Empty cards become undoable

As a side effect, once this undoable operation is used by AnkiDroid,
it means that "Empty cards" will send a notification to observers of
the collection. Hence the deck picker and the widgets can update.

ftl/core/actions.ftl

@@ -12,6 +12,7 @@ actions-decks = Decks
 actions-decrement-value = Decrement value
 actions-delete = Delete
 actions-export = Export
+actions-empty-cards = Empty Cards
 actions-filter = Filter
 actions-help = Help
 actions-increment-value = Increment value

proto/anki/cards.proto

@@ -13,7 +13,7 @@ import "anki/collection.proto";
 service CardsService {
   rpc GetCard(CardId) returns (Card);
   rpc UpdateCards(UpdateCardsRequest) returns (collection.OpChanges);
-  rpc RemoveCards(RemoveCardsRequest) returns (generic.Empty);
+  rpc RemoveCards(RemoveCardsRequest) returns (collection.OpChangesWithCount);
   rpc SetDeck(SetDeckRequest) returns (collection.OpChangesWithCount);
   rpc SetFlag(SetFlagRequest) returns (collection.OpChangesWithCount);
 }

pylib/anki/collection.py

@@ -604,9 +604,11 @@ def is_empty(self) -> bool:
     def card_count(self) -> Any:
         return self.db.scalar("select count() from cards")
 
-    def remove_cards_and_orphaned_notes(self, card_ids: Sequence[CardId]) -> None:
+    def remove_cards_and_orphaned_notes(
+        self, card_ids: Sequence[CardId]
+    ) -> OpChangesWithCount:
         "You probably want .remove_notes_by_card() instead."
-        self._backend.remove_cards(card_ids=card_ids)
+        return self._backend.remove_cards(card_ids=card_ids)
 
     def set_deck(self, card_ids: Sequence[CardId], deck_id: int) -> OpChangesWithCount:
         return self._backend.set_deck(card_ids=card_ids, deck_id=deck_id)

rslib/src/card/mod.rs

@@ -327,7 +327,7 @@ impl Collection {
 
     /// Remove cards and any resulting orphaned notes.
     /// Expects a transaction.
-    pub(crate) fn remove_cards_and_orphaned_notes(&mut self, cids: &[CardId]) -> Result<()> {
+    pub(crate) fn remove_cards_and_orphaned_notes(&mut self, cids: &[CardId]) -> Result<usize> {
         let usn = self.usn()?;
         let mut nids = HashSet::new();
         for cid in cids {
@@ -342,7 +342,7 @@ impl Collection {
             }
         }
 
-        Ok(())
+        Ok(cids.len())
     }
 
     pub fn set_deck(&mut self, cards: &[CardId], deck_id: DeckId) -> Result<OpOutput<usize>> {

rslib/src/card/service.rs

@@ -14,6 +14,7 @@ use crate::error::OrNotFound;
 use crate::notes::NoteId;
 use crate::prelude::TimestampSecs;
 use crate::prelude::Usn;
+use crate::undo::Op;
 
 impl crate::services::CardsService for Collection {
     fn get_card(
@@ -44,17 +45,20 @@ impl crate::services::CardsService for Collection {
             .map(Into::into)
     }
 
-    fn remove_cards(&mut self, input: anki_proto::cards::RemoveCardsRequest) -> error::Result<()> {
-        self.transact_no_undo(|col| {
+    fn remove_cards(
+        &mut self,
+        input: anki_proto::cards::RemoveCardsRequest,
+    ) -> error::Result<anki_proto::collection::OpChangesWithCount> {
+        self.transact(Op::EmptyCards, |col| {
             col.remove_cards_and_orphaned_notes(
                 &input
                     .card_ids
                     .into_iter()
                     .map(Into::into)
                     .collect::<Vec<_>>(),
-            )?;
-            Ok(())
+            )
         })
+        .map(Into::into)
     }
 
     fn set_deck(

rslib/src/ops.rs

@@ -15,6 +15,7 @@ pub enum Op {
     ChangeNotetype,
     ClearUnusedTags,
     CreateCustomStudy,
+    EmptyCards,
     EmptyFilteredDeck,
     FindAndReplace,
     ImageOcclusion,
@@ -57,6 +58,7 @@ impl Op {
             Op::AnswerCard => tr.actions_answer_card(),
             Op::Bury => tr.studying_bury(),
             Op::CreateCustomStudy => tr.actions_custom_study(),
+            Op::EmptyCards => tr.actions_empty_cards(),
             Op::Import => tr.actions_import(),
             Op::RemoveDeck => tr.decks_delete_deck(),
             Op::RemoveNote => tr.studying_delete_note(),