1 //
2 // Copyright 2019 Pixar
3 //
4 // Licensed under the Apache License, Version 2.0 (the "Apache License")
5 // with the following modification; you may not use this file except in
6 // compliance with the Apache License and the following modification to it:
7 // Section 6. Trademarks. is deleted and replaced with:
8 //
9 // 6. Trademarks. This License does not grant permission to use the trade
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11 //    and its affiliates, except as required to comply with Section 4(c) of
12 //    the License and to reproduce the content of the NOTICE file.
13 //
14 // You may obtain a copy of the Apache License at
15 //
16 //     http://www.apache.org/licenses/LICENSE-2.0
17 //
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19 // distributed under the Apache License with the above modification is
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24 #ifndef PXR_USD_USD_PAYLOADS_H
25 #define PXR_USD_USD_PAYLOADS_H
26 
27 #include "pxr/pxr.h"
28 #include "pxr/usd/usd/api.h"
29 #include "pxr/usd/usd/common.h"
30 #include "pxr/usd/usd/prim.h"
31 
32 #include "pxr/usd/sdf/declareHandles.h"
33 #include "pxr/usd/sdf/path.h"
34 #include "pxr/usd/sdf/payload.h"
35 
36 PXR_NAMESPACE_OPEN_SCOPE
37 
38 /// \class UsdPayloads
39 ///
40 /// UsdPayloads provides an interface to authoring and introspecting payloads.
41 /// Payloads behave the same as Usd references except that payloads can be
42 /// optionally loaded.
43 class UsdPayloads {
44     friend class UsdPrim;
45 
UsdPayloads(const UsdPrim & prim)46     explicit UsdPayloads(const UsdPrim& prim) : _prim(prim) {}
47 
48 public:
49     /// Adds a payload to the payload listOp at the current EditTarget, in the
50     /// position specified by \p position.
51     /// \sa \ref Usd_Failing_References "Why adding references may fail" for
52     /// explanation of expectations on \p payload and what return values and
53     /// errors to expect, and \ref Usd_OM_ListOps for details on list editing
54     /// and composition of listOps.
55     USD_API
56     bool AddPayload(const SdfPayload& payload,
57                     UsdListPosition position=UsdListPositionBackOfPrependList);
58 
59     /// \overload
60     USD_API
61     bool AddPayload(const std::string &identifier,
62                     const SdfPath &primPath,
63                     const SdfLayerOffset &layerOffset = SdfLayerOffset(),
64                     UsdListPosition position=UsdListPositionBackOfPrependList);
65 
66     /// \overload
67     /// \sa \ref Usd_DefaultPrim_References "Payloads Without Prim Paths"
68     USD_API
69     bool AddPayload(const std::string &identifier,
70                     const SdfLayerOffset &layerOffset = SdfLayerOffset(),
71                     UsdListPosition position=UsdListPositionBackOfPrependList);
72 
73     /// Add an internal payload to the specified prim.
74     /// \sa \ref Usd_Internal_References "Internal Payloads"
75     USD_API
76     bool AddInternalPayload(const SdfPath &primPath,
77                     const SdfLayerOffset &layerOffset = SdfLayerOffset(),
78                     UsdListPosition position=UsdListPositionBackOfPrependList);
79 
80     /// Removes the specified payload from the payloads listOp at the
81     /// current EditTarget.  This does not necessarily eliminate the payload
82     /// completely, as it may be added or set in another layer in the same
83     /// LayerStack as the current EditTarget.
84     /// \sa \ref Usd_OM_ListOps
85     USD_API
86     bool RemovePayload(const SdfPayload& ref);
87 
88     /// Removes the authored payload listOp edits at the current EditTarget.
89     /// The same caveats for Remove() apply to Clear().  In fact, Clear() may
90     /// actually increase the number of composed payloads, if the listOp being
91     /// cleared contained the "remove" operator.
92     /// \sa \ref Usd_OM_ListOps
93     USD_API
94     bool ClearPayloads();
95 
96     /// Explicitly set the payloads, potentially blocking weaker opinions that
97     /// add or remove items.
98     /// \sa \ref Usd_Failing_References "Why adding payloads may fail" for
99     /// explanation of expectations on \p items and what return values and
100     /// errors to expect, and \ref Usd_OM_ListOps for details on list editing
101     /// and composition of listOps.
102     USD_API
103     bool SetPayloads(const SdfPayloadVector& items);
104 
105     /// Return the prim this object is bound to.
GetPrim()106     const UsdPrim &GetPrim() const { return _prim; }
107 
108     /// \overload
GetPrim()109     UsdPrim GetPrim() { return _prim; }
110 
111     explicit operator bool() { return bool(_prim); }
112 
113 private:
114     UsdPrim _prim;
115 };
116 
117 PXR_NAMESPACE_CLOSE_SCOPE
118 
119 #endif // PXR_USD_USD_PAYLOADS_H
120