| /* |
| * Copyright (C) 2006, 2007, 2008, 2009 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef V8NodeFilterCondition_h |
| #define V8NodeFilterCondition_h |
| |
| #include "bindings/core/v8/ScopedPersistent.h" |
| #include "bindings/core/v8/ScriptState.h" |
| #include "core/dom/NodeFilterCondition.h" |
| #include "platform/heap/Handle.h" |
| #include "wtf/PassRefPtr.h" |
| #include <v8.h> |
| |
| namespace blink { |
| |
| class Node; |
| class ExceptionState; |
| |
| // V8NodeFilterCondition maintains a Javascript implemented callback for |
| // filtering Node returned by NodeIterator/TreeWalker. |
| // A NodeFilterCondition is referenced by a NodeFilter, and A NodeFilter is |
| // referenced by a NodeIterator/TreeWalker. As V8NodeFilterCondition maintains |
| // a Javascript callback which may reference Document, we need to avoid circular |
| // reference spanning V8/Blink object space. |
| // To address this issue, V8NodeFilterCondition holds a weak reference to |
| // |m_filter|, the Javascript value, and the whole reference is exposed to V8 to |
| // let V8 GC handle collection of |m_filter|. |
| // (DOM) |
| // NodeIterator ----RefPtr----> NodeFilter ----RefPtr----> NodeFilterCondition |
| // | ^ | ^ | |
| // weak | weak | ScopedPersistent(weak) |
| // | RefPtr | RefPtr | |
| // v | v | v |
| // NodeIterator --HiddenValue--> NodeFilter --HiddenValue--> JS Callback |
| // (V8) |
| class V8NodeFilterCondition final : public NodeFilterCondition { |
| public: |
| static PassRefPtrWillBeRawPtr<V8NodeFilterCondition> create(v8::Handle<v8::Value> filter, v8::Handle<v8::Object> owner, ScriptState* scriptState) |
| { |
| return adoptRefWillBeNoop(new V8NodeFilterCondition(filter, owner, scriptState)); |
| } |
| |
| virtual ~V8NodeFilterCondition(); |
| |
| virtual short acceptNode(Node*, ExceptionState&) const override; |
| |
| private: |
| // As the value |filter| is maintained by V8GC, the |owner| which references |
| // V8NodeFilterCondition, usually a wrapper of NodeFilter, is specified here |
| // to hold a strong reference to |filter|. |
| V8NodeFilterCondition(v8::Handle<v8::Value> filter, v8::Handle<v8::Object> owner, ScriptState*); |
| |
| static void setWeakCallback(const v8::WeakCallbackData<v8::Value, V8NodeFilterCondition>&); |
| |
| RefPtr<ScriptState> m_scriptState; |
| ScopedPersistent<v8::Value> m_filter; |
| }; |
| |
| } // namespace blink |
| |
| #endif // V8NodeFilterCondition_h |