/// <summary>
/// Update the position of the insertion point marker
/// </summary>
/// <param name="itemsControl"></param>
/// <param name="e"></param>
private void UpdateInsertAdorner(ItemsControl itemsControl, DragEventArgs e)
{
if (this._insertAdorner != null)
{
this._insertAdorner.InTopHalf = DragUtilities.IsPointInTopHalf(itemsControl, e);
this._insertAdorner.InvalidateVisual();
}
}
/// <summary>
/// Determine the proper insertion index
/// </summary>
/// <param name="itemsControl"></param>
/// <param name="e"></param>
/// <returns></returns>
private static int FindInsertionIndex(ItemsControl itemsControl, DragEventArgs e)
{
UIElement dropTargetContainer = DragUtilities.GetItemContainerFromPoint(itemsControl, e.GetPosition(itemsControl));
if (dropTargetContainer != null)
{
int index = itemsControl.ItemContainerGenerator.IndexFromContainer(dropTargetContainer);
return(DragUtilities.IsPointInTopHalf(itemsControl, e) ? index : index + 1);
}
return(itemsControl.Items.Count);
}
/// <summary>
/// Initialize the insertion point marker
/// </summary>
/// <param name="itemsControl"></param>
/// <param name="e"></param>
private void InitializeInsertAdorner(ItemsControl itemsControl, DragEventArgs e)
{
if (this._insertAdorner == null && this.ShowInsertAdorner)
{
UIElement itemContainer = DragUtilities.GetItemContainerFromPoint(itemsControl, e.GetPosition(itemsControl));
if (itemContainer != null)
{
this._insertAdorner = new InsertAdorner(DragUtilities.IsPointInTopHalf(itemsControl, e),
DragUtilities.IsItemControlOrientationHorizontal(itemsControl),
itemContainer, AdornerLayer.GetAdornerLayer(itemsControl), itemsControl);
}
}
}