Whatpm/CSS/Cascade.pm

package Whatpm::CSS::Cascade;

require Whatpm::CSS::Parser; ## NOTE: For property definitions.
require Whatpm::CSS::SelectorsSerializer;
use Scalar::Util qw/refaddr/;

## Cascading and value computations

sub new ($$) {
  my $self = bless {style_sheets => []}, shift;
  $self->{document} = shift;
  return $self;
} # new

## NOTE: This version does not support dynamic addition --- style
## sheets must be added before any other operation.
## NOTE: The $ss argument must be a value that can be interpreted as
## an array reference of CSSStyleSheet objects.
## NOTE: |type| and |media| attributes are not accounted by this
## method (and any others in the class); CSSStyleSheet objects must
## be filtered before they are passed to this method.
sub add_style_sheets ($$) {
  my ($self, $ss) = @_;

  push @{$self->{style_sheets}}, @$ss;
} # add_style_sheets

## TODO: non-CSS presentation hints
## TODO: style=""

sub ___associate_rules ($) {
  my $self = shift;

  my $selectors_to_elements;

  for my $sheet (@{$self->{style_sheets}}) {
    ## TODO: @media
    ## TODO: @import
    ## TODO: style sheet sources

    for my $rule (@{$sheet->css_rules}) {
      next if $rule->type != 1; # STYLE_RULE

      my $selectors_str = Whatpm::CSS::SelectorsSerializer->serialize_test
          ($$rule->{_selectors});
      unless ($selectors_to_elements->{$selectors_str}) {
        $selectors_to_elements->{$selectors_str}
            = $self->{document}->___query_selector_all ($$rule->{_selectors});
      }
      
      push @{$self->{element_to_sd}->{refaddr $_} ||= []}, $rule->style
          for @{$selectors_to_elements->{$selectors_str}};
      ## TODO: specificity
    }
  }

} # associate_rules

sub get_cascaded_value ($$$) {
  my ($self, $element, $prop_name) = @_;
  return undef unless $Whatpm::CSS::Parser::Prop->{$prop_name};

  my $key = $Whatpm::CSS::Parser::Prop->{$prop_name}->{key};

  ## TODO: cascading order
  for my $sd (reverse @{$self->{element_to_sd}->{refaddr $element} or []}) {
    my $vp = $$sd->{$key};
    return $vp->[0] if defined $vp;
  }

  return undef;
} # get_cascaded_value


1;
## $Date:$
1	wakaba	1.1	package Whatpm::CSS::Cascade;
2
3			require Whatpm::CSS::Parser; ## NOTE: For property definitions.
4			require Whatpm::CSS::SelectorsSerializer;
5			use Scalar::Util qw/refaddr/;
6
7			## Cascading and value computations
8
9			sub new ($$) {
10			my $self = bless {style_sheets => []}, shift;
11			$self->{document} = shift;
12			return $self;
13			} # new
14
15			## NOTE: This version does not support dynamic addition --- style
16			## sheets must be added before any other operation.
17			## NOTE: The $ss argument must be a value that can be interpreted as
18			## an array reference of CSSStyleSheet objects.
19			## NOTE: \|type\| and \|media\| attributes are not accounted by this
20			## method (and any others in the class); CSSStyleSheet objects must
21			## be filtered before they are passed to this method.
22			sub add_style_sheets ($$) {
23			my ($self, $ss) = @_;
24
25			push @{$self->{style_sheets}}, @$ss;
26			} # add_style_sheets
27
28			## TODO: non-CSS presentation hints
29			## TODO: style=""
30
31			sub ___associate_rules ($) {
32			my $self = shift;
33
34			my $selectors_to_elements;
35
36			for my $sheet (@{$self->{style_sheets}}) {
37			## TODO: @media
38			## TODO: @import
39			## TODO: style sheet sources
40
41			for my $rule (@{$sheet->css_rules}) {
42			next if $rule->type != 1; # STYLE_RULE
43
44			my $selectors_str = Whatpm::CSS::SelectorsSerializer->serialize_test
45			($$rule->{_selectors});
46			unless ($selectors_to_elements->{$selectors_str}) {
47			$selectors_to_elements->{$selectors_str}
48			= $self->{document}->___query_selector_all ($$rule->{_selectors});
49			}
50
51			push @{$self->{element_to_sd}->{refaddr $_} \|\|= []}, $rule->style
52			for @{$selectors_to_elements->{$selectors_str}};
53			## TODO: specificity
54			}
55			}
56
57			} # associate_rules
58
59			sub get_cascaded_value ($$$) {
60			my ($self, $element, $prop_name) = @_;
61			return undef unless $Whatpm::CSS::Parser::Prop->{$prop_name};
62
63			my $key = $Whatpm::CSS::Parser::Prop->{$prop_name}->{key};
64
65			## TODO: cascading order
66			for my $sd (reverse @{$self->{element_to_sd}->{refaddr $element} or []}) {
67			my $vp = $$sd->{$key};
68			return $vp->[0] if defined $vp;
69			}
70
71			return undef;
72			} # get_cascaded_value
73
74
75			1;
76			## $Date:$