converter.h

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//
// Copyright 2016 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
//    and its affiliates, except as required to comply with Section 4(c) of
//    the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
#ifndef PXR_BASE_JS_CONVERTER_H
#define PXR_BASE_JS_CONVERTER_H


#include "pxr/pxr.h"
#include "pxr/base/js/value.h"
#include "pxr/base/tf/diagnostic.h"

PXR_NAMESPACE_OPEN_SCOPE

// Converts a \c JsValue \p value holding an \c int value to a \c ValueType
// holding an \c int64_t.
template <class ValueType, class MapType, bool UseInt64 = true>
struct Js_ValueToInt {
    static ValueType Apply(const JsValue& value) {
        return value.IsUInt64() ?
            ValueType(value.GetUInt64()) : ValueType(value.GetInt64());
    }
};

// Converts a \c JsValue \p value holding an \c int value to a \c ValueType
// holding an \c int.
template <class ValueType, class MapType>
struct Js_ValueToInt<ValueType, MapType, false>
{
    static ValueType Apply(const JsValue& value) {
        return ValueType(value.GetInt());
    }
};

template <class ValueType, class MapType, bool UseInt64 = true>
class JsValueTypeConverter
{
    typedef std::vector<ValueType> VectorType;
public:
    static ValueType Convert(const JsValue& value) {
        return _ToValueType(value);
    }

private:
    static ValueType _ToValueType(const JsValue& value) {
        switch (value.GetType()) {
        case JsValue::ObjectType:
            return ValueType(_ObjectToMap(value.GetJsObject()));
        case JsValue::ArrayType:
            return ValueType(_ArrayToVector(value.GetJsArray()));
        case JsValue::BoolType:
            return ValueType(value.GetBool());
        case JsValue::StringType:
            return ValueType(value.GetString());
        case JsValue::RealType:
            return ValueType(value.GetReal());
        case JsValue::IntType:
            return Js_ValueToInt<ValueType, MapType, UseInt64>::Apply(value);
        case JsValue::NullType:
            return ValueType();
        default: {
            TF_CODING_ERROR("unknown value type");
            return ValueType();
            }
        }
    }

    static MapType _ObjectToMap(const JsObject& object) {
        MapType result;
        for (const auto& p : object) {
            result[p.first] = _ToValueType(p.second);
        }
        return result;
    }

    static VectorType _ArrayToVector(const JsArray& array) {
        VectorType result;
        result.reserve(array.size());
        for (const auto& value : array) {
            result.push_back(_ToValueType(value));
        }
        return result;
    }
};

template <class ValueType, class MapType>
ValueType JsConvertToContainerType(const JsValue& value) {
    return JsValueTypeConverter<ValueType, MapType>::Convert(value);
}

PXR_NAMESPACE_CLOSE_SCOPE

#endif // PXR_BASE_JS_CONVERTER_H