ladybird/Userland/Libraries/LibWeb/DOM/LiveNodeList.cpp
Shannon Booth 708263790a LibWeb: Implement LiveNodeList::first_matching
This function returns the first element which matches both the filter
for the LiveNodeList collection itself, and a further filter that is
supplied as an argument to this function.
2023-08-26 13:51:18 +02:00

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/*
* Copyright (c) 2021, Luke Wilde <lukew@serenityos.org>
* Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Heap/Heap.h>
#include <LibJS/Runtime/Error.h>
#include <LibWeb/DOM/LiveNodeList.h>
#include <LibWeb/DOM/Node.h>
namespace Web::DOM {
JS::NonnullGCPtr<NodeList> LiveNodeList::create(JS::Realm& realm, Node& root, Scope scope, Function<bool(Node const&)> filter)
{
return realm.heap().allocate<LiveNodeList>(realm, realm, root, scope, move(filter));
}
LiveNodeList::LiveNodeList(JS::Realm& realm, Node& root, Scope scope, Function<bool(Node const&)> filter)
: NodeList(realm)
, m_root(root)
, m_filter(move(filter))
, m_scope(scope)
{
}
LiveNodeList::~LiveNodeList() = default;
void LiveNodeList::visit_edges(Cell::Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(m_root.ptr());
}
JS::MarkedVector<Node*> LiveNodeList::collection() const
{
JS::MarkedVector<Node*> nodes(heap());
if (m_scope == Scope::Descendants) {
m_root->for_each_in_subtree([&](auto& node) {
if (m_filter(node))
nodes.append(const_cast<Node*>(&node));
return IterationDecision::Continue;
});
} else {
m_root->for_each_child([&](auto& node) {
if (m_filter(node))
nodes.append(const_cast<Node*>(&node));
return IterationDecision::Continue;
});
}
return nodes;
}
Node* LiveNodeList::first_matching(Function<bool(Node const&)> const& filter) const
{
Node* matched_node = nullptr;
if (m_scope == Scope::Descendants) {
m_root->for_each_in_subtree([&](auto& node) {
if (m_filter(node) && filter(node)) {
matched_node = const_cast<Node*>(&node);
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
} else {
m_root->for_each_child([&](auto& node) {
if (m_filter(node) && filter(node)) {
matched_node = const_cast<Node*>(&node);
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
}
return matched_node;
}
// https://dom.spec.whatwg.org/#dom-nodelist-length
u32 LiveNodeList::length() const
{
return collection().size();
}
// https://dom.spec.whatwg.org/#dom-nodelist-item
Node const* LiveNodeList::item(u32 index) const
{
// The item(index) method must return the indexth node in the collection. If there is no indexth node in the collection, then the method must return null.
auto nodes = collection();
if (index >= nodes.size())
return nullptr;
return nodes[index];
}
// https://dom.spec.whatwg.org/#ref-for-dfn-supported-property-indices
bool LiveNodeList::is_supported_property_index(u32 index) const
{
// The objects supported property indices are the numbers in the range zero to one less than the number of nodes represented by the collection.
// If there are no such elements, then there are no supported property indices.
return index < length();
}
}