Designing Gestural Interfaces

TAP TO SELECT

WHAT

Tapping an object with a single (index) finger selects that object for manipulation.

USE WHEN

One of the most basic gestures, this pattern can be used in almost any system in any location for selecting objects on-screen.

WHY

Use Tap to Select for selecting a single item from a set of many items that can be manipulated.

HOW

In touchscreens, Tap to Select is simply a matter of matching the position of a touch event with the position of an object on-screen. As with Tap to Open/Activate, there are two types of Tap to Select: activate-on-press and activate-on-release. Most mechanical buttons are activate-on-press, but it is a better practice for touchscreens to be activate-on-release because it gives the user time to move off the button if he changes his mind, especially if tapping will perform an action that cannot be undone.

Tap to Select is usually the alternative to Tap to Open/Activate. Either one tap selects an item (with perhaps a double tap to open), or one tap opens/activates that item.

EXAMPLES

Figure 3-4. Lemur is a controller for audio and media applications. One of its features allows the user to select items that are then activated at certain times (e.g., in time to the music). Courtesy JazzMutant.

Figure 3-5. Subway's sandwich ordering kiosk has users select condiments. ...