Apple 2 manual Index Tabs, 10A lengthy picker can include scroll arrows and index tabs

C H A P T E R 4

Pickers

Scrolling pickers are harder to use than pickers that don’t scroll, because users have to remember the picker items that aren’t currently visible. You should keep your pickers short and avoid scrolling pickers in your applications.

Index Tabs

If the list of picker items is very long, scrolling from one end to the other can be tedious. To give users a quicker method of traveling through a long list of picker items, you can augment scroll arrows with a series of small labeled index tabs displayed along the right edge of the picker. The tabs essentially divide the picker items into sections alphabetically, and a user taps a tab to see the section it identifies. Figure 4-10 illustrates picker scroll arrows and index tabs.

Figure 4-10A lengthy picker can include scroll arrows and index tabs

One, two, or three taps scroll to the picker items beginning with the first, second, or third letter of the tapped tab

Each tap scrolls the number of items displayed minus one

A tap closes the picker and selects the highlighted picker item, if any

Tapping an index tab scrolls to the picker items that begin with the first letter of the tapped tab. Double-tapping an index tab scrolls to the picker items that begin with the second letter of the tapped tab. Triple-tapping an index tab scrolls to the picker items that begin with the third letter of the tapped tab.

In a list picker with an index tab, tapping a listed item selects the item but doesn’t close the picker. To close the picker and confirm the selection, a user taps the picker’s Close box. To cancel the selection and close the picker, a user taps outside the picker.

List Pickers 4-13