connectableAPIBehavior.h

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//
// Copyright 2020 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_USD_USD_SHADE_CONNECTABLE_BEHAVIOR_H
#define PXR_USD_USD_SHADE_CONNECTABLE_BEHAVIOR_H
 
 
#include "pxr/pxr.h"
#include "pxr/usd/usdShade/api.h"
 
#include "pxr/base/gf/vec3f.h"
#include "pxr/base/vt/array.h"
 
#include "pxr/base/tf/type.h"
 
PXR_NAMESPACE_OPEN_SCOPE
 
class UsdAttribute;
class UsdShadeInput;
class UsdShadeOutput;
 
class UsdShadeConnectableAPIBehavior
{
public:
 
    enum ConnectableNodeTypes
    {
        BasicNodes, // Shader, NodeGraph
        DerivedContainerNodes, // Material, etc
    };
 
    // By default we want a connectableBehavior to not exhibit a container like
    // behavior. And we want encapsulation behavior enabled by default.
    USDSHADE_API
    UsdShadeConnectableAPIBehavior() 
        : _isContainer(false), _requiresEncapsulation(true) {}
 
    USDSHADE_API
    UsdShadeConnectableAPIBehavior(const bool isContainer, 
            const bool requiresEncapsulation)
        : _isContainer(isContainer), 
        _requiresEncapsulation(requiresEncapsulation) {}
 
    USDSHADE_API
    virtual ~UsdShadeConnectableAPIBehavior();
 
    USDSHADE_API
    virtual bool
    CanConnectInputToSource(const UsdShadeInput &,
                            const UsdAttribute &,
                            std::string *reason) const;
 
    USDSHADE_API
    virtual bool
    CanConnectOutputToSource(const UsdShadeOutput &,
                             const UsdAttribute &,
                             std::string *reason) const;
 
    USDSHADE_API
    virtual bool 
    IsContainer() const final;
 
    //
    USDSHADE_API
    virtual bool
    RequiresEncapsulation() const final;
 
protected:
    USDSHADE_API
    bool _CanConnectInputToSource(const UsdShadeInput&, const UsdAttribute&,
                                  std::string *reason, 
                                  ConnectableNodeTypes nodeType = 
                                    ConnectableNodeTypes::BasicNodes) const;
 
    USDSHADE_API
    bool _CanConnectOutputToSource(const UsdShadeOutput&, const UsdAttribute&,
                                   std::string *reason,
                                   ConnectableNodeTypes nodeType =
                                     ConnectableNodeTypes::BasicNodes) const;
private:
    bool _isContainer;
    bool _requiresEncapsulation;
};
 
template <class PrimType, class BehaviorType = UsdShadeConnectableAPIBehavior>
inline void 
UsdShadeRegisterConnectableAPIBehavior()
{
    UsdShadeRegisterConnectableAPIBehavior(
        TfType::Find<PrimType>(),
        std::shared_ptr<UsdShadeConnectableAPIBehavior>(new BehaviorType));
}
 
USDSHADE_API
void 
UsdShadeRegisterConnectableAPIBehavior(
    const TfType& connectablePrimType,
    const std::shared_ptr<UsdShadeConnectableAPIBehavior>& behavior);
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif // PXR_USD_USD_SHADE_CONNECTABLE_BEHAVIOR_H