vendor/phpoffice/phpexcel/Classes/PHPExcel/Shared/TimeZone.php

   1 <?php
   2
   3 /**
   4  * PHPExcel
   5  *
   6  * Copyright (c) 2006 - 2014 PHPExcel
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  21  *
  22  * @category   PHPExcel
  23  * @package     PHPExcel_Shared
  24  * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
  25  * @license     http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt   LGPL
  26  * @version     ##VERSION##, ##DATE##
  27  */
  28
  29
  30 /**
  31  * PHPExcel_Shared_TimeZone
  32  *
  33  * @category   PHPExcel
  34  * @package     PHPExcel_Shared
  35  * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
  36  */
  37 class PHPExcel_Shared_TimeZone
  38 {
  39         /*
  40          * Default Timezone used for date/time conversions
  41          *
  42          * @private
  43          * @var string
  44          */
  45         protected static $_timezone     = 'UTC';
  46
  47         /**
  48          * Validate a Timezone name
  49          *
  50          * @param        string         $timezone                       Time zone (e.g. 'Europe/London')
  51          * @return       boolean                                                Success or failure
  52          */
  53         public static function _validateTimeZone($timezone) {
  54                 if (in_array($timezone, DateTimeZone::listIdentifiers())) {
  55                         return TRUE;
  56                 }
  57                 return FALSE;
  58         }
  59
  60         /**
  61          * Set the Default Timezone used for date/time conversions
  62          *
  63          * @param        string         $timezone                       Time zone (e.g. 'Europe/London')
  64          * @return       boolean                                                Success or failure
  65          */
  66         public static function setTimeZone($timezone) {
  67                 if (self::_validateTimezone($timezone)) {
  68                         self::$_timezone = $timezone;
  69                         return TRUE;
  70                 }
  71                 return FALSE;
  72         }       //      function setTimezone()
  73
  74
  75         /**
  76          * Return the Default Timezone used for date/time conversions
  77          *
  78          * @return       string         Timezone (e.g. 'Europe/London')
  79          */
  80         public static function getTimeZone() {
  81                 return self::$_timezone;
  82         }       //      function getTimezone()
  83
  84
  85         /**
  86          *      Return the Timezone transition for the specified timezone and timestamp
  87          *
  88          *      @param          DateTimeZone            $objTimezone    The timezone for finding the transitions
  89          *      @param          integer                         $timestamp              PHP date/time value for finding the current transition
  90          *      @return         array                           The current transition details
  91          */
  92         private static function _getTimezoneTransitions($objTimezone, $timestamp) {
  93                 $allTransitions = $objTimezone->getTransitions();
  94                 $transitions = array();
  95                 foreach($allTransitions as $key => $transition) {
  96                         if ($transition['ts'] > $timestamp) {
  97                                 $transitions[] = ($key > 0) ? $allTransitions[$key - 1] : $transition;
  98                                 break;
  99                         }
 100                         if (empty($transitions)) {
 101                                 $transitions[] = end($allTransitions);
 102                         }
 103                 }
 104
 105                 return $transitions;
 106         }
 107
 108         /**
 109          *      Return the Timezone offset used for date/time conversions to/from UST
 110          *      This requires both the timezone and the calculated date/time to allow for local DST
 111          *
 112          *      @param          string                          $timezone               The timezone for finding the adjustment to UST
 113          *      @param          integer                         $timestamp              PHP date/time value
 114          *      @return         integer                         Number of seconds for timezone adjustment
 115          *      @throws         PHPExcel_Exception
 116          */
 117         public static function getTimeZoneAdjustment($timezone, $timestamp) {
 118                 if ($timezone !== NULL) {
 119                         if (!self::_validateTimezone($timezone)) {
 120                                 throw new PHPExcel_Exception("Invalid timezone " . $timezone);
 121                         }
 122                 } else {
 123                         $timezone = self::$_timezone;
 124                 }
 125
 126                 if ($timezone == 'UST') {
 127                         return 0;
 128                 }
 129
 130                 $objTimezone = new DateTimeZone($timezone);
 131                 if (version_compare(PHP_VERSION, '5.3.0') >= 0) {
 132                         $transitions = $objTimezone->getTransitions($timestamp,$timestamp);
 133                 } else {
 134                         $transitions = self::_getTimezoneTransitions($objTimezone, $timestamp);
 135                 }
 136
 137                 return (count($transitions) > 0) ? $transitions[0]['offset'] : 0;
 138         }
 139
 140 }