2 * Copyright (C) 2006, 2007, 2008, 2009 Google Inc. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 #ifndef V8NodeFilterCondition_h
32 #define V8NodeFilterCondition_h
34 #include "bindings/v8/ScopedPersistent.h"
35 #include "core/dom/NodeFilterCondition.h"
37 #include "wtf/PassRefPtr.h"
44 // V8NodeFilterCondition maintains a Javascript implemented callback for
45 // filtering Node returned by NodeIterator/TreeWalker.
46 // A NodeFilterCondition is referenced by a NodeFilter, and A NodeFilter is
47 // referenced by a NodeIterator/TreeWalker. As V8NodeFilterCondition maintains
48 // a Javascript callback which may reference Document, we need to avoid circular
49 // reference spanning V8/Blink object space.
50 // To address this issue, V8NodeFilterCondition holds a weak reference to
51 // |m_filter|, the Javascript value, and the whole reference is exposed to V8 to
52 // let V8 GC handle collection of |m_filter|.
54 // NodeIterator ----RefPtr----> NodeFilter ----RefPtr----> NodeFilterCondition
56 // weak | weak | ScopedPersistent(weak)
57 // | RefPtr | RefPtr |
59 // NodeIterator --HiddenValue--> NodeFilter --HiddenValue--> JS Callback
61 class V8NodeFilterCondition FINAL : public NodeFilterCondition {
63 static PassRefPtr<V8NodeFilterCondition> create(v8::Handle<v8::Value> filter, v8::Handle<v8::Object> owner, v8::Isolate* isolate)
65 return adoptRef(new V8NodeFilterCondition(filter, owner, isolate));
68 virtual ~V8NodeFilterCondition();
70 virtual short acceptNode(ScriptState*, Node*) const OVERRIDE;
73 // As the value |filter| is maintained by V8GC, the |owner| which references
74 // V8NodeFilterCondition, usually a wrapper of NodeFilter, is specified here
75 // to hold a strong reference to |filter|.
76 V8NodeFilterCondition(v8::Handle<v8::Value> filter, v8::Handle<v8::Object> owner, v8::Isolate*);
78 static void setWeakCallback(const v8::WeakCallbackData<v8::Value, V8NodeFilterCondition>&);
80 ScopedPersistent<v8::Value> m_filter;
83 } // namespace WebCore
85 #endif // V8NodeFilterCondition_h