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 <LibJS/Runtime/Object.h>
10#include <LibWeb/DOM/NodeFilter.h>
11
12namespace Web::DOM {
13
14// https://dom.spec.whatwg.org/#nodeiterator
15class NodeIterator final : public Bindings::PlatformObject {
16 WEB_PLATFORM_OBJECT(NodeIterator, Bindings::PlatformObject);
17
18public:
19 static WebIDL::ExceptionOr<JS::NonnullGCPtr<NodeIterator>> create(Node& root, unsigned what_to_show, JS::GCPtr<NodeFilter>);
20
21 virtual ~NodeIterator() override;
22
23 JS::NonnullGCPtr<Node> root() { return m_root; }
24 JS::NonnullGCPtr<Node> reference_node() { return m_reference.node; }
25 bool pointer_before_reference_node() const { return m_reference.is_before_node; }
26 unsigned what_to_show() const { return m_what_to_show; }
27
28 NodeFilter* filter() { return m_filter.ptr(); }
29
30 JS::ThrowCompletionOr<JS::GCPtr<Node>> next_node();
31 JS::ThrowCompletionOr<JS::GCPtr<Node>> previous_node();
32
33 void detach();
34
35 void run_pre_removing_steps(Node&);
36
37private:
38 explicit NodeIterator(Node& root);
39
40 virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
41 virtual void visit_edges(Cell::Visitor&) override;
42 virtual void finalize() override;
43
44 enum class Direction {
45 Next,
46 Previous,
47 };
48
49 JS::ThrowCompletionOr<JS::GCPtr<Node>> traverse(Direction);
50
51 JS::ThrowCompletionOr<NodeFilter::Result> filter(Node&);
52
53 // https://dom.spec.whatwg.org/#concept-traversal-root
54 JS::NonnullGCPtr<Node> m_root;
55
56 struct NodePointer {
57 JS::NonnullGCPtr<Node> node;
58
59 // https://dom.spec.whatwg.org/#nodeiterator-pointer-before-reference
60 bool is_before_node { true };
61 };
62
63 void run_pre_removing_steps_with_node_pointer(Node&, NodePointer&);
64
65 // https://dom.spec.whatwg.org/#nodeiterator-reference
66 NodePointer m_reference;
67
68 // While traversal is ongoing, we keep track of the current node pointer.
69 // This allows us to adjust it during traversal if calling the filter ends up removing the node from the DOM.
70 Optional<NodePointer> m_traversal_pointer;
71
72 // https://dom.spec.whatwg.org/#concept-traversal-whattoshow
73 unsigned m_what_to_show { 0 };
74
75 // https://dom.spec.whatwg.org/#concept-traversal-filter
76 JS::GCPtr<NodeFilter> m_filter;
77
78 // https://dom.spec.whatwg.org/#concept-traversal-active
79 bool m_active { false };
80};
81
82}