[Konsole-devel] Internationalized Text Rendering In Konsole

[Edward H. Trager]

Dear Konsole Development Team,

How much work would it be to get Konsole to render complex text layout
(CTL) scripts like Arabic and Thai correctly (in a UTF-8 locale)?

I suspect that it would not take too much work, since elsewhere in KDE
--i.e., programs like Kwrite and Konqueror, and widgets like the text 
entry and text label widgets-- handle right-to-left scripts like Arabic and 
other complex layout scripts like Thai correctly under a UTF-8 locale.  
So, the Unicode text layout and shaping classes are already present somewhere 
within KDE or QT, but perhaps Konsole is not using them?

The problem with Konsole (I tested version 1.2.3 using KDE 3.1.3 in SuSE 8.2.99 (9.0 beta))
currently is:

-> Arabic is rendered left-to-right without Arabic shaping rules, making
   the text illegible.

-> Thai consonants are rendered correctly, but all of the above-the-letter
   and below-the-letter vowels and tone marks are missing, making the text
   illegible.

The attached .png file shows the problem graphically.

If Konsole is to be a fully internationalized, the program must handle 
CTL scripts correctly.

As an example, on my internationalized KDE desktop, I have a number of links to
URLs where the titles are in non-Latin UTF-8 text.  On the desktop, the labels
are displayed with perfect legibility.  But, when I do something like "ls -l ~/Desktop"
from within Konsole, the ".desktop" file names are displayed illegibly for Arabic and Thai!
For an Arabic- or Thai-speaking user, this would not look good!

(For your consolation, I will note that Gnome-terminal also does not handle these languages
correctly -- its almost the identical situation, since Pango also has shaping modules for
these languages, but I guess they haven't been applied to the terminal application).

- Ed Trager
  Bioinformatics programmer
  Kellogg Eye Center
  University of Michigan
  Ann Arbor, Michigan, USA
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