variantSets.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_VARIANT_SETS_H
#define PXR_USD_USD_VARIANT_SETS_H

#include "pxr/pxr.h"
#include "pxr/usd/usd/api.h"
#include "pxr/usd/usd/common.h"
#include "pxr/usd/usd/editTarget.h"
#include "pxr/usd/usd/prim.h"

#include "pxr/usd/sdf/declareHandles.h"

#include <string>
#include <vector>

PXR_NAMESPACE_OPEN_SCOPE


SDF_DECLARE_HANDLES(SdfLayer);
SDF_DECLARE_HANDLES(SdfPrimSpec);
SDF_DECLARE_HANDLES(SdfVariantSetSpec);

class SdfPath;

class UsdVariantSet {
public:
    USD_API
    bool AddVariant(const std::string& variantName,
                    UsdListPosition position=UsdListPositionBackOfPrependList);

    USD_API
    std::vector<std::string> GetVariantNames() const;

    // named \p variantName in any layer.
    USD_API
    bool HasAuthoredVariant(const std::string& variantName) const;

    USD_API
    std::string GetVariantSelection() const;

    USD_API
    bool HasAuthoredVariantSelection(std::string *value = nullptr) const;

    USD_API
    bool SetVariantSelection(const std::string &variantName);

    USD_API
    bool ClearVariantSelection();

    USD_API
    bool BlockVariantSelection();

    USD_API
    UsdEditTarget
    GetVariantEditTarget(const SdfLayerHandle &layer = SdfLayerHandle()) const;

    USD_API
    std::pair<UsdStagePtr, UsdEditTarget>
    GetVariantEditContext(const SdfLayerHandle &layer = SdfLayerHandle()) const;


    UsdPrim const &GetPrim() const { return _prim; }


    std::string const &GetName() const { return _variantSetName; }


    bool IsValid() const {
        return static_cast<bool>(_prim);
    }

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

private:
    UsdVariantSet(const UsdPrim &prim,
                  const std::string &variantSetName)
        : _prim(prim)
        , _variantSetName(variantSetName)
    {
    }

    SdfPrimSpecHandle _CreatePrimSpecForEditing();
    SdfVariantSetSpecHandle _AddVariantSet(UsdListPosition position);

    UsdPrim _prim;
    std::string _variantSetName;

    friend class UsdPrim;
    friend class UsdVariantSets;
};


// TODO:
// VariantSet Names are stored as SdListOps, but a VariantSet is an actual spec
// (like a Prim). Is it important to make that distinction here?

class UsdVariantSets {
public:

    USD_API
    UsdVariantSet AddVariantSet(const std::string& variantSetName,
                UsdListPosition position=UsdListPositionBackOfPrependList);

    // TODO: don't we want remove and reorder, clear, etc. also?

    USD_API
    bool GetNames(std::vector<std::string>* names) const;

    USD_API
    std::vector<std::string> GetNames() const;

    UsdVariantSet operator[](const std::string& variantSetName) const {
        return GetVariantSet(variantSetName);
    }

    USD_API
    UsdVariantSet GetVariantSet(const std::string& variantSetName) const;

    USD_API
    bool HasVariantSet(const std::string& variantSetName) const;

    USD_API
    std::string GetVariantSelection(const std::string& variantSetName) const;

    USD_API
    bool SetSelection(const std::string& variantSetName,
                      const std::string& variantName);

    USD_API
    SdfVariantSelectionMap GetAllVariantSelections() const;


private:
    explicit UsdVariantSets(const UsdPrim& prim) 
        : _prim(prim)
    {
        /* NOTHING */
    }

    UsdPrim _prim;

    friend class UsdPrim;
};


PXR_NAMESPACE_CLOSE_SCOPE

#endif //PXR_USD_USD_VARIANT_SETS_H