chrome/common/time_format.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_COMMON_TIME_FORMAT_H__
   6 #define CHROME_COMMON_TIME_FORMAT_H__
   7 #pragma once
   8
   9 // This file defines methods to format time values as strings.
  10
  11 #include "base/string16.h"
  12
  13 namespace base {
  14 class Time;
  15 class TimeDelta;
  16 }
  17
  18 class TimeFormat {
  19  public:
  20   // TimeElapsed, TimeRemaining and TimeRemainingShort functions:
  21   // These functions return a localized string of approximate time duration. The
  22   // conditions are simpler than PastTime since these functions are used for
  23   // in-progress operations and users have different expectations of units.
  24
  25   // Returns times in elapsed-format: "3 mins ago", "2 days ago".
  26   static string16 TimeElapsed(const base::TimeDelta& delta);
  27
  28   // Returns times in remaining-format: "3 mins left", "2 days left".
  29   static string16 TimeRemaining(const base::TimeDelta& delta);
  30
  31   // Returns times in short-format: "3 mins", "2 days".
  32   static string16 TimeRemainingShort(const base::TimeDelta& delta);
  33
  34   // For displaying a relative time in the past.  This method returns either
  35   // "Today", "Yesterday", or an empty string if it's older than that.
  36   //
  37   // TODO(brettw): This should be able to handle days in the future like
  38   //    "Tomorrow".
  39   // TODO(tc): This should be able to do things like "Last week".  This
  40   //    requires handling singluar/plural for all languages.
  41   //
  42   // The second parameter is optional, it is midnight of "Now" for relative day
  43   // computations: Time::Now().LocalMidnight()
  44   // If NULL, the current day's midnight will be retrieved, which can be
  45   // slow. If many items are being processed, it is best to get the current
  46   // time once at the beginning and pass it for each computation.
  47   static string16 RelativeDate(const base::Time& time,
  48                                const base::Time* optional_midnight_today);
  49 };
  50
  51 #endif  // CHROME_COMMON_TIME_FORMAT_H__