components/payments/currency_formatter.h

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_PAYMENTS_CURRENCY_FORMATTER_H_
#define COMPONENTS_PAYMENTS_CURRENCY_FORMATTER_H_

#include <memory>
#include <string>

#include "base/macros.h"
#include "base/optional.h"
#include "base/strings/string16.h"
#include "third_party/icu/source/common/unicode/locid.h"
#include "third_party/icu/source/i18n/unicode/numfmt.h"

namespace payments {

// URI specifying the ISO4217 currency code specification. See for details:
// https://w3c.github.io/browser-payment-api/#paymentcurrencyamount-dictionary
extern const char kIso4217CurrencySystem[];

// Currency formatter for amounts, according to a currency code, which typically
// adheres to [ISO4217] (for example, "USD" for US Dollars).
class CurrencyFormatter {
 public:
  // Initializes the CurrencyFormatter for a given |currency_code|,
  // |currency_system| and |locale_name|. Note that |currency_code| and
  // |currency_system| should have been validated (as part of
  // payment_details_validation.h) before this is created.
  CurrencyFormatter(const std::string& currency_code,
                    const base::Optional<std::string> currency_system,
                    const std::string& locale_name);
  ~CurrencyFormatter();

  // Formats the |amount| according to the currency code that was set. The
  // result will NOT contain the currency code, nor a subset of it. Rather, the
  // caller of this function should display the currency code separately. The
  // return value may contain non-breaking space and is ready for display. In
  // the case of a failure in initialization of the formatter or during
  // formatter, this method will return |amount|.
  base::string16 Format(const std::string& amount);

  // Returns the formatted currency code (<= 6 characters including ellipsis if
  // applicable).
  std::string formatted_currency_code() { return formatted_currency_code_; }

 private:
  const icu::Locale locale_;
  std::unique_ptr<icu::UnicodeString> currency_code_;
  std::string formatted_currency_code_;
  std::unique_ptr<icu::NumberFormat> icu_formatter_;

  DISALLOW_COPY_AND_ASSIGN(CurrencyFormatter);
};

}  // namespace payments

#endif  // COMPONENTS_PAYMENTS_CURRENCY_FORMATTER_H_