- Introduced a new transact() method that wraps the return value
in a separate struct that describes the changes that were made.
- Changes are now gathered from the undo log, so we don't need to
guess at what was changed - eg if update_note() is called with identical
note contents, no changes are returned. Card changes will only be set
if cards were actually generated by the update_note() call, and tag
will only be set if a new tag was added.
- mw.perform_op() has been updated to expect the op to return the changes,
or a structure with the changes in it, and it will use them to fire the
change hook, instead of fetching the changes from undo_status(), so there
is no risk of race conditions.
- the various calls to mw.perform_op() have been split into separate
files like card_ops.py. Aside from making the code cleaner, this works
around a rather annoying issue with mypy. Because we run it with
no_strict_optional, mypy is happy to accept an operation that returns None,
despite the type signature saying it requires changes to be returned.
Turning no_strict_optional on for the whole codebase is not practical
at the moment, but we can enable it for individual files.
Still todo:
- The cursor keeps moving back to the start of a field when typing -
we need to ignore the refresh hook when we are the initiator.
- The busy cursor icon should probably be delayed a few hundreds ms.
- Still need to think about a nicer way of handling saveNow()
- op_made_changes(), op_affects_study_queue() might be better embedded
as properties in the object instead
'card modified' covers the common case where we need to rebuild the
study queue, but is also set when changing the card flags. We want to
avoid a queue rebuild in that case, as it causes UI flicker, and may
result in a different card being shown. Note marking doesn't trigger
a queue build, but still causes flicker, and may return the user back
to the front side when they were looking at the answer.
I still think entity-based change tracking is the simplest in the
common case, but to solve the above, I've introduced an enum describing
the last operation that was taken. This currently is not trying to list
out all possible operations, and just describes the ones we want to
special-case.
Other changes:
- Fire the old 'state_did_reset' hook after an operation is performed,
so legacy code can refresh itself after an operation is performed.
- Fire the new `operation_did_execute` hook when mw.reset() is called,
so that as the UI is updated to the use the new hook, it will still
be able to refresh after legacy code calls mw.reset()
- Update the deck browser, overview and review screens to listen to
the new hook, instead of relying on the main window to call moveToState()
- Add a 'set flag' backend action, so we can distinguish it from a
normal card update.
- Drop the separate added/modified entries in the change list in
favour of a single entry per entity.
- Add typing to mw.state
- Tweak perform_op()
- Convert a few more actions to use perform_op()
Fixes the following issue:
- some code directly modifies the database, causing modified_in_python
to be set to true
- an undoable operation is run, which calls autosave() at the end
- autosave() notices there's an undoable operation, and commits immediately
- because modified_in_python was true, col.mtime was bumped in Python
- that invalidated the undo queue, preventing the operation from being
undone
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.
