| // Copyright 2013 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| part of quiver.time; |
| |
| /// Returns current time. |
| typedef DateTime TimeFunction(); |
| |
| /// Return current system time. |
| DateTime systemTime() => new DateTime.now(); |
| |
| /// Days in a month. This array uses 1-based month numbers, i.e. January is |
| /// the 1-st element in the array, not the 0-th. |
| const _DAYS_IN_MONTH = const [ |
| 0, |
| 31, |
| 28, |
| 31, |
| 30, |
| 31, |
| 30, |
| 31, |
| 31, |
| 30, |
| 31, |
| 30, |
| 31 |
| ]; |
| |
| int _daysInMonth(int year, int month) => |
| (month == DateTime.FEBRUARY && _isLeapYear(year)) |
| ? 29 |
| : _DAYS_IN_MONTH[month]; |
| |
| bool _isLeapYear(int year) => |
| (year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0)); |
| |
| /// Takes a [date] that may be outside the allowed range of dates for a given |
| /// [month] in a given [year] and returns the closest date that is within the |
| /// allowed range. |
| /// |
| /// For example: |
| /// |
| /// February 31, 2013 => February 28, 2013 |
| /// |
| /// When jumping from month to month or from leap year to common year we may |
| /// end up in a month that has fewer days than the month we are jumping from. |
| /// In that case it is impossible to preserve the exact date. So we "clamp" the |
| /// date value to fit within the month. For example, jumping from March 31 one |
| /// month back takes us to February 28 (or 29 during a leap year), as February |
| /// doesn't have 31-st date. |
| int _clampDate(int date, int year, int month) => |
| date.clamp(1, _daysInMonth(year, month)); |
| |
| /// Provides points in time relative to the current point in time, for example: |
| /// now, 2 days ago, 4 weeks from now, etc. |
| /// |
| /// This class is designed with testability in mind. The current point in time |
| /// (or [now()]) is defined by a [TimeFunction]. By supplying your own time |
| /// function or by using fixed clock (see constructors), you can control |
| /// exactly what time a [Clock] returns and base your test expectations on |
| /// that. See specific constructors for how to supply time functions. |
| class Clock { |
| final TimeFunction _time; |
| |
| /// Creates a clock based on the given [timeFunc]. |
| /// |
| /// If [timeFunc] is not provided, creates [Clock] based on system clock. |
| /// |
| /// Custom [timeFunc] can be useful in unit-tests. For example, you might |
| /// want to control what time it is now and set date and time expectations in |
| /// your test cases. |
| const Clock([TimeFunction timeFunc = systemTime]) : _time = timeFunc; |
| |
| /// Creates [Clock] that returns fixed [time] value. Useful in unit-tests. |
| Clock.fixed(DateTime time) : _time = (() => time); |
| |
| /// Returns current time. |
| DateTime now() => _time(); |
| |
| /// Returns the point in time [Duration] amount of time ago. |
| DateTime agoBy(Duration duration) => now().subtract(duration); |
| |
| /// Returns the point in time [Duration] amount of time from now. |
| DateTime fromNowBy(Duration duration) => now().add(duration); |
| |
| /// Returns the point in time that's given amount of time ago. The |
| /// amount of time is the sum of individual parts. Parts are compatible with |
| /// ones defined in [Duration]. |
| DateTime ago( |
| {int days: 0, |
| int hours: 0, |
| int minutes: 0, |
| int seconds: 0, |
| int milliseconds: 0, |
| int microseconds: 0}) => |
| agoBy(new Duration( |
| days: days, |
| hours: hours, |
| minutes: minutes, |
| seconds: seconds, |
| milliseconds: milliseconds, |
| microseconds: microseconds)); |
| |
| /// Returns the point in time that's given amount of time from now. The |
| /// amount of time is the sum of individual parts. Parts are compatible with |
| /// ones defined in [Duration]. |
| DateTime fromNow( |
| {int days: 0, |
| int hours: 0, |
| int minutes: 0, |
| int seconds: 0, |
| int milliseconds: 0, |
| int microseconds: 0}) => |
| fromNowBy(new Duration( |
| days: days, |
| hours: hours, |
| minutes: minutes, |
| seconds: seconds, |
| milliseconds: milliseconds, |
| microseconds: microseconds)); |
| |
| /// Return the point in time [micros] microseconds ago. |
| DateTime microsAgo(int micros) => ago(microseconds: micros); |
| |
| /// Return the point in time [micros] microseconds from now. |
| DateTime microsFromNow(int micros) => fromNow(microseconds: micros); |
| |
| /// Return the point in time [millis] milliseconds ago. |
| DateTime millisAgo(int millis) => ago(milliseconds: millis); |
| |
| /// Return the point in time [millis] milliseconds from now. |
| DateTime millisFromNow(int millis) => fromNow(milliseconds: millis); |
| |
| /// Return the point in time [seconds] ago. |
| DateTime secondsAgo(int seconds) => ago(seconds: seconds); |
| |
| /// Return the point in time [seconds] from now. |
| DateTime secondsFromNow(int seconds) => fromNow(seconds: seconds); |
| |
| /// Return the point in time [minutes] ago. |
| DateTime minutesAgo(int minutes) => ago(minutes: minutes); |
| |
| /// Return the point in time [minutes] from now. |
| DateTime minutesFromNow(int minutes) => fromNow(minutes: minutes); |
| |
| /// Return the point in time [hours] ago. |
| DateTime hoursAgo(int hours) => ago(hours: hours); |
| |
| /// Return the point in time [hours] from now. |
| DateTime hoursFromNow(int hours) => fromNow(hours: hours); |
| |
| /// Return the point in time [days] ago. |
| DateTime daysAgo(int days) => ago(days: days); |
| |
| /// Return the point in time [days] from now. |
| DateTime daysFromNow(int days) => fromNow(days: days); |
| |
| /// Return the point in time [weeks] ago. |
| DateTime weeksAgo(int weeks) => ago(days: 7 * weeks); |
| |
| /// Return the point in time [weeks] from now. |
| DateTime weeksFromNow(int weeks) => fromNow(days: 7 * weeks); |
| |
| /// Return the point in time [months] ago on the same date. |
| DateTime monthsAgo(int months) { |
| var time = now(); |
| var m = (time.month - months - 1) % 12 + 1; |
| var y = time.year - (months + 12 - time.month) ~/ 12; |
| var d = _clampDate(time.day, y, m); |
| return new DateTime( |
| y, m, d, time.hour, time.minute, time.second, time.millisecond); |
| } |
| |
| /// Return the point in time [months] from now on the same date. |
| DateTime monthsFromNow(int months) { |
| var time = now(); |
| var m = (time.month + months - 1) % 12 + 1; |
| var y = time.year + (months + time.month - 1) ~/ 12; |
| var d = _clampDate(time.day, y, m); |
| return new DateTime( |
| y, m, d, time.hour, time.minute, time.second, time.millisecond); |
| } |
| |
| /// Return the point in time [years] ago on the same date. |
| DateTime yearsAgo(int years) { |
| var time = now(); |
| var y = time.year - years; |
| var d = _clampDate(time.day, y, time.month); |
| return new DateTime(y, time.month, d, time.hour, time.minute, time.second, |
| time.millisecond); |
| } |
| |
| /// Return the point in time [years] from now on the same date. |
| DateTime yearsFromNow(int years) => yearsAgo(-years); |
| } |