/// <summary>
/// Returns a new <see cref="RegionTree"/> with the specified child added at the end.
/// </summary>
/// <param name="child">The child to add.</param>
/// <returns>The updated <see cref="RegionTree"/>.</returns>
private RegionTree AddChild(RegionTree child)
{
return(new RegionTree(
this.Name,
this.SpanStart,
this.SpanEnd,
this.Children.Add(child),
this.IsRoot,
this.ItemCollection));
}
/// <summary>
/// Returns a new <see cref="RegionTree"/> with the specified child removed.
/// </summary>
/// <param name="childToRemove">The child to remove.</param>
/// <returns>The updated <see cref="RegionTree"/>.</returns>
private RegionTree RemoveChild(RegionTree childToRemove)
{
return(new RegionTree(
this.Name,
this.SpanStart,
this.SpanEnd,
this.Children.Remove(childToRemove),
this.IsRoot,
this.ItemCollection));
}
/// <summary>
/// Returns a new <see cref="RegionTree"/> with <paramref name="oldChild"/> replaced with
/// <paramref name="newChild"/>.
/// </summary>
/// <param name="oldChild">The child to be replaced.</param>
/// <param name="newChild">The replacemend child.</param>
/// <returns>The updated <see cref="RegionTree"/>.</returns>
private RegionTree UpdateChild(RegionTree oldChild, RegionTree newChild)
{
return(new RegionTree(
this.Name,
this.SpanStart,
this.SpanEnd,
this.Children.Replace(oldChild, newChild),
this.IsRoot,
this.ItemCollection));
}
/// <summary>
/// Builds a region tree from a list of <see cref="RegionDirectiveTriviaSyntax"/> and
/// <see cref="EndRegionDirectiveTriviaSyntax"/> elements. Builds up the item collections with only regions.
/// </summary>
/// <param name="directives">The directives to build the region tree from.</param>
/// <returns>The built region tree.</returns>
public RegionTree Create(IEnumerator <DirectiveTriviaSyntax> directives)
{
var result = this;
while (directives.MoveNext())
{
if (directives.Current is RegionDirectiveTriviaSyntax start)
{
// A new region is started, so try finding sub-regions inside it.
// Note that if there are more start-regions than end-regions, this will result the outermost
// region being ended at the same time as the last region that was ended.
var item = new TreeViewItem {
IsExpanded = true
};
var child = new RegionTree(start.ToString(), start.FullSpan, item.Items).Create(directives);
result = result.AddChild(child);
item.Header = new TreeElement(
child.Name.Substring("#region ".Length),
new TextSpan(child.SpanStart, child.SpanEnd - child.SpanStart),
TreeImages.GetImage(ElementType.Region),
regionId: child.Id)
{
TextColor = "#666"
};
this.ItemCollection.Add(item);
}
else if (directives.Current is EndRegionDirectiveTriviaSyntax end)
{
// We return the region currently being built up with its span-end filled in.
// Note that an additional endregion syntax will exit this method early, resulting in fewer regions
// being returned. But that is okay, since the syntax is not correct anyway.
return(result.SetSpanEnd(end.FullSpan.End));
}
}
// For the root, don't update the span end, it was set when creating the region.
// Otherwise, there are end-region directives missing, so end the current region at the end of its
// child regions (if it has any).
var lastChild = result.Children.LastOrDefault();
if (result.IsRoot || lastChild == null)
{
return(result);
}
else
{
return(result.SetSpanEnd(lastChild.SpanEnd));
}
}
/// <summary>
/// Handles nesting child nodes within regions. While regions are allowed in multiple levels,
/// we only use this on second level nodes.
/// </summary>
private static void HandleChildrenWithRegions(SyntaxNode node, ItemCollection itemCollection)
{
// Determine regions, so we know whether to put nodes inside the regions, or not.
var startRegionDirectives = node.DescendantNodes(descendIntoTrivia: true)
.OfType <RegionDirectiveTriviaSyntax>().Cast <DirectiveTriviaSyntax>()
.Where(s => node.Span.Contains(s.Span));
var endRegionDirectives = node.DescendantNodes(descendIntoTrivia: true).OfType <EndRegionDirectiveTriviaSyntax>()
.Where(s => node.Span.Contains(s.Span));
var regionDirectives = startRegionDirectives.Union(endRegionDirectives).OrderBy(x => x.FullSpan.Start);
var regionTree = new RegionTree(node.Span, itemCollection).Create(regionDirectives.GetEnumerator());
// Insert all nodes in the region tree, this will update itemCollection.
// Note that this uses an immutable structure to easily recurse over the region structure, while mutating
// the mutable itemCollection as the intended side-effect. Hence the return value is not used.
node.ChildNodes().Aggregate(regionTree, (current, child) => current.InsertNode(child));
}