Source/bindings/v8/ExceptionState.h

/*
 * Copyright (C) 2013 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:
 *
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 * 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
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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
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#ifndef ExceptionState_h
#define ExceptionState_h

#include "bindings/v8/ScopedPersistent.h"
#include "bindings/v8/V8ThrowException.h"
#include "wtf/Noncopyable.h"
#include "wtf/text/WTFString.h"
#include <v8.h>

namespace WebCore {

typedef int ExceptionCode;

class ExceptionState {
    WTF_MAKE_NONCOPYABLE(ExceptionState);
public:
    explicit ExceptionState(v8::Isolate* isolate)
        : m_code(0)
        , m_isolate(isolate) { }

    virtual void throwDOMException(const ExceptionCode&,  const String& message = String());
    virtual void throwTypeError(const String& message = String());

    bool hadException() const { return !m_exception.isEmpty() || m_code; }
    void clearException();

    bool throwIfNeeded()
    {
        if (m_exception.isEmpty()) {
            if (!m_code)
                return false;
            throwDOMException(m_code);
        }

        V8ThrowException::throwError(m_exception.newLocal(m_isolate));
        return true;
    }

    // FIXME: Remove the rest of the public methods/operators once the transition is done.
    typedef void* ExceptionState::*UnspecifiedBoolType;
    operator UnspecifiedBoolType*() const
    {
        return m_code ? reinterpret_cast<UnspecifiedBoolType*>(1) : 0;
    }

    operator ExceptionCode& () { return m_code; }

    ExceptionState& operator=(const ExceptionCode& ec)
    {
        throwDOMException(ec);
        return *this;
    }

protected:
    ExceptionCode m_code;

private:
    void setException(v8::Handle<v8::Value>);

    ScopedPersistent<v8::Value> m_exception;
    v8::Isolate* m_isolate;
};

class NonThrowExceptionState : public ExceptionState {
public:
    NonThrowExceptionState();
    virtual void throwDOMException(const ExceptionCode&, const String& message = String()) OVERRIDE FINAL;
    virtual void throwTypeError(const String& message = String()) OVERRIDE FINAL;
};

} // namespace WebCore

#endif // ExceptionState_h