Does Morphic support editing of bidirectional text? The java frameworks place a high emphasis on this, and I would like to know if similar support was included in the internationalization of Squeak?
Michael
"Michael Latta" lattam@mac.com asked:
Does Morphic support editing of bidirectional text? The java frameworks place a high emphasis on this, and I would like to know if similar support was included in the internationalization of Squeak?
As nobody else answered this question, I will do it: Squeak does not currently support bidirectional text processing. This is true for both the MVC framework and the Morphic framework. When Smalltalk was created, bidirectional text processing was not an issue at all. Until very recently bidirectionality was also not an issue for Squeak: Squeak used its own fonts that do not support scripts that are written from right to left. Now that we are in the process to add Unicode support to Squeak, we will have to think about BIDI support, too.
Regrettably, bidi support is not an easy thing to implement. The most difficult thing is certainly the support for arabic. For arabic it is not sufficient to simply display glyphs from right to left, you have also to choose the correct presentation forms. Personally I fear that support for arabic presentation forms will further slow down the performance of text display routines, which is of course not desireable.
Greetings, Boris
"Boris Gaertner" Boris.Gaertner@gmx.net wrote:
I fear that support for arabic presentation forms will further slow down the performance of text display routines, which is of course not desireable.
It certainly need not affect performance of 'ordinary' text if the code is written properly. Paragrpah/Editor/etc have no need of paying any attention whatsoever to bidirectional languages - nor indeed to embedded shapes or any other oddities. >IF< you have a case where an embedded shape or variant display rules is needed then a suitable alternate class (maybe a subclass, maybe not) should be swapped in and then you are explicitly accepting the performance cost.
The potential performance improvement possible can be estimated by looking at how fast text display can be in MVC.
tim -- Tim Rowledge, tim@sumeru.stanford.edu, http://sumeru.stanford.edu/tim Useful random insult:- When a thought crosses her mind, it's a long and lonely journey.
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