Williams, James P2 james.p2.willi...@lmco.com wrote:
How can I keep my automatic scrolling, even after these kinds of events?
I’ve tried reacting to various signals, but the tree view seems too stale
for $tree-get_visible_range() or $tree-scroll_to_cell() to work.
You might react to size-allocate events, but a slightly different approach
is necessary. Here's a hack around your test code:
Your suggestion was enough to get something running. I had to keep track of
how many items were added, and had to watch for scroll bar changes. As far as
I can tell, the scroll bar stays at the bottom now unless I move it, even if I
resize the window to be shorter. My modified version follows, for reference.
Thanks,
Jim
#!/usr/bin/perl
use strict;
use warnings;
use Glib qw(TRUE FALSE);
use Gtk2 -init;
my($numAdded)=0;
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,$model,$mustScroll);
$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'));
$tree-signal_connect(
size_allocate = sub {sizeCB(\$mustScroll,@_)});
$model-signal_connect(
row_inserted = sub {rowCB(\$mustScroll,$tree,@_)});
$scroll-get_vadjustment()-signal_connect(
value_changed = sub {$numAdded=0});
addWords($model,100);
showLast($tree,\$mustScroll);
return ($win,$tree);
}
#
# Called at regular intervals to add more random words to
# the bottom of the tree view. If the previous word was
# visible beforehand, scrolls the tree view so the new
# words are visible.
#
sub tickCB
{
my($tree)=@_;
addWords($tree-get_model(),100);
return TRUE;
}
#
# Adds random words to the bottom of the tree view.
#
sub addWords
{
my($model,$numAdd)=@_;
my(@cons)=grep !/[aeiou]/,'a' .. 'z';
for (1 .. $numAdd) {
$model-set($model-append(),0,
$cons[rand @cons] . 'oo');
$numAdded++;
}
}
#
# Scrolls the tree view so the last row is visible.
#
sub showLast
{
my($tree,$mustScroll)=@_;
my($numRows)=$tree-get_model()-iter_n_children(undef);
$tree-scroll_to_cell(
new Gtk2::TreePath($numRows-1),undef,TRUE,0.0,1.0);
$$mustScroll=TRUE;
$numAdded=0;
}
#
# Called each time the tree view is resized. This is where
# we correct the scroll bar, moving it to the bottom if
# appropriate.
#
sub sizeCB
{
my($mustScroll,$tree,$rect)=@_;
showLast($tree,$mustScroll) if $$mustScroll;
}
#
# Called each time a row is added to the model.
#
sub rowCB
{
my($mustScroll,$tree,$model,$path,$it)=@_;
my($numRows)=$model-iter_n_children(undef);
my($lastVis);
if ($tree-realized()) {
$lastVis=($tree-get_visible_range())[1];
$$mustScroll=$lastVis
$lastVis-get_indices() == $numRows-2-$numAdded;
} else {
$$mustScroll=TRUE;
}
}
___
gtk-perl-list mailing list
gtk-perl-list@gnome.org
http://mail.gnome.org/mailman/listinfo/gtk-perl-list
