Apple Newton Utilities Guide de l'utilisateur télécharger pdf (Page 839)

100

101

CHAPTER 23

Endpoint Interface

Using the Endpoint Interface 23-11

When you are ﬁnished with an endpoint, you must unbind it using the UnBind

method, then dispose of it using the

Dispose method.

Establishing a Connection 23

After instantiating and binding an endpoint, you establish a connection.

There are two ways you can create a connection. One way is to call the

Connect

method. If the physical connection is serial, for instance, you don't even need to

specify an address as an option. The

Connect method immediately establishes

communication with whatever is at the other end of the line.

Certain communication tools—for example, the modem and AppleTalk tools—

require you to specify an option of type

'address in order to make a connection.

The modem tool requires a phone number as an

'address option. You should

use the global function

MakePhoneOption to return a proper phone number

'address option. The AppleTalk tool requires an AppleTalk Name Binding

Protocol (NBP)

'address option. You should use the global function

MakeAppleTalkOption to return a proper NBP 'address option.

To establish a connection where you expect someone else to initiate the connection,

you need to call the

Listen method. Once the connection is made by using

Listen, you need to call the Accept method to accept the connection, or the

Disconnect method to reject the connection and disconnect.

Sending Data 23

To send data, use the Output method. This method is intelligent enough to ﬁgure

out the type of data you're sending and to convert it appropriately for transmission.

This is because NewtonScript objects have type information embedded in their

values, allowing the system to select appropriate default data forms for different

kinds of data being sent.

You can specify output options and a callback method by deﬁning an output spec,

which you pass as a parameter to the

Output method.

Certain communication tools may require or support the use of special ﬂags

indicating that particular protocols are in use. For example, the built-in infrared and

AppleTalk tools expect framed (or packetized) data, and there are special ﬂags to

indicate that this kind of protocol is in use. If you are using such a communication

tool to send data, you need to specify the

sendFlags slot in the output spec

frame. In this slot, you specify one or more ﬂag constants added together.

To send packetized data, you set

sendFlags to kPacket+kMore for each packet

of data that is not the last packet. For the last packet, set

sendFlags to

kPacket+kEOP.

1 2 ... 834 835 836 837 838 839 840 841 842 843 844 ... 941 942

Commentaires sur ces manuels

Pas de commentaire

Apple Newton Utilities Guide de l'utilisateur Page 839

Commentaires sur ces manuels

Produits connexes et manuels pour Logiciel Apple Newton Utilities