Blame view

app-ht/exts/PHPExcel/Shared/TimeZone.php 4.04 KB
2e86c939   xu   “首次提交”
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
<?php

/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2014 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package	PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license	http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version	1.8.0, 2014-03-02
 */


/**
 * PHPExcel_Shared_TimeZone
 *
 * @category   PHPExcel
 * @package	PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Shared_TimeZone
{
	/*
	 * Default Timezone used for date/time conversions
	 *
	 * @private
	 * @var	string
	 */
	protected static $_timezone	= 'UTC';

	/**
	 * Validate a Timezone name
	 *
	 * @param	 string		$timezone			Time zone (e.g. 'Europe/London')
	 * @return	 boolean						Success or failure
	 */
	public static function _validateTimeZone($timezone) {
		if (in_array($timezone, DateTimeZone::listIdentifiers())) {
			return TRUE;
		}
		return FALSE;
	}

	/**
	 * Set the Default Timezone used for date/time conversions
	 *
	 * @param	 string		$timezone			Time zone (e.g. 'Europe/London')
	 * @return	 boolean						Success or failure
	 */
	public static function setTimeZone($timezone) {
		if (self::_validateTimezone($timezone)) {
			self::$_timezone = $timezone;
			return TRUE;
		}
		return FALSE;
	}	//	function setTimezone()


	/**
	 * Return the Default Timezone used for date/time conversions
	 *
	 * @return	 string		Timezone (e.g. 'Europe/London')
	 */
	public static function getTimeZone() {
		return self::$_timezone;
	}	//	function getTimezone()


	/**
	 *	Return the Timezone transition for the specified timezone and timestamp
	 *
	 *	@param		DateTimeZone	 	$objTimezone	The timezone for finding the transitions
	 *	@param		integer	 			$timestamp		PHP date/time value for finding the current transition
	 *	@return	 	array				The current transition details
	 */
	private static function _getTimezoneTransitions($objTimezone, $timestamp) {
		$allTransitions = $objTimezone->getTransitions();
		$transitions = array();
		foreach($allTransitions as $key => $transition) {
			if ($transition['ts'] > $timestamp) {
				$transitions[] = ($key > 0) ? $allTransitions[$key - 1] : $transition;
				break;
			}
			if (empty($transitions)) {
				$transitions[] = end($allTransitions);
			}
		}

		return $transitions;
	}

	/**
	 *	Return the Timezone offset used for date/time conversions to/from UST
	 *	This requires both the timezone and the calculated date/time to allow for local DST
	 *
	 *	@param		string	 			$timezone		The timezone for finding the adjustment to UST
	 *	@param		integer	 			$timestamp		PHP date/time value
	 *	@return	 	integer				Number of seconds for timezone adjustment
	 *	@throws		PHPExcel_Exception
	 */
	public static function getTimeZoneAdjustment($timezone, $timestamp) {
		if ($timezone !== NULL) {
			if (!self::_validateTimezone($timezone)) {
				throw new PHPExcel_Exception("Invalid timezone " . $timezone);
			}
		} else {
			$timezone = self::$_timezone;
		}

		if ($timezone == 'UST') {
			return 0;
		}

		$objTimezone = new DateTimeZone($timezone);
		if (version_compare(PHP_VERSION, '5.3.0') >= 0) {
			$transitions = $objTimezone->getTransitions($timestamp,$timestamp);
		} else {
			$transitions = self::_getTimezoneTransitions($objTimezone, $timestamp);
		}

		return (count($transitions) > 0) ? $transitions[0]['offset'] : 0;
	}

}