KeyedDataStore;
------------------------------------------------------------------
-- Types
--
------------------------------------------------------------------
----------------------------------------------------------------------
-- Reader Task
--
-- Description:
-- This task encapsulates the process of reading the keyboard.
-- It is required due to the blocking nature of the console read.
-- Once Started it will continually read the Keyboard, placing the
-- latest command in the KeyedDataStore.
-- The Stop Entry allows task termination.
--
-- Implementation Notes:
-- None.
---------------------------------------------------------------------
task Reader is
entry Start;
entry Stop;
end;
----------------------------------------------------------------------
-- Read
--
-- Description:
-- This operation reads a line from the Win32 Console. The operation
-- blocks until the user presses <return>.
--
-- Implementation Notes:
-- None.
---------------------------------------------------------------------
procedure Read
(Buffer : out String;
Len : out Natural;
OK : out Boolean)
is
pragma Unreferenced (Buffer);
begin
OK := True;
Len := 0;
end Read;
----------------------------------------------------------------------
-- Reader Task
--
-- Implementation Notes:
-- None.
---------------------------------------------------------------------
task body Reader is
ReadData : Keyboard.DataTextT;
DataLength : Natural;
ReadOK : Boolean;
begin
select
accept Start;
loop
select
accept Stop;
exit;
else
Read(ReadData, DataLength, ReadOK);
if ReadOK then
KeyedDataStore.SetData(ReadData, DataLength);
end if;
end select;
end loop;
or
terminate;
end select;
end Reader;
------------------------------------------------------------------
-- ReadKeyboardData
--
-- Implementation Notes:
-- Converts to Upper case so that checks are case insensitive.
--
------------------------------------------------------------------
procedure ReadKeyboardData
(KeyedDataPresence : out CommonTypes.PresenceT;
KeyedData : out Keyboard.DataTextT;
KeyedDataLength : out Keyboard.DataLengthT)
is
LocalKeyedData : Keyboard.DataTextT;
begin
KeyedData := (others => ' ');
KeyedDataStore.GetData
(LocalKeyedData,
KeyedDataLength,
KeyedDataPresence);
if KeyedDataLength > 0 then
for I in DataI range 1 .. KeyedDataLength loop
KeyedData(I) :=
Ada.Characters.Handling.To_Upper(LocalKeyedData(I));
end loop;
end if;
end ReadKeyboardData;
------------------------------------------------------------------
-- Init
--
-- Implementation Notes:
-- None.
--
------------------------------------------------------------------
procedure Init is
begin
Reader.Start;
end Init;
------------------------------------------------------------------
-- Finalise
--
-- Implementation Notes:
-- In order to force the current Win32.WinCon.Read to terminate
-- we destroy the console.
-- It is then possible to stop the Reader Task.
--
------------------------------------------------------------------
procedure Finalise is
begin
Reader.Stop;
end Finalise;
------------------------------------------------------------------
-- Poll
--
-- Implementation Notes:
-- None.
--
------------------------------------------------------------------
procedure Poll is
begin
KeyedDataStore.Refresh;
end Poll;
end Keyboard.Interfac;
|