Section 2.5: Stand-alone browsers and viewers


Product:
DynaText
Associated Products:
DynaBase, DynaTag
Developer:
Electronic Book Technologies Inc. (USA)
UK Supplier(s):
Database Publishing Systems Ltd.
Price:
Indexer: n/a, Browser: n/a (a `free' browser is available)
Platforms:
Unix/X-Windows, MS-Windows, Macintosh
Description:
DynaText is an electronic book publishing system that accepts SGML text directly. A DynaText system has two major components: an Indexer that accepts source material in a variety of standard formats, and a Browser that allows users to read, query, and annotate the resulting electronic books over a network or on a stand-alone PC. An electronic book is created by giving the Indexer a collection of SGML files and associated artwork in a variety of formats. The results can be accessed with the Browser from one or more X-Window display platforms on a network, or can be published for stand-alone delivery on a CD-ROM-configured PC.

The Browser unites concepts found in many hypertext systems, full text retrieval engines, outline processors, and WYSIWYG text formatting systems. The Browser allows users to navigate and move through the book (`browse') by clicking on a dynamic table of contents that expands or contracts like many outline processors. Multiple windows may be open simultaneously, each displaying a different view of the document. Individual views are defined by style sheets that control the presentation and visibility of the SGML elements as well as the behaviour for any of the hypertext links that may exist. Tables, figures and footnotes, for example, can be either displayed inline with text or hidden behind icons.

Dynatext provides for annotations and bookmarks. Sections of the books being read may be printed. The system includes a set of template stylesheets for popular DTDs.


Product:
IADS (Interactive Authoring and Display System)
Associated Products:
Developer:
US Army MICOM (DoD CALS initiative)
UK Supplier(s):
available from `ftp.ex.ac.uk'
Price:
Public Domain
Platforms:
MS Windows
Description:
IADS allows users to:

IADS comes with an on-line help system, and advice on how to install.

Assessment:
IADS (Interactive Authoring and Display System) needs 4-8MB of RAM and 10MB of hard disk space, is easy to install and consists of several modules including IADS Author, Style Sheet, and IADS Reader.

The document to be displayed has to be separated into chunks (frames) by the author and each of these frames can be likened to the page of a book.

IADS uses a list of pre-defined terms (file, frame, graphic, button, hotspot, action) and processing instructions (?Assign, ?Display, ?Execute, ?If, ?Play ...) in order to display a document. The processing instructions allow the assigning of values to variables and performing actions based upon the current value of the variables ranging from executing a DOS command to playing a .WAV file.

The IADS Author application can be used to author a document although it is easier to use an SGML specific editor to create the document and then use IADS to incorporate the IADS specific elements and processing instructions.

The IADS Style Sheet application is used to control the formatting of an IADS document and the author associates formatting properties with the SGML tags in the document. The style sheet has a limit of 256 tags that it can define properties for. They can have context sensitive formatting in the sense that formatting can be based upon the parent tag's name. Formatting consists of: indent from left margin; indent from right margin; first line indent; spacing; justification (left, centre, right); tab settings (max of 10); font (typeface, size, style); and colour (foreground and background).

Tables in IADS are actually grids therefore spanning of columns or rows is not allowed and equations have to be incorporated as pictures.

Graphics cannot be positioned anywhere on the screen -- they are all left justified no matter how small the picture is. IADS can only read .BMP, .G4, .IMG or .PCX graphic formats in order to incorporate them as pictures. The Viewimage Author application creates hotspot overlays for embedded illustrations allowing a picture to have multiple hotspots within it.

If the author wishes to display text a separate (popup) window, for example footnotes, the maximum number of characters allowed in that window is 256.

The user interface consists of a menu bar together with a control panel. The menu bar is fixed but the control panel is user definable. This control panel contains a set of buttons providing shortcuts to navigate around the document (next/prev page, etc).

The IADS Reader application can be distributed as a separate package to enable others to read the information provided by the author of the IADS document. The Reader application also contains an in-built (primitive) commenting system that enables readers to send their comments to the author.

IADS, because it is free, has a use in prototyping systems for distribution of electronic documents, and in projects in which cost is a major factor. However, it has many restrictions which mean that it may not be suitable for many applications. Also, as only the executable code is in the public domain and not the source code, and there is no documented API or access to internal functions, it is not possible for the user to create additional functionality in the product to overcome these restrictions.