The barcode scanner and the quantity listener do not use
the same proccess although they act for the same operation.
(For example the quantity listener trigger onchange server side
while the barcode scanner not if 'notifychange' key on the
active_barcode is set to False)
Since quantity listener is based on candidate we could directly
call the _barcodeSelectedCandidate method in order to have a common
behavior and code.
Arnold Moyaux
e5305ca8b7