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
   8 #include "base/basictypes.h"
   9 #include "base/string16.h"
  10
  11 namespace base {
  12 class Time;
  13 class TimeDelta;
  14 }
  15
  16 // Methods to format time values as strings.
  17 class TimeFormat {
  18  public:
  19   // TimeElapsed, TimeRemaining and TimeRemainingShort functions:
  20   // These functions return a localized string of approximate time duration. The
  21   // conditions are simpler than PastTime since these functions are used for
  22   // in-progress operations and users have different expectations of units.
  23
  24   // Returns times in elapsed-format: "3 mins ago", "2 days ago".
  25   static string16 TimeElapsed(const base::TimeDelta& delta);
  26
  27   // Returns times in remaining-format: "3 mins left", "2 days left".
  28   static string16 TimeRemaining(const base::TimeDelta& delta);
  29
  30   // Returns times in remaining-long-format: "3 minutes left", "2 days left".
  31   // Currently, this only affects the minutes in long format, the rest
  32   // of the time units are formatted the same as TimeRemaining does.
  33   static string16 TimeRemainingLong(const base::TimeDelta& delta);
  34
  35   // Returns times in short-format: "3 mins", "2 days".
  36   static string16 TimeRemainingShort(const base::TimeDelta& delta);
  37
  38   // For displaying a relative time in the past.  This method returns either
  39   // "Today", "Yesterday", or an empty string if it's older than that.  Returns
  40   // the empty string for days in the future.
  41   //
  42   // TODO(brettw): This should be able to handle days in the future like
  43   //    "Tomorrow".
  44   // TODO(tc): This should be able to do things like "Last week".  This
  45   //    requires handling singluar/plural for all languages.
  46   //
  47   // The second parameter is optional, it is midnight of "Now" for relative day
  48   // computations: Time::Now().LocalMidnight()
  49   // If NULL, the current day's midnight will be retrieved, which can be
  50   // slow. If many items are being processed, it is best to get the current
  51   // time once at the beginning and pass it for each computation.
  52   static string16 RelativeDate(const base::Time& time,
  53                                const base::Time* optional_midnight_today);
  54
  55  private:
  56   DISALLOW_IMPLICIT_CONSTRUCTORS(TimeFormat);
  57 };
  58
  59 #endif  // CHROME_COMMON_TIME_FORMAT_H_