Avoid creating new Python instances
every time a scene, object, mesh .. etc are accessed.
Also resolves crashes T28724, T53530
although it's only valid for ID types, not modifiers vertices etc.
Back-ported from blender2.8 branch.
Use dynamically generated message publish/subscribe
so buttons and manipulators update properly.
This resolves common glitches where manipulators weren't updating
as well as the UI when add-ons exposed properties which
hard coded listeners weren't checking for.
Python can also publish/scribe changes via `bpy.msgbus`.
See D2917
Adds support for defining a number of tags as part of the rna-struct
definition, which its properties can set similar to property-flags.
BPY supports setting these tags when defining custom properties too.
* To define tags for a struct (which its properties can use then), define the tags in an `EnumPropertyItem` array, and assign them to the struct using `RNA_def_struct_property_tags(...)`.
* To set tags for an RNA-property in C, use the new `RNA_def_property_tags(...)`.
* To set tags for an RNA-property in Python, use the newly added tags parameter. E.g. `bpy.props.FloatProperty(name="Some Float", tags={'SOME_TAG', 'ANOTHER_TAG'})`.
Adds support for defining a number of tags as part of the rna-struct
definition, which its properties can set similar to property-flags.
BPY supports setting these tags when defining custom properties too.
* To define tags for a struct (which its properties can use then), define the tags in an `EnumPropertyItem` array, and assign them to the struct using `RNA_def_struct_property_tags(...)`.
* To set tags for an RNA-property in C, use the new `RNA_def_property_tags(...)`.
* To set tags for an RNA-property in Python, use the newly added tags parameter. E.g. `bpy.props.FloatProperty(name="Some Float", tags={'SOME_TAG', 'ANOTHER_TAG'})`.
Actual usage of this will be added in a follow-up commit.
The RenderResult struct still has a listbase of RenderLayer, but that's ok
since this is strictly for rendering.
* Subversion bump (to 2.80.2)
* DNA low level doversion (renames) - only for .blend created since 2.80 started
Note: We can't use DNA_struct_elem_find or get file version in init_structDNA,
so we are manually iterating over the array of the SDNA elements instead.
Note 2: This doversion change with renames can be reverted in a few months. But
so far it's required for 2.8 files created between October 2016 and now.
Reviewers: campbellbarton, sergey
Differential Revision: https://developer.blender.org/D2927
It seems that `typestr` does not always define the final size of the element. And it varies by operating system.
Then use the `typestr` only to know the itemtype is `float` type or not.
