tzlib.c File Reference

#include <stdlib.h>
#include <windef.h>
#include <winbase.h>
#include <winreg.h>
#include "tzlib.h"

Include dependency graph for tzlib.c:

Go to the source code of this file.

Functions
BOOL	GetTimeZoneListIndex (IN OUT PULONG pIndex)
LONG	QueryTimeZoneData (IN HKEY hZoneKey, OUT PULONG Index OPTIONAL, OUT PREG_TZI_FORMAT TimeZoneInfo, OUT PWCHAR Description OPTIONAL, IN OUT PULONG DescriptionSize OPTIONAL, OUT PWCHAR StandardName OPTIONAL, IN OUT PULONG StandardNameSize OPTIONAL, OUT PWCHAR DaylightName OPTIONAL, IN OUT PULONG DaylightNameSize OPTIONAL)
VOID	EnumerateTimeZoneList (IN PENUM_TIMEZONE_CALLBACK Callback, IN PVOID Context OPTIONAL)
BOOL	GetAutoDaylight (VOID)
VOID	SetAutoDaylight (IN BOOL EnableAutoDaylightTime)

Function Documentation

EnumerateTimeZoneList()

VOID EnumerateTimeZoneList	(	IN PENUM_TIMEZONE_CALLBACK	Callback,
		IN PVOID Context	OPTIONAL
	)

Definition at line 223 of file tzlib.c.

{
    LONG lError;
    HKEY hZonesKey;
    HKEY hZoneKey;
    DWORD dwIndex;
    DWORD dwNameSize;
    WCHAR szKeyName[256];
 
    /* Open the registry key containing the list of time zones */
    lError = RegOpenKeyExW(HKEY_LOCAL_MACHINE,
                           L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones",
                           0,
                           KEY_ENUMERATE_SUB_KEYS,
                           &hZonesKey);
    if (lError != ERROR_SUCCESS)
        return;
 
    /* Enumerate it */
    for (dwIndex = 0; ; dwIndex++)
    {
        dwNameSize = sizeof(szKeyName);
        lError = RegEnumKeyExW(hZonesKey,
                               dwIndex,
                               szKeyName,
                               &dwNameSize,
                               NULL,
                               NULL,
                               NULL,
                               NULL);
        // if (lError != ERROR_SUCCESS && lError != ERROR_MORE_DATA)
        if (lError == ERROR_NO_MORE_ITEMS)
            break;
 
        /* Open the time zone sub-key */
        if (RegOpenKeyExW(hZonesKey,
                          szKeyName,
                          0,
                          KEY_QUERY_VALUE,
                          &hZoneKey))
        {
            /* We failed, continue with another sub-key */
            continue;
        }
 
        /* Call the user-provided callback */
        lError = Callback(hZoneKey, Context);
        // lError = QueryTimeZoneData(hZoneKey, Context);
 
        RegCloseKey(hZoneKey);
    }
 
    RegCloseKey(hZonesKey);
}

Referenced by CreateTimeZoneList().

GetAutoDaylight()

BOOL GetAutoDaylight

(

VOID

)

Definition at line 283 of file tzlib.c.

{
    LONG lError;
    HKEY hKey;
    DWORD dwType;
    DWORD dwDisabled;
    DWORD dwValueSize;
 
    lError = RegOpenKeyExW(HKEY_LOCAL_MACHINE,
                           L"SYSTEM\\CurrentControlSet\\Control\\TimeZoneInformation",
                           0,
                           KEY_QUERY_VALUE,
                           &hKey);
    if (lError != ERROR_SUCCESS)
        return FALSE;
 
    // NOTE: On Vista+: REG_DWORD "DynamicDaylightTimeDisabled"
    dwValueSize = sizeof(dwDisabled);
    lError = RegQueryValueExW(hKey,
                              L"DisableAutoDaylightTimeSet",
                              NULL,
                              &dwType,
                              (LPBYTE)&dwDisabled,
                              &dwValueSize);
 
    RegCloseKey(hKey);
 
    if ((lError != ERROR_SUCCESS) || (dwType != REG_DWORD) || (dwValueSize != sizeof(dwDisabled)))
    {
        /*
         * The call failed (non zero) because the registry value isn't available,
         * which means auto-daylight shouldn't be disabled.
         */
        dwDisabled = FALSE;
    }
 
    return !dwDisabled;
}

Referenced by TimeZonePageProc().

GetTimeZoneListIndex()

BOOL GetTimeZoneListIndex

(

IN OUT PULONG

pIndex

)

Definition at line 20 of file tzlib.c.

{
    LONG lError;
    HKEY hKey;
    DWORD dwType;
    DWORD dwValueSize;
    DWORD Length;
    LPWSTR Buffer;
    LPWSTR Ptr, End;
    BOOL bFound = FALSE;
    unsigned long iLanguageID;
    WCHAR szLanguageIdString[9];
 
    if (*pIndex == -1)
    {
        *pIndex = 85; /* fallback to GMT time zone */
 
        lError = RegOpenKeyExW(HKEY_LOCAL_MACHINE,
                               L"SYSTEM\\CurrentControlSet\\Control\\NLS\\Language",
                               0,
                               KEY_QUERY_VALUE,
                               &hKey);
        if (lError != ERROR_SUCCESS)
        {
            return FALSE;
        }
 
        dwValueSize = sizeof(szLanguageIdString);
        lError = RegQueryValueExW(hKey,
                                  L"Default",
                                  NULL,
                                  NULL,
                                  (LPBYTE)szLanguageIdString,
                                  &dwValueSize);
        if (lError != ERROR_SUCCESS)
        {
            RegCloseKey(hKey);
            return FALSE;
        }
 
        iLanguageID = wcstoul(szLanguageIdString, NULL, 16);
        RegCloseKey(hKey);
    }
    else
    {
        iLanguageID = *pIndex;
    }
 
    lError = RegOpenKeyExW(HKEY_LOCAL_MACHINE,
                           L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones",
                           0,
                           KEY_QUERY_VALUE,
                           &hKey);
    if (lError != ERROR_SUCCESS)
    {
        return FALSE;
    }
 
    dwValueSize = 0;
    lError = RegQueryValueExW(hKey,
                              L"IndexMapping",
                              NULL,
                              &dwType,
                              NULL,
                              &dwValueSize);
    if ((lError != ERROR_SUCCESS) || (dwType != REG_MULTI_SZ))
    {
        RegCloseKey(hKey);
        return FALSE;
    }
 
    Buffer = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, dwValueSize);
    if (Buffer == NULL)
    {
        RegCloseKey(hKey);
        return FALSE;
    }
 
    lError = RegQueryValueExW(hKey,
                              L"IndexMapping",
                              NULL,
                              &dwType,
                              (LPBYTE)Buffer,
                              &dwValueSize);
 
    RegCloseKey(hKey);
 
    if ((lError != ERROR_SUCCESS) || (dwType != REG_MULTI_SZ))
    {
        HeapFree(GetProcessHeap(), 0, Buffer);
        return FALSE;
    }
 
    Ptr = Buffer;
    while (*Ptr != 0)
    {
        Length = wcslen(Ptr);
        if (wcstoul(Ptr, NULL, 16) == iLanguageID)
            bFound = TRUE;
 
        Ptr = Ptr + Length + 1;
        if (*Ptr == 0)
            break;
 
        if (bFound)
        {
            *pIndex = wcstoul(Ptr, &End, 10);
            HeapFree(GetProcessHeap(), 0, Buffer);
            return TRUE;
        }
 
        Length = wcslen(Ptr);
        Ptr = Ptr + Length + 1;
    }
 
    HeapFree(GetProcessHeap(), 0, Buffer);
    return FALSE;
}

Referenced by ShowTimeZoneList().

QueryTimeZoneData()

LONG QueryTimeZoneData	(	IN HKEY	hZoneKey,
		OUT PULONG Index	OPTIONAL,
		OUT PREG_TZI_FORMAT	TimeZoneInfo,
		OUT PWCHAR Description	OPTIONAL,
		IN OUT PULONG DescriptionSize	OPTIONAL,
		OUT PWCHAR StandardName	OPTIONAL,
		IN OUT PULONG StandardNameSize	OPTIONAL,
		OUT PWCHAR DaylightName	OPTIONAL,
		IN OUT PULONG DaylightNameSize	OPTIONAL
	)

Definition at line 141 of file tzlib.c.

{
    LONG lError;
    DWORD dwValueSize;
 
    if (Index)
    {
        dwValueSize = sizeof(*Index);
        lError = RegQueryValueExW(hZoneKey,
                                  L"Index",
                                  NULL,
                                  NULL,
                                  (LPBYTE)Index,
                                  &dwValueSize);
        if (lError != ERROR_SUCCESS)
            *Index = 0;
    }
 
    /* The time zone information structure is mandatory for a valid time zone */
    dwValueSize = sizeof(*TimeZoneInfo);
    lError = RegQueryValueExW(hZoneKey,
                              L"TZI",
                              NULL,
                              NULL,
                              (LPBYTE)TimeZoneInfo,
                              &dwValueSize);
    if (lError != ERROR_SUCCESS)
        return lError;
 
    if (Description && DescriptionSize && *DescriptionSize > 0)
    {
        lError = RegQueryValueExW(hZoneKey,
                                  L"Display",
                                  NULL,
                                  NULL,
                                  (LPBYTE)Description,
                                  DescriptionSize);
        if (lError != ERROR_SUCCESS)
            *Description = 0;
    }
 
    if (StandardName && StandardNameSize && *StandardNameSize > 0)
    {
        lError = RegQueryValueExW(hZoneKey,
                                  L"Std",
                                  NULL,
                                  NULL,
                                  (LPBYTE)StandardName,
                                  StandardNameSize);
        if (lError != ERROR_SUCCESS)
            *StandardName = 0;
    }
 
    if (DaylightName && DaylightNameSize && *DaylightNameSize > 0)
    {
        lError = RegQueryValueExW(hZoneKey,
                                  L"Dlt",
                                  NULL,
                                  NULL,
                                  (LPBYTE)DaylightName,
                                  DaylightNameSize);
        if (lError != ERROR_SUCCESS)
            *DaylightName = 0;
    }
 
    return ERROR_SUCCESS;
}

Referenced by RetrieveTimeZone().

SetAutoDaylight()

VOID SetAutoDaylight

(

IN BOOL

EnableAutoDaylightTime

)

Definition at line 323 of file tzlib.c.

{
    LONG lError;
    HKEY hKey;
    DWORD dwDisabled = TRUE;
 
    lError = RegOpenKeyExW(HKEY_LOCAL_MACHINE,
                           L"SYSTEM\\CurrentControlSet\\Control\\TimeZoneInformation",
                           0,
                           KEY_SET_VALUE,
                           &hKey);
    if (lError != ERROR_SUCCESS)
        return;
 
    if (!EnableAutoDaylightTime)
    {
        /* Auto-Daylight disabled: set the value to TRUE */
        // NOTE: On Vista+: REG_DWORD "DynamicDaylightTimeDisabled"
        RegSetValueExW(hKey,
                       L"DisableAutoDaylightTimeSet",
                       0,
                       REG_DWORD,
                       (LPBYTE)&dwDisabled,
                       sizeof(dwDisabled));
    }
    else
    {
        /* Auto-Daylight enabled: just delete the value */
        RegDeleteValueW(hKey, L"DisableAutoDaylightTimeSet");
    }
 
    RegCloseKey(hKey);
}

Referenced by TimeZonePageProc(), and WriteDateTimeSettings().