third_party/WebKit/Source/core/dom/custom/CEReactionsScope.h

// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CEReactionsScope_h
#define CEReactionsScope_h

#include "core/CoreExport.h"
#include "platform/heap/Handle.h"
#include "wtf/Allocator.h"
#include "wtf/Noncopyable.h"
#include "wtf/StdLibExtras.h"

namespace blink {

class CustomElementReaction;
class Element;
class FrameHost;

// https://html.spec.whatwg.org/multipage/scripting.html#cereactions
class CORE_EXPORT CEReactionsScope final {
    STACK_ALLOCATED();
    WTF_MAKE_NONCOPYABLE(CEReactionsScope);
public:
    static CEReactionsScope* current()
    {
        return s_topOfStack;
    }

    CEReactionsScope()
        : m_prev(s_topOfStack)
    {
        s_topOfStack = this;
    }

    ~CEReactionsScope()
    {
        if (m_frameHost.get())
            invokeReactions();
        s_topOfStack = s_topOfStack->m_prev;
    }

    void enqueueToCurrentQueue(Element*, CustomElementReaction*);

private:
    static CEReactionsScope* s_topOfStack;

    void invokeReactions();

    CEReactionsScope* m_prev;
    Member<FrameHost> m_frameHost;
};

} // namespace blink

#endif // CEReactionsScope_h