Called when a document interaction controller needs a view controller for presenting a document preview.
- iOS 3.2+
The document interaction controller requesting the parent view controller.
The view controller to use when presenting the document preview. The return value must not be
Although technically optional, this method is required if your application attempts to display a preview for a document. The view controller returned by this method is used as the parent for the document preview.
If you return a navigation controller from this method, the document interaction controller is pushed onto the navigation stack using the standard navigation controller animations. If you return any other type of view controller, the document interaction controller is displayed modally, in which case, the view controller you return must be capable of presenting a modal view controller.