Let inventory batch handler decide if case input is allowed

tailbone/views/batch/inventory.py

@@ -67,10 +67,6 @@ class InventoryBatchView(BatchMasterView):
     mobile_creatable = True
     mobile_rows_creatable = True
 
-    # set to False to prevent exposing case fields for user input,
-    # when the batch count mode is "adjust only"
-    allow_adjustment_cases = True
-
     # set to True for the UI to "prefer" case amounts, as opposed to unit
     prefer_cases = False
 
@@ -309,12 +305,9 @@ class InventoryBatchView(BatchMasterView):
             'prefer_cases': self.prefer_cases,
         })
 
+    # TODO: deprecate / remove this
     def allow_cases(self, batch):
-        if batch.mode == self.enum.INVENTORY_MODE_ADJUST:
-            if self.allow_adjustment_cases:
-                return True
-            return False
-        return True
+        return self.handler.allow_cases(batch)
 
     def should_aggregate_products(self, batch):
         """