SelectorEngine.cpp 6.1 KB

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  1. /*
  2. * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
  3. * All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions are met:
  7. *
  8. * 1. Redistributions of source code must retain the above copyright notice, this
  9. * list of conditions and the following disclaimer.
  10. *
  11. * 2. Redistributions in binary form must reproduce the above copyright notice,
  12. * this list of conditions and the following disclaimer in the documentation
  13. * and/or other materials provided with the distribution.
  14. *
  15. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  16. * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  18. * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  19. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  21. * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  22. * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  23. * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24. * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25. */
  26. #include <LibWeb/CSS/SelectorEngine.h>
  27. #include <LibWeb/DOM/AttributeNames.h>
  28. #include <LibWeb/DOM/Document.h>
  29. #include <LibWeb/DOM/Element.h>
  30. #include <LibWeb/DOM/Text.h>
  31. namespace Web {
  32. namespace SelectorEngine {
  33. static bool matches_hover_pseudo_class(const Element& element)
  34. {
  35. auto* hovered_node = element.document().hovered_node();
  36. if (!hovered_node)
  37. return false;
  38. if (&element == hovered_node)
  39. return true;
  40. return element.is_ancestor_of(*hovered_node);
  41. }
  42. bool matches(const Selector::SimpleSelector& component, const Element& element)
  43. {
  44. switch (component.pseudo_class) {
  45. case Selector::SimpleSelector::PseudoClass::None:
  46. break;
  47. case Selector::SimpleSelector::PseudoClass::Link:
  48. if (!element.is_link())
  49. return false;
  50. break;
  51. case Selector::SimpleSelector::PseudoClass::Hover:
  52. if (!matches_hover_pseudo_class(element))
  53. return false;
  54. break;
  55. case Selector::SimpleSelector::PseudoClass::Focus:
  56. // FIXME: Implement matches_focus_pseudo_class(element)
  57. return false;
  58. case Selector::SimpleSelector::PseudoClass::FirstChild:
  59. if (element.previous_element_sibling())
  60. return false;
  61. break;
  62. case Selector::SimpleSelector::PseudoClass::LastChild:
  63. if (element.next_element_sibling())
  64. return false;
  65. break;
  66. case Selector::SimpleSelector::PseudoClass::OnlyChild:
  67. if (element.previous_element_sibling() || element.next_element_sibling())
  68. return false;
  69. break;
  70. case Selector::SimpleSelector::PseudoClass::Empty:
  71. if (element.first_child_of_type<Element>() || element.first_child_of_type<Text>())
  72. return false;
  73. break;
  74. case Selector::SimpleSelector::PseudoClass::Root:
  75. if (!element.is_html_element())
  76. return false;
  77. break;
  78. }
  79. switch (component.attribute_match_type) {
  80. case Selector::SimpleSelector::AttributeMatchType::HasAttribute:
  81. if (!element.has_attribute(component.attribute_name))
  82. return false;
  83. break;
  84. case Selector::SimpleSelector::AttributeMatchType::ExactValueMatch:
  85. if (element.attribute(component.attribute_name) != component.attribute_value)
  86. return false;
  87. break;
  88. default:
  89. break;
  90. }
  91. switch (component.type) {
  92. case Selector::SimpleSelector::Type::Universal:
  93. return true;
  94. case Selector::SimpleSelector::Type::Id:
  95. return component.value == element.attribute(HTML::AttributeNames::id);
  96. case Selector::SimpleSelector::Type::Class:
  97. return element.has_class(component.value);
  98. case Selector::SimpleSelector::Type::TagName:
  99. return component.value == element.tag_name();
  100. default:
  101. ASSERT_NOT_REACHED();
  102. }
  103. }
  104. bool matches(const Selector& selector, int component_list_index, const Element& element)
  105. {
  106. auto& component_list = selector.complex_selectors()[component_list_index];
  107. for (auto& component : component_list.compound_selector) {
  108. if (!matches(component, element))
  109. return false;
  110. }
  111. switch (component_list.relation) {
  112. case Selector::ComplexSelector::Relation::None:
  113. return true;
  114. case Selector::ComplexSelector::Relation::Descendant:
  115. ASSERT(component_list_index != 0);
  116. for (auto* ancestor = element.parent(); ancestor; ancestor = ancestor->parent()) {
  117. if (!is<Element>(*ancestor))
  118. continue;
  119. if (matches(selector, component_list_index - 1, to<Element>(*ancestor)))
  120. return true;
  121. }
  122. return false;
  123. case Selector::ComplexSelector::Relation::ImmediateChild:
  124. ASSERT(component_list_index != 0);
  125. if (!element.parent() || !is<Element>(*element.parent()))
  126. return false;
  127. return matches(selector, component_list_index - 1, to<Element>(*element.parent()));
  128. case Selector::ComplexSelector::Relation::AdjacentSibling:
  129. ASSERT(component_list_index != 0);
  130. if (auto* sibling = element.previous_element_sibling())
  131. return matches(selector, component_list_index - 1, *sibling);
  132. return false;
  133. case Selector::ComplexSelector::Relation::GeneralSibling:
  134. ASSERT(component_list_index != 0);
  135. for (auto* sibling = element.previous_element_sibling(); sibling; sibling = sibling->previous_element_sibling()) {
  136. if (matches(selector, component_list_index - 1, *sibling))
  137. return true;
  138. }
  139. return false;
  140. }
  141. ASSERT_NOT_REACHED();
  142. }
  143. bool matches(const Selector& selector, const Element& element)
  144. {
  145. ASSERT(!selector.complex_selectors().is_empty());
  146. return matches(selector, selector.complex_selectors().size() - 1, element);
  147. }
  148. }
  149. }