[Note: Alpha stage. Final Specification subject to change without notice]
EZY
Prolog -
easy way to write prolog program
What is the Dialog Control Language?
I do not think it is new. 10 yeas ago I use to write dialogs using DCL inside AutoCAD rel 11 and 13. It was easy way to place controls, attach reactors (handlers).
The VP Studio DCL is something identical, but inside Visual Prolog. So, the text file (in final release it will be XML), defines objects, properties and their relationships as well as object handlers (Visual Prolog or Prolog Inference Engine clauses).
A history
After numerous experiments with VP Studio Shell, which provides rich functionality for Visual Prolog developers, I found a software paradigm, which allows easy way of creating GUI components inside Visual Prolog application. Some ideas are quite obvious, some of them were discussed on Visual Prolog forum, some ideas are real inventions (at least for me).
One of the ambitious goal is to create an easy way of GUI development, similar to Delphi or Visual Basic, where IDE provides programmer with set of control properties and do not need to spend time in manual programming of them.
Below is an Alpha-version of the DCL, which will be available inside Prolog Inference Engine (Prolog interpreter, written in Visual Prolog) and inside VP Studio Shell (Visual Prolog compiler).
DCL inside VP Studio Shell provides automatic Visual Prolog code generation for final application.
DCL statements can be precompiled or loaded dynamically inside Visual Prolog application.
DCL also will provide Visual Prolog application with GUI design capability, so, programmer can give a user functionality of changing GUI elements (form designers and various interpreters).
A Concept
It is not new. In general terms, it is defined in following set of declarations:
WINDOW = win(EXTERIOR_PROPERTIES,HANDLER_PROPERTIES,WINDOW_CONTROL_LIST)
WINDOW_CONTROL =
winctrl(WINTYPE, EXTERIOR_PROPERTIES,
HANDLER_PROPERTIES,
CONTROL_DATA,
WINDOW_CONTROL_LIST)
WINDOW_CONTROL_LIST = WINDOW_CONTROL*
and so on....
An implementation
DCL concept has been implemented via EZY Designer. It is Visual Prolog application, which provides intuitive and convenient interface for designing of various complex graphical interfaces.
EZY Designer is part of EZY Prolog and has been fully integrated into it.
EZY Designer provides declarations for GUI, which require minimal or no programming for GUI. EZY Prolog application simply loads DCL declarations from the file.
Programmer needs only to initialize callbacks and event handlers for GUI elements.
Compatibility
DCL is fully compatible with VP Studio Shell (which will be available later after Beta-version of DCL). VP Studio Shell will provide automatic code generation for DCL support.
VP Studio Shell is written using DCL codes.
DCL codes inherit various software paradigms of the Visual Prolog Studio Objects - proven functional code, implemented in various applications.
DCL will have a Win32 DLL for use inside various development environments - VB, C/C++, Delphi.
DCL will have functionality to include ActiveX and other Custom controls developed by 3rd party developers.
Technology
VP Studio DCL is fully Object Oriented which can be easily included into existing Visual Prolog applications (See VP Studio Shell for more information).
Copyright 1998-2002 EDMGROUP (Australia)
Last Updated: August 1, 2002