Apple Newton Programmer’s Newton 2.0 (for Newton 2.0) User Manual

Page 781

C H A P T E R 2 1

Routing Interface

Using Routing

21-33

Manually Putting Away Items

If an item is not put away automatically, it resides in the In Box until the user
chooses to put it away manually by tapping the Put Away button. When the user
taps the Put Away button, the In Box displays a slip showing to which application
the item will be put away. This application is the one that matches the

appSymbol

slot in the item. The In Box sends the

PutAwayScript

message to the base view

of that application. The item is passed as a parameter.

The item passed to your application’s

PutAwayScript

method is the entry from

the In Box. It has several slots in it that are used by the In Box or the transport. The
data your application uses is contained in the

body

slot.

Because the item could have been sent by a custom transport that sends
multiple-item target objects (such as those created by

CreateTargetCursor

you might need to check if the

body

slot contains such an object by using

TargetIsCursor

. If so, you can get a cursor for the object by using

GetTargetCursor

, and then iterate over the cursor to handle individual items.

If the

PutAwayScript

method returns

nil

, this signals that the item could not

be put away and the In Box leaves the item in the In Box and an alert is displayed
telling the user that the item could not be put away.

If the

PutAwayScript

method returns a non-

nil

value, it is assumed that the

application handled the item. The item is either saved in the In Box or deleted from
the In Box, depending on the user’s preference as set in the Put Away slip.

If multiple applications have registered to accept data of the item’s class, the system
displays a picker listing those applications in the Put Away slip. The application
that matches the

appSymbol

slot of the item is listed as the default choice. If there

is no

appSymbol

slot, or the application is missing, then a different application is

the default choice. The user can choose the application to which the data is to be
sent, and the

PutAwayScript

message is sent to that application.

The registry used for this operation is called the application data class registry;
note that it is different from the In Box application registry mentioned above.
Applications can register to accept data of one or more classes by using the

RegAppClasses

function.

It is recommended that all applications wanting to receive items through the In Box
register their capability to receive data of particular classes by calling the

RegAppClasses

function. If your application is no longer interested in data of

these classes, or your application is being uninstalled, you can unregister to receive
these data classes by using the

UnRegTheseAppClasses

function.

You can check which applications can accept data of a particular class by using the

ClassAppByClass

function.