CHAPTER 4
Pickers
List Pickers 4-13
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 4If 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 4-10 A lengthy picker can include scroll arrows and index tabs
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.
Each tap scrolls the number of items displayed minus one
A tap closes the picker and selects the highlighted picker item, if any
One, two, or three taps scroll to the picker items beginning with
the first, second, or third letter of the tapped tab