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package Whatpm::CSS::Cascade; |
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use strict; |
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|
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require Whatpm::CSS::Parser; ## NOTE: For property definitions. |
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require Whatpm::CSS::SelectorsSerializer; |
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use Scalar::Util qw/refaddr/; |
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|
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## Cascading and value computations |
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|
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sub new ($$) { |
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my $self = bless {style_sheets => []}, shift; |
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$self->{document} = shift; |
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return $self; |
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} # new |
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|
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## NOTE: This version does not support dynamic addition --- style |
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## sheets must be added before any other operation. |
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## NOTE: The $ss argument must be a value that can be interpreted as |
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## an array reference of CSSStyleSheet objects. |
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## NOTE: |type| and |media| attributes are not accounted by this |
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## method (and any others in the class); CSSStyleSheet objects must |
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## be filtered before they are passed to this method. |
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sub add_style_sheets ($$) { |
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my ($self, $ss) = @_; |
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|
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push @{$self->{style_sheets}}, @$ss; |
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} # add_style_sheets |
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|
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## TODO: non-CSS presentation hints |
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## TODO: style="" |
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|
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sub ___associate_rules ($) { |
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my $self = shift; |
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|
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my $selectors_to_elements; |
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|
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for my $sheet (@{$self->{style_sheets}}) { |
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## TODO: @media |
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## TODO: @import |
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## TODO: style sheet sources |
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|
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for my $rule (@{$sheet->css_rules}) { |
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next if $rule->type != 1; # STYLE_RULE |
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|
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my $elements_to_specificity = {}; |
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|
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for my $selector (@{$$rule->{_selectors}}) { |
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my $selector_str = Whatpm::CSS::SelectorsSerializer->serialize_test |
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([$selector]); |
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unless ($selectors_to_elements->{$selector_str}) { |
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$selectors_to_elements->{$selector_str} |
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= $self->{document}->___query_selector_all ([$selector]); |
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} |
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next unless @{$selectors_to_elements->{$selector_str}}; |
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|
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my $selector_specificity |
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= Whatpm::CSS::SelectorsParser->get_selector_specificity |
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($selector); |
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for (@{$selectors_to_elements->{$selector_str}}) { |
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my $current_specificity = $elements_to_specificity->{refaddr $_}; |
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if (not defined $current_specificity or ## "*"-only case. |
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$selector_specificity->[0] > $current_specificity->[0] or |
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$selector_specificity->[1] > $current_specificity->[1] or |
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$selector_specificity->[2] > $current_specificity->[2] or |
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$selector_specificity->[3] > $current_specificity->[3]) { |
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$elements_to_specificity->{refaddr $_} = $selector_specificity; |
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} |
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} |
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} |
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|
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my $sd = $rule->style; |
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for (keys %$elements_to_specificity) { |
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push @{$self->{element_to_sds}->{$_} ||= []}, |
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[$sd, $elements_to_specificity->{$_}]; |
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} |
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} |
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} |
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|
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for my $eid (keys %{$self->{element_to_sds} or {}}) { |
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$self->{element_to_sds}->{$eid} = [sort { |
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$a->[1]->[0] <=> $b->[1]->[0] or |
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$a->[1]->[1] <=> $b->[1]->[1] or |
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$a->[1]->[2] <=> $b->[1]->[2] or |
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$a->[1]->[3] <=> $b->[1]->[3] |
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## NOTE: Perl |sort| is stable. |
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} @{$self->{element_to_sds}->{$eid} or []}]; |
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} |
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} # associate_rules |
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|
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sub get_cascaded_value ($$$) { |
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my ($self, $element, $prop_name) = @_; |
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return undef unless $Whatpm::CSS::Parser::Prop->{$prop_name}; |
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|
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my $key = $Whatpm::CSS::Parser::Prop->{$prop_name}->{key}; |
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return undef unless defined $key; ## Shorthand property or some. |
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|
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my $value; |
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for my $sds (reverse @{$self->{element_to_sds}->{refaddr $element} or []}) { |
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my $vp = ${$sds->[0]}->{$key}; |
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if (defined $vp->[1] and $vp->[1] eq 'important') { |
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return $vp->[0]; |
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} else { |
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$value = $vp->[0] unless defined $value; |
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} |
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} |
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|
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return $value; # might be |undef|. |
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} # get_cascaded_value |
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|
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sub get_specified_value ($$$) { |
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my ($self, $element, $prop_name) = @_; |
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|
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## TODO: Remove {specified_value} caching, once we implement most |
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## of CSS 2.1 properties and confirm that it makes almost non sence |
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## because of its duplication with {computed_value} caching. |
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|
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my $eid = refaddr $element; |
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unless (exists $self->{specified_value}->{$eid}->{$prop_name}) { |
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my $cascaded = $self->get_cascaded_value ($element, $prop_name); |
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$self->{specified_value}->{$eid}->{$prop_name} = $cascaded; |
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|
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unless (defined $cascaded) { |
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my $prop_def = $Whatpm::CSS::Parser::Prop->{$prop_name}; |
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if (defined $prop_def) { |
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if ($prop_def->{inherited}) { |
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my $parent_element = $element->manakai_parent_element; |
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if (defined $parent_element) { |
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$self->{specified_value}->{$eid}->{$prop_name} |
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= $self->get_computed_value ($parent_element, $prop_name); |
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} else { |
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$self->{specified_value}->{$eid}->{$prop_name} |
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= $prop_def->{initial}; |
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} |
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} else { |
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$self->{specified_value}->{$eid}->{$prop_name} |
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= $prop_def->{initial}; |
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} |
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} else { |
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$self->{specified_value}->{$eid}->{$prop_name} = undef; |
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} |
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} |
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} |
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|
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## NOTE: Always |undef| for shorthand properties. |
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|
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return $self->{specified_value}->{$eid}->{$prop_name}; |
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} # get_specified_value |
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|
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sub get_computed_value ($$$) { |
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my ($self, $element, $prop_name) = @_; |
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|
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my $eid = refaddr $element; |
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unless (exists $self->{computed_value}->{$eid}->{$prop_name}) { |
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my $prop_def = $Whatpm::CSS::Parser::Prop->{$prop_name}; |
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if (defined $prop_def) { |
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my $specified = $self->get_specified_value ($element, $prop_name); |
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if (defined $specified and $specified->[0] eq 'INHERIT') { |
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## ISSUE: CSS 2.1 does not say to resolve computed value of the parent. |
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## However, it is necessary for some cases (see |
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## <http://suika.fam.cx/gate/2005/sw/inherit>). In addition, |
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## the initial value is not a computed value for some properties. |
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my $parent_element = $element->manakai_parent_element; |
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if (defined $parent_element) { |
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$specified = $self->get_computed_value ($parent_element, $prop_name); |
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} else { |
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$specified = $prop_def->{compute}->($self, $element, $prop_name, |
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$prop_def->{initial}); |
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} |
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## NOTE: Because of this handling, {compute} codes must be |
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## idempotent. |
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} |
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|
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$self->{computed_value}->{$eid}->{$prop_name} |
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= $prop_def->{compute}->($self, $element, $prop_name, $specified); |
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} else { |
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$self->{computed_value}->{$eid}->{$prop_name} = undef; |
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} |
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} |
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|
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## NOTE: Always |undef| for shorthand properties. |
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|
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return $self->{computed_value}->{$eid}->{$prop_name}; |
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} # get_computed_value |
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|
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1; |
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## $Date: 2008/01/01 15:56:24 $ |
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