refactor(deck-picker): inline result classes

Now we have UiEvent, we have no need for these classes

Assisted-by: Claude Opus 4.6

Author: david-allison

AnkiDroid/src/main/java/com/ichi2/anki/DeckPicker.kt

@@ -105,14 +105,11 @@ import com.ichi2.anki.databinding.IncludeDeckPickerBinding
 import com.ichi2.anki.databinding.IncludeFloatingAddButtonBinding
 import com.ichi2.anki.deckpicker.BITMAP_BYTES_PER_PIXEL
 import com.ichi2.anki.deckpicker.BackgroundImage
-import com.ichi2.anki.deckpicker.DeckDeletionResult
 import com.ichi2.anki.deckpicker.DeckPickerViewModel
 import com.ichi2.anki.deckpicker.DeckPickerViewModel.AnkiDroidEnvironment
 import com.ichi2.anki.deckpicker.DeckPickerViewModel.FlattenedDeckList
 import com.ichi2.anki.deckpicker.DeckPickerViewModel.StartupResponse
-import com.ichi2.anki.deckpicker.EmptyCardsResult
 import com.ichi2.anki.deckpicker.OptionsMenuState
-import com.ichi2.anki.deckpicker.ShortcutData
 import com.ichi2.anki.deckpicker.SyncIconState
 import com.ichi2.anki.deckpicker.UiEvent
 import com.ichi2.anki.dialogs.AsyncDialogFragment
@@ -654,14 +651,14 @@ open class DeckPicker :
 
     @Suppress("UNUSED_PARAMETER")
     private fun setupFlows() {
-        fun onDeckDeleted(result: DeckDeletionResult) {
-            showSnackbar(result.toHumanReadableString(), Snackbar.LENGTH_SHORT) {
+        fun onDeckDeleted(event: UiEvent.DeckDeleted) {
+            showSnackbar(event.toHumanReadableString(), Snackbar.LENGTH_SHORT) {
                 setAction(R.string.undo) { undo() }
             }
         }
 
-        fun onCardsEmptied(result: EmptyCardsResult) {
-            showSnackbar(result.toHumanReadableString(), Snackbar.LENGTH_SHORT) {
+        fun onCardsEmptied(event: UiEvent.EmptyCardsDeleted) {
+            showSnackbar(event.toHumanReadableString(), Snackbar.LENGTH_SHORT) {
                 setAction(R.string.undo) { undo() }
             }
         }
@@ -836,12 +833,12 @@ open class DeckPicker :
 
         viewModel.uiEvents.launchCollectionInLifecycleScope { event ->
             when (event) {
-                is UiEvent.DeckDeleted -> onDeckDeleted(event.result)
-                is UiEvent.EmptyCardsDeleted -> onCardsEmptied(event.result)
+                is UiEvent.DeckDeleted -> onDeckDeleted(event)
+                is UiEvent.EmptyCardsDeleted -> onCardsEmptied(event)
                 is UiEvent.Navigate -> onDestinationChanged(event.destination)
                 is UiEvent.ShowError -> onError(event.message)
                 is UiEvent.ExportDeck -> onExportDeck(event.deckId)
-                is UiEvent.CreateShortcut -> createIcon(event.data)
+                is UiEvent.CreateShortcut -> createIcon(event)
                 is UiEvent.DisableShortcuts -> disableDeckAndChildrenShortcuts(event.deckIds)
                 UiEvent.PromptUpdateScheduler -> onPromptUserToUpdateScheduler(Unit)
                 UiEvent.UndoUpdated -> onUndoUpdated(Unit)
@@ -2121,16 +2118,16 @@ open class DeckPicker :
         }
     }
 
-    private fun createIcon(shortcutData: ShortcutData) {
+    private fun createIcon(event: UiEvent.CreateShortcut) {
         // This code should not be reachable with lower versions
         val shortcut =
             ShortcutInfoCompat
-                .Builder(this, shortcutData.deckId.toString())
+                .Builder(this, event.deckId.toString())
                 .setIntent(
-                    intentToReviewDeckFromShortcuts(this, shortcutData.deckId),
+                    intentToReviewDeckFromShortcuts(this, event.deckId),
                 ).setIcon(IconCompat.createWithResource(this, R.mipmap.ic_launcher))
-                .setShortLabel(shortcutData.shortLabel)
-                .setLongLabel(shortcutData.longLabel)
+                .setShortLabel(event.shortLabel)
+                .setLongLabel(event.longLabel)
                 .build()
         try {
             val success = ShortcutManagerCompat.requestPinShortcut(this, shortcut, null)

AnkiDroid/src/main/java/com/ichi2/anki/deckpicker/DeckPickerViewModel.kt

@@ -25,7 +25,6 @@ import androidx.lifecycle.viewModelScope
 import anki.card_rendering.EmptyCardsReport
 import anki.collection.OpChanges
 import anki.decks.SetDeckCollapsedRequest
-import anki.i18n.GeneratedTranslations
 import anki.sync.SyncStatusResponse
 import com.ichi2.anki.CollectionManager
 import com.ichi2.anki.CollectionManager.TR
@@ -203,11 +202,7 @@ class DeckPickerViewModel :
             // to match and avoid unnecessary scrolls in `renderPage()`.
             focusedDeck = Consts.DEFAULT_DECK_ID
 
-            events.emit(
-                UiEvent.DeckDeleted(
-                    DeckDeletionResult(deckName = deckName, cardsDeleted = changes.count),
-                ),
-            )
+            events.emit(UiEvent.DeckDeleted(deckName = deckName, cardsDeleted = changes.count))
         }
 
     /**
@@ -245,7 +240,7 @@ class DeckPickerViewModel :
             }
         }
         val result = undoableOp { removeCardsAndOrphanedNotes(toDelete) }
-        events.emit(UiEvent.EmptyCardsDeleted(EmptyCardsResult(cardsDeleted = result.count)))
+        events.emit(UiEvent.EmptyCardsDeleted(cardsDeleted = result.count))
     }
 
     // TODO: move withProgress to the ViewModel, so we don't return 'Job'
@@ -447,11 +442,9 @@ class DeckPickerViewModel :
                 }
             events.emit(
                 UiEvent.CreateShortcut(
-                    ShortcutData(
-                        deckId = deckId,
-                        shortLabel = shortLabel,
-                        longLabel = longLabel,
-                    ),
+                    deckId = deckId,
+                    shortLabel = shortLabel,
+                    longLabel = longLabel,
                 ),
             )
         }
@@ -608,46 +601,8 @@ class DeckPickerViewModel :
     }
 }
 
-/** Result of [DeckPickerViewModel.deleteDeck] */
-data class DeckDeletionResult(
-    val deckName: String,
-    val cardsDeleted: Int,
-) {
-    /**
-     * @see GeneratedTranslations.browsingCardsDeletedWithDeckname
-     */
-    // TODO: Somewhat questionable meaning: {count} cards deleted from {deck_name}.
-    @CheckResult
-    fun toHumanReadableString() =
-        TR.browsingCardsDeletedWithDeckname(
-            count = cardsDeleted,
-            deckName = deckName,
-        )
-}
-
-/** Result of [DeckPickerViewModel.deleteEmptyCards] */
-data class EmptyCardsResult(
-    val cardsDeleted: Int,
-) {
-    /**
-     * @see GeneratedTranslations.emptyCardsDeletedCount */
-    @CheckResult
-    fun toHumanReadableString() = TR.emptyCardsDeletedCount(cardsDeleted)
-}
-
 fun DeckNode.onlyHasDefaultDeck() = children.singleOrNull()?.did == DEFAULT_DECK_ID
 
-/**
- * Data for creating a deck shortcut
- * @param shortLabel the basename of the deck (e.g., "Verbs" for "Language::English::Verbs")
- * @param longLabel the full deck name (e.g., "Language::English::Verbs")
- */
-data class ShortcutData(
-    val deckId: DeckId,
-    val shortLabel: String,
-    val longLabel: String,
-)
-
 enum class SyncIconState {
     Normal,
     PendingChanges,
@@ -656,18 +611,36 @@ enum class SyncIconState {
 }
 
 /**
- * One-shot UI events emitted by [DeckPickerViewModel].
- *
- * @see com.ichi2.anki.ui.UiEventHost
+ * One-shot UI events emitted by [DeckPickerViewModel] over a single channel and
+ * collected by [DeckPicker]. Use for navigation, snackbars, dialogs, errors —
+ * not for ongoing state (use a `StateFlow` for that).
  */
 sealed interface UiEvent {
+    /** A deck (and possibly child decks) was deleted. @see DeckPickerViewModel.deleteDeck */
     data class DeckDeleted(
-        val result: DeckDeletionResult,
-    ) : UiEvent
+        val deckName: String,
+        val cardsDeleted: Int,
+    ) : UiEvent {
+        /**
+         * @see anki.i18n.GeneratedTranslations.browsingCardsDeletedWithDeckname
+         */
+        // TODO: Somewhat questionable meaning: {count} cards deleted from {deck_name}.
+        @CheckResult
+        fun toHumanReadableString() =
+            TR.browsingCardsDeletedWithDeckname(
+                count = cardsDeleted,
+                deckName = deckName,
+            )
+    }
 
+    /** Empty cards were removed. @see DeckPickerViewModel.deleteEmptyCards */
     data class EmptyCardsDeleted(
-        val result: EmptyCardsResult,
-    ) : UiEvent
+        val cardsDeleted: Int,
+    ) : UiEvent {
+        /** @see anki.i18n.GeneratedTranslations.emptyCardsDeletedCount */
+        @CheckResult
+        fun toHumanReadableString() = TR.emptyCardsDeletedCount(cardsDeleted)
+    }
 
     data class Navigate(
         val destination: Destination,
@@ -681,8 +654,15 @@ sealed interface UiEvent {
         val deckId: DeckId,
     ) : UiEvent
 
+    /**
+     * Request to create a launcher shortcut for a deck.
+     * @param shortLabel the basename of the deck (e.g., "Verbs" for "Language::English::Verbs")
+     * @param longLabel the full deck name (e.g., "Language::English::Verbs")
+     */
     data class CreateShortcut(
-        val data: ShortcutData,
+        val deckId: DeckId,
+        val shortLabel: String,
+        val longLabel: String,
     ) : UiEvent
 
     data class DisableShortcuts(

AnkiDroid/src/test/java/com/ichi2/anki/deckpicker/DeckPickerViewModelTest.kt

@@ -53,22 +53,22 @@ class DeckPickerViewModelTest : RobolectricTest() {
                 viewModel.deleteEmptyCards(cardsToEmpty).join()
 
                 expectMostRecentItem().also {
-                    assertThat("cards deleted", it.result.cardsDeleted, equalTo(EXPECTED_CARDS))
+                    assertThat("cards deleted", it.cardsDeleted, equalTo(EXPECTED_CARDS))
                 }
 
                 // ensure a duplicate output is displayed to the user
                 val newCardsToEmpty = createEmptyCards()
                 viewModel.deleteEmptyCards(newCardsToEmpty).join()
 
                 expectMostRecentItem().also {
-                    assertThat("cards deleted: duplicate output", it.result.cardsDeleted, equalTo(EXPECTED_CARDS))
+                    assertThat("cards deleted: duplicate output", it.cardsDeleted, equalTo(EXPECTED_CARDS))
                 }
 
                 // test an empty list: a no-op should inform the user, rather than do nothing
                 viewModel.deleteEmptyCards(emptyCardsReport { }).join()
 
                 expectMostRecentItem().also {
-                    assertThat("'no cards deleted' is notified", it.result.cardsDeleted, equalTo(0))
+                    assertThat("'no cards deleted' is notified", it.cardsDeleted, equalTo(0))
                 }
             }
         }
@@ -96,13 +96,13 @@ class DeckPickerViewModelTest : RobolectricTest() {
                 viewModel.deleteEmptyCards(emptyCardsReport, preserveNotes = true).join()
 
                 expectMostRecentItem().also {
-                    assertThat("note is retained", it.result.cardsDeleted, equalTo(EXPECTED_CARDS - 1))
+                    assertThat("note is retained", it.cardsDeleted, equalTo(EXPECTED_CARDS - 1))
                 }
 
                 viewModel.deleteEmptyCards(emptyCardsReport, preserveNotes = false).join()
 
                 expectMostRecentItem().also {
-                    assertThat("note is deleted", it.result.cardsDeleted, equalTo(1))
+                    assertThat("note is deleted", it.cardsDeleted, equalTo(1))
                 }
             }
         }