Selector.h 11 KB

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  1. /*
  2. * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
  3. * Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>
  4. *
  5. * SPDX-License-Identifier: BSD-2-Clause
  6. */
  7. #pragma once
  8. #include <AK/FlyString.h>
  9. #include <AK/RefCounted.h>
  10. #include <AK/String.h>
  11. #include <AK/Vector.h>
  12. namespace Web::CSS {
  13. using SelectorList = Vector<NonnullRefPtr<class Selector>>;
  14. // This is a <complex-selector> in the spec. https://www.w3.org/TR/selectors-4/#complex
  15. class Selector : public RefCounted<Selector> {
  16. public:
  17. enum class PseudoElement {
  18. Before,
  19. After,
  20. FirstLine,
  21. FirstLetter,
  22. Marker,
  23. ProgressValue,
  24. ProgressBar,
  25. Placeholder,
  26. Selection,
  27. // Keep this last.
  28. PseudoElementCount,
  29. };
  30. struct SimpleSelector {
  31. enum class Type {
  32. Universal,
  33. TagName,
  34. Id,
  35. Class,
  36. Attribute,
  37. PseudoClass,
  38. PseudoElement,
  39. };
  40. struct ANPlusBPattern {
  41. int step_size { 0 }; // "A"
  42. int offset = { 0 }; // "B"
  43. // https://www.w3.org/TR/css-syntax-3/#serializing-anb
  44. ErrorOr<String> serialize() const
  45. {
  46. // 1. If A is zero, return the serialization of B.
  47. if (step_size == 0) {
  48. return String::formatted("{}", offset);
  49. }
  50. // 2. Otherwise, let result initially be an empty string.
  51. StringBuilder result;
  52. // 3.
  53. // - A is 1: Append "n" to result.
  54. if (step_size == 1)
  55. TRY(result.try_append('n'));
  56. // - A is -1: Append "-n" to result.
  57. else if (step_size == -1)
  58. TRY(result.try_append("-n"sv));
  59. // - A is non-zero: Serialize A and append it to result, then append "n" to result.
  60. else if (step_size != 0)
  61. TRY(result.try_appendff("{}n", step_size));
  62. // 4.
  63. // - B is greater than zero: Append "+" to result, then append the serialization of B to result.
  64. if (offset > 0)
  65. TRY(result.try_appendff("+{}", offset));
  66. // - B is less than zero: Append the serialization of B to result.
  67. if (offset < 0)
  68. TRY(result.try_appendff("{}", offset));
  69. // 5. Return result.
  70. return result.to_string();
  71. }
  72. };
  73. struct PseudoClass {
  74. enum class Type {
  75. Link,
  76. Visited,
  77. Hover,
  78. Focus,
  79. FocusWithin,
  80. FirstChild,
  81. LastChild,
  82. OnlyChild,
  83. NthChild,
  84. NthLastChild,
  85. Empty,
  86. Root,
  87. Host,
  88. FirstOfType,
  89. LastOfType,
  90. OnlyOfType,
  91. NthOfType,
  92. NthLastOfType,
  93. Disabled,
  94. Enabled,
  95. Checked,
  96. Indeterminate,
  97. Is,
  98. Not,
  99. Where,
  100. Active,
  101. Lang,
  102. Scope,
  103. Defined,
  104. Playing,
  105. Paused,
  106. Seeking,
  107. };
  108. Type type;
  109. // FIXME: We don't need this field on every single SimpleSelector, but it's also annoying to malloc it somewhere.
  110. // Only used when "pseudo_class" is "NthChild" or "NthLastChild".
  111. ANPlusBPattern nth_child_pattern {};
  112. SelectorList argument_selector_list {};
  113. // Used for :lang(en-gb,dk)
  114. Vector<FlyString> languages {};
  115. };
  116. struct Attribute {
  117. enum class MatchType {
  118. HasAttribute,
  119. ExactValueMatch,
  120. ContainsWord, // [att~=val]
  121. ContainsString, // [att*=val]
  122. StartsWithSegment, // [att|=val]
  123. StartsWithString, // [att^=val]
  124. EndsWithString, // [att$=val]
  125. };
  126. enum class CaseType {
  127. DefaultMatch,
  128. CaseSensitiveMatch,
  129. CaseInsensitiveMatch,
  130. };
  131. MatchType match_type;
  132. FlyString name {};
  133. String value {};
  134. CaseType case_type;
  135. };
  136. struct Name {
  137. Name(FlyString n)
  138. : name(move(n))
  139. , lowercase_name(name.to_string().to_lowercase().release_value_but_fixme_should_propagate_errors())
  140. {
  141. }
  142. FlyString name;
  143. FlyString lowercase_name;
  144. };
  145. Type type;
  146. Variant<Empty, Attribute, PseudoClass, PseudoElement, Name> value {};
  147. Attribute const& attribute() const { return value.get<Attribute>(); }
  148. Attribute& attribute() { return value.get<Attribute>(); }
  149. PseudoClass const& pseudo_class() const { return value.get<PseudoClass>(); }
  150. PseudoClass& pseudo_class() { return value.get<PseudoClass>(); }
  151. PseudoElement const& pseudo_element() const { return value.get<PseudoElement>(); }
  152. PseudoElement& pseudo_element() { return value.get<PseudoElement>(); }
  153. FlyString const& name() const { return value.get<Name>().name; }
  154. FlyString& name() { return value.get<Name>().name; }
  155. FlyString const& lowercase_name() const { return value.get<Name>().lowercase_name; }
  156. FlyString& lowercase_name() { return value.get<Name>().lowercase_name; }
  157. ErrorOr<String> serialize() const;
  158. };
  159. enum class Combinator {
  160. None,
  161. ImmediateChild, // >
  162. Descendant, // <whitespace>
  163. NextSibling, // +
  164. SubsequentSibling, // ~
  165. Column, // ||
  166. };
  167. struct CompoundSelector {
  168. // Spec-wise, the <combinator> is not part of a <compound-selector>,
  169. // but it is more understandable to put them together.
  170. Combinator combinator { Combinator::None };
  171. Vector<SimpleSelector> simple_selectors;
  172. };
  173. static NonnullRefPtr<Selector> create(Vector<CompoundSelector>&& compound_selectors)
  174. {
  175. return adopt_ref(*new Selector(move(compound_selectors)));
  176. }
  177. ~Selector() = default;
  178. Vector<CompoundSelector> const& compound_selectors() const { return m_compound_selectors; }
  179. Optional<PseudoElement> pseudo_element() const { return m_pseudo_element; }
  180. u32 specificity() const;
  181. ErrorOr<String> serialize() const;
  182. private:
  183. explicit Selector(Vector<CompoundSelector>&&);
  184. Vector<CompoundSelector> m_compound_selectors;
  185. mutable Optional<u32> m_specificity;
  186. Optional<Selector::PseudoElement> m_pseudo_element;
  187. };
  188. constexpr StringView pseudo_element_name(Selector::PseudoElement pseudo_element)
  189. {
  190. switch (pseudo_element) {
  191. case Selector::PseudoElement::Before:
  192. return "before"sv;
  193. case Selector::PseudoElement::After:
  194. return "after"sv;
  195. case Selector::PseudoElement::FirstLine:
  196. return "first-line"sv;
  197. case Selector::PseudoElement::FirstLetter:
  198. return "first-letter"sv;
  199. case Selector::PseudoElement::Marker:
  200. return "marker"sv;
  201. case Selector::PseudoElement::ProgressBar:
  202. return "-webkit-progress-bar"sv;
  203. case Selector::PseudoElement::ProgressValue:
  204. return "-webkit-progress-value"sv;
  205. case Selector::PseudoElement::Placeholder:
  206. return "placeholder"sv;
  207. case Selector::PseudoElement::Selection:
  208. return "selection"sv;
  209. case Selector::PseudoElement::PseudoElementCount:
  210. break;
  211. }
  212. VERIFY_NOT_REACHED();
  213. }
  214. Optional<Selector::PseudoElement> pseudo_element_from_string(StringView);
  215. constexpr StringView pseudo_class_name(Selector::SimpleSelector::PseudoClass::Type pseudo_class)
  216. {
  217. switch (pseudo_class) {
  218. case Selector::SimpleSelector::PseudoClass::Type::Link:
  219. return "link"sv;
  220. case Selector::SimpleSelector::PseudoClass::Type::Visited:
  221. return "visited"sv;
  222. case Selector::SimpleSelector::PseudoClass::Type::Hover:
  223. return "hover"sv;
  224. case Selector::SimpleSelector::PseudoClass::Type::Focus:
  225. return "focus"sv;
  226. case Selector::SimpleSelector::PseudoClass::Type::FocusWithin:
  227. return "focus-within"sv;
  228. case Selector::SimpleSelector::PseudoClass::Type::FirstChild:
  229. return "first-child"sv;
  230. case Selector::SimpleSelector::PseudoClass::Type::LastChild:
  231. return "last-child"sv;
  232. case Selector::SimpleSelector::PseudoClass::Type::OnlyChild:
  233. return "only-child"sv;
  234. case Selector::SimpleSelector::PseudoClass::Type::Empty:
  235. return "empty"sv;
  236. case Selector::SimpleSelector::PseudoClass::Type::Root:
  237. return "root"sv;
  238. case Selector::SimpleSelector::PseudoClass::Type::Host:
  239. return "host"sv;
  240. case Selector::SimpleSelector::PseudoClass::Type::FirstOfType:
  241. return "first-of-type"sv;
  242. case Selector::SimpleSelector::PseudoClass::Type::LastOfType:
  243. return "last-of-type"sv;
  244. case Selector::SimpleSelector::PseudoClass::Type::OnlyOfType:
  245. return "only-of-type"sv;
  246. case Selector::SimpleSelector::PseudoClass::Type::NthOfType:
  247. return "nth-of-type"sv;
  248. case Selector::SimpleSelector::PseudoClass::Type::NthLastOfType:
  249. return "nth-last-of-type"sv;
  250. case Selector::SimpleSelector::PseudoClass::Type::Disabled:
  251. return "disabled"sv;
  252. case Selector::SimpleSelector::PseudoClass::Type::Enabled:
  253. return "enabled"sv;
  254. case Selector::SimpleSelector::PseudoClass::Type::Checked:
  255. return "checked"sv;
  256. case Selector::SimpleSelector::PseudoClass::Type::Indeterminate:
  257. return "indeterminate"sv;
  258. case Selector::SimpleSelector::PseudoClass::Type::Active:
  259. return "active"sv;
  260. case Selector::SimpleSelector::PseudoClass::Type::NthChild:
  261. return "nth-child"sv;
  262. case Selector::SimpleSelector::PseudoClass::Type::NthLastChild:
  263. return "nth-last-child"sv;
  264. case Selector::SimpleSelector::PseudoClass::Type::Is:
  265. return "is"sv;
  266. case Selector::SimpleSelector::PseudoClass::Type::Not:
  267. return "not"sv;
  268. case Selector::SimpleSelector::PseudoClass::Type::Where:
  269. return "where"sv;
  270. case Selector::SimpleSelector::PseudoClass::Type::Lang:
  271. return "lang"sv;
  272. case Selector::SimpleSelector::PseudoClass::Type::Scope:
  273. return "scope"sv;
  274. case Selector::SimpleSelector::PseudoClass::Type::Defined:
  275. return "defined"sv;
  276. case Selector::SimpleSelector::PseudoClass::Type::Playing:
  277. return "playing"sv;
  278. case Selector::SimpleSelector::PseudoClass::Type::Paused:
  279. return "paused"sv;
  280. case Selector::SimpleSelector::PseudoClass::Type::Seeking:
  281. return "seeking"sv;
  282. }
  283. VERIFY_NOT_REACHED();
  284. }
  285. ErrorOr<String> serialize_a_group_of_selectors(Vector<NonnullRefPtr<Selector>> const& selectors);
  286. }
  287. namespace AK {
  288. template<>
  289. struct Formatter<Web::CSS::Selector> : Formatter<StringView> {
  290. ErrorOr<void> format(FormatBuilder& builder, Web::CSS::Selector const& selector)
  291. {
  292. return Formatter<StringView>::format(builder, TRY(selector.serialize()));
  293. }
  294. };
  295. }