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-- C3A0009.A

--

--                             Grant of Unlimited Rights

--

--     Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,

--     F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained

--     unlimited rights in the software and documentation contained herein.

--     Unlimited rights are defined in DFAR 252.227-7013(a)(19).  By making

--     this public release, the Government intends to confer upon all

--     recipients unlimited rights  equal to those held by the Government.

--     These rights include rights to use, duplicate, release or disclose the

--     released technical data and computer software in whole or in part, in

--     any manner and for any purpose whatsoever, and to have or permit others

--     to do so.

--

--                                    DISCLAIMER

--

--     ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR

--     DISCLOSED ARE AS IS.  THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED

--     WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE

--     SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE

--     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A

--     PARTICULAR PURPOSE OF SAID MATERIAL.

--*

--

-- OBJECTIVE:

--      Check that subprogram references may be passed as parameters using

--      access-to-subprogram types. Check that the passed subprograms may

--      be invoked from within the called subprogram.

--

-- TEST DESCRIPTION:

--      Declare an access to procedure type in a package specification.

--      Declare a root tagged type with the access to procedure type as a

--      component.  Declare three primitive procedures for the type that

--      can be referred to by the access to procedure type.  Use the access

--      to procedure type to initialize the component of a record.

--

--      Extend the root type with a private extension in the same package

--      specification. Declare two new primitive subprograms for the extension

--      (in addition to its three inherited subprograms).

--

--      In the main program, declare an operation for the root tagged type

--      which can be passed as an access value to change the initial value

--      of the component.  Call the inherited operations indirectly by

--      de-referencing the access value to set value in the extension.

--      Call the primitive function to modify the extension by passing

--      the access value designating the primitive procedure as a parameter.

--

--

-- CHANGE HISTORY:

--      06 Dec 94   SAIC    ACVC 2.0

--

--!

package C3A0009_0 is -- Push_Buttons

   type Button is tagged private;

   -- Type accesses to procedures Push and Default_Response

   type Button_Response_Ptr is access procedure

      (B : in out Button);

   procedure Push (B : in out Button);               -- to be inherited

   procedure Set_Response (B : in out Button;        -- to be inherited

                           R : in Button_Response_Ptr);

   procedure Default_Response  (B : in out Button);  -- to be inherited

   type Alert_Button is new Button with private;  -- private extension of

                                                  -- root tagged type

   -- Inherits procedure Push from Button

   -- Inherits procedure Set_Response from Button

   -- Inherits procedure Default_Response from Button

   procedure Replace_Action( B: in out Alert_Button );

   -- type accesses to procedure Default_Action

   type Button_Action_Ptr is access procedure;

   -- The following function is needed to set value in the

   -- extension's private component.

   function Alert (B : in Alert_Button) return Button_Action_Ptr;

private

   type Button is tagged                             -- root tagged type

      record

         Response :  Button_Response_Ptr

                  := Default_Response'Access;

      end record;

   procedure Default_Action;

   type Alert_Button is new Button with record

        Action :  Button_Action_Ptr

               := Default_Action'Access;

      end record;

end C3A0009_0;

-----------------------------------------------------------------------------

with TCTouch;

package body C3A0009_0 is

   procedure Push (B : in out Button) is

   begin

      TCTouch.Touch( 'P' ); --------------------------------------------- P

      -- Invoking subprogram designated by access value

      B.Response (B);

   end Push;

   procedure Set_Response (B : in out Button;

                           R : in     Button_Response_Ptr) is

   begin

      TCTouch.Touch( 'S' ); --------------------------------------------- S

      -- Set procedure value in record

      B.Response := R;

   end Set_Response;

   procedure Default_Response (B : in out Button) is

   begin

      TCTouch.Touch( 'D' ); --------------------------------------------- D

   end Default_Response;

   procedure Default_Action is

   begin

      TCTouch.Touch( 'd' ); --------------------------------------------- d

   end Default_Action;

   procedure Replacement_Action is

   begin

      TCTouch.Touch( 'r' ); --------------------------------------------- r

   end Replacement_Action;

   procedure Replace_Action( B: in out Alert_Button ) is

   begin

      TCTouch.Touch( 'R' ); --------------------------------------------- R

      B.Action := Replacement_Action'Access;

   end Replace_Action;

   function Alert (B : in Alert_Button) return Button_Action_Ptr is

   begin

      TCTouch.Touch( 'A' ); --------------------------------------------- A

      return (B.Action);

   end Alert;

end C3A0009_0;

-----------------------------------------------------------------------------

with C3A0009_0;

package C3A0009_1 is -- Emergency_Items

   package Push_Buttons renames C3A0009_0;

   procedure Emergency (B : in out Push_Buttons.Button);

end C3A0009_1;

with TCTouch;

package body C3A0009_1 is -- Emergency_Items

   procedure Emergency (B : in out Push_Buttons.Button) is

      begin

        TCTouch.Touch( 'E' ); ------------------------------------------- E

      end Emergency;

end C3A0009_1;

-----------------------------------------------------------------------------

with Report;

with C3A0009_0, C3A0009_1;

with TCTouch;

procedure C3A0009 is

   package Push_Buttons    renames C3A0009_0;

   package Emergency_Items renames C3A0009_1;

   Black_Button : Push_Buttons.Alert_Button;

   Alert_Ptr    : Push_Buttons.Button_Action_Ptr;

begin

   Report.Test ("C3A0009", "Check that subprogram references may be passed "

                         & "as parameters using access-to-subprogram types. "

                         & "Check that the passed subprograms may be "

                         & "invoked from within the called subprogram");

   Push_Buttons.Push( Black_Button );

   Push_Buttons.Alert( Black_Button ).all;

   TCTouch.Validate( "PDAd", "Default operation set" );

   -- Call inherited operations Set_Response and Push to set

   -- Emergency value in the extension.

   Push_Buttons.Set_Response (Black_Button, Emergency_Items.Emergency'Access);

   Push_Buttons.Push( Black_Button );

   Push_Buttons.Alert( Black_Button ).all;

   TCTouch.Validate( "SPEAd", "Altered Response set" );

   -- Call primitive operation to set action value in the extension.

   Push_Buttons.Replace_Action( Black_Button );

   Push_Buttons.Push( Black_Button );

   Push_Buttons.Alert( Black_Button ).all;

   TCTouch.Validate( "RPEAr", "Altered Action set" );

   Report.Result;

end C3A0009;