XPathNodeIterator.cs :  » 2.6.4-mono-.net-core » System.Xml » System » Xml » XPath » C# / CSharp Open Source

//
// System.Xml.XPath.XPathNodeIterator
//
// Author:
//   Jason Diamond (jason@injektilo.org)
//
// (C) 2002 Jason Diamond  http://injektilo.org/
//

//
// 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;
using System.Collections;
#if NET_2_0
using System.Diagnostics;
#endif

namespace System.Xml.XPath{
#if NET_2_0
  public abstract class XPathNodeIterator : ICloneable, IEnumerable
#else
  public abstract class XPathNodeIterator : ICloneable
#endif
  {
    private int _count = -1;

    #region Constructor

    protected XPathNodeIterator ()
    {
    }

    #endregion

    #region Properties

    public virtual int Count
    {
      get
      {
        if (_count == -1)
        {
          // compute and cache the count
          XPathNodeIterator tmp = Clone ();
          while (tmp.MoveNext ())
            ;
          _count = tmp.CurrentPosition;
        }
        return _count;
      }
    }

    public abstract XPathNavigator Current { get; }

    public abstract int CurrentPosition { get; }

    #endregion

    #region Methods

    public abstract XPathNodeIterator Clone ();

    object ICloneable.Clone ()
    {
      return Clone ();
    }

#if NET_2_0
    public virtual IEnumerator GetEnumerator ()
    {
      while (MoveNext ())
        yield return Current;
    }
#endif

    public abstract bool MoveNext ();
    
    #endregion
  }
}