Source/bindings/v8/ScriptPromise.h

/*
 * Copyright (C) 2013 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.
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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
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

#ifndef ScriptPromise_h
#define ScriptPromise_h

#include "bindings/v8/ScopedPersistent.h"
#include "bindings/v8/ScriptValue.h"
#include "bindings/v8/V8ScriptRunner.h"
#include <v8.h>

namespace WebCore {

class ExecutionContext;

// ScriptPromise is the class for representing Promise values in C++ world.
// ScriptPromise holds a Promise.
// So holding a ScriptPromise as a member variable in DOM object causes
// memory leaks since it has a reference from C++ to V8.
//
class ScriptPromise {
public:
    // Constructs an empty promise.
    ScriptPromise()
        : m_promise()
    {
    }

    explicit ScriptPromise(const ScriptValue& promise)
        : m_promise(promise)
    {
        ASSERT(!m_promise.hasNoValue());
    }

    ScriptPromise(v8::Handle<v8::Value> promise, v8::Isolate* isolate)
        : m_promise(promise, isolate)
    {
        ASSERT(!m_promise.hasNoValue());
    }

    bool isObject() const
    {
        return m_promise.isObject();
    }

    bool isNull() const
    {
        return m_promise.isNull();
    }

    bool isUndefinedOrNull() const
    {
        return m_promise.isUndefined() || m_promise.isNull();
    }

    v8::Handle<v8::Value> v8Value() const
    {
        return m_promise.v8Value();
    }

    bool hasNoValue() const
    {
        return m_promise.hasNoValue();
    }

    void clear()
    {
        m_promise.clear();
    }

    static ScriptPromise createPending();
    static ScriptPromise createPending(ExecutionContext*);

private:
    ScriptValue m_promise;
};

} // namespace WebCore


#endif // ScriptPromise_h