[Fclib-general] Where is the source?

[<rob...@at...>]

Sorry for not having posted any source code yet.  I'm 
applying the finishing touches, including reorganizing 
the directory hierarchy.  Of course, when I do upload 
it, it will only be the beginning.  I intend for 
FastClass to provide a uniform interface for all the 
services normally provided by different CAD programs' 
APIs.  It can't be done all at once, so the order of 
development reflects my own personal needs at the time.  
The first classes will provide support for:

(1) Abstract entity and graphical entity types.  
Concrete "wire-frame" entities (e.g., point, line, 
arc).  Primarily read operations, since I am working on 
a data exporter.

(2) An entity factory, which provides a uniform 
interface for creating entities, regardless of the 
target platform (e.g., CADKey or AutoCAD).  Currently, 
usage is like:

fcLineEnt = entFactorySingleton->makeLine();

But I intend to replace explicit function names with a 
registry, for extensibility.  For example:

fcLineEnt = entFactorySingleton->make("LINE");

See the book _Design Patterns: Elements of Reusable 
Object-Oriented Software_ (Gamma, et al) for details on 
the object factory (and singleton) design pattern.

(3) An abstract visitor class, which provides a single 
point of entry for any function that operates on 
entities (and other FastClass objects, eventually).  The 
visitor design pattern allows double-dispatch functions 
in C++ (i.e., the code that is executed depends on both 
the visitor class and the entity class).

See also Gamma, et al for details on the visitor design 
pattern.

(4) A parallel CADKey hierarchy, which implements 
FastClass for use with CADKey.  Currently, to use 
FastClass with a given CAD platform, only a counterpart 
for the fcEnt heirarchy needs to be written.  The rest 
of library references only itself.  No doubt, this will 
change as more functionality and complexity is added.  
But the goal is to implement as much advanced 
functionality as possible using only the FastClass API.

(5) A demo application, ckExplorer.  Pick and select 
entities to see their attributes.  Will later extend to 
include non-graphical entities (e.g., layouts and views) 
and editing of attributes.  Will also support platforms 
other than CADKey, but currently it uses a unique CADKey 
user interface element (the conversation bar).

I will release the source code as soon as possible.  
Until then, please don't hesitate to ask any questions.

Thanks,
Rob Campbell
rob...@at...