1 /*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 * Copyright (C) 2000 Frederik Holljen (frederik.holljen@hig.no)
4 * Copyright (C) 2001 Peter Kelly (pmk@post.com)
5 * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
6 * Copyright (C) 2004, 2008 Apple Inc. All rights reserved.
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public License
19 * along with this library; see the file COPYING.LIB. If not, write to
20 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
22 *
23 */
24
25 #include "third_party/blink/renderer/core/dom/node_iterator_base.h"
26
27 #include "third_party/blink/renderer/bindings/core/v8/v8_node_filter.h"
28 #include "third_party/blink/renderer/core/dom/node.h"
29 #include "third_party/blink/renderer/core/execution_context/execution_context.h"
30 #include "third_party/blink/renderer/core/frame/web_feature.h"
31 #include "third_party/blink/renderer/platform/bindings/exception_state.h"
32 #include "third_party/blink/renderer/platform/instrumentation/use_counter.h"
33
34 namespace blink {
35
NodeIteratorBase(Node * root_node,unsigned what_to_show,V8NodeFilter * node_filter)36 NodeIteratorBase::NodeIteratorBase(Node* root_node,
37 unsigned what_to_show,
38 V8NodeFilter* node_filter)
39 : root_(root_node), what_to_show_(what_to_show), filter_(node_filter) {}
40
AcceptNode(Node * node,ExceptionState & exception_state)41 unsigned NodeIteratorBase::AcceptNode(Node* node,
42 ExceptionState& exception_state) {
43 // DOM 6. Traversal
44 // https://dom.spec.whatwg.org/#traversal
45 // Each NodeIterator and TreeWalker object has an associated active flag to
46 // avoid recursive invocations.
47 if (active_flag_) {
48 // 1. If the active flag is set, then throw an "InvalidStateError"
49 // DOMException.
50 exception_state.ThrowDOMException(DOMExceptionCode::kInvalidStateError,
51 "Filter function can't be recursive");
52 return V8NodeFilter::FILTER_REJECT;
53 }
54
55 // 2. Let n be node’s nodeType attribute value minus 1.
56 // 3. If the nth bit (where 0 is the least significant bit) of whatToShow is
57 // not set, then return FILTER_SKIP.
58 //
59 // The bit twiddling here is done to map DOM node types, which are given as
60 // integers from 1 through 14, to whatToShow bit masks.
61 if (!(((1 << (node->getNodeType() - 1)) & what_to_show_)))
62 return V8NodeFilter::FILTER_SKIP;
63
64 // 4. If filter is null, then return FILTER_ACCEPT.
65 if (!filter_)
66 return V8NodeFilter::FILTER_ACCEPT;
67
68 // 5. Set the active flag.
69 base::AutoReset<bool> set_active_flag(&active_flag_, true);
70
71 // 6. Let result be the return value of call a user object’s operation with
72 // filter, "acceptNode", and « node ». If this throws an exception, then unset
73 // the active flag and rethrow the exception.
74 v8::TryCatch try_catch(filter_->GetIsolate());
75 uint16_t result = 0;
76 if (!filter_->acceptNode(nullptr, node).To(&result)) {
77 exception_state.RethrowV8Exception(try_catch.Exception());
78 return 0;
79 }
80
81 UseCounter::Count(
82 ExecutionContext::From(filter_->CallbackRelevantScriptState()),
83 filter_->IsCallbackObjectCallableForNodeIteratorBase()
84 ? WebFeature::kNodeFilterIsFunction
85 : WebFeature::kNodeFilterIsObject);
86
87 // 7. Unset the active flag.
88 // 8. Return result.
89 return result;
90 }
91
Trace(Visitor * visitor)92 void NodeIteratorBase::Trace(Visitor* visitor) {
93 visitor->Trace(root_);
94 visitor->Trace(filter_);
95 }
96
97 } // namespace blink
98