private void ClearTimer()
{
if (_hoverTimer != null)
{
_hoverTimer.Dispose();
_hoverTimer = null;
}
}
private void HoverExpand(object sender, EventArgs args)
{
HoverTimer timer = (HoverTimer)sender;
if (timer.Node != null)
{
timer.Node.Expand();
}
timer.Enabled = false;
}
protected override void OnDragOver(DragEventArgs args)
{
base.OnDragOver(args);
HoverAction newAction;
TreeNode newNode = null;
Point localPoint = PointToClient(new Point(args.X, args.Y));
if (localPoint.Y < HoverScrollMargin)
{
newAction = HoverAction.ScrollUp;
}
else if (localPoint.Y > (ClientSize.Height - HoverScrollMargin))
{
newAction = HoverAction.ScrollDown;
}
else
{
newAction = HoverAction.OverNode;
newNode = GetNodeAt(localPoint.X, localPoint.Y);
}
if (_hoverTimer != null)
{
if ((_hoverTimer.Action != newAction) || (_hoverTimer.Node != newNode))
{
ClearTimer();
}
else
{
return; // do not reset the timer if nothing has changed
}
}
if ((newAction != HoverAction.OverNode) || (newNode != null))
{
_hoverTimer = new HoverTimer(newAction, newNode);
switch (newAction)
{
case HoverAction.OverNode:
_hoverTimer.Interval = DragOverInterval;
_hoverTimer.Tick += new EventHandler(HoverExpand);
break;
case HoverAction.ScrollUp:
case HoverAction.ScrollDown:
_hoverTimer.Interval = HoverScrollInterval;
_hoverTimer.Tick += new EventHandler(HoverScroll);
break;
}
_hoverTimer.Enabled = true;
}
}
private void HoverScroll(object sender, EventArgs args)
{
HoverTimer timer = (HoverTimer)sender;
if (timer.Action == HoverAction.ScrollUp)
{
ScrollTree(-2);
}
else
{
ScrollTree(2);
}
}
