Package: PCSC.SCard.Monitor

Description

Copyright (c) 2008, Reto Buerki <reet@codelabs.ch>

This file is part of PCSC/Ada.

PCSC/Ada is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

PCSC/Ada is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with PCSC/Ada; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Purpose:
SCard reader monitoring package. This package provides types and functions / procedures to monitor card readers. The abstract type Observer can be extended to create new observers for specific reader state changes. Observers can be registered to a Reader_Monitor task by calling the Register() entry. A running Reader_Monitor task will inform all registered observers when a change in reader state occurs.

Header

package PCSC.SCard.Monitor is
 

Type Summary

Context_Handle
Observer
Primitive Operations:  Is_Interested, Notify
Reader_Monitor (task type)

Other Items:

type Context_Handle is access all SCard.Context;
Handle to Context object

type Observer is abstract tagged record
   States : Reader_States_Set;
   --  Reader states this observer is interested in
end record;
Abstract reader observer type. Valid Reader_Monitor observers must extend this type.

subtype Observer_Class is Observer'Class;
Observer class subtype

procedure Notify (O         : in Observer;
                  Condition : in Reader_Condition) is abstract;
This procedure is called to inform an observer about status changes in reader states for all states this observer is interested in.

function Is_Interested (O      : in Observer;
                        States : in Reader_States_Set) return Boolean;
Function is used to check whether an observer is interested in one of the states given by 'States' set.

task type Reader_Monitor is
 
entry Init (Context : in Context_Handle);
Initialization entry for a Reader_Monitor task

entry Start;
Start the Reader_Monitor task

entry Stop;
Stop the Reader_Monitor task

entry Register (O : in Observer_Class);
Register a new observer to the Reader_Monitor
end Reader_Monitor;

private

   --  Implementation-defined ...
end PCSC.SCard.Monitor;