problem of split-cursor

[miaocheng <snopy-xj 163 com>]

  I use red hat linux 8.0, the version of XFree86 is 4.0.3 ,  the 
desktop manager is Gnome and Gnome's version is 2.0
  I encounter a problem about split-cursor. Uyghur is one kind of Arbic 
and written from right to left .  the Uyghur's characters are adopted on 
Unicode standard 3.1 and puted in Arabic Presention A , B . When I input 
character of Uyghur in a  GtkEntry or GtkTextBuffer , two cursors appear 
. one is at the left end of line , the other is at the right end of line 
. According to some reference , this is called split-cursor. But this 
don't conform to our tradition . In my zone , when people inputed Uyghur 
, they would like to look at a cursor glittering in character insertion 
position . I put 'gtk-split-cursor = 0' in my /etc/gtk-2.0/gtkrc to 
remove the split-cursor.  When I input Uyghur in a  GtkEntry or 
GtkTextBuffer which contain only one line Uyghur characters, the cursor 
at insertion position of inputed Uyghur character, in the left end of 
line , disappear and the cursor at the other end of line is still 
glittering . the visible cursor is located in position that has not any 
relation with where to insert inputed Uyghur character . So I want to 
make the cursor at insertion position visible and the other cursor 
disappear . In other word , the cursor at the left end of line glitter 
,at the same time the right cursor disappear . Please tell me how to 
realize it . which functions do I modify in Gtk+ widght or Pango  ? 
which library , Gtk's widget , Pango or both, control the cursor show . 
Another question , where I can find speciafications that demonstrate the 
Pango library how to work on the hierarchy of GTK+ in detail and 
relation within Pango functions .