Re: Gtk2::CellRendererText vs TextView right alignment on hebrew text

[muppet <scott asofyet org>]

On Jan 24, 2008, at 11:45 PM, Mitchell Laks wrote:

> On 12:21 Thu 24 Jan     , Mitchell Laks wrote:
> > Hi,
> >
> > I have been using gtk2-perl with hebrew according to the wonderful  
> > Dov Grobgeld tutorial.
> >
> > Now, I am trying to display text with a Gtk2::CellRendererText in a  
> > TreeViewColumn in a TreeView.
> >
> > However I notice that the text is displayed 'left justified' which  
> > is wrong since hebrew is written from right to left.
>
> I love that I can answer my own questions,
> because that means there is  alot of available data to be mined with  
> google!
>
> Ok the answer is
>
>
> $renderer->set_property('xalign',1.0);
>
> where $renderer is the Gtk2::CellRendererText.


I don't think this is really what you want.  That will cause text to  
be right-aligned even if your user is *not* using a right-to-left  
locale.

I just checked gtk/gtkcellrenderertext.c, and indeed, there's this:

      if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
        align = PANGO_ALIGN_RIGHT;
      else
        align = PANGO_ALIGN_LEFT;

      pango_layout_set_alignment (layout, align);

and

          if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
	    *x_offset = (1.0 - cell->xalign) * (cell_area->width - (rect.x +  
rect.width + (2 * cell->xpad)));
          else
	    *x_offset = cell->xalign * (cell_area->width - (rect.x +  
rect.width + (2 * cell->xpad)));

so, provided your locale is being set up properly, this should Just  
Work.

You may be interested in experimenting with some combination of  
Gtk2::Widget::set_direction() and Gtk2::Widget::set_default_direction().

E.g.,

   if (magically_determine_if_locale_is_rtl ()) {
      $toplevel->set_default_direction ('rtl');
   }

My system insists that the "he" locale is not installed, so i can't  
really tell if this works completely.

If nothing really does the trick, you can do

  $renderer->set_property (xalign => 1.0) if $renderer->get_direction  
eq 'rtl';

to avoid breaking ltr users, but, again, i really do think it should  
work automatically, so there's likely a config problem.



> which uses the following code, which I find puzzling:
>
> #Attach a 'renderer_number' value to the renderer.
>            #This can be used to differentiate between renderers
>            #when we have a few renderers which can be edited
>            $renderer->{'renderer_number'} = RENDERER_FIRST_TEXT;
>
> Looks like he is arbitrarily extending the renderer perl base hash  
> for his own nefarious purposes.
> which seem cool.
> Am  I right?


It is intended that you can store whatever you want in the instance  
hash of a Glib::Object.  Now, normal rules of perl OO apply in that if  
you overwrite a key you don't control, you can break stuff.  But, the  
blessed hash references you get back from the bindings themselves  
typically will have the underlying C object attached by magic, so you  
can't break them.



--
So this new album took us quite a while, to get it together, to find a  
title and things like that - and we were travelling quite a bit - we  
made a few sort of gestures in the East, and a few gestures in the  
West, and then we got thrown out because of our gestures - this is  
something that we decided was an apt title for a thing that's called  
'The Song Remains The Same'.
  -- Robert Plant, rambling to introduce a song