1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 ********************************************************************************
5 * Copyright (C) 2005-2015, International Business Machines
6 * Corporation and others. All Rights Reserved.
7 ********************************************************************************
8 *
9 * File WINTZ.CPP
10 *
11 ********************************************************************************
12 */
13
14 #include "unicode/utypes.h"
15
16 #if U_PLATFORM_USES_ONLY_WIN32_API
17
18 #include "wintz.h"
19 #include "cmemory.h"
20 #include "cstring.h"
21
22 #include "unicode/ures.h"
23 #include "unicode/ustring.h"
24 #include "uresimp.h"
25
26 #ifndef WIN32_LEAN_AND_MEAN
27 # define WIN32_LEAN_AND_MEAN
28 #endif
29 # define VC_EXTRALEAN
30 # define NOUSER
31 # define NOSERVICE
32 # define NOIME
33 # define NOMCX
34 #include <windows.h>
35
36 U_NAMESPACE_BEGIN
37
38 // The max size of TimeZoneKeyName is 128, defined in DYNAMIC_TIME_ZONE_INFORMATION
39 #define MAX_TIMEZONE_ID_LENGTH 128
40
41 /**
42 * Main Windows time zone detection function.
43 * Returns the Windows time zone converted to an ICU time zone as a heap-allocated buffer, or nullptr upon failure.
44 * Note: We use the Win32 API GetDynamicTimeZoneInformation to get the current time zone info.
45 * This API returns a non-localized time zone name, which we can then map to an ICU time zone name.
46 */
47 U_INTERNAL const char* U_EXPORT2
uprv_detectWindowsTimeZone()48 uprv_detectWindowsTimeZone()
49 {
50 UErrorCode status = U_ZERO_ERROR;
51 char* icuid = nullptr;
52 char dynamicTZKeyName[MAX_TIMEZONE_ID_LENGTH];
53 char tmpid[MAX_TIMEZONE_ID_LENGTH];
54 int32_t len;
55 int id = GEOID_NOT_AVAILABLE;
56 int errorCode;
57 wchar_t ISOcodeW[3] = {}; /* 2 letter ISO code in UTF-16 */
58 char ISOcode[3] = {}; /* 2 letter ISO code in UTF-8 */
59
60 DYNAMIC_TIME_ZONE_INFORMATION dynamicTZI;
61 uprv_memset(&dynamicTZI, 0, sizeof(dynamicTZI));
62 uprv_memset(dynamicTZKeyName, 0, sizeof(dynamicTZKeyName));
63 uprv_memset(tmpid, 0, sizeof(tmpid));
64
65 /* Obtain TIME_ZONE_INFORMATION from the API and get the non-localized time zone name. */
66 if (TIME_ZONE_ID_INVALID == GetDynamicTimeZoneInformation(&dynamicTZI)) {
67 return nullptr;
68 }
69
70 id = GetUserGeoID(GEOCLASS_NATION);
71 errorCode = GetGeoInfoW(id, GEO_ISO2, ISOcodeW, 3, 0);
72
73 // convert from wchar_t* (UTF-16 on Windows) to char* (UTF-8).
74 u_strToUTF8(ISOcode, UPRV_LENGTHOF(ISOcode), nullptr,
75 reinterpret_cast<const UChar*>(ISOcodeW), UPRV_LENGTHOF(ISOcodeW), &status);
76
77 LocalUResourceBundlePointer bundle(ures_openDirect(nullptr, "windowsZones", &status));
78 ures_getByKey(bundle.getAlias(), "mapTimezones", bundle.getAlias(), &status);
79
80 // convert from wchar_t* (UTF-16 on Windows) to char* (UTF-8).
81 u_strToUTF8(dynamicTZKeyName, UPRV_LENGTHOF(dynamicTZKeyName), nullptr,
82 reinterpret_cast<const UChar*>(dynamicTZI.TimeZoneKeyName), -1, &status);
83
84 if (U_FAILURE(status)) {
85 return nullptr;
86 }
87
88 if (dynamicTZI.TimeZoneKeyName[0] != 0) {
89 StackUResourceBundle winTZ;
90 ures_getByKey(bundle.getAlias(), dynamicTZKeyName, winTZ.getAlias(), &status);
91
92 if (U_SUCCESS(status)) {
93 const UChar* icuTZ = nullptr;
94 if (errorCode != 0) {
95 icuTZ = ures_getStringByKey(winTZ.getAlias(), ISOcode, &len, &status);
96 }
97 if (errorCode == 0 || icuTZ == nullptr) {
98 /* fallback to default "001" and reset status */
99 status = U_ZERO_ERROR;
100 icuTZ = ures_getStringByKey(winTZ.getAlias(), "001", &len, &status);
101 }
102
103 if (U_SUCCESS(status)) {
104 int index = 0;
105
106 while (!(*icuTZ == '\0' || *icuTZ == ' ')) {
107 // time zone IDs only contain ASCII invariant characters.
108 tmpid[index++] = (char)(*icuTZ++);
109 }
110 tmpid[index] = '\0';
111 }
112 }
113 }
114
115 // Copy the timezone ID to icuid to be returned.
116 if (tmpid[0] != 0) {
117 icuid = uprv_strdup(tmpid);
118 }
119
120 return icuid;
121 }
122
123 U_NAMESPACE_END
124 #endif /* U_PLATFORM_USES_ONLY_WIN32_API */
125