private void UpdateTopNode()
{
if (!inUpdateTopNode)
{
inUpdateTopNode = true;
try
{
lock ( _nodeCollection )
{
_topNode = null;
int delta = _scrollOffset;
IVisibleNodeEnumerator enumerator = _visibleNodeCollection.GetFullEnumerator();
while (enumerator.MoveNext())
{
int height = GetRowHeight(enumerator.CurrentNode);
if (delta < height)
{
_topNode = enumerator.CurrentNode;
_topNodeOffset = delta;
break;
}
delta -= height;
}
}
}
finally
{
inUpdateTopNode = false;
}
}
}
public int GetWheelScrollDistance(int lines)
{
// the wheel scroll can be requested between BeginUpdate() and EndUpdate(),
// when the node which was _topNode has already been removed from the collection
// but UpdateTopNode() was not yet called (OM-10633)
int result = 0;
lock ( _nodeCollection )
{
IViewNode topNode = _topNode; // avoid race condition (OM-11963)
if (topNode != null && _visibleNodeCollection.IsNodeVisible(topNode))
{
IVisibleNodeEnumerator enumerator = _visibleNodeCollection.GetDirectionalEnumerator(topNode,
(lines < 0) ? MoveDirection.Up : MoveDirection.Down);
while (enumerator.MoveNext() && lines != 0)
{
int rowHeight = GetRowHeight(enumerator.CurrentNode);
if (lines > 0)
{
result += rowHeight;
lines--;
}
else
{
result -= rowHeight;
lines++;
}
}
}
}
return(result);
}
private void HandleMultipleNodesChanged(object sender, MultipleNodesChangedEventArgs e)
{
// ensure correct lock ordering - lock node collection before selection
lock ( _nodeCollection )
{
lock ( SelectionLock )
{
if (Count > 0)
{
if (_nodeCollection.IsEmpty)
{
Clear();
}
else
{
IViewNode[] selNodes = SelectionToArray();
foreach (IViewNode selNode in selNodes)
{
if (!_visibleNodeCollection.IsNodeVisible(selNode))
{
UnselectNode(selNode);
}
}
if (Count == 0)
{
IVisibleNodeEnumerator enumerator = _visibleNodeCollection.GetFullEnumerator();
if (enumerator.MoveNext())
{
SelectAndFocusNode(enumerator.CurrentNode);
}
}
}
}
}
}
}
private void RemoveNodeFromSelection(IViewNode viewNode)
{
if ((UnselectNode(viewNode) && Count == 0) || viewNode == _focusNode)
{
IViewNode nextNode = null, prevNode = null;
IVisibleNodeEnumerator enumerator = _visibleNodeCollection.GetDirectionalEnumerator(viewNode, MoveDirection.Down);
enumerator.MoveNext();
// make sure we don't move the selection to the node being deleted if we delete
// the node and its group in one VisibleNodeRemoving operation
if (enumerator.MoveNext() && enumerator.CurrentNode != _lastRemovedNode)
{
nextNode = enumerator.CurrentNode;
}
enumerator = _visibleNodeCollection.GetDirectionalEnumerator(viewNode, MoveDirection.Up);
enumerator.MoveNext();
if (enumerator.MoveNext() && enumerator.CurrentNode != _lastRemovedNode)
{
prevNode = enumerator.CurrentNode;
}
if (nextNode == null)
{
if (prevNode != null)
{
SelectAndFocusNode(prevNode);
}
else
{
SetFocusNode(null);
}
}
else if (prevNode != null && viewNode is JetListViewNode)
{
JetListViewNode prevLvNode = prevNode as JetListViewNode;
JetListViewNode nextLvNode = nextNode as JetListViewNode;
int removedNodeLevel = (viewNode as JetListViewNode).Level;
if (prevLvNode != null && nextLvNode != null &&
prevLvNode.Level == removedNodeLevel && nextLvNode.Level != removedNodeLevel)
{
SelectAndFocusNode(prevNode);
}
else if (prevLvNode != null && nextLvNode != null &&
prevLvNode.Level != removedNodeLevel && nextLvNode.Level == removedNodeLevel)
{
SelectAndFocusNode(nextNode);
}
else if (prevNode == (viewNode as JetListViewNode).Parent)
{
SelectAndFocusNode(prevNode);
}
else if (prevLvNode != null && nextLvNode == null)
{
SelectAndFocusNode(prevNode);
}
else
{
SelectAndFocusNode(nextNode);
}
}
else
{
SelectAndFocusNode(nextNode);
}
}
_lastRemovedNode = viewNode;
}
private void AdjustTopNode(int delta)
{
lock ( _nodeCollection )
{
IViewNode topNode = _topNode; // avoid race conditions (OM-12038)
if (topNode == null || !_visibleNodeCollection.IsNodeVisible(topNode))
{
UpdateTopNode();
return;
}
try
{
IVisibleNodeEnumerator enumerator = _visibleNodeCollection.GetDirectionalEnumerator(topNode,
(delta > 0) ? MoveDirection.Down : MoveDirection.Up);
if (_topNodeOffset != 0)
{
if (delta > 0)
{
int curNodeDelta = GetRowHeight(topNode) - _topNodeOffset;
if (delta < curNodeDelta)
{
_topNodeOffset += delta;
return;
}
delta -= curNodeDelta;
enumerator.MoveNext();
}
else
{
if (_topNodeOffset >= -delta)
{
_topNodeOffset += delta;
return;
}
delta += _topNodeOffset;
}
}
if (delta < 0)
{
enumerator.MoveNext();
}
int absDelta = Math.Abs(delta);
_topNodeOffset = 0;
while (enumerator.MoveNext())
{
int curRowHeight = GetRowHeight(enumerator.CurrentNode);
if (absDelta < curRowHeight)
{
if (delta > 0 || absDelta == 0)
{
_topNodeOffset = absDelta;
}
else
{
_topNodeOffset = curRowHeight - absDelta;
}
break;
}
absDelta -= curRowHeight;
if (delta < 0 && absDelta == 0)
{
break;
}
}
_topNode = enumerator.CurrentNode;
}
catch (ArgumentOutOfRangeException ex) // mega-hacky crappy fix for OM-11090
{
Trace.WriteLine("Exception in UpdateTopNode: " + ex.ToString());
UpdateTopNode();
}
}
}
