bool ExpandSelection(List <XObject> nodePath, XmlSpineParser spine, SnapshotSpan activeSpan, ref int index, ref SelectionLevel level)
{
if (index - 1 < 0)
{
return(false);
}
//if an index is selected, we may need to transition level rather than transitioning index
if (index < nodePath.Count)
{
var current = nodePath[index];
if (current is XElement element)
{
switch (level)
{
case SelectionLevel.Self:
if (spine != null && !spine.AdvanceUntilClosed(element, activeSpan.Snapshot, 5000))
{
return(false);
}
if (!element.IsSelfClosing)
{
level = SelectionLevel.OuterElement;
return(true);
}
break;
case SelectionLevel.Content:
level = SelectionLevel.OuterElement;
return(true);
case SelectionLevel.Name:
level = SelectionLevel.Self;
return(true);
case SelectionLevel.Attributes:
level = SelectionLevel.Self;
return(true);
}
}
else if (current is XAttribute)
{
switch (level)
{
case SelectionLevel.Name:
case SelectionLevel.Content:
level = SelectionLevel.Self;
return(true);
}
}
else if (level == SelectionLevel.Name)
{
level = SelectionLevel.Self;
return(true);
}
else if (level == SelectionLevel.Document)
{
return(false);
}
}
//advance up the node path
index--;
var newNode = nodePath[index];
//determine the starting selection level for the new node
if (newNode is XDocument)
{
level = SelectionLevel.Document;
return(true);
}
if (spine != null && !spine.AdvanceUntilEnded(newNode, activeSpan.Snapshot, 5000))
{
return(false);
}
bool ContainsSelection(TextSpan span) => activeSpan.Start >= span.Start && activeSpan.End <= span.End;
if (ContainsSelection(newNode.Span))
{
if ((newNode as INamedXObject)?.NameSpan is TextSpan nr && ContainsSelection(nr))
{
level = SelectionLevel.Name;
return(true);
}
if (newNode is XAttribute attribute)
{
var valRegion = attribute.ValueSpan;
if (ContainsSelection(valRegion))
{
level = SelectionLevel.Content;
return(true);
}
}
if (newNode is XText)
{
level = SelectionLevel.Content;
return(true);
}
if (newNode is XElement xElement && xElement.Attributes.Count > 1)
{
if (xElement.GetAttributesSpan() is TextSpan attsSpan && ContainsSelection(attsSpan))
{
level = SelectionLevel.Attributes;
return(true);
}
}
level = SelectionLevel.Self;
return(true);
}
if (spine != null && !spine.AdvanceUntilClosed(newNode, activeSpan.Snapshot, 5000))
{
return(false);
}
if (newNode is XElement el && el.ClosingTag != null)
{
if (el.IsSelfClosing)
{
level = SelectionLevel.Self;
return(true);
}
if (ContainsSelection((TextSpan)el.InnerSpan))
{
level = SelectionLevel.Content;
return(true);
}
level = SelectionLevel.OuterElement;
return(true);
}
level = SelectionLevel.Self;
return(true);
}
/// <summary> /// Advances the parser until the specified object is closed i.e. has a closing tag. /// </summary> /// <param name="parser">A spine parser. Its state will be modified.</param> /// <param name="ob">The object to complete</param> /// <param name="snapshot"></param> /// <param name="snapshot">The text snapshot corresponding to the parser.</param> /// <param name="maximumReadahead">Maximum number of characters to advance before giving up.</param> /// <returns>Whether the object was successfully completed</returns> public static bool AdvanceUntilClosed(this XmlSpineParser parser, XObject ob, ITextSnapshot snapshot, int maximumReadahead = DEFAULT_READAHEAD_LIMIT) => parser.AdvanceUntilClosed(ob, new SnapshotTextSource(snapshot), maximumReadahead);