Note: Change applies to Grease Pencil 3.0 only (experimental feature).
Enables use of drag & drop to reorder grease pencil layers through the layer
tree UI, as well as inserting layers into groups. This is an intuitive and
often requested method of managing such data-structures. Visual feedback should
be improved still, and the gap between items be removed, to reduce flickering
while dragging. These are general improvements for tree views however which
should be done separately.
There is no support yet for dragging layer groups, this requires further
changes in the internal grease pencil APIs.
#109825 introduced the necessary drag & drop support for tree views, #109824
prepared the internal grease pencil API for it.
Pull Request: https://projects.blender.org/blender/blender/pulls/109826
d31a0e8393