Thanks for the suggestion. And, oops, on the Window/MainWindow thing. See the corrected version below, still with the shrink problem.

What you suggested is not quite what I'm after, since it unconditionally moves the scroll bar to the bottom of the view anytime a new item is added. I'm trying to move the scroll bar only if it is already at the bottom just before the new item is added. That way, I can be looking around somewhere else with the scroll bar, without it jumping to the bottom everytime another item is added.

So it's an annoyance issue: I want this auto-scrolling, but not while I'm looking somewhere else in the tree view. What I've got works, except when the tree view shrinks. That causes the scroll bar to move slightly off the bottom, mistakenly turning off auto-scrolling.

By the way, I've tried attaching to many different signals, but the tree view internals seem too stale for $tree->get_visible_range(), $tree->scroll_to_cell(), or whatever to work.

Still searching,

Jim

#!/usr/bin/perl

use strict;
use warnings;

use Glib qw(TRUE FALSE);
use Gtk2 -init;

my($win,$tree)=createWin();
Glib::Timeout->add(1000,sub {tickCB($tree)});

$win->show_all();
Gtk2->main();


#
# Creates the widgets in the application.  Returns the main
# window and tree view.
#
sub createWin
{
   my($win,$scroll,$tree,$model);


   $win=new Gtk2::Window();
   $win->set_default_size(250,300);
   $win->signal_connect(destroy => \&Gtk2::main_quit);

   $win->add($scroll=new Gtk2::ScrolledWindow());
   $scroll->add($tree=new Gtk2::TreeView());
   $tree->set_rules_hint(TRUE);

   $tree->insert_column_with_attributes(-1,'Goo',
      new Gtk2::CellRendererText(),text => 0);
   $tree->set_model($model=
      new Gtk2::ListStore('Glib::String'));

   addWord($model) for 0 .. 100;
   showLast($tree);

   return ($win,$tree);
}


#
# Called at regular intervals to add another random "word"
# to the bottom of the tree view.  If the previous word was
# visible beforehand, scrolls the tree view so the new word
# is visible.
#
sub tickCB
{
   my($tree)=@_;
   my($model)=$tree->get_model();
   my($numRows)=$model->iter_n_children(undef);
   my($lastVis)=($tree->get_visible_range())[1];
   my($mustScroll)=$lastVis &&
      $lastVis->get_indices() == $numRows-1;


   addWord($model);
   showLast($tree) if $mustScroll;

   return TRUE;
}


#
# Adds a random "word" to the bottom of the tree view.
#
sub addWord
{
   my($model)=@_;
   my(@cons)=grep !/[aeiou]/,'a' .. 'z';

   $model->set($model->append(),0,
      $cons[rand @cons] . 'oo');
}


#
# Scrolls the tree view so the last row is visible.
#
sub showLast
{
   my($tree)=@_;
   my($numRows)=$tree->get_model()->iter_n_children(undef);

   $tree->scroll_to_cell(
      new Gtk2::TreePath($numRows-1),undef,TRUE,0.0,1.0);
}
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.