/// <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>
/// Creates a segment representing the specified string of decimal digits.
/// The segment is encoded in numeric mode.
/// </summary>
/// <param name="digits">The text to encode, consisting of digits from 0 to 9 only.</param>
/// <returns>The created segment containing the text.</returns>
/// <exception cref="ArgumentNullException"><c>digits</c> is <c>null</c>.</exception>
/// <exception cref="ArgumentOutOfRangeException"><c>digits</c> contains non-digit characters</exception>
public static QrSegment MakeNumeric(string digits)
{
if (!NumericRegex.IsMatch(digits))
{
throw new ArgumentOutOfRangeException(nameof(digits), "String contains non-numeric characters");
}
BitArray ba = new BitArray(0);
for (int i = 0; i < digits.Length;)
{
// Consume up to 3 digits per iteration
int n = Math.Min(digits.Length - i, 3);
ba.AppendBits(uint.Parse(digits.Substring(i, n)), n * 3 + 1);
i += n;
}
return(new QrSegment(Mode.Numeric, digits.Length, ba));
}
private bool IsNumeric(string numericStr)
{
return(NumericRegex.IsMatch(numericStr));
}
/// <summary>
/// Tests whether the specified string can be encoded as a segment in numeric mode.
/// <para>
/// A string is encodable iff each character is in the range "0" to "9".
/// </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 range "0" to "9".</returns>
/// <exception cref="NullReferenceException">if the string is <c>null</c></exception>
/// <seealso cref="MakeNumeric(string)"/>
public static bool IsNumeric(string text)
{
return(NumericRegex.IsMatch(text));
}
