[nfbcs] [Fwd: Preparing documents for Braille printing - Announcing Transcribo: a plain text renderer for Docutils]

Thu May 7 13:45:21 UTC 2009

This may be of interest to some of you.  Replies should go to Dr. Leo, who 
appears to be in Germany.

>Date: Thu, 07 May 2009 10:18:39 +0200
>From: Hans Zoebelein <hzoebelein at gmail.com>
>To: blinux-announce at redhat.com
>Subject: [Fwd: Preparing documents for Braille printing - Announcing
>  Transcribo: a plain text renderer for Docutils]
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>         <mailto:blinux-announce-request at redhat.com?subject=subscribe>
>Sender: blinux-announce-bounces at redhat.com
>
>
>
>-------- Original Message --------
>Subject: Preparing documents for Braille printing - Announcing Transcribo: 
>a plain text renderer for Docutils
>Date: Sun, 26 Apr 2009 12:59:32 +0200
>From: Leo <mailto:fhaxbox66 at googlemail.com><fhaxbox66 at googlemail.com>
>Reply-To: <mailto:fhaxbox66 at googlemail.com>fhaxbox66 at googlemail.com, 
>Developing software for blind Linux users 
><mailto:blinux-develop at redhat.com><blinux-develop at redhat.com>
>To: <mailto:blinux-develop at redhat.com><blinux-develop at redhat.com>
>
>
>
>Hi all,
>
>looking for a cross-platform, open-source software preparing structured
>documents for Braille printing, I finally decided to start my own project
>named Transcribo. It is hosted on 
><http://transcribo.berlios.de/>http://transcribo.berlios.de/. It is
>written in the Python programming language and builds on Docutils
>(<http://docutils.sourceforge.net>http://docutils.sourceforge.net). 
>Docutils parses text written in a
>light-weight, easy-to-learn, extensible mark-up language called
>reStructuredText (rst). While rst has many features that make it suitable
>for writing technical documentation, it is general enough to allow authoring
>any kind of structured document. The simplicity and power of
>reStructuredText make it suitable for authoring large documents for Braille
>printing as well. One objective of Transcribo is to distinguish different
>content types in a single document and associate dedicated translators with
>these. Hence, Transcribo easily integrates with third-party software for
>contracted Braille (see e.g. <http://yabt.berlios.de>http://yabt.berlios.de).
>
>  Transcribo consists of two parts:
>- first, a general purpose plain text renderer that is based on frames to
>handle the layout, and ContentManagers responsible for translations, text
>wrapping etc.
>  - second, a writer component for Docutils called rst2txt. It provides the
>bridge between the Docutils raw output and the renderer.
>
>The output of rst2txt is customizable through styles. All this is very
>much pre-alpha, even if the demo scripts show that nested lists and
>enumerations can already be rendered.
>
>I believe that Transcribo's planned features could make it a very powerful
>authoring solution for Braille printing. Apart from the Docutils - rst2txt -
>renderer tool chain, other input formats such as odf, rtf etc. are
>conceivable if a good soul wrote suitable frontends for the renderer.
>Clearly, all this requires really really a lot of work which I can hardly do
>alone due to many other commitments.
>
>See a more detailed description including all the links below. Any
>feedback and help is warmly welcomed. Feel free to join the mailing list.
>The source code can be obtained by checking out the Mercurial repository.
>
>Regards
>
>Leo
>
>
>
>
>Transcribo - a plain text rendering library written in Python
>=================================================================
>
>Project home: <http://transcribo.berlios.de/>http://transcribo.berlios.de/
>
>Mercurial repository: 
><http://hg.berlios.de/repos/transcribo/>http://hg.berlios.de/repos/transcribo/
>
>Mailing-List: <mailto:transcribo-dev at berlios.de>transcribo-dev at berlios.de
>
>Version: 0.1 (experimental)
>
>Author: Dr. Leo <mailto:dr-leo at users.berlios.de><dr-leo at users.berlios.de>
>
>License: GPL 
>(<http://www.opensource.org/licenses/gpl-license.html>http://www.opensource.org/licenses/gpl-license.html)
>
>(c) 2009 Dr. leo
>
>
>
>
>1. Introduction
>=================
>
>Transcribo is a pure Python library to render input from various
>sources as plain unicode text. It currently
>consists of two subpackages:
>
>1.1 rst2txt
>--------------
>
>In combination with the renderer, this will be a Writer component for
>Docutils (<http://docutils.sourceforge.net/>http://docutils.sourceforge.net/).
>Once finished, it will allow to render
>reStructuredText files as plain text. At the same time it demonstrates
>how the renderer (see below) can be
>used. rst2txt roughly maps the nodes of the Docutils doctree to Frame
>instances that form a fram tree. However, the frame tree
>has a somewhat different structure than the docutils doc tree as frames do
>not
>necessarily reflect the document structure. E.g., sections are not
>rendered as parent frames of the section content,
>but at the same level.
>
>The rst2txt package is heavily under construction. Currently, the following
>node types are supported:
>
>document, title, section, paragraph, text, bullet_list,
>enumerated_list, list_item
>
>
>1.2 The renderer
>-------------------------
>
>The renderer is the core of Transcribo. It is premised on an almost
>complete abstraction of layout and content.
>
>*   The key concept to achieve simple yet
>     powerful layout capabilities is the Frame class. Each Frame
>instance represents a
>     rectangular area within the final output. Its position and size
>are determined dynamically
>     relative to other frames during the rendering process. Frames can be
>nested.
>     The RootFrame instance controls the rendering process and assembles the
>line
>     snippets rendered by each frame to form complete text lines. This allows
>     things like multiple columns, nested enumerations etc. In future
>versions,
>     the RootFrame will also control pagination features.
>
>*   Content: Leafs of the tree of Frame instances store the actual
>content within a
>     content.ContentManager instance which, in turn, may store various
>content elements such as
>     text, mathematical expressions, MusicXML etc. Currently, only
>GenericText is supported.
>     More precisely, each leaf Frame must have a ContentManager
>instance which controls the
>     rendering of the content it contains. Each content element is
>rendered separately.
>     A special feature is the possibility to attach a translator instance to
>each
>     content object as well as to the ContentManager. This feature is
>required,
>     in particular, for Braille translation. The ContentManager is also
>responsible
>     for wrapping and hyphenating the content, if required.
>
>All aforementioned features are highly configurable through
>dictionaries passed to the
>constructors.
>
>
>2. the Frame API
>======================
>
>(to be completed; meanwhile please see the documented sources and the
>test.py script)
>
>
>3. The ContentManager API
>==============================
>
>(to be completed; meanwhile please see the documented sources and the
>test.py script)
>
>
>
>4. Testing
>==============
>
>The test subdirectory contains two test scripts that should work out of the
>box:
>
>* test.py: demonstrates the renderer API by rendering a nested enumeration.
>* rst2txt.py is a command line tool. A demo text file shows some of
>the features of the rst2txt writer.
>
>
>
>5. Contributing
>==================
>
>Development is in an early stage. Any help is very much appreciated.
>Feel free to join the mailing
>list, check out the Mercurial repository and start coding,
>
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>

Lloyd Rasmussen, Senior Project Engineer, Engineering Section
National Library Service for the Blind and Physically Handicapped
Library of Congress    (202) 707-0535   <http://www.loc.gov/nls>
HOME:  <http://lras.home.sprynet.com>
The opinions expressed here are my own and do not necessarily represent 
those of NLS.