Outliner: Collections are collapsed when opening file
Closed, ResolvedPublic


Short description of error
Outliner always collapse the collections when seeing "Active Render Layer" or "Master Collection".

Exact steps for others to reproduce the error

  • Factory Startup
  • Look at outliner, the initial collection is expanded
  • Save
  • Open file

The collection is now collapsed.

@Danrae Pray (spockTheGray) hey, have you already investigated this? Asking because I think this should be done carefully.
We could just fix this bug, however there are quite some glitches with collapsing of collections in the outliner. So I'd prefer a better solution for this in general which would also fix this issue. Finding a good solution may require good knowledge of outliner, file read/write and versioning code. Feel free to go ahead if you're up for the challenge, otherwise I'd pick it up again.

Basically, what we want (I guess) is an un-collapsed collection if there only is one, and if the user hasn't manually collapsed it before. Sounds easy, but I'm afraid it isn't due to the way we handle data for the outliner and the collections it shows.

This was partially changed since be9e469ead2. Although the original report seems to be fixed, there are other related issues with it.

For instance:

  • Create a new collection
  • Move Cube to new collection
  • Undo

Collections now collapse, and highlight is messed up. According to @Julian Eisel (Severin):

what we need is a way to uniquely identify a TreeStoreElem representing a view-layer from memory

Although I should add that we need this working for scene collections as well, when viewing Collections instead of active view layer.