1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
# SPDX-License-Identifier: GPL-2.0-or-later
"""
This module contains utility functions to handle custom previews.
It behaves as a high-level 'cached' previews manager.
This allows scripts to generate their own previews, and use them as icons in UI widgets
('icon_value' for UILayout functions).
Custom Icon Example
-------------------
.. literalinclude:: __/__/__/release/scripts/templates_py/ui_previews_custom_icon.py
"""
__all__ = (
"new",
"remove",
"ImagePreviewCollection",
)
import _bpy
_utils_previews = _bpy._utils_previews
del _bpy
_uuid_open = set()
# High-level previews manager.
# not accessed directly
class ImagePreviewCollection(dict):
"""
Dictionary-like class of previews.
This is a subclass of Python's built-in dict type,
used to store multiple image previews.
.. note::
- instance with :mod:`bpy.utils.previews.new`
- keys must be ``str`` type.
- values will be :class:`bpy.types.ImagePreview`
"""
# Internal notes:
# - Blender's internal 'PreviewImage' struct uses 'self._uuid' prefix.
# - Blender's preview.new/load return the data if it exists,
# don't do this for the Python API as it allows accidental re-use of names,
# anyone who wants to reuse names can use dict.get() to check if it exists.
# We could use this for the C API too (would need some investigation).
def __init__(self):
super().__init__()
self._uuid = hex(id(self))
_uuid_open.add(self._uuid)
def __del__(self):
if self._uuid not in _uuid_open:
return
raise ResourceWarning(
"%r: left open, remove with 'bpy.utils.previews.remove()'" % self
)
self.close()
def _gen_key(self, name):
return ":".join((self._uuid, name))
def new(self, name):
if name in self:
raise KeyError("key %r already exists" % name)
p = self[name] = _utils_previews.new(
self._gen_key(name))
return p
new.__doc__ = _utils_previews.new.__doc__
def load(self, name, path, path_type, force_reload=False):
if name in self:
raise KeyError("key %r already exists" % name)
p = self[name] = _utils_previews.load(
self._gen_key(name), path, path_type, force_reload)
return p
load.__doc__ = _utils_previews.load.__doc__
def clear(self):
"""Clear all previews."""
for name in self.keys():
_utils_previews.release(self._gen_key(name))
super().clear()
def close(self):
"""Close the collection and clear all previews."""
self.clear()
_uuid_open.remove(self._uuid)
def __delitem__(self, key):
_utils_previews.release(self._gen_key(key))
super().__delitem__(key)
def __repr__(self):
return "<%s id=%s[%d], %r>" % (
self.__class__.__name__, self._uuid, len(self), super()
)
def new():
"""
:return: a new preview collection.
:rtype: :class:`ImagePreviewCollection`
"""
return ImagePreviewCollection()
def remove(pcoll):
"""
Remove the specified previews collection.
:arg pcoll: Preview collection to close.
:type pcoll: :class:`ImagePreviewCollection`
"""
pcoll.close()
# don't complain about resources on exit (only unregister)
import atexit
def exit_clear_warning():
del ImagePreviewCollection.__del__
atexit.register(exit_clear_warning)
del atexit, exit_clear_warning
|
