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Synchronizing External Language Interface in Smalltalk with Events Handler

IP.com Disclosure Number: IPCOM000116762D
Original Publication Date: 1995-Nov-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Bynum Jr, R: AUTHOR

Abstract

A method for synchronizing external language interfaces using event handling in IBM* Smalltalk* is disclosed. The asynchronous events are synchronuzed by creating new events that signal their completion.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 55% of the total text.

Synchronizing External Language Interface in Smalltalk with Events
Handler

      A method for synchronizing external language interfaces using
event handling in IBM* Smalltalk* is disclosed.  The asynchronous
events are synchronuzed by creating new events that signal their
completion.

      The External Language Interface of IBM Smalltalk enables the
construction of object wrappers of well defined legacy applications.
Well-defined legacy applications are procedural in design with
clearly defined API interfaces.  APIs to procedural applications use
a Call-return paradigm versus the messaging paradigm used in
object-oriented technology.  These opposing technologies must be
normalized to make object wrapping successful.

      The Call-return interface uses by procedural applications is a
synchronous interface.  The message interface used by Object-Oriented
Technology in an asynchronous interface.  When the object model is
expressed with a GUI view, the view object needs to know when the
Application Program Interface (API) call completes.  This invention
provides a solution to this problem.

      IBM Smalltalk used events and callbacks to notify an object of
change.  An event is the mechanism used to notify the application
when the user performs a mouse or or keyboard operation.  A callback
is the mechanism used to notify the application when some higher
level action is preformed on a widget (e.g., CwPushButton pressed and
released).  This invention...