ladybird/Userland/Libraries/LibWeb/DOM/TreeWalker.h
Andreas Kling bfd354492e LibWeb: Put most LibWeb GC objects in type-specific heap blocks
With this change, we now have ~1200 CellAllocators across both LibJS and
LibWeb in a normal WebContent instance.

This gives us a minimum heap size of 4.7 MiB in the scenario where we
only have one cell allocated per type. Of course, in practice there will
be many more of each type, so the effective overhead is quite a bit
smaller than that in practice.

I left a few types unconverted to this mechanism because I got tired of
doing this. :^)
2023-11-19 22:00:48 +01:00

76 lines
2.2 KiB
C++

/*
* Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibWeb/DOM/NodeFilter.h>
namespace Web::DOM {
// https://dom.spec.whatwg.org/#treewalker
class TreeWalker final : public Bindings::PlatformObject {
WEB_PLATFORM_OBJECT(TreeWalker, Bindings::PlatformObject);
JS_DECLARE_ALLOCATOR(TreeWalker);
public:
[[nodiscard]] static JS::NonnullGCPtr<TreeWalker> create(Node& root, unsigned what_to_show, JS::GCPtr<NodeFilter>);
virtual ~TreeWalker() override;
JS::NonnullGCPtr<Node> current_node() const;
void set_current_node(Node&);
JS::ThrowCompletionOr<JS::GCPtr<Node>> parent_node();
JS::ThrowCompletionOr<JS::GCPtr<Node>> first_child();
JS::ThrowCompletionOr<JS::GCPtr<Node>> last_child();
JS::ThrowCompletionOr<JS::GCPtr<Node>> previous_sibling();
JS::ThrowCompletionOr<JS::GCPtr<Node>> next_sibling();
JS::ThrowCompletionOr<JS::GCPtr<Node>> previous_node();
JS::ThrowCompletionOr<JS::GCPtr<Node>> next_node();
JS::NonnullGCPtr<Node> root() { return m_root; }
NodeFilter* filter() { return m_filter.ptr(); }
unsigned what_to_show() const { return m_what_to_show; }
private:
explicit TreeWalker(Node& root);
virtual void initialize(JS::Realm&) override;
virtual void visit_edges(Cell::Visitor&) override;
enum class ChildTraversalType {
First,
Last,
};
JS::ThrowCompletionOr<JS::GCPtr<Node>> traverse_children(ChildTraversalType);
enum class SiblingTraversalType {
Next,
Previous,
};
JS::ThrowCompletionOr<JS::GCPtr<Node>> traverse_siblings(SiblingTraversalType);
JS::ThrowCompletionOr<NodeFilter::Result> filter(Node&);
// https://dom.spec.whatwg.org/#concept-traversal-root
JS::NonnullGCPtr<Node> m_root;
// https://dom.spec.whatwg.org/#treewalker-current
JS::NonnullGCPtr<Node> m_current;
// https://dom.spec.whatwg.org/#concept-traversal-whattoshow
unsigned m_what_to_show { 0 };
// https://dom.spec.whatwg.org/#concept-traversal-filter
JS::GCPtr<NodeFilter> m_filter;
// https://dom.spec.whatwg.org/#concept-traversal-active
bool m_active { false };
};
}