An optical scanner is configured to scan multiple print portions of a body part such as a finger. The optical scanner identifies a first one of the print portions in an area of an optical surface. An event such as launching an application is generated based on identifying the first print portion in the area of the optical surface. In addition, various events can be generated based on different combinations of print portions in different areas of the optical surface.In a second embodiment, a property detector is configured to identify different properties of a sleeve in different areas of a surface. An event is generated based on the detection of a property of the sleeve in an area of the surface.