public TextAnchor CreateAnchor(int offset)
{
Log("CreateAnchor(" + offset + ")");
TextAnchor anchor = new TextAnchor(document);
anchor.node = new TextAnchorNode(anchor);
if (root == null) {
// creating the first text anchor
root = anchor.node;
root.totalLength = root.length = offset;
} else if (offset >= root.totalLength) {
// append anchor at end of tree
anchor.node.totalLength = anchor.node.length = offset - root.totalLength;
InsertAsRight(root.RightMost, anchor.node);
} else {
// insert anchor in middle of tree
TextAnchorNode n = FindNode(ref offset);
Debug.Assert(offset < n.length);
// split segment 'n' at offset
anchor.node.totalLength = anchor.node.length = offset;
n.length -= offset;
InsertBefore(n, anchor.node);
}
DeleteMarkedNodes();
return anchor;
}
private void SetTextAnchor(int offset)
{
if(textAnchor != null)
textAnchor.Deleted -= OnAnchorDeleted;
textAnchor = Document.CreateAnchor(offset);
textAnchor.Deleted += OnAnchorDeleted;
}
internal int totalLength; // totalLength = length + left.totalLength + right.totalLength
#endregion Fields
#region Constructors
public TextAnchorNode(TextAnchor anchor)
: base(anchor)
{
}