protected override void OnBeginDrag()
{
if (this.DraggedElements.Count > MoveStrategy.GetMaxChildrenForElement((SceneElement)this.LayoutContainer, (IProperty)null))
{
throw new InvalidOperationException(ExceptionStringTable.BehaviorCannotHandleMultipleElements);
}
this.PrepareDraggedElementsForDragging();
}
private static MoveStrategy CreateForLayoutMode(MoveStrategyContext context, SceneElement hitElement)
{
SceneElement sceneElement = hitElement;
while (sceneElement != null)
{
BaseFrameworkElement frameworkElement = sceneElement as BaseFrameworkElement;
if (frameworkElement != null && context.RootNode.IsAncestorOf((SceneNode)frameworkElement))
{
if (!MoveStrategyFactory.CanMoveInside(context, frameworkElement))
{
sceneElement = frameworkElement.ParentElement;
continue;
}
MoveStrategy byParentType = MoveStrategyFactory.CreateByParentType(context, frameworkElement);
if (byParentType != null)
{
bool flag = false;
ItemsControlElement itemsControlElement = frameworkElement.ParentElement as ItemsControlElement;
ContentControlElement contentControlElement = frameworkElement as ContentControlElement;
if (itemsControlElement != null && contentControlElement != null && (ItemsControlElement.ItemsProperty.Equals((object)itemsControlElement.GetPropertyForChild((SceneNode)frameworkElement)) && (itemsControlElement.ViewObject as IViewItemsControl).IsItemItsOwnContainer(contentControlElement.ViewObject)))
{
flag = true;
}
if (!flag)
{
IProperty contentProperty = MoveStrategyFactory.GetContentProperty(context, (SceneNode)frameworkElement);
int childrenForElement = MoveStrategy.GetMaxChildrenForElement((SceneElement)frameworkElement, contentProperty);
if (context.DraggedElements.Count <= childrenForElement && (childrenForElement != 1 || context.DraggedElements.Count != 1 || (!frameworkElement.IsAncestorOf((SceneNode)context.DraggedElements[0]) || context.DraggedElements[0].Parent == frameworkElement)))
{
byParentType.LayoutContainer = frameworkElement;
return(byParentType);
}
}
}
}
if (sceneElement != context.RootNode)
{
sceneElement = sceneElement.ParentElement;
}
else
{
break;
}
}
return((MoveStrategy)null);
}
