/// <summary>
/// Return true if an element matches a specific DOM position-type filter
/// </summary>
/// <param name="obj"></param>
/// <param name="position"></param>
/// <param name="criteria"></param>
/// <returns></returns>
protected bool MatchesDOMPosition(IDomElement obj, PositionType position, string criteria)
{
switch (position)
{
case PositionType.FirstChild:
return(obj.PreviousElementSibling == null);
case PositionType.LastChild:
return(obj.NextElementSibling == null);
case PositionType.Odd:
return(obj.ElementIndex % 2 != 0);
case PositionType.Even:
return(obj.ElementIndex % 2 == 0);
case PositionType.All:
return(true);
case PositionType.NthChild:
return(NthChildMatcher.IndexMatches(obj.ElementIndex, criteria));
default:
throw new NotImplementedException("Unimplemented position type selector");
}
}
/// <summary>
/// Return the index of obj within its siblings, including only elements with the same node name.
/// </summary>
///
/// <param name="obj">
/// The object to seek
/// </param>
/// <param name="onlyOfSameType">
/// true to only objects of the same NodeName should be considered
/// </param>
/// <param name="fromLast">
/// Count from the last element instead of the first.
/// </param>
///
/// <returns>
/// The zero-based index of obj within its siblings (or its siblings of the same type)
/// </returns>
private int IndexOf(IDomElement obj, bool onlyOfSameType, bool fromLast = false)
{
// get the index just for this type
int typeIndex = 0;
var childNodes = obj.ParentNode.ChildNodes;
int length = childNodes.Count;
for (int index = 0; index < length; index++)
{
var el = NthChildMatcher.GetEffectiveChild(childNodes, index, fromLast);
if (el.NodeType == NodeType.ELEMENT_NODE)
{
if (!onlyOfSameType || el.NodeNameID == obj.NodeNameID)
{
if (ReferenceEquals(el, obj))
{
return(typeIndex);
}
typeIndex++;
}
}
}
return(-1);
}
/// <summary>
/// Determine if an element matches a position-type filter
/// </summary>
/// <param name="elm"></param>
/// <param name="selector"></param>
/// <returns></returns>
protected IEnumerable <IDomObject> GetDomPositionMatches(IDomElement elm, Selector selector)
{
if (selector.PositionType == PositionType.NthChild)
{
return(NthChildMatcher.GetMatchingChildren(elm, selector.Criteria));
}
else
{
return(GetSimpleDomPostionMatches(elm, selector.PositionType));
}
}
