Unidraw

Unidraw is a general C++ framework written by John Vlissides for creating custom graphical editing applications. It was implemented using the InterViews library. John Vlissides' thesis Generalized Graphical Object Editing (technical report CSL-TR-90-427, Stanford University, send e-mail request to schulman@shasta.stanford.edu ) describes the basic ideas behind Unidraw; if you are interested look at chapters 1, 3 (skip 3.3), 4 (skip 4.6, 4.7) and 5.1 as an introduction to Unidraw concepts. The InterViews idraw program is a basic figure drawing application that shows many of the capabilities of the Unidraw library.

John Vlissides has authored many books on Design Patterns, and used Unidraw for a lot of the examples. He periodically writes about Unidraw-derived patterns in his C++ Report Pattern Hatching column. Vlissides and Linton published a paper in ACM Transactions on Information Systems called Unidraw: a framework for building domain-specific graphical editors

online copies: unidraw.ps, .gz or ftp://interviews.stanford.edu/pub/papers/unidraw.ps.Z

Unidraw class man pages

Unidraw auf Deutsch.

HotDraw is a similar environment written in Smalltalk.

Pattern Hatching, a book by John Vlissides on usage of design patterns compiled from his column.

A chapter in this book is written by Vlissides about Unidraw.

Basic abstractions:

Components and ComponentViews represent domain-specific data objects and their corresponding graphical views
Commands define operations on components and other objects
Tools support direct manipulation of component views with the mouse
External representations provide for save and restore of components, PostScript rendering, etc.

Structure of a Unidraw application: (thesis page 29)

Unidraw: top level object
Editor: contains tools, commands, viewers
Viewer: displays tree of graphical views
ComponentView: graphical view of a data object
Component: wrapper around primitive data object
Catalog: manage external representations

Other features:

multiple views/viewers
command history undo/redo
tool manipulators and rubberbanding
selection
viewer zoom/pan

Within ivtools and vhclmaps there are several other libraries (and sample programs) layered on top of the basic Unidraw (and idraw) capabilities. Other uses of Unidraw here

ivtools layers

UniIdraw -- librarification of 3.1 idraw

OverlayUnidraw -- generic extensions

ComUnidraw -- command interpreter integration

FrameUnidraw -- multi-frame extensions

GraphUnidraw -- graph/network extensions

DrawServ -- merger of graph and frame layers

vhclmaps layers for building

MapUnidraw -- map feature viewers

DlgUnidraw -- DLG format map viewers

VpfUnidraw -- VPF format map viewers

MapServ -- map feature processing server

UtmUnidraw -- UTM projected viewers

ProjServ -- projected map feature processing servers

ProjUnidraw -- map feature viewers with arbitrary projection

VhclServ -- vehicle state servers

VhclUnidraw -- vehicle state viewers

DemUnidraw -- 3d terrain viewers

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