chromium/third_party/icu/source/i18n/unicode/reldatefmt.h

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*****************************************************************************
* Copyright (C) 2014-2016, International Business Machines Corporation and
* others.
* All Rights Reserved.
*****************************************************************************
*
* File RELDATEFMT.H
*****************************************************************************
*/

#ifndef __RELDATEFMT_H
#define __RELDATEFMT_H

#include "unicode/utypes.h"

#if U_SHOW_CPLUSPLUS_API

#include "unicode/uobject.h"
#include "unicode/udisplaycontext.h"
#include "unicode/ureldatefmt.h"
#include "unicode/locid.h"
#include "unicode/formattedvalue.h"

/**
 * \file
 * \brief C++ API: Formats relative dates such as "1 day ago" or "tomorrow"
 */

#if !UCONFIG_NO_FORMATTING

/**
 * Represents the unit for formatting a relative date. e.g "in 5 days"
 * or "in 3 months"
 * @stable ICU 53
 */
UDateRelativeUnit;

/**
 * Represents an absolute unit.
 * @stable ICU 53
 */
UDateAbsoluteUnit;

/**
 * Represents a direction for an absolute unit e.g "Next Tuesday"
 * or "Last Tuesday"
 * @stable ICU 53
 */
UDateDirection;

U_NAMESPACE_BEGIN

class BreakIterator;
class RelativeDateTimeCacheData;
class SharedNumberFormat;
class SharedPluralRules;
class SharedBreakIterator;
class NumberFormat;
class UnicodeString;
class FormattedRelativeDateTime;
class FormattedRelativeDateTimeData;

/**
 * An immutable class containing the result of a relative datetime formatting operation.
 *
 * Instances of this class are immutable and thread-safe.
 *
 * Not intended for public subclassing.
 *
 * @stable ICU 64
 */
class U_I18N_API FormattedRelativeDateTime : public UMemory, public FormattedValue { … };

/**
 * Formats simple relative dates. There are two types of relative dates that
 * it handles:
 * <ul>
 *   <li>relative dates with a quantity e.g "in 5 days"</li>
 *   <li>relative dates without a quantity e.g "next Tuesday"</li>
 * </ul>
 * <p>
 * This API is very basic and is intended to be a building block for more
 * fancy APIs. The caller tells it exactly what to display in a locale
 * independent way. While this class automatically provides the correct plural
 * forms, the grammatical form is otherwise as neutral as possible. It is the
 * caller's responsibility to handle cut-off logic such as deciding between
 * displaying "in 7 days" or "in 1 week." This API supports relative dates
 * involving one single unit. This API does not support relative dates
 * involving compound units,
 * e.g "in 5 days and 4 hours" nor does it support parsing.
 * <p>
 * This class is mostly thread safe and immutable with the following caveats:
 * 1. The assignment operator violates Immutability. It must not be used
 *    concurrently with other operations.
 * 2. Caller must not hold onto adopted pointers.
 * <p>
 * This class is not intended for public subclassing.
 * <p>
 * Here are some examples of use:
 * <blockquote>
 * <pre>
 * UErrorCode status = U_ZERO_ERROR;
 * UnicodeString appendTo;
 * RelativeDateTimeFormatter fmt(status);
 * // Appends "in 1 day"
 * fmt.format(
 *     1, UDAT_DIRECTION_NEXT, UDAT_RELATIVE_DAYS, appendTo, status);
 * // Appends "in 3 days"
 * fmt.format(
 *     3, UDAT_DIRECTION_NEXT, UDAT_RELATIVE_DAYS, appendTo, status);
 * // Appends "3.2 years ago"
 * fmt.format(
 *     3.2, UDAT_DIRECTION_LAST, UDAT_RELATIVE_YEARS, appendTo, status);
 * // Appends "last Sunday"
 * fmt.format(UDAT_DIRECTION_LAST, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 * // Appends "this Sunday"
 * fmt.format(UDAT_DIRECTION_THIS, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 * // Appends "next Sunday"
 * fmt.format(UDAT_DIRECTION_NEXT, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 * // Appends "Sunday"
 * fmt.format(UDAT_DIRECTION_PLAIN, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 *
 * // Appends "yesterday"
 * fmt.format(UDAT_DIRECTION_LAST, UDAT_ABSOLUTE_DAY, appendTo, status);
 * // Appends "today"
 * fmt.format(UDAT_DIRECTION_THIS, UDAT_ABSOLUTE_DAY, appendTo, status);
 * // Appends "tomorrow"
 * fmt.format(UDAT_DIRECTION_NEXT, UDAT_ABSOLUTE_DAY, appendTo, status);
 * // Appends "now"
 * fmt.format(UDAT_DIRECTION_PLAIN, UDAT_ABSOLUTE_NOW, appendTo, status);
 *
 * </pre>
 * </blockquote>
 * <p>
 * In the future, we may add more forms, such as abbreviated/short forms
 * (3 secs ago), and relative day periods ("yesterday afternoon"), etc.
 *
 * The RelativeDateTimeFormatter class is not intended for public subclassing.
 *
 * @stable ICU 53
 */
class U_I18N_API RelativeDateTimeFormatter : public UObject { … };

U_NAMESPACE_END

#endif /* !UCONFIG_NO_FORMATTING */

#endif /* U_SHOW_CPLUSPLUS_API */

#endif /* __RELDATEFMT_H */