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 USDVIEWQ_UTILS_H
  #define USDVIEWQ_UTILS_H
  
  #include "pxr/usd/usd/prim.h"
  #include "pxr/usd/usd/timeCode.h"
  
  #include <vector>
  
  class UsdStage;
  
  /// Performance enhancing utilities for usdview.
  class UsdviewqUtils {
  public:
  
      struct PrimInfo {
          bool hasCompositionArcs;  
          bool isActive;  
          bool isImageable;
          bool isDefined;
          bool isAbstract;
          bool isInMaster;
          bool isInstance;
          bool isVisibilityInherited;
          bool visVaries;
          std::string name;
          std::string typeName;
      };
  
      /// For the given \p stage and \p schemaType, return all active, defined
      /// prims that either match the schemaType exactly or are a descendant type.
      //
      //      Furthermore, this method is not intended to be used publically,
      //      ultimately Usd will have better core support for fast prim
      //      filtering by typeName. 
      static
      std::vector<UsdPrim> _GetAllPrimsOfType(UsdStagePtr const &stage, 
                                              TfType const& schemaType);
  
      /// Fetch prim-related data in batch to to speed up Qt treeview item
      /// population.  Takes a time argument so that we can evaluate the prim's
      /// visibiity if it is imageable.
      static UsdviewqUtils::PrimInfo GetPrimInfo(UsdPrim prim, UsdTimeCode time);
  
  };
  
  #endif //USDVIEWQ_UTILS_H
  