Apple 2 manual Using a List Picker, Picking an Item

C H A P T E R 4

Pickers

Figure 4-6How a list picker should align with its label or button

Button hidden behind picker

Best—picker next to its label or button and aligned at top or bottom

OK—wide picker above or below its label or button

Avoid—picker and its label or button misaligned, or picker completely covering its label or button

If you want your application to work when a user rotates the display (with the Extras Drawer’s Rotate button), your application may need to make picker alignment dependent on screen size.

Using a List Picker

A user makes a list picker pop up by tapping the button or label that controls it. While the picker is open, the application highlights the picker’s controlling button or label. Nothing else happens until the user touches the screen again. The user does not have to press and hold the pen on the button or label to keep the picker open; the picker stays open until the user touches the screen again. If the user touches the screen outside the list, the picker goes away.

Picking an Item

A user picks an item listed in a list picker by tapping the item. The picked item blinks briefly, the picker disappears, and the action or effect associated with the picked item happens. Figure 4-7 shows the sequence of events for the Set button in the built-in Clock application.

List Pickers 4-9