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	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	## $Date:$