1 files changed, 123 insertions, 0 deletions
diff --git a/chromium/third_party/blink/renderer/core/html/custom/custom_state_set.cc b/chromium/third_party/blink/renderer/core/html/custom/custom_state_set.cc
new file mode 100644
index 00000000000..0a17d3656ef
--- /dev/null
+++ b/chromium/third_party/blink/renderer/core/html/custom/custom_state_set.cc
@@ -0,0 +1,123 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "third_party/blink/renderer/core/html/custom/custom_state_set.h"
+
+#include "third_party/blink/renderer/core/css/css_selector.h"
+#include "third_party/blink/renderer/core/css/parser/css_parser_idioms.h"
+#include "third_party/blink/renderer/core/dom/element.h"
+
+namespace blink {
+
+CustomStateSet::CustomStateSet(Element& element) : element_(element) {}
+
+void CustomStateSet::Trace(Visitor* visitor) const {
+  visitor->Trace(element_);
+  ScriptWrappable::Trace(visitor);
+}
+
+void CustomStateSet::add(const String& value, ExceptionState& exception_state) {
+  // https://wicg.github.io/custom-state-pseudo-class/#dom-customstateset-add
+
+  // 1. If value does not match to <dashed-ident>, then throw a "SyntaxError"
+  // DOMException.
+  if (!value.StartsWith("--")) {
+    exception_state.ThrowDOMException(
+        DOMExceptionCode::kSyntaxError,
+        "The specified value '" + value + "' must start with '--'.");
+    return;
+  }
+  for (wtf_size_t i = 2; i < value.length(); ++i) {
+    if (IsNameCodePoint(value[i]))
+      continue;
+    exception_state.ThrowDOMException(
+        DOMExceptionCode::kSyntaxError,
+        "The specified value '" + value +
+            "' must match to <dashed-ident> production. '" + value[i] +
+            "' is invalid.");
+    return;
+  }
+
+  // 2. Invoke the default add operation, which the setlike<DOMString> would
+  // have if CustomStateSet interface had no add(value) operation, with value
+  // argument.
+  set_.insert(value);
+
+  InvalidateStyle();
+}
+
+uint32_t CustomStateSet::size() const {
+  return set_.size();
+}
+
+void CustomStateSet::clearForBinding(ScriptState*, ExceptionState&) {
+  set_.clear();
+  InvalidateStyle();
+}
+
+bool CustomStateSet::deleteForBinding(ScriptState*,
+                                      const String& value,
+                                      ExceptionState&) {
+  auto iter = set_.find(value);
+  if (iter == set_.cend())
+    return false;
+  set_.erase(iter);
+  InvalidateStyle();
+  return true;
+}
+
+bool CustomStateSet::hasForBinding(ScriptState*,
+                                   const String& value,
+                                   ExceptionState&) const {
+  return Has(value);
+}
+
+bool CustomStateSet::Has(const String& value) const {
+  return set_.Contains(value);
+}
+
+class CustomStateIterationSource : public CustomStateSet::IterationSource {
+ public:
+  explicit CustomStateIterationSource(CustomStateSet& states)
+      : states_(states), iterator_(states.set_.begin()) {}
+
+  void Trace(Visitor* visitor) const override {
+    visitor->Trace(states_);
+    CustomStateSet::IterationSource::Trace(visitor);
+  }
+
+  bool Next(ScriptState*,
+            String& out_key,
+            String& out_value,
+            ExceptionState&) override {
+    if (iterator_ == states_->set_.end())
+      return false;
+    String value = *iterator_;
+    ++iterator_;
+    out_key = value;
+    out_value = value;
+    return true;
+  }
+
+ private:
+  Member<CustomStateSet> states_;
+  LinkedHashSet<String>::const_iterator iterator_;
+};
+
+CustomStateSet::IterationSource* CustomStateSet::StartIteration(
+    ScriptState*,
+    ExceptionState&) {
+  return MakeGarbageCollected<CustomStateIterationSource>(*this);
+}
+
+void CustomStateSet::InvalidateStyle() const {
+  // TOOD(tkent): The following line invalidates all of rulesets with any
+  // custom state pseudo classes though we should invalidate only rulesets
+  // with the updated state ideally. We can improve style resolution
+  // performance in documents with various custom state pseudo classes by
+  // having blink::InvalidationSet for each of states.
+  element_->PseudoStateChanged(CSSSelector::kPseudoState);
+}
+
+}  // namespace blink