package jalview.datamodel;

/**
 * An immutable object representing one or more residue and corresponding
 * alignment column positions for a sequence
 */
public class SequenceCursor
{
  /**
   * the aligned sequence this cursor applies to
   */
  public final SequenceI sequence;

  /**
   * residue position in sequence (start...), 0 if undefined
   */
  public final int residuePosition;

  /**
   * column position (1...) corresponding to residuePosition, or 0 if undefined
   */
  public final int columnPosition;

  /**
   * a token which may be used to check whether this cursor is still valid for
   * its sequence (allowing it to be ignored if the sequence has changed)
   */
  public final int token;

  public SequenceCursor(SequenceI seq, int resPos, int column, int tok)
  {
    sequence = seq;
    residuePosition = resPos;
    columnPosition = column;
    token = tok;
  }
}