Pre
Handle returned immediately by Terminal.startPreTransaction.
Call getResult to retrieve the PreTransactionResult - it always returns one, either blocking until the wait is over or returning immediately with the current state. Call cancel to stop waiting early - from another thread, if getResult is currently blocked in a call from a different thread.
Continue the payment through PreTransactionResult.startTransaction, or discard it with PreTransactionResult.abort. Cancelling the local wait does not discard the payment.
Functions
Stops waiting for loyalty data early - interrupts the local background wait if it is still running, and unblocks any concurrent getResult call that is currently blocked waiting for a result, which then returns a PreTransactionResult whose PreTransactionResult.getLoyaltyData is null. Does not affect the terminal or the payment itself - the wait and the payment are independent. Continue through PreTransactionResult.startTransaction afterwards. A direct Terminal.startTransaction call remains blocked until the pre-transaction is continued or discarded with Terminal.abort.
Retrieves the PreTransactionResult - never null. Call PreTransactionResult.getLoyaltyData on it to check whether loyalty card data was collected.