icuSources/common/wintz.cpp

   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
  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  */