Apple Newton Programmer’s Newton 2.0 (for Newton 2.0) - Manual (Page 823)

C H A P T E R 2 2
Transport Interface
Using the Transport Interface 22-35
For example, the built-in Print transport uses the protoTransportPrefs proto
for its preferences view. Since the ReceiveRequest method does not exist in
the Print transport, the In Box preference element is not displayed, as shown in
Figure 22-10.
Figure 22-10 Print preferences
The Info button is included in the protoTransportPrefs template so you can
give the user access to About and Help views for the transport. The button is built
from the standard
protoInfoButton proto. To include items on the Info picker,
you must provide handler methods in the infoPrefs slot of your transport
preferences view. The protoTransportPrefs template includes a handler for
the “Help” item that displays the system help book, open to the routing section.
You’ll need to override this method if you want to provide your own help information.
You can add custom items to the Info picker by supplying GenInfoAuxItems
and DoInfoAux methods in the infoPrefs frame. For more information about
these methods and how the Info button works, see “protoInfoButton” (page 6-10)
in Newton Programmer’s Reference.
The defaultConfiguration slot in the protoTransport holds the initial
preferences associated with the transport. This slot is set up by default with a frame
holding an initial selection of preferences items. The child views of the
protoTransportPrefs proto are designed to manipulate the slots in this frame.
If you want to override the default preferences frame, you need to construct an
identical one with different values. You can’t use a
_proto slot in your default
frame since the contents of the defaultConfiguration slot are stored in a
soup and _proto slots can’t be stored in soup entries.