attributeQuery.h

//
// 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_USD_USD_ATTRIBUTE_QUERY_H
#define PXR_USD_USD_ATTRIBUTE_QUERY_H

#include "pxr/pxr.h"
#include "pxr/usd/usd/api.h"
#include "pxr/usd/usd/attribute.h"
#include "pxr/usd/usd/common.h"
#include "pxr/usd/usd/prim.h"
#include "pxr/usd/usd/resolveInfo.h"
#include "pxr/usd/usd/resolveTarget.h"
#include "pxr/usd/usd/timeCode.h"

#include "pxr/base/tf/token.h"

#include <vector>

PXR_NAMESPACE_OPEN_SCOPE


class UsdAttributeQuery
{
public:
    USD_API
    UsdAttributeQuery();

    USD_API
    UsdAttributeQuery(const UsdAttributeQuery &other);

    USD_API
    UsdAttributeQuery(UsdAttributeQuery &&other) = default;

    USD_API
    explicit UsdAttributeQuery(const UsdAttribute& attr);

    USD_API
    UsdAttributeQuery(const UsdPrim& prim, const TfToken& attrName);

    USD_API
    UsdAttributeQuery(const UsdAttribute &attr, 
        const UsdResolveTarget &resolveTarget);

    USD_API
    static std::vector<UsdAttributeQuery> CreateQueries(
        const UsdPrim& prim, const TfTokenVector& attrNames);

    // --------------------------------------------------------------------- //
    // --------------------------------------------------------------------- //


    USD_API
    const UsdAttribute& GetAttribute() const;

    bool IsValid() const {
        return GetAttribute().IsValid();
    }

public:
    explicit operator bool() const {
        return IsValid();
    }

    USD_API
    UsdAttributeQuery &operator=(const UsdAttributeQuery &other);

    USD_API
    UsdAttributeQuery &operator=(UsdAttributeQuery &&other) = default;


    // --------------------------------------------------------------------- //
    // --------------------------------------------------------------------- //


    template <typename T>
    bool Get(T* value, UsdTimeCode time = UsdTimeCode::Default()) const {
        static_assert(SdfValueTypeTraits<T>::IsValueType,
                      "T must be an SdfValueType.");
        return _Get(value, time);
    }
    USD_API
    bool Get(VtValue* value, UsdTimeCode time = UsdTimeCode::Default()) const;
    
    //
    USD_API
    bool GetTimeSamples(std::vector<double>* times) const;

    USD_API
    bool GetTimeSamplesInInterval(const GfInterval& interval,
                                  std::vector<double>* times) const;

    USD_API
    static bool GetUnionedTimeSamples(
        const std::vector<UsdAttributeQuery> &attrQueries, 
        std::vector<double> *times);

    USD_API
    static bool GetUnionedTimeSamplesInInterval(
        const std::vector<UsdAttributeQuery> &attrQueries, 
        const GfInterval &interval,
        std::vector<double> *times);

    USD_API
    size_t GetNumTimeSamples() const;

    USD_API
    bool GetBracketingTimeSamples(double desiredTime, 
                                  double* lower, 
                                  double* upper, 
                                  bool* hasTimeSamples) const;

    USD_API
    bool HasValue() const;

    USD_API
    bool HasAuthoredValueOpinion() const;

    USD_API
    bool HasAuthoredValue() const;

    USD_API
    bool HasFallbackValue() const;

    USD_API
    bool ValueMightBeTimeVarying() const;


private:
    void _Initialize();

    void _Initialize(const UsdResolveTarget &resolveTarget);

    template <typename T>
    USD_API
    bool _Get(T* value, UsdTimeCode time) const;

private:
    UsdAttribute _attr;
    UsdResolveInfo _resolveInfo;
    std::unique_ptr<UsdResolveTarget> _resolveTarget;
};

PXR_NAMESPACE_CLOSE_SCOPE

#endif // PXR_USD_USD_ATTRIBUTE_QUERY_H