ITreeTableEntry ITreeTable.GetPreviousEntry(ITreeTableEntry current)
{
return(GetPreviousEntry((GenericTreeTableWithSummaryEntry <V>)current));
}
ITreeTableEntry ITreeTable.GetNextEntry(ITreeTableEntry current)
{
return(GetNextEntry((GenericTreeTableEntry <V>)current));
}
ITreeTableEntry ITreeTable.GetPreviousEntry(ITreeTableEntry current)
{
return(GetPreviousEntry((GenericTreeTableWithCounterEntry <V, C>)current));
}
/// <summary>
/// Returns the previous entry in the collection for which the specific counter is not empty.
/// A cookie defines the type of counter.
/// </summary>
/// <param name="current">The current.</param>
/// <param name="cookie">The cookie.</param>
/// <returns></returns>
public ITreeTableEntry GetPreviousNotEmptyCounterEntry(ITreeTableEntry current, int cookie)
{
ITreeTableBranch parent = current.Parent;
ITreeTableNode next;
if (parent == null)
{
next = null;
return(null);
}
else
{
next = current;
// walk up until we find a branch that has visible entries
do
{
if (Object.ReferenceEquals(next, parent.Right))
{
next = parent.Left;
}
else
{
ITreeTableBranch parentParent = parent.Parent;
Debug.Assert(parentParent != parent);
if (parentParent == null)
{
return(null);
}
else
{
while (Object.ReferenceEquals(parentParent.Left, parent)
// TODO: this second statement is a workaround
// for something that most likely went wrong when
// adding the node or when doing a rotation ...
|| Object.ReferenceEquals(parentParent.Left, next)
)
{
parent = parentParent;
parentParent = parentParent.Parent;
if (parentParent == null)
{
return(null);
}
}
//Debug.Assert(next != parentParent.Right);
if (next == parentParent.Left)
{
throw new Exception();
//return null;
}
else
{
next = parentParent.Left;
}
}
}
}while (next != null && ((ITreeTableCounterNode)next).GetCounterTotal().IsEmpty(cookie));
// walk down to most left leaf that has visible entries
while (!next.IsEntry())
{
var branch = (ITreeTableBranch)next;
next = !((ITreeTableCounterNode)branch.Right).GetCounterTotal().IsEmpty(cookie) ? branch.Right : branch.Left;
}
}
return(next as ITreeTableEntry);
}
