/// <summary>
/// Starts a new placement operation that changes the placement of <paramref name="placedItems"/>.
/// </summary>
/// <param name="placedItems">The items to be placed.</param>
/// <param name="type">The type of the placement.</param>
/// <returns>A PlacementOperation object.</returns>
/// <remarks>
/// You MUST call either <see cref="Abort"/> or <see cref="Commit"/> on the returned PlacementOperation
/// once you are done with it, otherwise a ChangeGroup will be left open and Undo/Redo will fail to work!
/// </remarks>
public static PlacementOperation Start(ICollection <DesignItem> placedItems, PlacementType type)
{
if (placedItems == null)
{
throw new ArgumentNullException("placedItems");
}
if (type == null)
{
throw new ArgumentNullException("type");
}
DesignItem[] items = placedItems.ToArray();
if (items.Length == 0)
{
throw new ArgumentException("placedItems.Length must be > 0");
}
PlacementOperation op = new PlacementOperation(items, type);
try
{
if (op.currentContainerBehavior == null)
{
throw new PlacementOperationException("Starting the operation is not supported");
}
op.currentContainerBehavior.BeginPlacement(op);
foreach (PlacementInformation info in op.placedItems)
{
info.OriginalBounds = op.currentContainerBehavior.GetPosition(op, info.Item);
info.Bounds = info.OriginalBounds;
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.ToString());
op.changeGroup.Abort();
throw;
}
return(op);
}
internal PlacementInformation(DesignItem item, PlacementOperation operation)
{
this.item = item;
this.operation = operation;
}