C++ SdfPath::AppendRelationalAttribute方法代码示例

static SdfPath
_AppendNode(const SdfPath &path, const Sdf_PathNodeConstRefPtr &node) {

    switch (node->GetNodeType()) {
        case Sdf_PathNode::PrimNode:
            return path.AppendChild(node->GetName());
        case Sdf_PathNode::PrimPropertyNode:
            return path.AppendProperty(node->GetName());
        case Sdf_PathNode::PrimVariantSelectionNode:
        {
            const Sdf_PathNode::VariantSelectionType& selection =
                node->GetVariantSelection();
            return path.AppendVariantSelection(selection.first.GetString(),
                                               selection.second.GetString());
        }
        case Sdf_PathNode::TargetNode:
            return path.AppendTarget( node->GetTargetPath());
        case Sdf_PathNode::RelationalAttributeNode:
            return path.AppendRelationalAttribute(node->GetName());
        case Sdf_PathNode::MapperNode:
            return path.AppendMapper(node->GetTargetPath());
        case Sdf_PathNode::MapperArgNode:
            return path.AppendMapperArg(node->GetName());
        case Sdf_PathNode::ExpressionNode:
            return path.AppendExpression();
        default:
            // CODE_COVERAGE_OFF
            // Should never get here.  All reasonable cases are
            // handled above.
            TF_CODING_ERROR("Unexpected node type %i", node->GetNodeType());
            return SdfPath::EmptyPath();
            // CODE_COVERAGE_ON
    }
}

SdfAttributeSpecHandle
SdfAttributeSpec::_New(
    const SdfRelationshipSpecHandle& owner,
    const SdfPath& path,
    const std::string& name,
    const SdfValueTypeName& typeName,
    SdfVariability variability,
    bool custom)
{
    if (not owner) {
        TF_CODING_ERROR("NULL owner");
        return TfNullPtr;
    }
    if (not typeName) {
        TF_CODING_ERROR("Cannot create attribute spec <%s> with invalid type",
                        owner->GetPath().AppendTarget(path).
                            AppendProperty(TfToken(name)).GetText());
	return TfNullPtr;
    }

    SdfChangeBlock block;

    // Determine the path of the relationship target
    SdfPath absPath = path.MakeAbsolutePath(owner->GetPath().GetPrimPath());
    SdfPath targetPath = owner->GetPath().AppendTarget(absPath);

    // Check to make sure that the name is valid
    if (not Sdf_ChildrenUtils<Sdf_AttributeChildPolicy>::IsValidName(name)) {
        TF_CODING_ERROR(
            "Cannot create attribute on %s with invalid name: %s",
            targetPath.GetText(), name.c_str());
        return TfNullPtr;
    }

    // Create the relationship target if it doesn't already exist. Note
    // that this does not automatically get added to the relationship's
    // target path list.
    SdfSpecHandle targetSpec = owner->_FindOrCreateTargetSpec(path);

    // AttributeSpecs are considered initially to have only required fields 
    // only if they are not custom.
    bool hasOnlyRequiredFields = (not custom);

    // Create the relational attribute spec
    SdfPath attrPath = targetPath.AppendRelationalAttribute(TfToken(name));
    if (not Sdf_ChildrenUtils<Sdf_AttributeChildPolicy>::CreateSpec(
            owner->GetLayer(), attrPath, SdfSpecTypeAttribute, 
            hasOnlyRequiredFields)) {
        return TfNullPtr;
    }

    SdfAttributeSpecHandle spec =
        owner->GetLayer()->GetAttributeAtPath(attrPath);
    
    // Avoid expensive dormancy checks in the case of binary-backed data.
    SdfAttributeSpec *specPtr = get_pointer(spec);
    if (TF_VERIFY(specPtr)) {
        specPtr->SetField(SdfFieldKeys->Custom, custom);
        specPtr->SetField(SdfFieldKeys->TypeName, typeName.GetAsToken());
        specPtr->SetField(SdfFieldKeys->Variability, variability);
    }

    return spec;
}