DescendantQuery.cs

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using System.Xml.XPath;
 
namespace MS.Internal.Xml.XPath;
 
internal sealed class DescendantQuery : DescendantBaseQuery
{
    private XPathNodeIterator _nodeIterator;
 
    internal DescendantQuery(Query qyParent, string Name, string Prefix, XPathNodeType Type, bool matchSelf, bool abbrAxis)
        : base(qyParent, Name, Prefix, Type, matchSelf, abbrAxis)
    {
    }
 
    public DescendantQuery(DescendantQuery other)
        : base(other)
    {
        _nodeIterator = Query.Clone(other._nodeIterator);
    }
 
    public override void Reset()
    {
        _nodeIterator = null;
        base.Reset();
    }
 
    public override XPathNavigator Advance()
    {
        while (true)
        {
            if (_nodeIterator == null)
            {
                position = 0;
                XPathNavigator xPathNavigator = qyInput.Advance();
                if (xPathNavigator == null)
                {
                    return null;
                }
                if (base.NameTest)
                {
                    if (base.TypeTest == XPathNodeType.ProcessingInstruction)
                    {
                        _nodeIterator = new IteratorFilter(xPathNavigator.SelectDescendants(base.TypeTest, matchSelf), base.Name);
                    }
                    else
                    {
                        _nodeIterator = xPathNavigator.SelectDescendants(base.Name, base.Namespace, matchSelf);
                    }
                }
                else
                {
                    _nodeIterator = xPathNavigator.SelectDescendants(base.TypeTest, matchSelf);
                }
            }
            if (_nodeIterator.MoveNext())
            {
                break;
            }
            _nodeIterator = null;
        }
        position++;
        currentNode = _nodeIterator.Current;
        return currentNode;
    }
 
    public override XPathNodeIterator Clone()
    {
        return new DescendantQuery(this);
    }
}