PyAPI: temporary context override support

Support a way to temporarily override the context from Python.

- Added method `Context.temp_override` context manager.
- Special support for windowing variables "window", "area" and "region",
  other context members such as "active_object".
- Nesting context overrides is supported.
- Previous windowing members are restored when the context exists unless
  they have been removed.
- Overriding context members by passing a dictionary into operators in
  `bpy.ops` has been deprecated and warns when used.

This allows the window in a newly loaded file to be used, see: T92464

Reviewed by: mont29

Ref D13126

1 files changed, 15 insertions, 0 deletions

diff --git a/doc/python_api/examples/bpy.types.Context.temp_override.2.py b/doc/python_api/examples/bpy.types.Context.temp_override.2.py
new file mode 100644
index 00000000000..ce3e1594baa
--- /dev/null
+++ b/doc/python_api/examples/bpy.types.Context.temp_override.2.py
@@ -0,0 +1,15 @@
+"""
+Overriding the context can be useful to set the context after loading files
+(which would otherwise by None). For example:
+"""
+
+import bpy
+from bpy import context
+
+# Reload the current file and select all.
+bpy.ops.wm.open_mainfile(filepath=bpy.data.filepath)
+window = context.window_manager.windows[0]
+with context.temp_override(window=window):
+    bpy.ops.mesh.primitive_uv_sphere_add()
+    # The context override is needed so it's possible to set edit-mode.
+    bpy.ops.object.mode_set(mode='EDIT')