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/*
* Copyright (C) 2010 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.
*/
/*
This file contains the declaration for CppVariant, a type used by C++ classes
that are to be bound to JavaScript objects.
CppVariant exists primarily as an interface between C++ callers and the
corresponding NPVariant type. CppVariant also provides a number of
convenience constructors and accessors, so that the NPVariantType values
don't need to be exposed, and a destructor to free any memory allocated for
string values.
*/
#ifndef CppVariant_h
#define CppVariant_h
#include "public/WebBindings.h"
#include "webkit/support/webkit_support.h"
#include <string>
#include <wtf/Vector.h>
class CppVariant : public NPVariant {
public:
CppVariant();
~CppVariant();
void setNull();
void set(bool);
void set(int32_t);
void set(double);
// Note that setting a CppVariant to a string value involves copying the
// string data, which must be freed with a call to freeData() when the
// CppVariant is set to a different value or is no longer needed. Normally
// this is handled by the other set() methods and by the destructor.
void set(const char*); // Must be a null-terminated string.
void set(const std::string&);
void set(const NPString&);
void set(const NPVariant&);
// Note that setting a CppVariant to an NPObject involves ref-counting
// the actual object. freeData() should only be called if the CppVariant
// is no longer needed. The other set() methods handle this internally.
// Also, the object's NPClass is expected to be a static object: neither
// the NP runtime nor CppVariant will ever free it.
void set(NPObject*_value);
// These three methods all perform deep copies of any string data. This
// allows local CppVariants to be released by the destructor without
// corrupting their sources. In performance-critical code, or when strings
// are very long, avoid creating new CppVariants.
// In case of NPObject as the data, the copying involves ref-counting
// as opposed to deep-copying. The ref-counting ensures that sources don't
// get corrupted when the copies get destroyed.
void copyToNPVariant(NPVariant* result) const;
CppVariant& operator=(const CppVariant& original);
CppVariant(const CppVariant& original);
// Calls NPN_ReleaseVariantValue, which frees any string data
// held by the object and sets its type to null.
// In case of NPObject, the NPN_ReleaseVariantValue decrements
// the ref-count (releases when ref-count becomes 0)
void freeData();
// Compares this CppVariant's type and value to another's. They must be
// identical in both type and value to be considered equal. For string and
// object types, a deep comparison is performed; that is, the contents of the
// strings, or the classes and refcounts of the objects, must be the same,
// but they need not be the same pointers.
bool isEqual(const CppVariant&) const;
// The value of a CppVariant may be read directly from its NPVariant (but
// should only be set using one of the set() methods above). Although the
// type of a CppVariant is likewise public, it can be accessed through these
// functions rather than directly if a caller wishes to avoid dependence on
// the NPVariantType values.
bool isBool() const { return (type == NPVariantType_Bool); }
bool isInt32() const { return (type == NPVariantType_Int32); }
bool isDouble() const { return (type == NPVariantType_Double); }
bool isNumber() const { return (isInt32() || isDouble()); }
bool isString() const { return (type == NPVariantType_String); }
bool isVoid() const { return (type == NPVariantType_Void); }
bool isNull() const { return (type == NPVariantType_Null); }
bool isEmpty() const { return (isVoid() || isNull()); }
bool isObject() const { return (type == NPVariantType_Object); }
// Converters. The CppVariant must be of a type convertible to these values.
// For example, toInt32() works only if isNumber() is true.
std::string toString() const;
int32_t toInt32() const;
double toDouble() const;
bool toBoolean() const;
// Returns a vector of strings for the specified argument. This is useful
// for converting a JavaScript array of strings into a vector of strings.
Vector<std::string> toStringVector() const;
// Invoke method of the given name on an object with the supplied arguments.
// The first argument should be the object on which the method is to be
// invoked. Returns whether the method was successfully invoked. If the
// method was invoked successfully, any return value is stored in the
// CppVariant specified by result.
bool invoke(const std::string&, const CppVariant* arguments,
uint32_t argumentCount, CppVariant& result) const;
};
#endif // CppVariant_h
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