Node.cs :  » 2.6.4-mono-.net-core » System.Data » System » Data » C# / CSharp Open Source

//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;

namespace System.Data{
  /// <summary>
  /// Summary description for Node.
  /// </summary>
  internal class Node
  {
    protected int _iBalance;    // currently, -2 means 'deleted'
    internal Node _nNext;       // node of next index (nNext==null || nNext.iId=iId+1)
    protected Node _nLeft;
    protected Node _nRight;
    protected Node _nParent;

    protected DataRow _row;
    
    public Node(DataRow row)
    {
      _row = row;
    }

    internal int GetBalance()
    {
      if (_iBalance == -2)
        throw new SystemException ("Node is deleted.");

      return _iBalance;
    }

    internal void Delete()
    {
      _iBalance = -2;
      _nLeft = null;
      _nRight = null;
      _nParent = null;
    }


    internal DataRow Row
    {
      get {
        return _row;
      }
    }

    internal Node Left
    {
      get {
        if (_iBalance == -2)
          throw new SystemException ("Node is deleted.");

        return _nLeft;
      }

      set {
        if (_iBalance == -2)
          throw new SystemException ("Node is deleted.");

        _nLeft = value;
      }
    }

    internal Node Right
    {
      get {
        if (_iBalance == -2)
          throw new SystemException ("Node is deleted.");
        return _nRight;
      }

      set {
        if (_iBalance == -2)
          throw new SystemException ("Node is deleted.");

        _nRight = value;
      }
    }


    internal Node Parent
    {
      get {
        if (_iBalance == -2)
          throw new SystemException ("Node is deleted.");

        return _nParent;
      }

      set {
        if (_iBalance == -2)
          throw new SystemException ("Node is deleted.");
        _nParent = value;
      }
    }

    internal bool IsRoot()
    {
      return _nParent == null;
    }


    internal void SetBalance(int b)
    {

      if (_iBalance == -2)
        throw new SystemException ("Node is deleted.");

      _iBalance = b;
    }

    internal bool From()
    {

      if (this.IsRoot()){
        return true;
      }

      if (_iBalance == -2)
        throw new SystemException ("Node is deleted.");
      Node parent = Parent;

      return Equals(parent.Left);
    }

    internal Object[] GetData()
    {

      if (_iBalance == -2)
        throw new SystemException ("Node is deleted.");
      return _row.ItemArray;
    }

    internal bool Equals(Node n)
    {

      if (_iBalance == -2)
        throw new SystemException ("Node is deleted.");

      return n == this;
    }
  }
}