Class MinimalECIInput

core/src/main/java/com/google/zxing/common/MinimalECIInput.java:30–346

Class that converts a character string into a sequence of ECIs and bytes The implementation uses the Dijkstra algorithm to produce minimal encodings @author Alex Geller

 * @author Alex Geller
 */
public class MinimalECIInput implements ECIInput {

  private static final int COST_PER_ECI = 3; // approximated (latch + 2 codewords)
  private final int[] bytes;
  private final int fnc1;

 /**
  * Constructs a minimal input
  *
  * @param stringToEncode the character string to encode
  * @param priorityCharset The preferred {@link Charset}. When the value of the argument is null, the algorithm
  *   chooses charsets that leads to a minimal representation. Otherwise the algorithm will use the priority
  *   charset to encode any character in the input that can be encoded by it if the charset is among the
  *   supported charsets.
  * @param fnc1 denotes the character in the input that represents the FNC1 character or -1 if this is not GS1
  *   input.
  */
  public MinimalECIInput(String stringToEncode, Charset priorityCharset, int fnc1) {
    this.fnc1 = fnc1;
    ECIEncoderSet encoderSet = new ECIEncoderSet(stringToEncode, priorityCharset, fnc1);
    if (encoderSet.length() == 1) { //optimization for the case when all can be encoded without ECI in ISO-8859-1
      bytes = new int[stringToEncode.length()];
      for (int i = 0; i < bytes.length; i++) {
        char c = stringToEncode.charAt(i);
        bytes[i] = c == fnc1 ? 1000 : (int) c;
      }
    } else {
      bytes = encodeMinimally(stringToEncode, encoderSet, fnc1);
    }
  }

  public int getFNC1Character() {
    return fnc1;
  }

 /**
  * Returns the length of this input.  The length is the number
  * of {@code byte}s, FNC1 characters or ECIs in the sequence.
  *
  * @return  the number of {@code char}s in this sequence
  */
  public int length() {
    return bytes.length;
  }

  public boolean haveNCharacters(int index, int n) {
    if (index + n - 1 >= bytes.length) {
      return false;
    }
    for (int i = 0; i < n; i++) {
      if (isECI(index + i)) {
        return false;
      }
    }
    return true;
  }

 /**