1 files changed, 133 insertions, 0 deletions
diff --git a/intl/components/src/Calendar.h b/intl/components/src/Calendar.h
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+++ b/intl/components/src/Calendar.h
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef intl_components_Calendar_h_
+#define intl_components_Calendar_h_
+
+#include "mozilla/Assertions.h"
+#include "mozilla/EnumSet.h"
+#include "mozilla/intl/ICU4CGlue.h"
+#include "mozilla/intl/ICUError.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/Result.h"
+#include "mozilla/Span.h"
+#include "mozilla/UniquePtr.h"
+
+using UCalendar = void*;
+
+namespace mozilla::intl {
+
+/**
+ * Weekdays in the ISO-8601 calendar.
+ */
+enum class Weekday : uint8_t {
+  Monday = 1,
+  Tuesday,
+  Wednesday,
+  Thursday,
+  Friday,
+  Saturday,
+  Sunday,
+};
+
+/**
+ * This component is a Mozilla-focused API for working with calendar systems in
+ * internationalization code. It is used in coordination with other operations
+ * such as datetime formatting.
+ */
+class Calendar final {
+ public:
+  explicit Calendar(UCalendar* aCalendar) : mCalendar(aCalendar) {
+    MOZ_ASSERT(aCalendar);
+  };
+
+  // Do not allow copy as this class owns the ICU resource. Move is not
+  // currently implemented, but a custom move operator could be created if
+  // needed.
+  Calendar(const Calendar&) = delete;
+  Calendar& operator=(const Calendar&) = delete;
+
+  /**
+   * Create a Calendar.
+   */
+  static Result<UniquePtr<Calendar>, ICUError> TryCreate(
+      const char* aLocale,
+      Maybe<Span<const char16_t>> aTimeZoneOverride = Nothing{});
+
+  /**
+   * Get the BCP 47 keyword value string designating the calendar type. For
+   * instance "gregory", "chinese", "islamic-civil", etc.
+   */
+  Result<Span<const char>, ICUError> GetBcp47Type();
+
+  /**
+   * Return the set of weekdays which are considered as part of the weekend.
+   */
+  Result<EnumSet<Weekday>, ICUError> GetWeekend();
+
+  /**
+   * Return the weekday which is considered the first day of the week.
+   */
+  Weekday GetFirstDayOfWeek();
+
+  /**
+   * Return the minimal number of days in the first week of a year.
+   */
+  int32_t GetMinimalDaysInFirstWeek();
+
+  /**
+   * Set the time for the calendar relative to the number of milliseconds since
+   * 1 January 1970, UTC.
+   */
+  Result<Ok, ICUError> SetTimeInMs(double aUnixEpoch);
+
+  /**
+   * Return ICU legacy keywords, such as "gregorian", "islamic",
+   * "islamic-civil", "hebrew", etc.
+   */
+  static Result<SpanEnumeration<char>, ICUError>
+  GetLegacyKeywordValuesForLocale(const char* aLocale);
+
+ private:
+  /**
+   * Internal function to convert a legacy calendar identifier to the newer
+   * BCP 47 identifier.
+   */
+  static SpanResult<char> LegacyIdentifierToBcp47(const char* aIdentifier,
+                                                  int32_t aLength);
+
+ public:
+  enum class CommonlyUsed : bool {
+    /**
+     * Select all possible values, even when not commonly used by a locale.
+     */
+    No,
+
+    /**
+     * Only select the values which are commonly used by a locale.
+     */
+    Yes,
+  };
+
+  using Bcp47IdentifierEnumeration =
+      Enumeration<char, SpanResult<char>, Calendar::LegacyIdentifierToBcp47>;
+
+  /**
+   * Return BCP 47 Unicode locale extension type keywords.
+   */
+  static Result<Bcp47IdentifierEnumeration, ICUError>
+  GetBcp47KeywordValuesForLocale(const char* aLocale,
+                                 CommonlyUsed aCommonlyUsed = CommonlyUsed::No);
+
+  ~Calendar();
+
+ private:
+  friend class DateIntervalFormat;
+  UCalendar* GetUCalendar() const { return mCalendar; }
+
+  UCalendar* mCalendar = nullptr;
+};
+
+}  // namespace mozilla::intl
+
+#endif