[reportlab-users] MediaWiki's "Download as PDF" feature uses ReportLab but has a problem

[Andy Robinson]

On 10 January 2012 16:19, Ziyuan Yao <yaoziyuan at gmail.com> wrote:

>

>

> Actually, ReportLab doesn't need a wordwrap=CJK option. Instead, ReportLab

> can wrap text (Western or CJK or mixed) in a unified manner:

>

> IF there is a whitespace near the page's right margin THEN

>         wrap after that whitespace;

> ELSE IF there is a CJK character near the page's right margin THEN

>         wrap after that CJK character;

> ELSE

>         wrap forcibly at the page's right margin.

>



I understand the principles fully, but I am sorry that we haven't yet
found the time to implement this.  When we launched it was
pre-Unicode.  ReportLab has one major Asian-language commercial
customer, who is quite happy with their output now as they don't mix
languages or have long english technical expressions.  When we first
wrote the package it was before Python's unicode support.  We would
probably also need some support from C code for speed.

If some contributors (e.g. you?) have time to work on this and supply
a better wrapping algorithm, we would be very happy to review code and
migrate everything onto it.

The ideal wrapping algorithm must support
(a) CJK wrapping when detected
(b) hyphenation (for long German words etc), and some sane rules for
breaking long URLs
(c) inline non-text objects, such as equation images used heavily by Wikipedia
(d) support for varying fonts, and maybe even kerning or horizontal
compression, and
(e) right-to-left text for Arabic.

This is not a trivial problem.  We "cheated" badly by having an
English and then a CJK wrapping algorithm which is how we got to the
present position.

I would love to have some more people working on it but sadly it's not
a requirement for current customers and our team is pretty busy these
days...


Best Regards,
-- 
Andy Robinson
Managing Director
ReportLab Europe Ltd.
Thornton House, Thornton Road, Wimbledon, London SW19 4NG, UK
Tel +44-20-8405-6420