Payment/Model/PaymentSubjectTrait.php
public function getRemainingAmount()
    {
        $amount = 0;
        $currency = $this->getCurrency()->getCode();

        $hasDeposit = 1 === Money::compare($this->depositTotal, 0, $currency);

        // If deposit total is greater than zero and paid total is lower than deposit total
        if ($hasDeposit && (-1 === Money::compare($this->paidTotal, $this->depositTotal, $currency))) {
            // Pay deposit
            $total = $this->depositTotal;
        } else {
            // Pay grand total
            $total = $this->grandTotal;
        }

        $c = Money::compare($total, $this->paidTotal + $this->outstandingAccepted + $this->pendingTotal, $currency);

        // If (paid total + accepted outstanding + pending total) is lower limit
        if (1 === $c) {
            // Pay difference
            $amount = $total - $this->paidTotal - $this->outstandingAccepted - $this->pendingTotal;
        } else if (0 === $c && 0 < $this->outstandingAccepted) {
            // Pay outstanding
            $amount = $this->outstandingAccepted;
        }

        if (0 < $amount) {
            return $amount;
        }

        return 0;
    }
public function getRemainingAmount()
    {
        $amount = 0;
        $currency = $this->getCurrency()->getCode();

        $hasDeposit = 1 === Money::compare($this->depositTotal, 0, $currency);

        // If deposit total is greater than zero and paid total is lower than deposit total
        if ($hasDeposit && (-1 === Money::compare($this->paidTotal, $this->depositTotal, $currency))) {
            // Pay deposit
            $total = $this->depositTotal;
        } else {
            // Pay grand total
            $total = $this->grandTotal;
        }

        $c = Money::compare($total, $this->paidTotal + $this->outstandingAccepted + $this->pendingTotal, $currency);

        // If (paid total + accepted outstanding + pending total) is lower limit
        if (1 === $c) {
            // Pay difference
            $amount = $total - $this->paidTotal - $this->outstandingAccepted - $this->pendingTotal;
        } else if (0 === $c && 0 < $this->outstandingAccepted) {
            // Pay outstanding
            $amount = $this->outstandingAccepted;
        }

        if (0 < $amount) {
            return $amount;
        }

        return 0;
    }
Returns the payment remaining amount.

@return float