The pose library registered a double-click keymap item for the file
browser keymap, because that was the only way to add keymap items to the
asset browser (which is just the file browser under the hood). Since
450f428434, the pose library apply & blend operators are available in
more contexts, since their check for an active asset was moved from the
operator poll to the operator execution. So the pose apply operator
would end up triggering.
The poll function could be adjusted somehow to return false in this
case, e.g. by checking if it's executed from a file browser (not an
asset browser).
However, the operator should be independent of where it's called from.
So instead this registers a separate keymap for the asset browser, so
the pose library operators can be registered exclusively for the asset
browser.
This was quite involved to get to work. Basic idea is to make
`bl_activate_operator` work for the pose library asset shelf, and
introducing a `bl_drag_operator` for blending poses.
- Make pose asset operators take an asset reference, which is how
`bl_activate_operator` usually gets the asset to operate on. This way
poses references can be assigned to a shortcut, identified by asset
library and relative asset path within the library. Falls back to
getting the asset from context.
- Trigger `bl_activate_operator` on every click, instead of only when
an un-active item becomes active. Needed so poses can be re-applied
as before.
- Fix button context not passed to the `bl_activate_operator` when
force-activating, e.g. on right-click events.
- Allow registering a `bl_drag_operator` in the asset shelf definition.
Executed when dragging an asset in the shelf.
- When dragging an asset, highlight it as active, without calling the
`bl_activate_operator`. This is important feedback to the user.
- Activate/select view items on click instead of drag, so dragging is
possible.
- Let pose applying operators handle the Ctrl key to apply poses
flipped. There's no simple way to attach such alternative behaviors
to `bl_activate_operator`/`bl_drag_operator`
- Remove keymap items that were there for the previous "hacky" solution
to apply & blend poses.
Pull Request: https://projects.blender.org/blender/blender/pulls/144023
