Re: Adding context to GtkIMContextIM

[Theppitak Karoonboonyanan <thep links nectec or th>]

On Wed, Oct 24, 2001 at 08:49:13AM -0400, Owen Taylor wrote:
> 
> Theppitak Karoonboonyanan <thep links nectec or th> writes:
> 
> > However, the reconversion is useful for more sophisticated Thai XIM,
> > where invalid sequences can be corrected, instead of just being rejected.
> > (This is supported in most Windows Thai Editions.)
> 
> Can you describe how this works in detail? (From the user's point
> of view.)

The input method must ensure that the input text is in cannonical form.
A basic XIM just filters out key events that would create a non-cannonical
form, without touching the text buffer.

A sophisticated XIM tries to "normalize" the order by editing the
previous cell and managing the input char to be placed eventually.

The cannonical order for a cell is BV?T?, where B is a base char,
V is an above/below vowel/diacritic, and T is a top tone mark/diacritic.

Suppose B = { a, b, c }, V = { p, q, r }, T = { x, y, z }

  (ap)  + x --> apx   // usual appending
  (ap)  + q --> aq    // substitution for same class
  (ax)  + y --> ay    // ..(ditto)..
  (ax)  + p --> apx   // reordering
  (apx) + y --> apy   // substitution for same class
  (apx) + q --> aqx   // ..(ditto)..
  (apx) + b --> apxb  // no substitution for base char, however
  (ap)  + b --> apb   // ..(ditto)..
  (ax)  + b --> axb   // ..(ditto)..

That's all.

Regards,
-Thep.
-- 
Theppitak Karoonboonyanan
Information Research and Development Division, NECTEC
http://www.links.nectec.or.th/~thep/  mailto:theppitak nectec or th