DerBoolean.cs :  » PDF » iTextSharp » Org » BouncyCastle » Asn1 » C# / CSharp Open Source

using System;

namespace Org.BouncyCastle.Asn1{
    public class DerBoolean
        : Asn1Object
    {
        private readonly byte value;

    public static readonly DerBoolean False = new DerBoolean(false);
        public static readonly DerBoolean True  = new DerBoolean(true);

    /**
         * return a bool from the passed in object.
         *
         * @exception ArgumentException if the object cannot be converted.
         */
        public static DerBoolean GetInstance(
            object obj)
        {
            if (obj == null || obj is DerBoolean)
            {
                return (DerBoolean) obj;
            }

      if (obj is Asn1OctetString)
            {
                return new DerBoolean(((Asn1OctetString) obj).GetOctets());
            }

      if (obj is Asn1TaggedObject)
            {
                return GetInstance(((Asn1TaggedObject) obj).GetObject());
            }

      throw new ArgumentException("illegal object in GetInstance: " + obj.GetType().Name);
        }

    /**
         * return a DerBoolean from the passed in bool.
         */
        public static DerBoolean GetInstance(
            bool value)
        {
            return value ? True : False;
        }

    /**
         * return a Boolean from a tagged object.
         *
         * @param obj the tagged object holding the object we want
         * @param explicitly true if the object is meant to be explicitly
         *              tagged false otherwise.
         * @exception ArgumentException if the tagged object cannot
         *               be converted.
         */
        public static DerBoolean GetInstance(
            Asn1TaggedObject  obj,
            bool        explicitly)
        {
            return GetInstance(obj.GetObject());
        }

    public DerBoolean(
            byte[] value)
        {
      // TODO Are there any constraints on the possible byte values?
            this.value = value[0];
        }

    private DerBoolean(
            bool value)
        {
            this.value = value ? (byte)0xff : (byte)0;
        }

    public bool IsTrue
    {
      get { return value != 0; }
    }

    internal override void Encode(
            DerOutputStream derOut)
        {
      // TODO Should we make sure the byte value is one of '0' or '0xff' here?
      derOut.WriteEncoded(Asn1Tags.Boolean, new byte[]{ value });
        }

    protected override bool Asn1Equals(
      Asn1Object asn1Object)
        {
      DerBoolean other = asn1Object as DerBoolean;

      if (other == null)
        return false;

      return IsTrue == other.IsTrue;
        }

    protected override int Asn1GetHashCode()
    {
      return IsTrue.GetHashCode();
        }

    public override string ToString()
    {
      return IsTrue ? "TRUE" : "FALSE";
    }
  }
}