Qt is pretty enthusiastic about redrawing the card list when any sort
of activity occurs, and by serving blank cells while the DB was busy,
we were getting ugly flashes, and cells getting stuck blank.
Resolve the issue by calculating a row up front and caching it, then
serving stale content when updates are blocked.
- clear_unused_tags() is now undoable, and returns the number of removed
notes
- add a new mw.query_op() helper for immutable queries
- decouple "freeze/unfreeze ui state" hooks from the "interface update
required" hook, so that the former is fired even on error, and can be
made re-entrant
- use a 'block_updates' flag in Python, instead of setUpdatesEnabled(),
as the latter has the side-effect of preventing child windows like
tooltips from appearing, and forces a full redrawn when updates are
enabled again. The new behaviour leads to the card list blanking out
when a long-running op is running, but in the future if we cache the
cell values we can just display them from the cache instead.
- we were indiscriminately saving the note with saveNow(), due to the
call to saveTags(). Changed so that it only saves when the tags field
is focused.
- drain the "on_done" queue on main before launching a new background
task, to lower the chances of something in on_done making a small query
to the DB and hanging until a long op finishes
- the duplicate check in the editor was executed after the webview loads,
leading to it hanging until the sidebar finishes loading. Run it at
set_note() time instead, so that the editor loads first.
- don't throw an error when a long-running op started with with_progress()
finishes after the window it was launched from has closed
- don't throw an error when the browser is closed before the sidebar
has finished loading
Setting it straight away causes the cursor to flash on quick operations,
like saving the current note. Delay it for 300ms, which should hopefully
be long enough to not get in the way, but short enough to give indication
that long-running requests are being processed.
- need to drop cardObjs cache when updating cells
- stop listening on editor_did_* hooks. unfocus_field and typing_timer
are covered by operation_did_execute on note save already, and the
user potentially has editors open in other windows as well
- distinguish between card queue refresh and note text redraw in review
screen again
- update preview window when note updated
- defer setUpdatesEnabled(True) until we receive focus again, as it
causes cells to redraw. We might want to use our own flag to prevent
updating in the model instead of using Qt for this
- 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
Issues that need fixing:
- when the editor saves the note with perform_op(), if it isn't modified,
no new undo entry is created, and perform_op then returns the changes
made by the previous operation instead
- the approach of fetching the last action in a subsequent backend
method is unsound, as another queued operation may sneak in first before
we have a chance to query the result - it would be better if it were
returned in a single atomic action
- redrawing the current card while editing is likely to make sound
autoplay annoyingly, and it has an unpleasant redraw. We may be better off
fading it out instead
Side note: the editor cursor moves to the start of the field when the
note is updated in another window - it might be nicer to have it move
the cursor to the end instead.
- This avoids the need for a separate screen, though we may want to
slightly fade out the display when information is stale.
- Means the browser can delay updates just like the main window does.
'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()
Basic proof of concept, where the 'delete note' operation in the
reviewer has been updated to use mw.perform_op(). Instead of manually
calling .reset() afterwards, a summary of the changes is returned as
part of the undo status query, and various parts of the GUI can listen
to gui_hooks.operation_did_execute and decide whether they want to
redraw based on the scope of the changes. This should allow the sidebar
to selectively redraw just the tags area in the future for example.
Currently we're just listing out all possible areas that might be changed;
in the future we could theoretically inspect the specific changes in the
undo log to provide a more accurate report (avoiding refreshing the tags
list when no tags were added for example).
You can test it out by opening the browse screen while studying, and
then deleting the current card - the browser should update to show (deleted)
on the cards due the earlier change.
If going ahead with this, aside from updating all the screens that currently
listen for resets, some thought will be required on how we can integrate
it with legacy code that expects to called when resets are made, and expects
to call .reset() when it makes changes.
Thoughts?
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
Up until now, we've been forcing a new search whenever reset is called.
The primary reason was that the card list display routines did not expect
a card or note to have been removed. By updating the model to show
"(deleted)" when a card or note is missing, we no longer have to repeat
the search.
This has a few advantages:
- Searches, especially complex ones, can be slow to execute. When we
perform them after every operation like a delete, it can make Anki feel
sluggish.
- The fact that notes have been deleted becomes more obvious - some users
found it easy to miss the "deleted" pop-up in the past.
This change does not just affect deletions, as many other operations
trigger a reset as well. In the past, when using 'set due date' in the
review screen for example, it caused an ugly flicker in the browser screen,
and could be slow when the current search couldn't be quickly redone.
The disadvantage of this approach is that the displayed content may
not reflect the specified search, which has the potential to be confusing.
But if that turns out to be a problem, it could be (partly) alleviated by
displaying a refresh button next to the search bar when the search may
need to be refreshed.
Feedback welcome!
This correct the probably rare bug as follow:
I got a note type with a field whose name is "\".
When I made any change to this note type, even unrelated, I get a message stating that there is an empty field. This is
strange because I can see it to be false. Investigating show that "\" is normalized to empty field. This ensure that
it's shown
