Apple 2 manual User Editing of Pickers

C H A P T E R 4

Pickers

If a user touches a picker list and slides the pen instead of lifting it, the picker tracks the pen movement. As the pen appears over an item in the list, the item is highlighted. When the user lifts the pen within the list, the currently high- lighted item blinks briefly, the picker disappears, and the effect associated with the picked item happens. If the user slides the pen outside the list, so that no item is highlighted, and then lifts the pen, the picker simply goes away. The display of electronic ink is turned off while the pen is tracked.

An item that can’t be selected, such as a separator line, is not highlighted when a user taps it or slides the pen over it. Tapping an unselectable item or lifting the pen while it is over an unselectable item makes the picker go away.

After the user picks an item and the picker disappears, your application must continue to highlight the label or button that controls the picker until the action or effect associated with the picked item is complete. In the case of a picker item that displays an ordinary slip (not a status slip), the picker’s controlling label or button stays highlighted only until the slip appears. Keeping the label or button highlighted provides the minimal feedback to the user that the applica- tion is still working. When a process begun by a picker item takes more than a few seconds, your application should provide more feedback by displaying a status slip that names the process underway (as described in “Status Slips” on page 2-20).

User Editing of Pickers

If you want to allow users to be able to add, remove, and change items in a list picker, include an item “Edit” or “Edit Picker” at the bottom of the picker, with a separator line above it. Choosing this item should bring up a slip in which users can edit the picker. The slip should clearly indicate how many items the picker can contain. Title the slip to make its purpose clear, for example “Edit Category List.”

Instead of allowing users to edit picker items, an application could auto- matically include recent inputs for an input field in that field’s picker. For information on input fields, see Chapter 6, “Data Input.”

List Pickers 4-11