Returns the current (non- null) drop location for the component, when this TransferSupport represents a drop.

Note: For components with built-in drop support, this location will be a subclass of DropLocation of the same type returned by that component's getDropLocation method.

This method is only for use with drag and drop transfers. Calling it when isDrop() is false results in an IllegalStateException.

Returns: the drop location

Exceptions:

IllegalStateException if this is not a drop