Pie Menu

A pie menu is a list of menu items arranged not in the usual, dropdown menu style, but instead splayed out from a central point. The idea is to minimize the mouse movement, and therefore the time wasted, between a menu's opening, and user selection from that menu.

In other words, when you click on Edit, you get this:

    _______      _____        
   |_Undo_ \    | Cut_|           
          \ \__/ /_______          
           | Edit___Copy_|                   
   _______/ /  \ \______         
  |_Redo___/    \_Paste_|       

Instead of this:

 
|_Edit_|____
|           |
| Undo      |
| Redo      |
|  _______  |
|           |
| Cut       |
| Copy      |
| Paste     |
|___________|

Making the pie menu translucent would also be a good interface decision, as it would allow the user to see any context that might have been otherwise hidden by the menu. There are deviders in the pulldown menu allow it to have menu items in groups. This could be done in a pie menu by having the legs and text be different colors for different functional areas. Shortcut keys might be shown on the pie menu with a second line on each node, or with a tooltip-like (but again translucent) popup. All of the GUI components you can have in a pulldown menu, you can also have in a pie menu.

There's really no excuse for today's applications and window managers having anything but pie menus. In the past, it wasn't done because these menus take up a largeish amount of screen real estate. Today, however, with 1024x768 being the lowest resolution you're likely to see, the speed, efficiency, and information density of pie menus outweigh this small disadvantage.

What Are Pie Menus?

Pie Menus are a naturally efficient user interface technique: directional selection of pie slice shaped targets. The cursor starts out in the center of the pie, so all targets are large, nearby, and in different directions. Fitts' Law explains the advantages of pie menus, relating fast selection speed and low error rate to large target size and small distance. Pie menus are easy for novice users, who just follow the directions, and efficient for experienced users, who can quickly "mouse ahead" once they know the way.

Where Are Pie Menus?

Pie Menu Central: http://www.piemenu.com

The Sims uses pie menus to control the behavior of the characters.

A convenient User Interface concept, a pie menu is one where the cursor starts in the center of a circle, and menu options surround it. The result can be viewed like a pie chart, with each of n options occupying 1/n of the pie. The user ends up moving the mouse little compared to normal pull-down menus, and power users can easily remember item placement as a function of angles. The Pie Menus concept even allows for submenus: where one pie slice ends, another pie can begin.

To date, The Sims is the most commercially successful application to integrate pie menus. Maxis used the concept extensively in character interactions.