Controlling autoscroll on trackpads using the force

Operating systems support autoscroll to allow users to scroll a window while in dragging mode: the user moves the pointer near the window's edge to trigger an "automatic" scrolling. Scrolling rate is typically proportional to the distance between the pointer and the window's edge. This approach suffers from several problems, especially when the window is maximized resulting in a very limited space around the window. An other problem is that for some operations, such as object drag-and-drop, the source and destination might be located in different windows, making it complicated for the computer system to understand user's intention. In this paper, we present ForceEdge, a novel autoscroll technique relying on trackpads with force-sensing capabilities to alleviate all the problems related to autoscroll. We present the theoretical foundations of ForceEdge and the implementation of a demonstrator that can be used to compare ForceEdge to the other autoscroll methods.