py api: add restrict state context manager (thats python's context not blenders context),

which restricts bpy.context and bpy.data.

enable this for loading scripts in 'startup' too.

1 files changed, 57 insertions, 0 deletions

diff --git a/release/scripts/modules/bpy_restrict_state.py b/release/scripts/modules/bpy_restrict_state.py
new file mode 100644
index 00000000000..21c69212731
--- /dev/null
+++ b/release/scripts/modules/bpy_restrict_state.py
@@ -0,0 +1,57 @@
+# ##### BEGIN GPL LICENSE BLOCK #####
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ##### END GPL LICENSE BLOCK #####
+
+# <pep8-80 compliant>
+
+"""
+This module contains RestrictBlend context manager.
+"""
+
+__all__ = (
+    "RestrictBlend",
+    )
+
+import bpy as _bpy
+
+class _RestrictContext():
+    __slots__ = ()
+    _real_data = _bpy.data
+    @property
+    def window_manager(self):
+        return self._real_data.window_managers[0]
+
+
+class _RestrictData():
+    __slots__ = ()
+
+
+_context_restrict = _RestrictContext()
+_data_restrict = _RestrictData()
+
+
+class RestrictBlend():
+    __slots__ = ("context", "data")
+    def __enter__(self):
+        self.data = _bpy.data
+        self.context = _bpy.context
+        _bpy.data = _data_restrict
+        _bpy.context = _context_restrict
+
+    def __exit__(self, type, value, traceback):
+        _bpy.data = self.data
+        _bpy.context = self.context