mcs/class/referencesource/System.Xml/System/Xml/XPath/Internal/ResetableIterator.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="ResetableIterator.cs" company="Microsoft">
   3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 // <owner current="true" primary="true">Microsoft</owner>
   6 //------------------------------------------------------------------------------
   7
   8 namespace MS.Internal.Xml.XPath {
   9     using System;
  10     using System.Xml;
  11     using System.Xml.XPath;
  12     using System.Diagnostics;
  13     using System.Globalization;
  14
  15     internal abstract class ResetableIterator : XPathNodeIterator {
  16         // the best place for this constructors to be is XPathNodeIterator, to avoid DCR at this time let's ground them here
  17         public ResetableIterator() {
  18             base.count = -1;
  19         }
  20         protected ResetableIterator(ResetableIterator other) {
  21             base.count = other.count;
  22         }
  23         protected void ResetCount() {
  24             base.count = -1;
  25         }
  26
  27         public abstract void Reset();
  28         public virtual bool MoveToPosition(int pos) {
  29             Reset();
  30             for(int i = CurrentPosition; i < pos ; i ++) {
  31                 if(!MoveNext()) {
  32                     return false;
  33                 }
  34             }
  35             return true;
  36         }
  37
  38         // Contruct extension: CurrentPosition should return 0 if MoveNext() wasn't called after Reset()
  39         // (behavior is not defined for XPathNodeIterator)
  40         public abstract override int CurrentPosition { get; }
  41     }
  42 }