schemaBase.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_SCHEMA_BASE_H
#define PXR_USD_USD_SCHEMA_BASE_H

#include "pxr/pxr.h"
#include "pxr/usd/usd/api.h"
#include "pxr/usd/usd/prim.h"
#include "pxr/usd/usd/attribute.h"
#include "pxr/usd/usd/relationship.h"
#include "pxr/usd/usd/references.h"

PXR_NAMESPACE_OPEN_SCOPE


class UsdSchemaBase {
public:
    static const UsdSchemaKind schemaKind = UsdSchemaKind::AbstractBase;

    bool IsConcrete() const {
        return GetSchemaKind() == UsdSchemaKind::ConcreteTyped;
    }

    bool IsTyped() const {
        return GetSchemaKind() == UsdSchemaKind::ConcreteTyped
            || GetSchemaKind() == UsdSchemaKind::AbstractTyped;
    }

    bool IsAPISchema() const {
        return GetSchemaKind() == UsdSchemaKind::NonAppliedAPI
            || GetSchemaKind() == UsdSchemaKind::SingleApplyAPI
            || GetSchemaKind() == UsdSchemaKind::MultipleApplyAPI;
    }

    bool IsAppliedAPISchema() const {
        return GetSchemaKind() == UsdSchemaKind::SingleApplyAPI
            || GetSchemaKind() == UsdSchemaKind::MultipleApplyAPI;
    }

    bool IsMultipleApplyAPISchema() const {
        return GetSchemaKind() == UsdSchemaKind::MultipleApplyAPI;
    }

    UsdSchemaKind GetSchemaKind() const {
        return _GetSchemaKind();
    }

    USD_API
    explicit UsdSchemaBase(const UsdPrim& prim = UsdPrim());

    USD_API
    explicit UsdSchemaBase(const UsdSchemaBase& otherSchema);

    USD_API
    virtual ~UsdSchemaBase();



    UsdPrim GetPrim() const { return UsdPrim(_primData, _proxyPrimPath); }

    SdfPath GetPath() const { 
        if (!_proxyPrimPath.IsEmpty()) {
            return _proxyPrimPath;
        }
        else if (Usd_PrimDataConstPtr p = get_pointer(_primData)) {
            return p->GetPath();
        }
        return SdfPath::EmptyPath();
    }




    USD_API
    const UsdPrimDefinition *GetSchemaClassPrimDefinition() const;


    static const TfTokenVector &
    GetSchemaAttributeNames(bool includeInherited=true)
    {
        /* This only exists for consistency */
        static TfTokenVector names;
        return names;
    }

    USD_API
    explicit operator bool() const {
        return _primData && _IsCompatible();
    }

protected:
    virtual UsdSchemaKind _GetSchemaKind() const {
        return schemaKind;
    }

    virtual UsdSchemaKind _GetSchemaType() const {
        return schemaKind;
    }

    // Helper for subclasses to get the TfType for this schema object's dynamic
    // C++ type.
    const TfType &_GetType() const {
        return _GetTfType();
    }

    USD_API
    UsdAttribute _CreateAttr(TfToken const &attrName,
                             SdfValueTypeName const & typeName,
                             bool custom, SdfVariability variability,
                             VtValue const &defaultValue, 
                             bool writeSparsely) const;
    
    USD_API
    virtual bool _IsCompatible() const;

private:
    // needs to invoke _GetStaticTfType.
    friend class UsdSchemaRegistry;
    USD_API
    static const TfType &_GetStaticTfType();

    // Subclasses should not override _GetTfType.  It is implemented by the
    // schema class code generator.
    USD_API
    virtual const TfType &_GetTfType() const;

    // The held prim and proxy prim path.
    Usd_PrimDataHandle _primData;
    SdfPath _proxyPrimPath;
};


PXR_NAMESPACE_CLOSE_SCOPE

#endif //PXR_USD_USD_SCHEMA_BASE_H