[immodule-qt] Surrounding text

[Daisuke Kameda]

On Tuesday 07 September 2004 13:05, Anuradha Ratnaweera wrote:
> On Tue, 7 Sep 2004 00:03:41 +0900, Daisuke Kameda <kaminmat at cc.rim.or.jp> 
wrote:
> > > What's the status of surrounding text support in the QT 3 patches?
> >
> > We want to support surrounding text. But nothing is implemented yet.
> > And, Although based on the quantity of changes, probably it will be
> > introduced in Qt4 or after it.
>
> If we are interested in implementing it (not necessarily commiting to
> QT proper) hope you guys will help us getting in to the world of
> qt-immodules!  (I am sure you don't have all the time in the world,
> but an occational tip or an anwer will be sufficient ;-))

Thank you for reply. I want to cooperate with you about 
surrounding text support.


> > - Are there any good material about surrounding text?
> >
> > - Does the code about surrounding text implemented in gtk have
> >   sufficient function?
>
> Let me answer the both question in one:  The only good material about
> surrounding text we found is in GTK.  I think XIM also has something
> like that, but we never could figure out how.  (Yes, I have looked at
> IMDKIT).
>
> Surrounding text in gtk has [at least] two functions.
> gtk_im_context_get_surrounding() gets the surrounding text and the
> present location of the `cursor' in that text, and
> gtk_im_context_delete_surrounding() which allows deleting characters
> (not bytes) around the cursor.  This is sufficiant to do what we need
> to do.
>
> It would have been better if the former function accepted a "max
> offset" kind of parameters, because we don't need all the characters
> in the surrounding.

I have read GTK's code. GTK's surrounding text support is consisting
of retrieve_surrounding signal, delete_surrounding signal, 
gtk_im_context_get_surrounding(), gtk_im_context_set_surrounding() and
gtk_im_context_delete_surrounding(). 

Probably, this design will not be able to be simply transplantable to Qt. 
However, for example, realization of the function will become possible 
by adding IMEvent (IMGetSurrounding and IMDeleteSurrounding) and
QInputContext::getSurrounding().


And, I plan to investigate the usage of it in XIM.


> > - Which country needs surrounding text support?
>
> We are adding Sinhala language support.  Sinhala is the main language
> used in Sri Lanka.  Our project page is http://sinhala.linux.lk .
> Surrounding text is necessary to implement the traditional Wijesekara
> Keyboard and the new national standard being developed based on it.
> We also have a transliterated keymap (already implemented for GTK)
> which again produces different characters based on context.
>
> Of course we _could_ create a keymap, but according to our experience
> and user feedback, usability of a context sensitive input method is
> far far superior.  The main reason is, characters, keystrokes, and
> visual glyphs don't have a one to one relationship.



-- 
Daisuke Kameda <kaminmat at cc.rim.or.jp>