# Copyright (c) 2007 bivio Software, Inc.  All Rights Reserved.
#
# Visit http://www.bivio.biz for more info.
# 
# This library is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation; either version 2.1 of the
# License, or (at your option) any later version.
# 
# This library is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
# 
# You should have received a copy of the GNU Lesser General Public
# License along with this library;  If not, you may get a copy from:
# http://www.opensource.org/licenses/lgpl-license.html
# 
# $Id: NestedList.pm,v 1.1 2007/03/10 23:12:01 nagler Exp $
package Bivio::UI::XHTML::Widget::NestedList;
use strict;
use Bivio::Base 'Bivio::UI::Widget::List';
use Bivio::UI::ViewLanguageAUTOLOAD;

our($VERSION) = sprintf('%d.%02d', q$Revision: 1.1 $ =~ /\d+/g);

sub initialize {
    my($self) = @_;
    my($c) = $self->unsafe_get('columns');
    $self->die(columns => undef, $c, ': must contain exactly one element')
	unless @$c == 1;
    $self->put(_nested_list => Tag(
 	$self->get_or_default(tag => 'ul'),
 	"\n",
	$self->unsafe_get('class'),
    ));
    $self->put(_nested_list_item => Join([
	Tag(
	    $self->get_or_default('item_tag', 'li'),
	    $c->[0],
	    $self->unsafe_get('item_class'),
	),
	"\n",
    ]));
    $self->put(_nested_list_state => my $state = {});
    $self->put(columns => [[\&_render_item, ['node_level'], $c->[0], $self]]);
    return shift->SUPER::initialize(@_);
}

sub render {
    my($self, $source, $buffer) = @_;
    my($t) = $self->render_attr('_nested_list', $source);
    my($state) = $self->get('_nested_list_state');
    $$t =~ /^(.+\n)(\S+)$/s;
    %$state = (
	level => -1,
	list_start => $1,
	list_end => $2,
	count => 0,
    );
    shift->SUPER::render(@_);
    _close(-1, $state, $buffer);
    return;
}

sub _close {
    my($to_level, $state, $buffer) = @_;
    while ($state->{level} > $to_level) {
	$$buffer .= $state->{list_end};
	$state->{level}--;
    }
    return;
}

sub _render_item {
    my($source, $node_level, $value, $self) = @_;
    my($state) = $self->get('_nested_list_state');
    $state->{count}++;
    my($b);
    if ($state->{level} < $node_level) {
	$b .= $state->{list_start};
	$state->{level}++;
    }
    else {
	_close($node_level, $state, \$b);
    }
    $self->render_attr('_nested_list_item', $source, \$b);
    return $b;
}

1;