C++ nsAString::CharAt方法代码示例

bool
ValidateGLSLString(const nsAString& string, WebGLContext* webgl, const char* funcName)
{
    for (size_t i = 0; i < string.Length(); ++i) {
        if (!IsValidGLSLCharacter(string.CharAt(i))) {
           webgl->ErrorInvalidValue("%s: String contains the illegal character '%d'",
                                    funcName, string.CharAt(i));
           return false;
        }
    }

    return true;
}

PRBool HasRTLChars(nsAString& aString)
{
  PRInt32 length = aString.Length();
  for (PRInt32 i = 0; i < length; i++) {
    if ((UCS2_CHAR_IS_BIDI(aString.CharAt(i)) ) ||
        ((NS_IS_HIGH_SURROGATE(aString.CharAt(i))) &&
         (++i < length) &&
         (NS_IS_LOW_SURROGATE(aString.CharAt(i))) &&
         (UTF32_CHAR_IS_BIDI(SURROGATE_TO_UCS4(aString.CharAt(i-1),
                                               aString.CharAt(i)))))) {
      return PR_TRUE;
    }
  }
  return PR_FALSE;
}

bool BasicCardService::IsValidExpiryYear(const nsAString& aExpiryYear) {
  // ExpiryYear can only be
  //   1. empty string
  //   2. 0000 ~ 9999
  if (!aExpiryYear.IsEmpty()) {
    if (aExpiryYear.Length() != 4) {
      return false;
    }
    for (uint32_t index = 0; index < 4; ++index) {
      if (aExpiryYear.CharAt(index) < '0' || aExpiryYear.CharAt(index) > '9') {
        return false;
      }
    }
  }
  return true;
}

bool
nsMsgLocalStoreUtils::nsShouldIgnoreFile(nsAString& name)
{
  PRUnichar firstChar = name.First();
  if (firstChar == '.' || firstChar == '#' ||
      name.CharAt(name.Length() - 1) == '~')
    return true;

  if (name.LowerCaseEqualsLiteral("msgfilterrules.dat") ||
      name.LowerCaseEqualsLiteral("rules.dat") ||
      name.LowerCaseEqualsLiteral("filterlog.html") ||
      name.LowerCaseEqualsLiteral("junklog.html") ||
      name.LowerCaseEqualsLiteral("rulesbackup.dat"))
    return true;

  // don't add summary files to the list of folders;
  // don't add popstate files to the list either, or rules (sort.dat).
  if (StringEndsWith(name, NS_LITERAL_STRING(".snm")) ||
      name.LowerCaseEqualsLiteral("popstate.dat") ||
      name.LowerCaseEqualsLiteral("sort.dat") ||
      name.LowerCaseEqualsLiteral("mailfilt.log") ||
      name.LowerCaseEqualsLiteral("filters.js") ||
      StringEndsWith(name, NS_LITERAL_STRING(".toc")))
    return true;

  // ignore RSS data source files
  if (name.LowerCaseEqualsLiteral("feeds.rdf") ||
      name.LowerCaseEqualsLiteral("feeditems.rdf"))
    return true;

  // The .mozmsgs dir is for spotlight support
    return (StringEndsWith(name, NS_LITERAL_STRING(".mozmsgs")) ||
            StringEndsWith(name, NS_LITERAL_STRING(".sbd")) ||
            StringEndsWith(name, NS_LITERAL_STRING(SUMMARY_SUFFIX)));
}

static bool
IsMatchingParameter(const nsAString &aString, const nsAString &aParameterName)
{
  // The first two tests ensure aString.Length() > aParameterName.Length()
  // so it's then safe to do the third test
  return StringBeginsWith(aString, aParameterName) &&
         aString.Last() == ')' &&
         aString.CharAt(aParameterName.Length()) == '(';
}

bool WebGLContext::ValidateGLSLString(const nsAString& string, const char *info)
{
    for (PRUint32 i = 0; i < string.Length(); ++i) {
        if (!ValidateGLSLCharacter(string.CharAt(i))) {
             ErrorInvalidValue("%s: string contains the illegal character '%d'", info, string.CharAt(i));
             return false;
        }
    }

    return true;
}

bool BasicCardService::IsValidExpiryMonth(const nsAString& aExpiryMonth) {
  // ExpiryMonth can only be
  //   1. empty string
  //   2. 01 ~ 12
  if (aExpiryMonth.IsEmpty()) {
    return true;
  }
  if (aExpiryMonth.Length() != 2) {
    return false;
  }
  // can only be 00 ~ 09
  if (aExpiryMonth.CharAt(0) == '0') {
    if (aExpiryMonth.CharAt(1) < '0' || aExpiryMonth.CharAt(1) > '9') {
      return false;
    }
    return true;
  }
  // can only be 11 or 12
  if (aExpiryMonth.CharAt(0) == '1') {
    if (aExpiryMonth.CharAt(1) != '1' && aExpiryMonth.CharAt(1) != '2') {
      return false;
    }
    return true;
  }
  return false;
}

/**
 * Provides a fallback for getting the path to APPDATA or LOCALAPPDATA by
 * querying the registry when the call to SHGetSpecialFolderLocation or
 * SHGetPathFromIDListW is unable to provide these paths (Bug 513958).
 */
static nsresult
GetRegWindowsAppDataFolder(bool aLocal, nsAString& _retval)
{
  HKEY key;
  NS_NAMED_LITERAL_STRING(keyName,
  "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders");
  DWORD res = ::RegOpenKeyExW(HKEY_CURRENT_USER, keyName.get(), 0, KEY_READ,
                              &key);
  if (res != ERROR_SUCCESS) {
    _retval.SetLength(0);
    return NS_ERROR_NOT_AVAILABLE;
  }

  DWORD type, size;
  res = RegQueryValueExW(key, (aLocal ? L"Local AppData" : L"AppData"),
                         nullptr, &type, nullptr, &size);
  // The call to RegQueryValueExW must succeed, the type must be REG_SZ, the
  // buffer size must not equal 0, and the buffer size be a multiple of 2.
  if (res != ERROR_SUCCESS || type != REG_SZ || size == 0 || size % 2 != 0) {
    ::RegCloseKey(key);
    _retval.SetLength(0);
    return NS_ERROR_NOT_AVAILABLE;
  }

  // |size| may or may not include room for the terminating null character
  DWORD resultLen = size / 2;

  _retval.SetLength(resultLen);
  nsAString::iterator begin;
  _retval.BeginWriting(begin);
  if (begin.size_forward() != resultLen) {
    ::RegCloseKey(key);
    _retval.SetLength(0);
    return NS_ERROR_NOT_AVAILABLE;
  }

  res = RegQueryValueExW(key, (aLocal ? L"Local AppData" : L"AppData"),
                         nullptr, nullptr, (LPBYTE) begin.get(), &size);
  ::RegCloseKey(key);
  if (res != ERROR_SUCCESS) {
    _retval.SetLength(0);
    return NS_ERROR_NOT_AVAILABLE;
  }

  if (!_retval.CharAt(resultLen - 1)) {
    // It was already null terminated.
    _retval.Truncate(resultLen - 1);
  }

  return NS_OK;
}

PRBool HasRTLChars(const nsAString& aString)
{
// This is used to determine whether to enable bidi if a string has 
// right-to-left characters. To simplify things, anything that could be a
// surrogate or RTL presentation form is covered just by testing >= 0xD800).
// It's fine to enable bidi in rare cases where it actually isn't needed.
  PRInt32 length = aString.Length();
  for (PRInt32 i = 0; i < length; i++) {
    PRUnichar ch = aString.CharAt(i);
    if (ch >= 0xD800 || IS_IN_BMP_RTL_BLOCK(ch)) {
      return PR_TRUE;
    }
  }
  return PR_FALSE;
}

NS_IMETHODIMP
nsWindowsRegKey::ReadStringValue(const nsAString& aName, nsAString& aResult)
{
  if (NS_WARN_IF(!mKey)) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  DWORD type, size;

  const nsString& flatName = PromiseFlatString(aName);

  LONG rv = RegQueryValueExW(mKey, flatName.get(), 0, &type, nullptr, &size);
  if (rv != ERROR_SUCCESS) {
    return NS_ERROR_FAILURE;
  }

  // This must be a string type in order to fetch the value as a string.
  // We're being a bit forgiving here by allowing types other than REG_SZ.
  if (type != REG_SZ && type != REG_EXPAND_SZ && type != REG_MULTI_SZ) {
    return NS_ERROR_FAILURE;
  }

  // The buffer size must be a multiple of 2.
  if (size % 2 != 0) {
    return NS_ERROR_UNEXPECTED;
  }

  if (size == 0) {
    aResult.Truncate();
    return NS_OK;
  }

  // |size| may or may not include the terminating null character.
  DWORD resultLen = size / 2;

  if (!aResult.SetLength(resultLen, mozilla::fallible)) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  nsAString::iterator begin;
  aResult.BeginWriting(begin);

  rv = RegQueryValueExW(mKey, flatName.get(), 0, &type, (LPBYTE)begin.get(),
                        &size);

  if (!aResult.CharAt(resultLen - 1)) {
    // The string passed to us had a null terminator in the final position.
    aResult.Truncate(resultLen - 1);
  }

  // Expand the environment variables if needed
  if (type == REG_EXPAND_SZ) {
    const nsString& flatSource = PromiseFlatString(aResult);
    resultLen = ExpandEnvironmentStringsW(flatSource.get(), nullptr, 0);
    if (resultLen > 1) {
      nsAutoString expandedResult;
      // |resultLen| includes the terminating null character
      --resultLen;
      if (!expandedResult.SetLength(resultLen, mozilla::fallible)) {
        return NS_ERROR_OUT_OF_MEMORY;
      }

      nsAString::iterator begin;
      expandedResult.BeginWriting(begin);

      resultLen = ExpandEnvironmentStringsW(flatSource.get(),
                                            wwc(begin.get()),
                                            resultLen + 1);
      if (resultLen <= 0) {
        rv = ERROR_UNKNOWN_FEATURE;
        aResult.Truncate();
      } else {
        rv = ERROR_SUCCESS;
        aResult = expandedResult;
      }
    } else if (resultLen == 1) {
      // It apparently expands to nothing (just a null terminator).
      aResult.Truncate();
    }
  }

  return (rv == ERROR_SUCCESS) ? NS_OK : NS_ERROR_FAILURE;
}