/// <summary>
/// Finds the remaining item after some items have been deleted.
/// </summary>
/// <param name="predicate">Function that determines whether an item is acceptable.</param>
/// <returns>The first accepted item, or null.</returns>
public TreeViewItemViewModel FindRemainingItem(Predicate <TreeViewItemViewModel> predicate)
{
// Start on the current tree level
TreeViewItemViewModel level = this;
do
{
// Try the following siblings
TreeViewItemViewModel position = level;
do
{
position = position.FindNextSibling();
if (position != null && predicate(position))
{
return(position);
}
}while (position != null);
// Try the preceding siblings
position = this;
do
{
position = position.FindPreviousSibling();
if (position != null && predicate(position))
{
return(position);
}
}while (position != null);
// Continue on the parent level (stop on the root item)
level = level.Parent;
}while (level != null && level.Parent != null);
// Nothing remains
return(null);
}
