A user interface apparatus, a method for controlling a user interface apparatus, and a computer-readable medium are provided. The user interface apparatus includes a display unit comprising an object display area, the display unit displaying an object in the object display area; a detection area control unit that (1) defines a detection area for the object, the detection area including the object display area and having a size and a location, and (2) changes at least one of the size and the location of the detection area to create a modified detection area; and an activation detection unit that detects a position of a user activation. Furthermore, the detection area control unit changes the detection area after the activation detection unit detects the activation position as being within the detection area.