Re: Scrolling to the row in TreeView when selected?

[muppet <scott asofyet org>]

On Sep 13, 2005, at 4:42 PM, Yu Wang wrote:

> I tried your code, it gives me:
>
> Gtk-CRITICAL **: gtk_tree_selection_get_selected: assertion  
> `selection->type !=
> GTK_SELECTION_MULTIPLE' failed at /home/wangy22/trunk/destcnltr  
> line 670.
>
> I modified it and it works again:
>
>     $treeview->get_selection->signal_connect (changed => sub {
>         my ($selection) = @_;
>         my $path = $selection->get_selected_rows;
>         $selection->get_tree_view->scroll_to_cell ($path) if ($path);
>     });
>
> Any comments?

You didn't mention multiple selection; that changes things.  ;-)

get_selected_rows() returns a *list* of paths.  You're implicitly  
taking one of them, apparently the last.  This isn't always correct.   
Say row 17 is already selected, and the user selects 3; since 17 is  
numerically largest, it is the last value returned by  
get_selected_rows(), and the view will scroll to row 17.

Another way to do it would be to ignore the selection's "changed"  
signal, and put the scroll_to_cell() call after the call to  
select_path(), like this:

  $button->signal_connect (clicked => sub {
      my $path = Gtk2::TreePath->new_from_indices ($spinner- 
>get_value);
      $treeview->get_selection->select_path ($path);
      $treeview->scroll_to_cell ($path);
  });

This has the advantage that the last row selected (by clicking this  
button) is always visible.


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