/*

 * Copyright (C) 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

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef ScriptState_h

#define ScriptState_h

#include "DOMWrapperWorld.h"

#include <v8.h>

#include <wtf/Noncopyable.h>

#include <wtf/RefCounted.h>

namespace WebCore {

class DOMWrapperWorld;

class Frame;

class Node;

class Page;

class ScriptState : public Noncopyable {

public:

    bool hadException() { return !m_exception.IsEmpty(); }

    void setException(v8::Local<v8::Value> exception)

    {

        m_exception = exception;

    }

    v8::Local<v8::Value> exception() { return m_exception; }

    v8::Local<v8::Context> context() const

    {

        return v8::Local<v8::Context>::New(m_context);

    }

    static ScriptState* forContext(v8::Local<v8::Context>);

    static ScriptState* current();

protected:

    ScriptState() { }

    ~ScriptState();

private:

    friend ScriptState* mainWorldScriptState(Frame*);

    explicit ScriptState(v8::Handle<v8::Context>);

    static void weakReferenceCallback(v8::Persistent<v8::Value> object, void* parameter);

    v8::Local<v8::Value> m_exception;

    v8::Persistent<v8::Context> m_context;

};

class EmptyScriptState : public ScriptState {

public:

    EmptyScriptState() : ScriptState() { }

    ~EmptyScriptState() { }

};

class ScriptStateProtectedPtr : public Noncopyable {

public:

    ScriptStateProtectedPtr() : m_scriptState(0) { }

    ScriptStateProtectedPtr(ScriptState* scriptState) : m_scriptState(scriptState)

    {

        v8::HandleScope handleScope;

        // Keep the context from being GC'ed. ScriptState is guaranteed to be live while the context is live.

        m_context = v8::Persistent<v8::Context>::New(scriptState->context());

    }

    ~ScriptStateProtectedPtr()

    {

        if (!m_context.IsEmpty()) {

            m_context.Dispose();

            m_context.Clear();

        }

    }

    ScriptState* get() { return m_scriptState; }

private:

    ScriptState* m_scriptState;

    v8::Persistent<v8::Context> m_context;

};

ScriptState* mainWorldScriptState(Frame*);

ScriptState* scriptStateFromNode(DOMWrapperWorld*, Node*);

ScriptState* scriptStateFromPage(DOMWrapperWorld*, Page*);

inline DOMWrapperWorld* debuggerWorld() { return mainThreadNormalWorld(); }

inline DOMWrapperWorld* pluginWorld() { return mainThreadNormalWorld(); }

}

#endif // ScriptState_h