refactor

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

@@ -176,12 +176,51 @@ class DeckPickerWidgetConfig : AnkiActivity(), DeckSelectionListener {
 
     /** Updates the visibility of the FloatingActionButton based on the number of selected decks */
     private fun updateFabVisibility() {
-        val fab = findViewById<FloatingActionButton>(R.id.fabWidgetDeckPicker)
-        fab.visibility = if (deckAdapter.itemCount >= MAX_DECKS_ALLOWED) {
-            View.GONE
-        } else {
-            View.VISIBLE
+        lifecycleScope.launch {
+            // Check if the default deck is empty
+            val defaultDeckEmpty = isDefaultDeckEmpty()
+
+            // Fetch the total number of selectable decks
+            val totalSelectableDecks = getTotalSelectableDecks()
+
+            // Adjust totalSelectableDecks if the default deck is empty
+            var adjustedTotalSelectableDecks = totalSelectableDecks
+            if (defaultDeckEmpty) {
+                adjustedTotalSelectableDecks -= 1
+            }
+
+            // Get the number of selected decks
+            val selectedDeckCount = deckAdapter.itemCount
+            Timber.d("Selected decks count: $selectedDeckCount")
+
+            // Determine FAB visibility
+            val fab = findViewById<FloatingActionButton>(R.id.fabWidgetDeckPicker)
+            fab.visibility = if (selectedDeckCount >= MAX_DECKS_ALLOWED || selectedDeckCount >= adjustedTotalSelectableDecks) {
+                View.GONE
+            } else {
+                View.VISIBLE
+            }
+        }
+    }
+
+    /** Returns the total number of selectable decks. */
+    private suspend fun getTotalSelectableDecks(): Int {
+        return withContext(Dispatchers.IO) {
+            SelectableDeck.fromCollection(includeFiltered = false).size
+        }
+    }
+
+    private fun isDefaultDeckEmpty(): Boolean {
+        val tree = dueTree ?: run {
+            Timber.d("Due tree is null")
+            return true
+        }
+        val defaultDeck = tree.children.find { it.did == 1L }
+        if (defaultDeck == null) {
+            return true
         }
+        val defaultDeckHasCards = defaultDeck.hasCardsReadyToStudy()
+        return !defaultDeckHasCards
     }
 
     /** Loads saved preferences and updates the RecyclerView */
@@ -360,10 +399,11 @@ class DeckPickerWidgetConfig : AnkiActivity(), DeckSelectionListener {
      *         `false` otherwise.
      */
     private fun isCollectionEmpty(tree: DeckNode): Boolean {
-        val isEmpty = tree.children.size == 1 && tree.children[0].did == 1L
-        Timber.d("isEmpty: $isEmpty")
-
-        return isEmpty
+        if (tree.children.size == 1 && tree.children[0].did == 1L) {
+            val defaultDeckHasCards = tree.children[0].hasCardsReadyToStudy()
+            return !defaultDeckHasCards
+        }
+        return false
     }
 
     /**