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LibWeb: Implement CSSRule and CSSStyleDeclaration serialization

There are a handful of FIXME's here, but this seems generally good.
Note that CSS *values* don't get serialized in a spec-compliant way
since we currently rely on StyleValue::to_string() which is ad-hoc.
This commit is contained in:
Andreas Kling 2021-10-01 19:57:45 +02:00
parent c953103d2f
commit 3db847c64a
14 changed files with 461 additions and 9 deletions

View file

@ -18,10 +18,316 @@ CSSStyleRule::~CSSStyleRule()
{
}
// https://drafts.csswg.org/cssom/#dom-cssstylerule-style
CSSStyleDeclaration* CSSStyleRule::style()
{
return m_declaration;
}
static StringView to_string(Selector::SimpleSelector::PseudoElement pseudo_element)
{
switch (pseudo_element) {
case Selector::SimpleSelector::PseudoElement::Before:
return "before"sv;
case Selector::SimpleSelector::PseudoElement::After:
return "after"sv;
case Selector::SimpleSelector::PseudoElement::FirstLine:
return "first-line"sv;
case Selector::SimpleSelector::PseudoElement::FirstLetter:
return "first-letter"sv;
case Selector::SimpleSelector::PseudoElement::None:
break;
}
VERIFY_NOT_REACHED();
}
static StringView to_string(Selector::SimpleSelector::PseudoClass::Type pseudo_class)
{
switch (pseudo_class) {
case Selector::SimpleSelector::PseudoClass::Type::Link:
return "link"sv;
case Selector::SimpleSelector::PseudoClass::Type::Visited:
return "visited"sv;
case Selector::SimpleSelector::PseudoClass::Type::Hover:
return "hover"sv;
case Selector::SimpleSelector::PseudoClass::Type::Focus:
return "focus"sv;
case Selector::SimpleSelector::PseudoClass::Type::FirstChild:
return "first-child"sv;
case Selector::SimpleSelector::PseudoClass::Type::LastChild:
return "last-child"sv;
case Selector::SimpleSelector::PseudoClass::Type::OnlyChild:
return "only-child"sv;
case Selector::SimpleSelector::PseudoClass::Type::Empty:
return "empty"sv;
case Selector::SimpleSelector::PseudoClass::Type::Root:
return "root"sv;
case Selector::SimpleSelector::PseudoClass::Type::FirstOfType:
return "first-of-pseudo_class"sv;
case Selector::SimpleSelector::PseudoClass::Type::LastOfType:
return "last-of-pseudo_class"sv;
case Selector::SimpleSelector::PseudoClass::Type::Disabled:
return "disabled"sv;
case Selector::SimpleSelector::PseudoClass::Type::Enabled:
return "enabled"sv;
case Selector::SimpleSelector::PseudoClass::Type::Checked:
return "checked"sv;
case Selector::SimpleSelector::PseudoClass::Type::Active:
return "active"sv;
case Selector::SimpleSelector::PseudoClass::Type::NthChild:
return "nth-child"sv;
case Selector::SimpleSelector::PseudoClass::Type::NthLastChild:
return "nth-last-child"sv;
case Selector::SimpleSelector::PseudoClass::Type::Not:
return "not"sv;
case Selector::SimpleSelector::PseudoClass::Type::None:
break;
}
VERIFY_NOT_REACHED();
}
static String serialize_a_group_of_selectors(NonnullRefPtrVector<Selector> const&);
// https://drafts.csswg.org/cssom/#serialize-a-simple-selector
static String serialize_a_simple_selector(Selector::SimpleSelector const& simple_selector)
{
StringBuilder builder;
switch (simple_selector.type) {
case Selector::SimpleSelector::Type::TagName:
case Selector::SimpleSelector::Type::Universal:
// FIXME: 1. If the namespace prefix maps to a namespace that is not the default namespace and is not the null namespace (not in a namespace) append the serialization of the namespace prefix as an identifier, followed by a "|" (U+007C) to s.
// FIXME: 2. If the namespace prefix maps to a namespace that is the null namespace (not in a namespace) append "|" (U+007C) to s.
// 3. If this is a type selector append the serialization of the element name as an identifier to s.
if (simple_selector.type == Selector::SimpleSelector::Type::TagName) {
// FIXME: Use the "serialize an identifier" algorithm.
builder.append(simple_selector.value);
}
// 4. If this is a universal selector append "*" (U+002A) to s.
if (simple_selector.type == Selector::SimpleSelector::Type::Universal)
builder.append('*');
break;
case Selector::SimpleSelector::Type::Attribute:
// 1. Append "[" (U+005B) to s.
builder.append('[');
// FIXME: 2. If the namespace prefix maps to a namespace that is not the null namespace (not in a namespace) append the serialization of the namespace prefix as an identifier, followed by a "|" (U+007C) to s.
// 3. Append the serialization of the attribute name as an identifier to s.
// FIXME: Use the "serialize an identifier" algorithm.
builder.append(simple_selector.attribute.name);
// 4. If there is an attribute value specified, append "=", "~=", "|=", "^=", "$=", or "*=" as appropriate (depending on the type of attribute selector),
// followed by the serialization of the attribute value as a string, to s.
if (!simple_selector.attribute.value.is_null()) {
switch (simple_selector.attribute.match_type) {
case Selector::SimpleSelector::Attribute::MatchType::ExactValueMatch:
builder.append("=");
break;
case Selector::SimpleSelector::Attribute::MatchType::ContainsWord:
builder.append("~=");
break;
case Selector::SimpleSelector::Attribute::MatchType::ContainsString:
builder.append("*=");
break;
case Selector::SimpleSelector::Attribute::MatchType::StartsWithSegment:
builder.append("|=");
break;
case Selector::SimpleSelector::Attribute::MatchType::StartsWithString:
builder.append("^=");
break;
case Selector::SimpleSelector::Attribute::MatchType::EndsWithString:
builder.append("$=");
break;
default:
break;
}
}
// FIXME: 5. If the attribute selector has the case-sensitivity flag present, append " i" (U+0020 U+0069) to s.
// 6. Append "]" (U+005D) to s.
builder.append(']');
break;
case Selector::SimpleSelector::Type::Class:
// Append a "." (U+002E), followed by the serialization of the class name as an identifier to s.
builder.append('.');
// FIXME: Use the "serialize an identifier" algorithm.
builder.append(simple_selector.value);
break;
case Selector::SimpleSelector::Type::Id:
// Append a "#" (U+0023), followed by the serialization of the ID as an identifier to s.
builder.append('#');
// FIXME: Use the "serialize an identifier" algorithm.
builder.append(simple_selector.value);
break;
case Selector::SimpleSelector::Type::PseudoClass:
switch (simple_selector.pseudo_class.type) {
case Selector::SimpleSelector::PseudoClass::Type::Link:
case Selector::SimpleSelector::PseudoClass::Type::Visited:
case Selector::SimpleSelector::PseudoClass::Type::Hover:
case Selector::SimpleSelector::PseudoClass::Type::Focus:
case Selector::SimpleSelector::PseudoClass::Type::FirstChild:
case Selector::SimpleSelector::PseudoClass::Type::LastChild:
case Selector::SimpleSelector::PseudoClass::Type::OnlyChild:
case Selector::SimpleSelector::PseudoClass::Type::Empty:
case Selector::SimpleSelector::PseudoClass::Type::Root:
case Selector::SimpleSelector::PseudoClass::Type::FirstOfType:
case Selector::SimpleSelector::PseudoClass::Type::LastOfType:
case Selector::SimpleSelector::PseudoClass::Type::Disabled:
case Selector::SimpleSelector::PseudoClass::Type::Enabled:
case Selector::SimpleSelector::PseudoClass::Type::Checked:
case Selector::SimpleSelector::PseudoClass::Type::Active:
// If the pseudo-class does not accept arguments append ":" (U+003A), followed by the name of the pseudo-class, to s.
builder.append(':');
builder.append(to_string(simple_selector.pseudo_class.type));
break;
case Selector::SimpleSelector::PseudoClass::Type::NthChild:
case Selector::SimpleSelector::PseudoClass::Type::NthLastChild:
case Selector::SimpleSelector::PseudoClass::Type::Not:
// Otherwise, append ":" (U+003A), followed by the name of the pseudo-class, followed by "(" (U+0028),
// followed by the value of the pseudo-class argument(s) determined as per below, followed by ")" (U+0029), to s.
builder.append(':');
builder.append(to_string(simple_selector.pseudo_class.type));
builder.append('(');
if (simple_selector.pseudo_class.type == Selector::SimpleSelector::PseudoClass::Type::NthChild
|| simple_selector.pseudo_class.type == Selector::SimpleSelector::PseudoClass::Type::NthLastChild) {
// FIXME: The result of serializing the value using the rules to serialize an <an+b> value.
TODO();
} else if (simple_selector.pseudo_class.type == Selector::SimpleSelector::PseudoClass::Type::Not) {
// The result of serializing the value using the rules for serializing a group of selectors.
builder.append(serialize_a_group_of_selectors(simple_selector.pseudo_class.not_selector));
}
builder.append(')');
break;
default:
VERIFY_NOT_REACHED();
}
break;
default:
dbgln("FIXME: Unsupported simple selector serialization for type {}", to_underlying(simple_selector.type));
break;
}
return builder.to_string();
}
// https://drafts.csswg.org/cssom/#serialize-a-selector
static String serialize_a_selector(Selector const& selector)
{
StringBuilder builder;
// To serialize a selector let s be the empty string, run the steps below for each part of the chain of the selector, and finally return s:
for (size_t i = 0; i < selector.compound_selectors().size(); ++i) {
auto const& compound_selector = selector.compound_selectors()[i];
// 1. If there is only one simple selector in the compound selectors which is a universal selector, append the result of serializing the universal selector to s.
if (compound_selector.simple_selectors.size() == 1
&& compound_selector.simple_selectors.first().type == Selector::SimpleSelector::Type::Universal) {
builder.append(serialize_a_simple_selector(selector.compound_selectors().first().simple_selectors.first()));
}
// 2. Otherwise, for each simple selector in the compound selectors...
// FIXME: ...that is not a universal selector of which the namespace prefix maps to a namespace that is not the default namespace...
// ...serialize the simple selector and append the result to s.
else {
for (auto& simple_selector : compound_selector.simple_selectors) {
builder.append(serialize_a_simple_selector(simple_selector));
}
}
// 3. If this is not the last part of the chain of the selector append a single SPACE (U+0020),
// followed by the combinator ">", "+", "~", ">>", "||", as appropriate, followed by another
// single SPACE (U+0020) if the combinator was not whitespace, to s.
if (i != selector.compound_selectors().size() - 1) {
builder.append(' ');
switch (compound_selector.combinator) {
case Selector::Combinator::ImmediateChild:
builder.append('>');
break;
case Selector::Combinator::NextSibling:
builder.append('+');
break;
case Selector::Combinator::SubsequentSibling:
builder.append('~');
break;
case Selector::Combinator::Column:
builder.append("||");
break;
default:
break;
}
} else {
// 4. If this is the last part of the chain of the selector and there is a pseudo-element, append "::" followed by the name of the pseudo-element, to s.
// FIXME: This doesn't feel entirely correct. Our model of pseudo-elements seems off.
if (!compound_selector.simple_selectors.is_empty()
&& compound_selector.simple_selectors.first().type == Selector::SimpleSelector::Type::PseudoElement) {
builder.append("::");
builder.append(to_string(compound_selector.simple_selectors.first().pseudo_element));
}
}
}
return builder.to_string();
}
// https://drafts.csswg.org/cssom/#serialize-a-group-of-selectors
static String serialize_a_group_of_selectors(NonnullRefPtrVector<Selector> const& selectors)
{
// To serialize a group of selectors serialize each selector in the group of selectors and then serialize a comma-separated list of these serializations.
StringBuilder builder;
for (auto& selector : selectors)
builder.append(serialize_a_selector(selector));
return builder.to_string();
}
// https://drafts.csswg.org/cssom/#serialize-a-css-rule
String CSSStyleRule::serialized() const
{
StringBuilder builder;
// 1. Let s initially be the result of performing serialize a group of selectors on the rules associated selectors,
// followed by the string " {", i.e., a single SPACE (U+0020), followed by LEFT CURLY BRACKET (U+007B).
builder.append(serialize_a_group_of_selectors(selectors()));
builder.append(" {"sv);
// 2. Let decls be the result of performing serialize a CSS declaration block on the rules associated declarations, or null if there are no such declarations.
auto decls = declaration().serialized();
// FIXME: 3. Let rules be the result of performing serialize a CSS rule on each rule in the rules cssRules list, or null if there are no such rules.
String rules;
// 4. If decls and rules are both null, append " }" to s (i.e. a single SPACE (U+0020) followed by RIGHT CURLY BRACKET (U+007D)) and return s.
if (decls.is_null() && rules.is_null()) {
builder.append(" }"sv);
return builder.to_string();
}
// 5. If rules is null:
if (rules.is_null()) {
// 1. Append a single SPACE (U+0020) to s
builder.append(' ');
// 2. Append decls to s
builder.append(decls);
// 3. Append " }" to s (i.e. a single SPACE (U+0020) followed by RIGHT CURLY BRACKET (U+007D)).
builder.append(" }"sv);
// 4. Return s.
return builder.to_string();
}
// FIXME: 6. Otherwise:
// FIXME: 1. If decls is not null, prepend it to rules.
// FIXME: 2. For each rule in rules:
// FIXME: 1. Append a newline followed by two spaces to s.
// FIXME: 2. Append rule to s.
// FIXME: 3. Append a newline followed by RIGHT CURLY BRACKET (U+007D) to s.
// FIXME: 4. Return s.
TODO();
}
// https://drafts.csswg.org/cssom/#dom-cssstylerule-selectortext
String CSSStyleRule::selector_text() const
{
TODO();
// The selectorText attribute, on getting, must return the result of serializing the associated group of selectors.
return serialized();
}
// https://drafts.csswg.org/cssom/#dom-cssstylerule-selectortext
@ -37,10 +343,4 @@ void CSSStyleRule::set_selector_text(StringView selector_text)
TODO();
}
// https://drafts.csswg.org/cssom/#dom-cssstylerule-style
CSSStyleDeclaration* CSSStyleRule::style()
{
return m_declaration;
}
}