sky/engine/bindings/core/v8/DOMWrapperWorld.h

/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
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 * 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.
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 * 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
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#ifndef SKY_ENGINE_BINDINGS_CORE_V8_DOMWRAPPERWORLD_H_
#define SKY_ENGINE_BINDINGS_CORE_V8_DOMWRAPPERWORLD_H_

#include "sky/engine/bindings/core/v8/ScriptState.h"
#include "sky/engine/wtf/HashSet.h"
#include "sky/engine/wtf/MainThread.h"
#include "sky/engine/wtf/PassRefPtr.h"
#include "sky/engine/wtf/RefCounted.h"
#include "sky/engine/wtf/RefPtr.h"
#include "sky/engine/wtf/text/WTFString.h"
#include "v8/include/v8.h"

namespace blink {

class DOMDataStore;
class ExecutionContext;
class ScriptController;

enum FakeWorldMarker {
    MainWorld,
    FakeWorld, // Used by garbage collection and testing, not sure why.
};

// This class represent a collection of DOM wrappers for a specific world.
class DOMWrapperWorld : public RefCounted<DOMWrapperWorld> {
public:
    static PassRefPtr<DOMWrapperWorld> create(FakeWorldMarker);

    ~DOMWrapperWorld();
    void dispose();

    static DOMWrapperWorld& world(v8::Handle<v8::Context> context)
    {
        return ScriptState::from(context)->world();
    }

    static DOMWrapperWorld& current(v8::Isolate* isolate)
    {
        if (isMainThread() && worldOfInitializingWindow) {
            // It's possible that current() is being called while window is being initialized.
            // In order to make current() workable during the initialization phase,
            // we cache the world of the initializing window on worldOfInitializingWindow.
            // If there is no initiazing window, worldOfInitializingWindow is 0.
            return *worldOfInitializingWindow;
        }
        return world(isolate->GetCurrentContext());
    }

    static DOMWrapperWorld& mainWorld();

    bool isMainWorld() const { return !m_isFakeWorld; }

    DOMDataStore& domDataStore() const { return *m_domDataStore; }

    static void setWorldOfInitializingWindow(DOMWrapperWorld* world)
    {
        ASSERT(isMainThread());
        worldOfInitializingWindow = world;
    }
    // FIXME: Remove this method once we fix crbug.com/345014.
    static bool windowIsBeingInitialized() { return !!worldOfInitializingWindow; }

private:
    class DOMObjectHolderBase {
    public:
        DOMObjectHolderBase(v8::Isolate* isolate, v8::Handle<v8::Value> wrapper)
            : m_wrapper(isolate, wrapper)
            , m_world(0)
        {
        }
        virtual ~DOMObjectHolderBase() { }

        DOMWrapperWorld* world() const { return m_world; }
        void setWorld(DOMWrapperWorld* world) { m_world = world; }
        void setWeak(void (*callback)(const v8::WeakCallbackData<v8::Value, DOMObjectHolderBase>&))
        {
            m_wrapper.setWeak(this, callback);
        }

    private:
        ScopedPersistent<v8::Value> m_wrapper;
        DOMWrapperWorld* m_world;
    };

    template<typename T>
    class DOMObjectHolder : public DOMObjectHolderBase {
    public:
        static PassOwnPtr<DOMObjectHolder<T> > create(v8::Isolate* isolate, T* object, v8::Handle<v8::Value> wrapper)
        {
            return adoptPtr(new DOMObjectHolder(isolate, object, wrapper));
        }

    private:
        DOMObjectHolder(v8::Isolate* isolate, T* object, v8::Handle<v8::Value> wrapper)
            : DOMObjectHolderBase(isolate, wrapper)
            , m_object(object)
        {
        }

        OwnPtr<T> m_object;
    };

public:
    template<typename T>
    void registerDOMObjectHolder(v8::Isolate* isolate, T* object, v8::Handle<v8::Value> wrapper)
    {
        registerDOMObjectHolderInternal(DOMObjectHolder<T>::create(isolate, object, wrapper));
    }

private:
    DOMWrapperWorld(FakeWorldMarker);

    static void weakCallbackForDOMObjectHolder(const v8::WeakCallbackData<v8::Value, DOMObjectHolderBase>&);
    void registerDOMObjectHolderInternal(PassOwnPtr<DOMObjectHolderBase>);
    void unregisterDOMObjectHolder(DOMObjectHolderBase*);

    static DOMWrapperWorld* worldOfInitializingWindow;

    bool m_isFakeWorld;
    OwnPtr<DOMDataStore> m_domDataStore;
    HashSet<OwnPtr<DOMObjectHolderBase> > m_domObjectHolders;
};

} // namespace blink

#endif  // SKY_ENGINE_BINDINGS_CORE_V8_DOMWRAPPERWORLD_H_