private void DragSource_PreviewMouseLeftButtonDown(object sender,
MouseButtonEventArgs e)
{
var fe = DynamicFormUtilities.GetItemContainer(sender as ItemsControl,
e.OriginalSource as
Visual) as FrameworkElement;
if (fe != null && fe.DataContext is PropertyInformation &&
(fe.DataContext as PropertyInformation
).HasBeenUsed)
{
e.Handled = true;
return;
}
InitialMousePosition = e.GetPosition(TopWindow);
SourceItemsControl = (ItemsControl)sender;
TopWindow = DynamicFormUtilities.FindAncestor(typeof(Window),
SourceItemsControl) as Window;
SourceItemContainer = DynamicFormUtilities.GetItemContainer(
SourceItemsControl, e.OriginalSource
as Visual);
if (SourceItemContainer != null)
{
DraggedData = SourceItemContainer.DataContext;
}
}
private void DecideDropTarget(DragEventArgs e)
{
logger.Trace("Entered DecideDropTarget()");
var targetItemsControlCount = TargetItemsControl.Items.Count;
var draggedItem = e.Data.GetData(Format.Name);
if (IsDropDataTypeAllowed(draggedItem))
{
if (targetItemsControlCount > 0)
{
HasVerticalOrientation = DynamicFormUtilities.HasVerticalOrientation(
TargetItemsControl.
ItemContainerGenerator.ContainerFromIndex(0) as FrameworkElement);
TargetItemContainer = DynamicFormUtilities.GetItemContainer(
TargetItemsControl, e.
OriginalSource as Visual);
if (TargetItemContainer != null)
{
IsInFirstHalf = DynamicFormUtilities.IsInFirstHalf(TargetItemContainer,
e.GetPosition(TargetItemContainer),
HasVerticalOrientation);
InsertionIndex =
TargetItemsControl.ItemContainerGenerator.IndexFromContainer(
TargetItemContainer);
if (!IsInFirstHalf)
{
InsertionIndex++;
}
}
else
{
TargetItemContainer =
TargetItemsControl.ItemContainerGenerator.ContainerFromIndex(
targetItemsControlCount - 1) as FrameworkElement;
IsInFirstHalf = false;
InsertionIndex = targetItemsControlCount;
}
}
else
{
TargetItemContainer = null;
InsertionIndex = 0;
}
}
else
{
TargetItemContainer = null;
InsertionIndex = -1;
e.Effects = DragDropEffects.None;
}
}