public int IndexOf(object item)
{
SharpTreeNode node = item as SharpTreeNode;
if (node != null && node.IsVisible && node.GetListRoot() == root)
{
if (includeRoot)
{
return(SharpTreeNode.GetVisibleIndexForNode(node));
}
else
{
return(SharpTreeNode.GetVisibleIndexForNode(node) - 1);
}
}
else
{
return(-1);
}
}
internal static int GetVisibleIndexForNode(SharpTreeNode node)
{
int index = node.left != null?node.left.GetTotalListLength() : 0;
while (node.listParent != null)
{
if (node == node.listParent.right)
{
if (node.listParent.left != null)
{
index += node.listParent.left.GetTotalListLength();
}
if (node.listParent.isVisible)
{
index++;
}
}
node = node.listParent;
}
return(index);
}
/// <summary>
/// Balances the subtree rooted in <paramref name="node"/> and recomputes the 'height' field.
/// This method assumes that the children of this node are already balanced and have an up-to-date 'height' value.
/// </summary>
/// <returns>The new root node</returns>
static SharpTreeNode Rebalance(SharpTreeNode node)
{
Debug.Assert(node.left == null || Math.Abs(node.left.Balance) <= 1);
Debug.Assert(node.right == null || Math.Abs(node.right.Balance) <= 1);
// Keep looping until it's balanced. Not sure if this is stricly required; this is based on
// the Rope code where node merging made this necessary.
while (Math.Abs(node.Balance) > 1)
{
// AVL balancing
// note: because we don't care about the identity of concat nodes, this works a little different than usual
// tree rotations: in our implementation, the "this" node will stay at the top, only its children are rearranged
if (node.Balance > 1)
{
if (node.right.Balance < 0)
{
node.right = node.right.RotateRight();
}
node = node.RotateLeft();
// If 'node' was unbalanced by more than 2, we've shifted some of the inbalance to the left node; so rebalance that.
node.left = Rebalance(node.left);
}
else if (node.Balance < -1)
{
if (node.left.Balance > 0)
{
node.left = node.left.RotateLeft();
}
node = node.RotateRight();
// If 'node' was unbalanced by more than 2, we've shifted some of the inbalance to the right node; so rebalance that.
node.right = Rebalance(node.right);
}
}
Debug.Assert(Math.Abs(node.Balance) <= 1);
node.height = (byte)(1 + Math.Max(Height(node.left), Height(node.right)));
node.totalListLength = -1; // mark for recalculation
// since balancing checks the whole tree up to the root, the whole path will get marked as invalid
return(node);
}
static void InsertNodeAfter(SharpTreeNode pos, SharpTreeNode newNode)
{
// newNode might be the model root of a whole subtree, so go to the list root of that subtree:
newNode = newNode.GetListRoot();
if (pos.right == null)
{
pos.right = newNode;
newNode.listParent = pos;
}
else
{
// insert before pos.right's leftmost:
pos = pos.right;
while (pos.left != null)
{
pos = pos.left;
}
Debug.Assert(pos.left == null);
pos.left = newNode;
newNode.listParent = pos;
}
RebalanceUntilRoot(pos);
}
SharpTreeNode Successor()
{
if (right != null)
{
SharpTreeNode node = right;
while (node.left != null)
{
node = node.left;
}
return(node);
}
else
{
SharpTreeNode node = this;
SharpTreeNode oldNode;
do
{
oldNode = node;
node = node.listParent;
// loop while we are on the way up from the right part
} while (node != null && node.right == oldNode);
return(node);
}
}
SharpTreeNode RotateRight()
{
/* Rotate tree to the right
*
* this left
* / \ / \
* left C ===> A this
* / \ / \
* A B B C
*/
SharpTreeNode b = left.right;
SharpTreeNode newTop = left;
if (b != null)
{
b.listParent = this;
}
this.left = b;
newTop.right = this;
newTop.listParent = this.listParent;
this.listParent = newTop;
newTop.right = Rebalance(this);
return(newTop);
}
static void DumpTree(SharpTreeNode node)
{
node.GetListRoot().DumpTree();
}
static int Height(SharpTreeNode node)
{
return(node != null ? node.height : 0);
}
internal protected virtual void OnChildrenChanged(NotifyCollectionChangedEventArgs e)
{
if (e.OldItems != null)
{
foreach (SharpTreeNode node in e.OldItems)
{
Debug.Assert(node.modelParent == this);
node.modelParent = null;
Debug.WriteLine("Removing {0} from {1}", node, this);
SharpTreeNode removeEnd = node;
while (removeEnd.modelChildren != null && removeEnd.modelChildren.Count > 0)
{
removeEnd = removeEnd.modelChildren.Last();
}
List <SharpTreeNode> removedNodes = null;
int visibleIndexOfRemoval = 0;
if (node.isVisible)
{
visibleIndexOfRemoval = GetVisibleIndexForNode(node);
removedNodes = node.VisibleDescendantsAndSelf().ToList();
}
RemoveNodes(node, removeEnd);
if (removedNodes != null)
{
var flattener = GetListRoot().treeFlattener;
if (flattener != null)
{
flattener.NodesRemoved(visibleIndexOfRemoval, removedNodes);
}
}
}
}
if (e.NewItems != null)
{
SharpTreeNode insertionPos;
if (e.NewStartingIndex == 0)
{
insertionPos = null;
}
else
{
insertionPos = modelChildren[e.NewStartingIndex - 1];
}
foreach (SharpTreeNode node in e.NewItems)
{
Debug.Assert(node.modelParent == null);
node.modelParent = this;
node.UpdateIsVisible(isVisible && isExpanded, false);
//Debug.WriteLine("Inserting {0} after {1}", node, insertionPos);
while (insertionPos != null && insertionPos.modelChildren != null && insertionPos.modelChildren.Count > 0)
{
insertionPos = insertionPos.modelChildren.Last();
}
InsertNodeAfter(insertionPos ?? this, node);
insertionPos = node;
if (node.isVisible)
{
var flattener = GetListRoot().treeFlattener;
if (flattener != null)
{
flattener.NodesInserted(GetVisibleIndexForNode(node), node.VisibleDescendantsAndSelf());
}
}
}
}
RaisePropertyChanged("ShowExpander");
RaiseIsLastChangedIfNeeded(e);
}