Pie menu
From Wikipedia, the free encyclopedia
A pie menu (sometimes called radial menu), invented by Don Hopkins, is a circular popup menu where selection depends on direction. A pie menu is made of several "pie slices" around an inactive center and works best with stylus input, and well with a mouse. Pie menus work well with keyboard acceleration, particularly four and eight item menus, on the cursor keys and the number pad.
A slice can lead to another pie menu; selecting this may center the mouse cursor in the new menu.
Pie menus are often context-sensitive, showing different options depending on what the mouse cursor was pointing at when the menu was requested.
Pie menus are drawn as pie slices with a hole in the middle for an easy way to exit the menu.
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[edit] Comparison with other interaction techniques
Pie menus are faster and more reliable to select from than linear menus, because selection depends on direction instead of distance. The circular menu slices are large in size and near the pointer for fast interaction (see Fitts' law). Experienced users use muscle memory without looking at the menu while selecting from it. Nested pie menus can efficiently offer many options, and some pie menus can pop up linear ones. Pie menus are only shown when requested, resulting in less distraction and clutter than toolbars and menu bars which are always shown.
Pie menus show available options, in contrast to invisible mouse gestures. Pie menus which delay appearance until the mouse button is released reduce intrusiveness to the same level as mouse gestures and pie menus for experienced users. Pie menus take up more screen space than linear menus, and the number of slices in an individual menu must be kept low for effectiveness by using submenus. When using pie menus, submenus may overlap with the parent menu, but the parent menu may become translucent or hidden.
Pie menus are most suited for actions which have been laid out by humans, and have a logical grouping choices. Linear menus are most suited for dynamic, large menus which have many possible options, without any logical grouping.
[edit] Usage
Beginner:
- press and release the mouse button assigned to the menu, causing the pie menu to display
- move the mouse into the desired slice
- click the desired action
Exit by clicking the center.
Expert (rely on muscle memory):
- click and hold down the mouse button
- move mouse onto the desired action
- release mouse button
[edit] Implementations
- Video games: Beyond Good & Evil, Full Throttle, The Legend of Zelda: Twilight Princess, The Curse of Monkey Island, Neverwinter Nights, Normality, The Sims, Planescape: Torment, Second Life, Battlefield 2, Freedom Fighters, Ratchet and Clank, Silver, Secret of Mana.
- Mozilla and Mozilla Firefox extensions RadialContext and easyGestures
- Radialm, an open source pie menu implementation for windows
- Maya, a commercial 3D modelling program
- Quicksilver via the Constellation plug-in
- Pie menus for PyQt
- Unix Desktop Environment, a window manager for the X Window System
- Windows "Vienna", Microsoft's future operating system, may feature a pie-menu-type circular interface
[edit] Pie menu rarity
Why pie menus are rare despite their interfacial advantages:
- Unavailability of pie menus as standard widgets. Video games often require custom widget development, so pie menu cost is higher.
- Difficulty of adding new widgets to popular user interface toolkits
[edit] References
- Jack Callahan, Don Hopkins, Mark Weiser, Ben Shneiderman (1988). "An empirical comparison of pie vs. linear menus". Proceedings of ACM CHI Conference on Human Factors in Computing Systems, 95–100.
- Why pie menus aren't ubiquitous
