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      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 value of MAX_TIMEZONE_ID_LENGTH is 128, which is 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_CFUNC 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), UPRV_LENGTHOF(dynamicTZI.TimeZoneKeyName), &status);
     83 
     84     if (U_FAILURE(status)) {
     85         return nullptr;
     86     }
     87 
     88     if (dynamicTZI.TimeZoneKeyName[0] != 0) {
     89         UResourceBundle winTZ;
     90         ures_initStackObject(&winTZ);
     91         ures_getByKey(bundle.getAlias(), dynamicTZKeyName, &winTZ, &status);
     92 
     93         if (U_SUCCESS(status)) {
     94             const UChar* icuTZ = nullptr;
     95             if (errorCode != 0) {
     96                 icuTZ = ures_getStringByKey(&winTZ, ISOcode, &len, &status);
     97             }
     98             if (errorCode == 0 || icuTZ == nullptr) {
     99                 /* fallback to default "001" and reset status */
    100                 status = U_ZERO_ERROR;
    101                 icuTZ = ures_getStringByKey(&winTZ, "001", &len, &status);
    102             }
    103 
    104             if (U_SUCCESS(status)) {
    105                 int index = 0;
    106 
    107                 while (!(*icuTZ == '\0' || *icuTZ == ' ')) {
    108                     // time zone IDs only contain ASCII invariant characters.
    109                     tmpid[index++] = (char)(*icuTZ++);
    110                 }
    111                 tmpid[index] = '\0';
    112             }
    113         }
    114         ures_close(&winTZ);
    115     }
    116 
    117     // Copy the timezone ID to icuid to be returned.
    118     if (tmpid[0] != 0) {
    119         icuid = uprv_strdup(tmpid);
    120     }
    121 
    122     return icuid;
    123 }
    124 
    125 U_NAMESPACE_END
    126 #endif /* U_PLATFORM_USES_ONLY_WIN32_API  */
    127