jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#pragma once
8
9#include <LibWeb/DOM/NodeFilter.h>
10
11namespace Web::DOM {
12
13// https://dom.spec.whatwg.org/#treewalker
14class TreeWalker final : public Bindings::PlatformObject {
15 WEB_PLATFORM_OBJECT(TreeWalker, Bindings::PlatformObject);
16
17public:
18 static WebIDL::ExceptionOr<JS::NonnullGCPtr<TreeWalker>> create(Node& root, unsigned what_to_show, JS::GCPtr<NodeFilter>);
19
20 virtual ~TreeWalker() override;
21
22 JS::NonnullGCPtr<Node> current_node() const;
23 void set_current_node(Node&);
24
25 JS::ThrowCompletionOr<JS::GCPtr<Node>> parent_node();
26 JS::ThrowCompletionOr<JS::GCPtr<Node>> first_child();
27 JS::ThrowCompletionOr<JS::GCPtr<Node>> last_child();
28 JS::ThrowCompletionOr<JS::GCPtr<Node>> previous_sibling();
29 JS::ThrowCompletionOr<JS::GCPtr<Node>> next_sibling();
30 JS::ThrowCompletionOr<JS::GCPtr<Node>> previous_node();
31 JS::ThrowCompletionOr<JS::GCPtr<Node>> next_node();
32
33 JS::NonnullGCPtr<Node> root() { return m_root; }
34
35 NodeFilter* filter() { return m_filter.ptr(); }
36
37 unsigned what_to_show() const { return m_what_to_show; }
38
39private:
40 explicit TreeWalker(Node& root);
41
42 virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
43 virtual void visit_edges(Cell::Visitor&) override;
44
45 enum class ChildTraversalType {
46 First,
47 Last,
48 };
49 JS::ThrowCompletionOr<JS::GCPtr<Node>> traverse_children(ChildTraversalType);
50
51 enum class SiblingTraversalType {
52 Next,
53 Previous,
54 };
55 JS::ThrowCompletionOr<JS::GCPtr<Node>> traverse_siblings(SiblingTraversalType);
56
57 JS::ThrowCompletionOr<NodeFilter::Result> filter(Node&);
58
59 // https://dom.spec.whatwg.org/#concept-traversal-root
60 JS::NonnullGCPtr<Node> m_root;
61
62 // https://dom.spec.whatwg.org/#treewalker-current
63 JS::NonnullGCPtr<Node> m_current;
64
65 // https://dom.spec.whatwg.org/#concept-traversal-whattoshow
66 unsigned m_what_to_show { 0 };
67
68 // https://dom.spec.whatwg.org/#concept-traversal-filter
69 JS::GCPtr<NodeFilter> m_filter;
70
71 // https://dom.spec.whatwg.org/#concept-traversal-active
72 bool m_active { false };
73};
74
75}