background image
C H A P T E R 1
Application Components
Communication Tool Interface
Underlying the NewtonScript interface is the low-level communications system.
This system consists of a communications manager module and several code
components known as communication tools. These communication tools interact
directly with the communication hardware devices installed in the system. The
communication tools are written in C++ and are not directly accessible from
NewtonScript--they are accessed indirectly through an endpoint object.
The built-in communication tools include:
Synchronous and asynchronous serial
Fax/data modem (data is V.34 with MNP/V.42 and fax is V.17 with Class 1, 2,
and 2.0 support)
Point-to-point infrared--called beaming (Sharp 9600 and Apple IR-enhanced
AppleTalk ADSP protocol
For information about configuring the built-in communication tools through the
endpoint interface, refer to Chapter 24, "Built-in Communications Tools."
Note that the communications manager module, and each of the individual
communication tools, runs as a separate operating system task. All NewtonScript
code is in a different task, called the Application task.
The system is extensible--additional communication tools can be installed at run
time. Installed tools are made available to NewtonScript client applications through
the same endpoint interface as the built-in tools.
At some point, Apple Computer, Inc. may release the tools and interfaces that
allow C++ communication tool development.
Application Components
At the highest level of system software are dozens of components that applications
can use to construct their user interfaces and other nonvisible objects. These
reusable components neatly package commonly needed user interface objects such
as buttons, lists, tables, input fields, and so on. These components incorporate
NewtonScript code that makes use of other system services, and which an
application can override to customize an object.
These components are built into the Newton ROM. When you reference one of
these components in your application, the code isn't copied into your application--
your application simply makes a reference to the component in the ROM. This
conserves memory at run time and still allows your application to easily override
any attributes of the built-in component. Because you can build much of your
© 2007-2017, o7 studio » при воспроизведении материала сайта ссылка обязательна