|
Copyright ® (1999-2003) EDMGROUP Pty Ltd - EZY Prolog Reference |
New in EZY Prolog Tutorials Download EZY Prolog main page
[Note: Alpha stage. Final Specification subject to change without notice]
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) in easy semi-declarative style.
The EZY Prolog DCL is something identical, but more powerful and provides more functionality. 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 EZY Prolog clauses).
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.
DCL inside EZY Prolog provides complete separation of GUI design and programming. EZY Designer can be used to define properties of GUI elements without changing associated program code.
In general terms, Graphical User Interface 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....
see DCL domains declarations here
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 visual editing of GUI elements and their properties, 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.
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.
EZY Prolog is written using DCL declarations.
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.
EZY Prolog DCL interpreter is fully Object Oriented which can be easily included into existing Visual Prolog applications (See VP Studio Shell for more information).