smelter: scroll wheel to operate the item slots

src/net/torvald/terrarum/modulebasegame/gameactors/ActorInventory.kt

@@ -40,11 +40,11 @@ class ActorInventory() : FixtureInventory() {
     val quickSlot = Array<ItemID?>(UIQuickslotBar.SLOT_COUNT) { null } // 0: Slot 1, 9: Slot 10
 
 
-    override fun remove(itemID: ItemID, count: Long) = remove(ItemCodex[itemID]!!, count)
+    override fun remove(itemID: ItemID, count: Long): Long = remove(ItemCodex[itemID]!!, count)
     /** Will check existence of the item using its Dynamic ID; careful with command order!
      *      e.g. re-assign after this operation */
-    override fun remove(item: GameItem, count: Long) {
-        super.remove(item, count) { existingItem ->
+    override fun remove(item: GameItem, count: Long): Long {
+        return super.remove(item, count) { existingItem ->
             // unequip, if applicable
             actor.unequipItem(existingItem.itm)
             // also unequip on the quickslot

src/net/torvald/terrarum/modulebasegame/gameactors/FixtureInventory.kt

@@ -136,19 +136,23 @@ open class FixtureInventory() {
     open fun remove(itemID: ItemID, count: Long, unequipFun: (InventoryPair) -> Unit) =
             remove(ItemCodex[itemID]!!, count, unequipFun)
     /** Will check existence of the item using its Dynamic ID; careful with command order!
-     *      e.g. re-assign after this operation */
-    open fun remove(item: GameItem, count: Long = 1, unequipFun: (InventoryPair) -> Unit) {
+     *      e.g. re-assign after this operation
+     *
+     * @return the actual amount of item that has been removed
+     **/
+    open fun remove(item: GameItem, count: Long = 1, unequipFun: (InventoryPair) -> Unit): Long {
 
 //        printdbg(this, "remove $item, $count")
 
         if (count == 0L)
 //            throw IllegalArgumentException("[${this.javaClass.canonicalName}] Item count is zero.")
-            return
+            return 0L
         if (count < 0L)
             throw IllegalArgumentException("[${this.javaClass.canonicalName}] Item count is negative number. If you intended adding items, use add()" +
                                            "These commands are NOT INTERCHANGEABLE; they handle things differently according to the context.")
 
 
+        var delta = 0L
 
         val existingItem = searchByID(item.dynamicID)
         if (existingItem != null) { // if the item already exists
@@ -158,10 +162,12 @@ open class FixtureInventory() {
                 throw InventoryFailedTransactionError("[${this.javaClass.canonicalName}] Tried to remove $count of $item, but the inventory only contains ${existingItem.qty} of them.")
             }
             else*/ if (newCount > 0) {
+                delta = count
                 // decrement count
                 existingItem.qty = newCount
             }
             else {
+                delta = existingItem.qty
                 // unequip must be done before the entry removal
                 unequipFun(existingItem)
                 // depleted item; remove entry from inventory
@@ -170,11 +176,14 @@ open class FixtureInventory() {
         }
         else {
 //            throw InventoryFailedTransactionError("[${this.javaClass.canonicalName}] Tried to remove $item, but the inventory does not have it.")
+            return 0L
         }
 
-        itemList.sumOf { ItemCodex[it.itm]!!.mass * it.qty }
+//        itemList.sumOf { ItemCodex[it.itm]!!.mass * it.qty } // ???
 
         updateEncumbrance()
+
+        return delta
     }
 
     open fun clear(): List<InventoryPair> {