/// <summary>
/// Creates a segment representing the specified text string.
/// The segment is encoded in alphanumeric mode.
/// <para>
/// Allowed characters are: 0 to 9, A to Z (uppercase only), space,
/// dollar, percent, asterisk, plus, hyphen, period, slash, colon.
/// </para>
/// </summary>
/// <param name="text">The text to encode, consisting of allowed characters only.</param>
/// <returns>The created segment containing the text.</returns>
/// <exception cref="ArgumentNullException"><c>text</c> is <c>null</c>.</exception>
/// <exception cref="ArgumentOutOfRangeException"><c>text</c> contains non-encodable characters.</exception>
public static QrSegment MakeAlphanumeric(string text)
{
Objects.RequireNonNull(text);
if (!AlphanumericRegex.IsMatch(text))
{
throw new ArgumentOutOfRangeException(nameof(text), "String contains unencodable characters in alphanumeric mode");
}
BitArray ba = new BitArray(0);
int i;
for (i = 0; i <= text.Length - 2; i += 2)
{
// Process groups of 2
uint temp = (uint)AlphanumericCharset.IndexOf(text[i]) * 45;
temp += (uint)AlphanumericCharset.IndexOf(text[i + 1]);
ba.AppendBits(temp, 11);
}
if (i < text.Length) // 1 character remaining
{
ba.AppendBits((uint)AlphanumericCharset.IndexOf(text[i]), 6);
}
return(new QrSegment(Mode.Alphanumeric, text.Length, ba));
}
/// <summary>
/// Creates a list of zero or more segments representing the specified text string.
/// <para>
/// The text may contain the full range of Unicode characters.
/// </para>
/// <para>
/// The result may multiple segments with various encoding modes in order to minimize the length of the bit stream.
/// </para>
/// </summary>
/// <param name="text">The text to be encoded.</param>
/// <returns>The created mutable list of segments representing the specified text.</returns>
/// <exception cref="ArgumentNullException"><c>text</c> is <c>null</c>.</exception>
/// <remarks>
/// The current implementation does not use multiple segments.
/// </remarks>
public static List <QrSegment> MakeSegments(string text)
{
Objects.RequireNonNull(text);
// Select the most efficient segment encoding automatically
var result = new List <QrSegment>();
if (text == "")
{
// Leave result empty
}
else if (NumericRegex.IsMatch(text))
{
result.Add(MakeNumeric(text));
}
else if (AlphanumericRegex.IsMatch(text))
{
result.Add(MakeAlphanumeric(text));
}
else
{
result.Add(MakeBytes(Encoding.UTF8.GetBytes(text)));
}
return(result);
}
/// <summary>
/// Tests whether the specified string can be encoded as a segment in alphanumeric mode.
/// <para>
/// A string is encodable iff each character is in the range "0" to "9", "A" to "Z" (uppercase only),
/// space, dollar, percent, asterisk, plus, hyphen, period, slash, colon.
/// </para>
/// </summary>
/// <param name="text">the string to test for encodability (not <c>null</c>)</param>
/// <returns><c>true</c> iff each character is in the alphanumeric mode character set.</returns>
/// <exception cref="NullReferenceException">if the string is <c>null</c></exception>
/// <seealso cref="MakeAlphanumeric(string)"/>
public static bool IsAlphanumeric(string text)
{
return(AlphanumericRegex.IsMatch(text));
}
