fix: keep deck selection dialog open for multi-select in widget config

AnkiDroid/src/main/java/com/ichi2/anki/dialogs/DeckSelectionDialog.kt

@@ -77,6 +77,7 @@ import java.util.Locale
 open class DeckSelectionDialog : AnalyticsDialogFragment() {
     private lateinit var binding: DialogDeckPickerBinding
     private var dialog: AlertDialog? = null
+    private lateinit var decksAdapter: DecksArrayAdapter
     private lateinit var expandImage: Drawable
     private lateinit var collapseImage: Drawable
     private lateinit var decksRoot: DeckNode
@@ -113,9 +114,9 @@ open class DeckSelectionDialog : AnalyticsDialogFragment() {
         val dividerItemDecoration = DividerItemDecoration(binding.list.context, DividerItemDecoration.VERTICAL)
         binding.list.addItemDecoration(dividerItemDecoration)
         val decks: List<SelectableDeck> = getDeckNames(arguments)
-        val adapter = DecksArrayAdapter(decks)
-        binding.list.adapter = adapter
-        adjustToolbar(binding.root, adapter)
+        decksAdapter = DecksArrayAdapter(decks)
+        binding.list.adapter = decksAdapter
+        adjustToolbar(binding.root, decksAdapter)
         dialog =
             AlertDialog.Builder(requireActivity()).create {
                 negativeButton(R.string.dialog_cancel)
@@ -239,13 +240,26 @@ open class DeckSelectionDialog : AnalyticsDialogFragment() {
 
     var deckCreationListener: DeckCreationListener? = null
 
+    private val keepOpen: Boolean
+        get() = requireArguments().getBoolean(KEEP_OPEN)
+
     /**
      * Same action as pressing on the deck in the list. I.e. send the deck to listener and close the dialog.
+     * When [keepOpen] is true, the dialog stays open and removes the selected deck from the list.
      */
     protected fun selectDeckAndClose(deck: SelectableDeck) {
         Timber.d("selected deck '%s'", deck)
         onDeckSelected(deck)
-        dialog!!.dismiss()
+        if (keepOpen) {
+            if (deck is SelectableDeck.Deck) {
+                decksAdapter.removeDeck(deck.deckId)
+            }
+            if (decksAdapter.itemCount == 0) {
+                dialog?.dismiss()
+            }
+        } else {
+            dialog!!.dismiss()
+        }
     }
 
     protected fun displayErrorAndCancel() {
@@ -308,6 +322,11 @@ open class DeckSelectionDialog : AnalyticsDialogFragment() {
             notifyDataSetChanged()
         }
 
+        fun removeDeck(deckId: DeckId) {
+            allDecksList.removeAll { it.did == deckId }
+            updateCurrentlyDisplayedDecks()
+        }
+
         private val allDecksList = ArrayList<DeckNode>()
         private val currentlyDisplayedDecks = ArrayList<DeckNode>()
 
@@ -437,6 +456,7 @@ open class DeckSelectionDialog : AnalyticsDialogFragment() {
         private const val TITLE = "title"
         private const val KEEP_RESTORE_DEFAULT_BUTTON = "keepRestoreDefaultButton"
         private const val DECK_NAMES = "deckNames"
+        private const val KEEP_OPEN = "keepOpen"
 
         /**
          * A dialog which handles selecting a deck
@@ -446,13 +466,15 @@ open class DeckSelectionDialog : AnalyticsDialogFragment() {
             summaryMessage: String?,
             keepRestoreDefaultButton: Boolean,
             decks: List<SelectableDeck>,
+            keepOpen: Boolean = false,
         ): DeckSelectionDialog {
             val f = DeckSelectionDialog()
             val args = Bundle()
             args.putString(SUMMARY_MESSAGE, summaryMessage)
             args.putString(TITLE, title)
             args.putBoolean(KEEP_RESTORE_DEFAULT_BUTTON, keepRestoreDefaultButton)
             args.putParcelableArrayList(DECK_NAMES, ArrayList(decks))
+            args.putBoolean(KEEP_OPEN, keepOpen)
             f.arguments = args
             return f
         }

AnkiDroid/src/main/java/com/ichi2/widget/deckpicker/DeckPickerWidgetConfig.kt

@@ -154,8 +154,6 @@ class DeckPickerWidgetConfig :
 
         setupDoneButton()
 
-        // TODO: Implement multi-select functionality so that user can select desired decks in once.
-        // TODO: Implement a functionality to hide already selected deck.
         binding.fabWidgetDeckPicker.setOnClickListener {
             showDeckSelectionDialog()
         }
@@ -302,10 +300,10 @@ class DeckPickerWidgetConfig :
         }
     }
 
-    /** Asynchronously displays the list of deck in the selection dialog. */
+    /** Displays the deck selection dialog, filtering out already-selected decks. */
     private fun showDeckSelectionDialog() {
         lifecycleScope.launch {
-            val decks = fetchDecks()
+            val decks = fetchDecks().filter { it.deckId !in deckAdapter.deckIds }
             displayDeckSelectionDialog(decks)
         }
     }
@@ -324,8 +322,13 @@ class DeckPickerWidgetConfig :
                 summaryMessage = null,
                 keepRestoreDefaultButton = false,
                 decks = decks,
+                keepOpen = true,
             )
-        dialog.show(supportFragmentManager, "DeckSelectionDialog")
+        dialog.show(supportFragmentManager, DECK_SELECTION_DIALOG_TAG)
+    }
+
+    private fun dismissDeckSelectionDialog() {
+        (supportFragmentManager.findFragmentByTag(DECK_SELECTION_DIALOG_TAG) as? DeckSelectionDialog)?.dismiss()
     }
 
     /** Called when a deck is selected from the deck selection dialog. */
@@ -338,31 +341,27 @@ class DeckPickerWidgetConfig :
         val isDeckAlreadySelected = deckAdapter.deckIds.contains(deck.deckId)
 
         if (isDeckAlreadySelected) {
-            // TODO: Eventually, ensure that the user can't select a deck that is already selected.
             showSnackbar(getString(R.string.deck_already_selected_message))
             return
         }
 
-        // Check if the deck is being added to a fully occupied selection
         if (deckAdapter.itemCount >= MAX_DECKS_ALLOWED) {
-            // Snackbar will only be shown when adding the 5th deck
             if (deckAdapter.itemCount == MAX_DECKS_ALLOWED) {
                 showSnackbar(resources.getQuantityString(R.plurals.deck_limit_reached, MAX_DECKS_ALLOWED, MAX_DECKS_ALLOWED))
             }
-            // The FAB visibility should be handled in updateFabVisibility()
-        } else {
-            // Add the deck and update views
-            deckAdapter.addDeck(deck)
-            updateViewVisibility()
-            updateFabVisibility()
-            setupDoneButton()
-            hasUnsavedChanges = true
-            setUnsavedChanges(true)
+            return
+        }
 
-            // Show snackbar if the deck is the 5th deck
-            if (deckAdapter.itemCount == MAX_DECKS_ALLOWED) {
-                showSnackbar(resources.getQuantityString(R.plurals.deck_limit_reached, MAX_DECKS_ALLOWED, MAX_DECKS_ALLOWED))
-            }
+        deckAdapter.addDeck(deck)
+        updateViewVisibility()
+        updateFabVisibility()
+        setupDoneButton()
+        hasUnsavedChanges = true
+        setUnsavedChanges(true)
+
+        if (deckAdapter.itemCount == MAX_DECKS_ALLOWED) {
+            showSnackbar(resources.getQuantityString(R.plurals.deck_limit_reached, MAX_DECKS_ALLOWED, MAX_DECKS_ALLOWED))
+            dismissDeckSelectionDialog()
         }
     }
 
@@ -459,9 +458,7 @@ class DeckPickerWidgetConfig :
         }
 
     companion object {
-        /**
-         * Maximum number of decks allowed in the widget.
-         */
         private const val MAX_DECKS_ALLOWED = 5
+        private const val DECK_SELECTION_DIALOG_TAG = "DeckSelectionDialog"
     }
 }