Cloning is a process when one or more objects from a presentation are duplicated. Objects can be duplicated to the same or another presentation and to the same or another location (for example, to another slide).
Cloning methods are available on collection types, such as SlideCollection, DrawingCollection, TextParagraphCollection or TextElementCollection. Exception is the PresentationDocument type that has a method used to make a deep clone of the entire presentation. Cloning methods available on the collection types have two forms: AddClone Overload and InsertClone Overload to append the duplicate to the collection or insert it into a specific location in the collection.
Objects contained in the presentation can contain references to other objects. For example, Slide contains a reference to its parent layout template, Connector can contain a reference to drawings that it connects (BeginConnection and EndConnection), Action can contain a reference to Slide or CustomSlideShow that should be shown when the action is triggered.
When cloning multiple objects, the desired behavior is to maintain these references in the duplicated objects so that, for example, when Connector is cloned, and later when drawings that it connects are cloned, the duplicated Connector also connects duplicates of the original drawings that are connected.
This reference mapping between an original object and its duplicate is maintained by the instance of the CloneContext type. CloneContext instance is created with Create(PresentationDocument, PresentationDocument) static method. Each object can be cloned exactly once using the same CloneContext instance. If you want to clone the same object multiple times, each time a new CloneContext instance must be used. CloneContext is the most useful when cloning multiple objects one after another or when you want to change a behavior of the cloning operation.
Behavior of the cloning operation can be changed by using SetT(T, T) method. With this method you can make an explicit mapping between objects and cloning process will respect that mapping. For example, if you are cloning a Slide instance to another PresentationDocument default behavior would be that its parent template LayoutSlide and MasterSlide would also be cloned to another PresentationDocument. This behavior can be changed by making an explicit mapping from the LayoutSlide that is the ParentTemplate of the Slide that will be cloned to some LayoutSlide in the another PresentationDocument that we wish to be a ParentTemplate of the duplicated Slide. Explicit mapping with SetT(T, T) method can currently be made between following type (and their derivatives) instances: SlideObject, Drawing, TableStyle and CustomSlideShow.