CHI 2008 Proceedings · Menu and Command Selection April 5-10, 2008 · Florence, Italy 1361 PieCursor: Merging Pointing and Command Selection for Rapid In-place Tool Switching George Fitzmaurice, Justin Matejka, Azam Khan, Michael Glueck, Gordon Kurtenbach Autodesk Research 210 King St. East, Toronto, Ontario, Canada, M5A 1J7 {firstname.lastname}@autodesk.com Figure 1. The PieCursor concept: a collection of tools arranged in a radial pattern Tracking Menu and shrunk to the size of a cursor. ABSTRACT We describe a new type of graphical user interface widget called the ―PieCursor.‖ The PieCursor is based on the Tracking Menu technique and consists of a radial cluster of command wedges, is roughly the size of a cursor, and replaces the traditional cursor. The PieCursor technique merges the normal cursor function of pointing with command selection into a single action. A controlled experiment was conducted to compare the performance of rapid command and target selection using the PieCursor against larger versions of Tracking Menus and a status quo Toolbar configuration. Results indicate that for small clusters of tools (4 and 8 command wedges) the PieCursor can outperform the toolbar by 20.8% for coarse pointing. For fine pointing, the performance of the PieCursor degrades approximately to the performance found for the Toolbar condition. Author Keywords Tracking menus, radial menus, marking menus, pie menus, control menus, flow menus, pen based user interfaces, floating palette, multifunction cursor. ACM Classification Keywords H.5.2 [User Interfaces]: Graphical User Interfaces (GUI), 3D graphics. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. CHI 2008, April 5–10, 2008, Florence, Italy. Copyright 2008 ACM 978-1-60558-011-1/08/04…$5.00. INTRODUCTION Much research has been conducted on finding efficient ways of selecting commands. Toolbars, floating palettes, hotkeys, command lines and pop-up menus all offer ways of switching amongst a collection of tools. Since a user’s focus of attention is typically at the cursor location, our investigation explores the potential benefits of adapting the cursor to both point and switch commands on the fly. Movement of the cursor is performed for a variety of purposes: precision pixel pointing; coarse pointing to select an object; movement to prepare for a subsequent gesture, manipulation and as a user shifts their visual focus in anticipation of action; using the cursor as a visual aid or placeholder when inspecting data; etc. In addition, many commands do not require any spatial information from the cursor (e.g. undo), or only require relative movement during the drag phase as a command parameter (e.g. panning a 2D image). Given these observations, we investigate opportunities where the cursor could both point and select tools at the same time for the benefit of rapid in-place command selection and operation. In this paper we introduce the PieCursor and report on an exploratory study, a formal performance experiment on the PieCursor, and a set of usability studies which characterize and show advantages of the PieCursor over traditional toolbar workflows. PIECURSOR TECHNIQUE A PieCursor is a small (e.g., 32 by 32 pixel) semi- transparent graphical user interface widget that can be controlled by a mouse, pen, or touch screen input device. The PieCursor technique is based on a Tracking Menu [8] design which combines both pointing and selecting a command at the same time.