Instead of using a separate undo queue, the code now defers checking for
newly-due learning cards until the answering stage, and logs the updated
cutoff time as an undoable change, so that any newly-due learning cards
won't appear instead of a new/review card that was just undone.
Queue redo now uses a similar approach to undo, instead of rebuilding the
queues.
The original rationale was avoiding a possible O(n) insertion if
the learning card was due outside the cutoff, but the increased code
complexity doesn't seem worth it, given that learning cards will
rarely grow above 1000.
Also added a currently-disabled test that demonstrates the current undo
handling behaviour is yielding incorrect counts; that will be reworked
in the next commit, and this change will make that easier.
So, this is fun. Apparently "DeckId" is considered preferable to the
"DeckID" were were using until now, and the latest clippy will start
warning about it. We could of course disable the warning, but probably
better to bite the bullet and switch to the naming that's generally
considered best.
To coalesce successive note edits into a single undo op we'll need to
be able to get the original Undoable type, which is awkward to do with
a trait object.
- transact() now automatically clears card queues unless an op
opts-out (and currently only AnswerCard does). This means there's no
risk of forgetting to clear the queues in an operation, or when undoing/
redoing
- CollectionOp->UndoableOp
- clear queues when redoing "answer card", instead of clearing redo
when clearing queues
- use dataclasses for the review/checkpoint undo cases, instead of the
nasty ad-hoc list structure
- expose backend review undo to Python, and hook it into GUI
- redo is not currently exposed on the GUI, and the backend can only
cope with reviews done by the new scheduler at the moment
- the initial undo prototype code was bumping mtime/usn on undo, but
that was not ideal, as it was breaking the queue handling which expected
the mtime to match. The original rationale for bumping mtime/usn was
to avoid problems with syncing, but various operations like removing
a revlog can't be synced anyway - so we just need to ensure we clear the
undo queue prior to syncing
