Re: GtkTextMark right gravity

[Darryl Ross <djr dazco com au>]

Havoc Pennington wrote:

> On Wed, Feb 05, 2003 at 02:58:49PM +1100, Darryl Ross wrote:
>  
>
> > I am trying to mark a section of text within a GtkTextBuffer and then 
> > later retrieve the text along with any changes made within the section. 
> > I have done the following:
> >
> >    /* mark the section */
> >    start_mark = gtk_text_buffer_create_mark(buffer, NULL, &iter, TRUE);
> >    gtk_text_buffer_insert(buffer, &iter, "Hello, this is some text", -1);
> >    end_mark = gtk_text_buffer_create_mark(buffer, NULL, &iter, FALSE);
> >    /* here is some more text */   
> >    gtk_text_buffer_insert(buffer, &iter, "some more text", -1);
> >
> >    /* retrieve the section */
> >    gtk_text_buffer_get_iter_at_mark(buffer, &start, start_mark);
> >    gtk_text_buffer_get_iter_at_mark(buffer, &end, end_mark);
> >    text = gtk_text_buffer_get_text(buffer, &start, &end, FALSE);
> >
> > When I get the text the "some more text" text is included if end_mark 
> > has left gravity set to false, but it is not included if end_mark has 
> > left gravity set to true. I want end_mark to be right gravity as I want 
> > insertions at the end of the section to remain within the marked section.
> >
> >    
>
> If end_mark has right gravity and you insert at end_mark, then the
> inserted text should be to the left of end_mark, thus inside your
> marked section.
>
> Is the problem just how to keep "some more text" from being inside the
> section? To do that you probably have to move the end_mark after
> inserting "some more text", or create end_mark after inserting it, or
> something.
Thanks for the help Havoc.

Ahh, now I get it. By putting a mark with right gravity at the end of my 
text, the mark stays to the right of  the next piece of text inserted by 
my code. It's so obvious now :)

Here's my solution, just in case anyone wants to know:

   /* mark the section */
   start_mark = gtk_text_buffer_create_mark(buffer, NULL, &iter, TRUE);
   gtk_text_buffer_insert(buffer, &iter, "Hello, this is some text", -1);
   end_mark_left = gtk_text_buffer_create_mark(buffer, NULL, &iter,  TRUE);
    /* here is some more text */
   gtk_text_buffer_insert(buffer, &iter, "some more text", -1);

   /* now create a mark with right gravity at the end of the section 
(marked by end_mark_left). */
   gtk_text_buffer_get_iter_at_mark(buffer, &end_mark_iter, end_mark_left);
   end_mark = gtk_text_buffer_create_mark(buffer, NULL, &end_mark_iter, 
FALSE);

   /* retrieve the section */
   gtk_text_buffer_get_iter_at_mark(buffer, &start, start_mark);
   gtk_text_buffer_get_iter_at_mark(buffer, &end, end_mark);
   text = gtk_text_buffer_get_text(buffer, &start, &end, FALSE);

--
Darryl Ross
Principal Consultant, Dazco Technology ABN: 58 829 870 455
+61 3 9734 2466 http://www.dazco.com.au