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List:       kde-devel
Subject:    unicode support in X11, QT and konsole
From:       Lars Doelle <lars.doelle () on-line ! de>
Date:       1999-08-11 8:32:48
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All,

working on unicode support for konsole, i have investigated
the font and codec situation a little.

These are my findings.

1) X11 has flaws with scalable fonts when it comes to unicode.
     Especially, type 1 fonts (pfa,pfb) do not allow character sets
    beyond 256 codes/glyphs.

2) The the pixel fonts (pcf) can be used with up to 65K different
     codes/glyphs.

3) A QTextCodec cannot be set to QFont (QT does wrong in
     detecting the encoding from raw xlfd names, also).

4) The encoding of the fixed width fonts as used for xterminal
     emulations is not iso8859-1, though it is indicated so in their
     xlfd. The difference is the lowest 32 codes, which contain
     special vt100 glyphs (used e.g. for line drawings)

Consequences:

from 1) No type 1 unicode font can be made.

from 3) No font with an encoding that is unsupported by
              QT can be used (without workarounds).

The problems can be solved by extensions to QT, possibly.

for 1), QPainter::drawText could split the QString into parts
that correspond to a font which character set contains the
codes of interest. Since the PolyText16 request allows to
set fonts, the operation could be implement efficiently.

for 3) here is a method missing in QT, clearly.


Comments, approvals, corrections, anyone?

Lars

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