Enhancing Pie-Menu Selection with Pen Pressure

Pie-menu, a very effective item-selection widget, has been proposed to enhance item-selection tasks in pen-based devices such as PDAs (personal digital assistants) and Tablet PCs. The significant advantage of Pie-menu is that it enables users to select items within a menu with only a short distance for the pen-tip to move. However, as the number of items to be selected increases, the architecture of Pie-menu becomes more complex, and this makes such tasks more difficult. Therefore, with a view to overcoming this problem, we developed a novel menu widget called Layer-Pie-Menu which is designed to reduce the architectural complexity by layering numbers of Pie-menus and using pressure as the switch mode to differentiate between the layers. An experiment was conducted to examine the functional efficiency of Layer-Pie-Menu. Experimental results showed that the most suitable number of layers that can be controlled by pressure is two.