The System 7.0 Environment
This section briefly describes the general user interface recommendations
that affect your application when it runs in the system 7.0 environment. The
changes to system software and the operating environment are described in the
Introduction to the System Software Version 7.0 Environment in Inside
Macintosh, Volume VI, and in the
In previous versions of system software, a cooperative multitasking
environment was available to users with MultiFinder. Users could turn on
MultiFinder so that they could open multiple applications at one time; however,
most people did not use MultiFinder regularly. In system 7.0 the cooperative
multitasking environment is standard. Now all users can open as many
applications and desk accessories as their computer's memory can support. The
Macintosh computer manages applications in much the same way that each
application handles its own windows.
As in previous versions of system software, only one application can be active
at a time. The frontmost application, the one interacting with the user, is the
Your application should update the controls in the frontmost window whenever
the user switches to your application. If you previously did not update your
application to be compatible with MultiFinder, you now need to modify your
application's event loop to accommodate a cooperative environment. For more
information on the operating environment in system 7.0 , see the
User Feedback
When your application is the active application, you need to provide feedback
to the user to indicate what's happening. A user learns to predict how long
certain operations last. In the system 7.0 environment, multitasking, virtual
memory, and network connectivity cause task length to become more variable. A
user will not always be able to predict the length of time per task. Therefore it
becomes more essential to display feedback about what is taking place. If you do
not, the user may think that the Operating System stopped running and may
attempt to correct a perceived error condition, perhaps by manually
restarting the machine. At least use the spinning beach ball or animated watch
cursor to indicate an operation in process. If you can approximately determine
the amount of time a task will last, it's even better to use a progress indicator
so that a user knows that the Operating System is still running and that an
operation is occurring. The Figure below shows an example of a progress
indicator.
A progress indicator
Background Notification
When your application runs in the background, you may need to get the user's
attention to respond to a task completion or a request for input. The
Notification Manager provides several ways for your application to alert
the user. When a background task is running and you need to notify the user,
should display an icon that corresponds to your application or system
extension, so that the user gets a visual clue about which application is
requesting attention. In addition, you should display a diamond-shaped mark
sound. The Figure below shows an example of a notification symbol.
Nothing more should happen until the user chooses to activate your
application, at which time you can display a modal dialog box. Your dialog box
or message must inform the user about what needs attention, why attention is
needed, and what to do. For example, a dialog box might say "Transmission of
the file My Phone List to 415-555-1212 could not be completed because the
phone line went dead," and it might present the user with two buttons, Try
Again and Cancel.
A background application should not take control from the user by placing an
alert box on the screen when the user has not activated the application. If an
immediate response is crucial and the user does not respond to the notification
request, your application needs to handle the situation gracefully.
techniques.
Referenced by (1):