A BDragger is a view that lets users drag and drop some other view. The other view is the target of the BDragger and its immediate relative—a sibling, a parent, or an only child. The BDragger draws a handle, usually at the corner of the target view, that the user can grab. When the user drags the handle the target view appears to move with the handle.

When dragged in this way, the target view itself doesn't actually move. Instead, the view is archived in a BMessage object and the BMessage is dragged. When the BMessage is dropped, the target BView can be reconstructed from the archive (along with the BDragger). The new object is a duplicate—a replicant—of the target view.

This class works closely with the BShelf class. A BShelf object accepts dragged BViews, reconstructs them from their archives, and installs them in another view hierarchy.

BDraggers are under the control of DeskBar's "Show Replicants" / "Hide Replicants" menu item. Showing replicants means that the BDragger handles are visible on-screen; hiding replicants means that the handles are hidden.