Re: Another --> Re: GtkMovementStep of GtkTextView

[Owen Taylor <otaylor redhat com>]

Chookij Vanatham <chookij thestork eng Sun COM> writes:

> Hi Roozbeh, Pablo,...
> 
> > Kaixo!
> > 
> > On Mon, May 21, 2001 at 03:44:53PM +0430, Roozbeh Pournader wrote:
> >  
> > > > > Neither do Arabic people like the Backspace after "Lam-Alef" to delete
> > > > > both letters.
> > > > 
> > > > Indeed.
> > > > But what about the vowels and other diacritic marks?
> > > 
> > > It depends. If the base letter with the diacratic makes (or 'composes to'
> > > in Unicode terms) another letter, like one of the characters
> > > U+0622..U+0626, you "may" treat it as a single letter. Otherwise, they
> > > must be treated separate.
> > 
> > Those have also their own keys on Arabic keyboards I think.
> 
> So, I think that, in arabic script, users like to have <backspac> to delete
> the previous key typed. This is the same as Thai/Indic/Korean/Vietnamese...
> One difference in arabic is that those base letter with diacritic
> (U+0622..U+0626) will be treated as a single letter and that is also typed
> by one key stroke. The <backspace> algorithm still works with those letters
> because they have their own codepoints. <backspace> algorithm is just removing
> one codepoint from logical stream...
> For lam+alif case, <backspace> algorithm (if it's just removing one logical
> codepoint before the current cursor) will just remove "alif" first and this
> should satify arabic users as well...., I guess.....

lam+alif is different than, e.g., Thai because while (in Pango
terminology) the two characters form a "cluster", they aren't a single
grapheme.  It is possible to position the cursor between them.  (The
cursor is displayed halfway through the glyph).

Regards,
                                        Owen