Hierarchy Objects.

Copyright, Warranty information:
============================================================================

The HierObj.pas and StreamUt.pas files are copyright 
(c), 1996 - HyperAct, Inc.

We release this code for free use in your applications, you are not 
allowed in any way, shape or form to distribute the source code for profit.

You are free to use the code in your applications, dlls and components, and
to distribute the code in compiled form (exe, dll, ocx, dcu etc..).

There are no warranties what so ever, Hyperact, Inc, will not be responsible
in any way, shape or form for any damages, lost profits or other problems
caused by the use or inability to use this code.

What's in the package:
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StreamUt.pas - Basic Stream utilities - to write basic variable types to
stream.

HierObj.pas - Objects in hierarchy.

TObjectInHierarchy - An abstact class of an object that is part of a 
hierarchy. The object knows about it's parent, it's childs, and knows
how to communicate with a hierarchy viewer by performing promotion,
demotion and movement. An object has access to it's next and previous 
siblings, and to the root object. The object knows how to save and read
itself to/from a stream.

The main concept behind a TObjectInHierarchy is that it is part of a 
"project" - the Root object defines the "project" attributes. Project
operation will be performed by the Root - these include things like 
saving and reading the hierarchy, communicating with object editors
etc..

THierarchyViewerInterface - An abstract class that defines an interface 
between the object in the hierarchy and the hierarchy viewer. The viewer
has access to the root project, and to all the other objects in the
hierarchy, but sometimes the hierarchy needs to notify the viewer
of changes - such as new objects in the hierarchy etc.. - The 
viewer interface is the intermediate object that is called by the
object hierarchy to implement this.

Why we wrote TObjectInHierarchy:
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HyperAct developed TObjectInHierarchy as part of the eAuthor architecture.
eAuthor is a framework for the creation of template based authoring tools.
The first eAuthor based tool - eAuthor/Catalog Builder is scheduled for
release in March '97, with beta testing starting in January '97.

TObjectInHierarchy is the base of the hierarchy - other objects of interest
in the framework include:

THierarchyViewer - A visual component that automatically knows how to 
display a hierarchy and connect objects to object editors and 
object inspectors. 

TFieldType - base property type.

TObjectWithFields - A TObjectInHierarchy with hidden and "published" 
properties.

TInspectorGrid - An Object inspector that can be used to display, and edit
properties of objects.

TObjectEditor - An object that is used as a visual editor for a 
TObjectWithFields, or as a field (property) editor.

How to contact us:
============================================================================

HyperAct, Inc.
3437 335th St.
West Des Moines,
IA 50266

Internet: rhalevi@hyperact.com
CIS : 76350,333
Web : http://www.hyperact.com/