erp5_trade: add `getTotalQuantity` method to offset

bt5/erp5_trade/DocumentTemplateItem/portal_components/document.erp5.InventoryOffsetLine.py

@@ -55,3 +55,31 @@ class InventoryOffsetLine(DeliveryLine):
                     , PropertySheet.VariationRange
                     , PropertySheet.ItemAggregation
                     )
+
+  security.declareProtected(Permissions.AccessContentsInformation, 'getTotalQuantity')
+  def getTotalQuantity(self):
+    """
+    Returns the quantity if no cell or the total quantity if cells
+    """
+    if not self.hasCellContent():
+      return self.getQuantity()
+    else:
+      total_quantity = 0.0
+      for cell in self.getCellValueList(base_id='movement'):
+        if cell.getQuantity() is not None:
+          total_quantity += cell.getQuantity()
+      return total_quantity
+
+  security.declareProtected(Permissions.AccessContentsInformation, 'getTotalPrice')
+  def getTotalPrice(self):
+    """
+    Returns the price if no cell or the total price if cells
+    """
+    if not self.hasCellContent():
+      return self.getPrice()
+    else:
+      total_price = 0.0
+      for cell in self.getCellValueList(base_id='movement'):
+        if cell.getPrice() is not None:
+          total_price += cell.getPrice()
+      return total_price

bt5/erp5_trade/DocumentTemplateItem/portal_components/document.erp5.InventoryOffsetLine.xml

@@ -35,7 +35,10 @@
         <item>
             <key> <string>text_content_warning_message</string> </key>
             <value>
-              <tuple/>
+              <tuple>
+                <string>W: 60,  2: Arguments number differs from overridden \'getTotalQuantity\' method (arguments-differ)</string>
+                <string>W: 74,  2: Arguments number differs from overridden \'getTotalPrice\' method (arguments-differ)</string>
+              </tuple>
             </value>
         </item>
         <item>