[ComVisible(true)]
    [TypeConverter(typeof(ExpandableObjectConverter))]
    [CategoryAttribute("Configuration")]
    [Serializable]
    public class Zone
    {
        #region Private Fields

        private bool active;
        private string dir;
        private Heading heading = new Heading();
        private int id;
        private int intID;
        private Position start = new Position();
        private Position finish = new Position();
        private int width;
        private Position[] corners = new Position[4];
        private Streets streets = new Streets();

        #endregion

        #region Constructors

        public Zone()
        {
            if (Program.main != null)
            {
                IntID = Program.main.intID;

                Intersection intersection = Program.data.Intersections.list.Find(
                    delegate(Intersection tInt)
                    {
                        return tInt.ID == IntID;
                    }
                );

                if (intersection != null)
                {
                    Streets.Crossing = intersection.Streets.Crossing;
                    Streets.Route = intersection.Streets.Route;
                }
            }
        }

        #endregion

        #region Properties

        public virtual long PK { get; set; }

        [Browsable(false)]
        public virtual bool Active
        {
            get { return active; }
            set { active = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The direction for the Zone.")]
        public virtual string Dir
        {
            get { return dir; }
            set { dir = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The heading for the Zone.")]
        public virtual Heading Heading
        {
            get { return heading; }
            set { heading = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The Zone Identification Number.")]
        public virtual int ID
        {
            get { return id; }
            set { id = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The Identification Number associated with the Priority Detector of the Zone.")]
        public virtual int IntID
        {
            get { return intID; }
            set { intID = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The location of the Zone's Start.")]
        public virtual Position Start
        {
            get { return start; }
            set { start = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The location of the Zone's Finish.")]
        public virtual Position Finish
        {
            get { return finish; }
            set { finish = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The width of the Zone.")]
        public virtual int Width
        {
            get { return width; }
            set { width = value; }
        }

        [Browsable(false)]
        public virtual Position[] Corners
        {
            get { return corners; }
            set { corners = value; }
        }

        [CategoryAttribute("Configuration"),
            DescriptionAttribute("The streets associated with the Zone."),
            DisplayName("Zone Streets")]
        public virtual Streets Streets
        {
            get { return streets; }
            set { streets = value; }
        }

        #endregion
}

public class ZoneCollection : CollectionBase, ICustomTypeDescriptor
    {
        #region Collection Implementation

        /// <summary>
        /// Adds an zone object to the collection
        /// </summary>
        /// <param name="emp"></param>
        public void Add(Zone zone)
        {
            this.List.Add(zone);
        }

        /// <summary>
        /// Removes an zone object from the collection
        /// </summary>
        /// <param name="emp"></param>
        public void Remove(Zone zone)
        {
            this.List.Remove(zone);
        }

        /// <summary>
        /// Returns an employee object at index position.
        /// </summary>
        public Zone this[int index]
        {
            get
            {
                return (Zone)this.List[index];
            }
        }

        #endregion

        // Implementation of interface ICustomTypeDescriptor
        #region ICustomTypeDescriptor impl

        public String GetClassName()
        {
            return TypeDescriptor.GetClassName(this, true);
        }

        public AttributeCollection GetAttributes()
        {
            return TypeDescriptor.GetAttributes(this, true);
        }

        public String GetComponentName()
        {
            return TypeDescriptor.GetComponentName(this, true);
        }

        public TypeConverter GetConverter()
        {
            return TypeDescriptor.GetConverter(this, true);
        }

        public EventDescriptor GetDefaultEvent()
        {
            return TypeDescriptor.GetDefaultEvent(this, true);
        }

        public PropertyDescriptor GetDefaultProperty()
        {
            return TypeDescriptor.GetDefaultProperty(this, true);
        }

        public object GetEditor(Type editorBaseType)
        {
            return TypeDescriptor.GetEditor(this, editorBaseType, true);
        }

        public EventDescriptorCollection GetEvents(Attribute[] attributes)
        {
            return TypeDescriptor.GetEvents(this, attributes, true);
        }

        public EventDescriptorCollection GetEvents()
        {
            return TypeDescriptor.GetEvents(this, true);
        }

        public object GetPropertyOwner(PropertyDescriptor pd)
        {
            return this;
        }


        /// <summary>
        /// Called to get the properties of this type. Returns properties with certain
        /// attributes. this restriction is not implemented here.
        /// </summary>
        /// <param name="attributes"></param>
        /// <returns></returns>
        public PropertyDescriptorCollection GetProperties(Attribute[] attributes)
        {
            return GetProperties();
        }

        /// <summary>
        /// Called to get the properties of this type.
        /// </summary>
        /// <returns></returns>
        public PropertyDescriptorCollection GetProperties()
        {
            //return ((ICustomTypeDescriptor)this).GetProperties(new Attribute[0]);
            // Create a collection object to hold property descriptors
            PropertyDescriptorCollection pds = new PropertyDescriptorCollection(null);

            // Iterate the list of employees
            for (int i = 0; i < this.List.Count; i++)
            {
                // Create a property descriptor for the employee item and add to the property descriptor collection
                ZoneCollectionPropertyDescriptor pd = new ZoneCollectionPropertyDescriptor(this, i);
                pds.Add(pd);
            }
            // return the property descriptor collection
            return pds;
        }

        #endregion
    }

    /// <summary>
    /// Summary description for CollectionPropertyDescriptor.
    /// </summary>
    public class ZoneCollectionPropertyDescriptor : PropertyDescriptor
    {
        private ZoneCollection collection = null;
        private int index = -1;

        public ZoneCollectionPropertyDescriptor(ZoneCollection coll, int idx) :
            base("#" + idx.ToString(), null)
        {
            this.collection = coll;
            this.index = idx;
        }

        public override AttributeCollection Attributes
        {
            get
            {
                return new AttributeCollection(null);
            }
        }

        public override bool CanResetValue(object component)
        {
            return true;
        }

        public override Type ComponentType
        {
            get
            {
                return this.collection.GetType();
            }
        }

        public override string DisplayName
        {
            get
            {
                Zone zone = this.collection[index];
                return zone.ID.ToString();
            }
        }

        public override string Description
        {
            get
            {
                Zone zone = this.collection[index];
                StringBuilder sb = new StringBuilder();
                sb.Append(zone.ID.ToString());

                if ( zone.Streets.Route != String.Empty || zone.Streets.Crossing != String.Empty)
                    sb.Append("::");
                if (zone.Streets.Route != String.Empty)
                    sb.Append(zone.Streets.Route);
                if ( zone.Streets.Crossing != String.Empty)
                {
                    sb.Append(" and ");
                    sb.Append(zone.Streets.Crossing);
                }

                return sb.ToString();
            }
        }

        public override object GetValue(object component)
        {
            return this.collection[index];
        }

        public override bool IsReadOnly
        {
            get { return false; }
        }

        public override string Name
        {
            get { return "#" + index.ToString(); }
        }

        public override Type PropertyType
        {
            get { return this.collection[index].GetType(); }
        }

        public override void ResetValue(object component)
        {
        }

        public override bool ShouldSerializeValue(object component)
        {
            return true;
        }

        public override void SetValue(object component, object value)
        {
            // this.collection[index] = value;
        }
    }

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class xmlns="urn:nhibernate-mapping-2.2" name="EMTRAC.Devices.Device, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Device`" lazy="false">
    <id name="PK" type="System.Int64, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="PK" />
      <generator class="identity" />
    </id>
    <many-to-one class="EMTRAC.Connections.Connection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="LocalConnection" lazy="false" cascade="all">
      <column name="LocalConnection_id" />
    </many-to-one>
    <many-to-one class="EMTRAC.Connections.Connection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Connection" lazy="false" cascade="all">
      <column name="Connection_id" />
    </many-to-one>
    <many-to-one class="EMTRAC.Packets.Packet, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Configuration" lazy="false" cascade="all">
      <column name="Configuration_id" />
    </many-to-one>
    <joined-subclass name="EMTRAC.Intersections.Intersection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" lazy="false">
      <key>
        <column name="Device_id" />
      </key>
      <bag name="Zones" cascade="all-delete-orphan">
        <key>
          <column name="Intersection_id" />
        </key>
        <one-to-many class="EMTRAC.Zones.Zone, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
      </bag>
      <many-to-one class="EMTRAC.Intersections.Streets, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Streets" lazy="false" cascade="all">
        <column name="Streets_id" />
      </many-to-one>
      <many-to-one class="EMTRAC.Positions.Position, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Position" lazy="false" cascade="all">
        <column name="Position" />
      </many-to-one>
    </joined-subclass>
  </class>
</hibernate-mapping>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class xmlns="urn:nhibernate-mapping-2.2" name="EMTRAC.Zones.Zone, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Zone`" lazy="false">
    <id name="ID" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="PK" />
      <generator class="identity" />
    </id>
    <property name="Active" type="System.Boolean, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Active" />
    </property>
    <property name="Dir" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Dir" />
    </property>
    <property name="IntID" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="IntID" />
    </property>
    <property name="Width" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Width" />
    </property>
    <many-to-one class="EMTRAC.Headings.Heading, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Heading" cascade="all-delete-orphan">
      <column name="Heading_id" />
    </many-to-one>
    <many-to-one class="EMTRAC.Positions.Position, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Start" cascade="all-delete-orphan">
      <column name="Start_id" />
    </many-to-one>
    <many-to-one class="EMTRAC.Positions.Position, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Finish" cascade="all-delete-orphan">
      <column name="Finish_id" />
    </many-to-one>
  </class>
</hibernate-mapping>