text: //
  // 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 USD_CRATEDATA_H
  #define USD_CRATEDATA_H
  
  #include "pxr/pxr.h"
  #include "pxr/usd/sdf/abstractData.h"
  
  #include "pxr/base/tf/declarePtrs.h"
  #include "pxr/base/tf/token.h"
  #include "pxr/base/vt/value.h"
  
  #include <memory>
  #include <vector>
  #include <set>
  
  PXR_NAMESPACE_OPEN_SCOPE
  
  
  /// \class Usd_CrateData
  ///
  class Usd_CrateData : public SdfAbstractData
  {
  public:
  
      Usd_CrateData();
      virtual ~Usd_CrateData(); 
  
      static TfToken const &GetSoftwareVersionToken();
  
      static bool CanRead(const std::string &fileName);
      bool Save(const std::string &fileName);
      bool Open(const std::string &fileName);
  
      virtual void CreateSpec(const SdfAbstractDataSpecId &id, 
                              SdfSpecType specType);
      virtual bool HasSpec(const SdfAbstractDataSpecId &id) const;
      virtual void EraseSpec(const SdfAbstractDataSpecId &id);
      virtual void MoveSpec(const SdfAbstractDataSpecId& oldId, 
                            const SdfAbstractDataSpecId& newId);
      virtual SdfSpecType GetSpecType(const SdfAbstractDataSpecId &id) const;
  
      virtual bool Has(const SdfAbstractDataSpecId& id, const TfToken& fieldName,
                       SdfAbstractDataValue* value) const;
      virtual bool Has(const SdfAbstractDataSpecId& id, const TfToken& fieldName,
                       VtValue *value=NULL) const;
      virtual VtValue Get(const SdfAbstractDataSpecId& id, 
                          const TfToken& fieldName) const;
      virtual void Set(const SdfAbstractDataSpecId& id, const TfToken& fieldName,
                       const VtValue& value);
      virtual void Set(const SdfAbstractDataSpecId& id, const TfToken& fieldName,
                       const SdfAbstractDataConstValue& value);
      virtual void Erase(const SdfAbstractDataSpecId& id, 
                         const TfToken& fieldName);
      virtual std::vector<TfToken> List(const SdfAbstractDataSpecId& id) const;
      
      /// \name Time-sample API
      /// @{
  
      virtual std::set<double>
      ListAllTimeSamples() const;
      
      virtual std::set<double>
      ListTimeSamplesForPath(const SdfAbstractDataSpecId& id) const;
  
      virtual bool
      GetBracketingTimeSamples(double time, double* tLower, double* tUpper) const;
  
      virtual size_t
      GetNumTimeSamplesForPath(const SdfAbstractDataSpecId& id) const;
  
      virtual bool
      GetBracketingTimeSamplesForPath(const SdfAbstractDataSpecId& id,
                                      double time,
                                      double* tLower, double* tUpper) const;
      
      virtual bool
      QueryTimeSample(const SdfAbstractDataSpecId& id, double time,
                      SdfAbstractDataValue *value) const;
      virtual bool
      QueryTimeSample(const SdfAbstractDataSpecId& id, double time, 
                      VtValue *value) const;
  
      virtual void
      SetTimeSample(const SdfAbstractDataSpecId& id, double time, 
                    const VtValue & value);
  
      virtual void
      EraseTimeSample(const SdfAbstractDataSpecId& id, double time);
  
      /// @}
  
  private:
  
      // SdfAbstractData overrides
      virtual void _VisitSpecs(SdfAbstractDataSpecVisitor* visitor) const;
  
      friend class Usd_CrateDataImpl;
      std::unique_ptr<class Usd_CrateDataImpl> _impl;
  };
  
  
  PXR_NAMESPACE_CLOSE_SCOPE
  
  #endif // USD_CRATEDATA_H
  