public static Rect CalculateDropMarker(Panel panel, UIElementCollection children, Orientation orientation, int dropIndex)
{
Rect DropMarker;
if (children.Count > 0)
{
if (dropIndex == 0)
{
Rect ItemRect = children[0].TransformToVisual(panel).TransformBounds(VisualTreeHelperEx.GetBounds(children[0]));
DropMarker = orientation == Orientation.Vertical
? new Rect(ItemRect.Left, ItemRect.Top, ItemRect.Width, 0)
: new Rect(ItemRect.Left, ItemRect.Top, 0, ItemRect.Height);
}
else
{
Rect ItemRect = children[dropIndex - 1].TransformToVisual(panel).TransformBounds(VisualTreeHelperEx.GetBounds(children[dropIndex - 1]));
DropMarker = orientation == Orientation.Vertical
? new Rect(ItemRect.Left, ItemRect.Bottom, ItemRect.Width, 0)
: new Rect(ItemRect.Right, ItemRect.Top, 0, ItemRect.Height);
}
}
else
{
DropMarker = new Rect();
}
return(DropMarker);
}
public static int CalculateDropIndex(Panel panel, UIElementCollection children, Orientation orientation, Point position)
{
HitTestResult HitTestResult = VisualTreeHelper.HitTest(panel, position);
DependencyObject HitItem;
if (HitTestResult != null)
{
DependencyObject[] Ancestors = VisualTreeHelperEx.GetVisualAncestors(HitTestResult.VisualHit, panel);
HitItem = Ancestors.Length >= 1 ? Ancestors[1] : null;
}
else
{
HitItem = null;
}
if (HitItem is UIElement)
{
int ItemIndex = children.IndexOf((UIElement)HitItem);
Rect Bounds = ((Visual)HitItem).TransformToAncestor(panel).TransformBounds(VisualTreeHelperEx.GetBounds((Visual)HitItem));
Rect FirstHalfBounds = orientation == Orientation.Vertical
? new Rect(Bounds.Left, Bounds.Top, Bounds.Width, Bounds.Height / 2)
: new Rect(Bounds.Left, Bounds.Top, Bounds.Width / 2, Bounds.Height);
if (FirstHalfBounds.Contains(position))
{
return(ItemIndex);
}
else
{
return(ItemIndex + 1);
}
}
else
{
// Hit cannot be processed or is on the panel -> return index to insert at the end
return(children.Count);
}
}