Re: Restoring a List View's position

[Matthew Braid <ptkperl mdb id au>]

Hi all,

2009/3/17 muppet <scott asofyet org>:
> Were you asking for the visible range after having removed the model?

I thought that might be the issue since I was disconnecting the model
to load data and reconnecting afterwards, but the reconnection happens
before the position restore.

> You may need to wait for the adjustment change to take effect.  Try setting
> the new scrollbar positions in an idle handler.  This may result in
> undesirable flicker, in which case, your next idea isn't terribly
> inappropriate.

This seems to have done the trick - even the standard priority seems
to do it with little to no flicker as far as I can tell, and puts it
exactly at the right place. Ta :)
Incidentally I tried a timeout handler as well - still worked, but
there was visible flicker no matter how 'soon' I scheduled it for. In
case someone is searching for some code to help in future, the
following works (although doesn't handle the horizontal scrollbars
obviously):

Glib::Idle->add(sub {
  my $args = shift;
  my ($pos, $list) = @$args;
  my $adj = $list->get_vadjustment;
  return 0 if not defined $adj; ## JIC
  $pos = $adj->upper if $pos > $adj->upper; # In case the list has shrunk since
  $adj->set_value($pos);
  0;
}, [$listposition, $listview]);

> Well, if you want it to look to the user as though the view is just as he
> left it, then simply scrolling a certain row onscreen may not be sufficient.
>  If i understand correctly, when you scroll to the list item, it's somewhat
> random as to where it will be (depends on your parameters).  So, scroll to
> point isn't that bad of a compromise.

True - i forgot that scroll_to_cell doesn't really define where in the
view the cell will be.

2009/3/17 Kevin Ryde <user42 zip com au>:
> > I initially tried using $treeview->get_visible_range and
> > $treeview->scroll_to_cell, but get_visible_range seems to be a little
> > flakey on my system and often aborts with a message about some
> > assertion failing (something != nil I think).
>
> Sounds like a bug.

It probably is - it seems the age of the current (approved) install of
Gtk and perl/Gtk is somewhat ancient. Maybe it would have been better
if I didn't find a solution to force an upgrade :)

MB