Moving to manual class registration means its easier to accidentally
miss registering classes.
Now detect missing class registration
and warn when running with `--debug-python`
This adds the ability to switch between different application-configurations
without interfering with Blender's normal operation.
This commit doesn't include any templates,
so its mostly to allow collaboration for the Blender 101 project
and other custom configurations.
Application templates can be installed & selected from the file menu.
Other details:
- The `bl_app_template_utils` module handles template activation
(similar to `addon_utils`).
- The `bl_app_override` module is a general module
to assist scripts overriding parts of Blender in reversible way.
See docs:
https://docs.blender.org/manual/en/dev/advanced/app_templates.html
See patch: D2565
This commit mainly:
* Exposes PreviewImage struct in RNA, including ways for user to set images data.
* Adds a new kind of PreviewImage, using a file path and IMB_thumb to get image.
* Adds a new kind of custom icon using PreviewImage, unrelated to ID previews system.
* Adds a python API (utils.previews) to allow python scripts to access those custom previews/icons.
Note that loading image from files' thumbnails is done when needed (deferred loading), not
when defining the custom preview/icon.
WARNING: for release addons who would want to use this, please keep it to a strict minimum, really needed level.
We do not want our UI to explode under hundreds of different flashy icons!
For more info, see also the release notes of Blender 2.75 (http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.75/Addons)
and the example/templates featured with Blender.
Patch by Campbell (ideasman42), Inês (brita) and Bastien (mont29).
Differential Revision: https://developer.blender.org/D1255
