Apple 2 manual View Position, Position of a Main View

C H A P T E R 2

Container Views

Although modeless views give users more flexibility, modal views have the advantage of being less ambiguous. Nothing a user does in a modal view should take effect until the user taps a button to confirm the state of the modal view. A modal view avoids intermediate states that can occur with a modeless view, where a user’s changes take effect without the user being aware that this is happening.

You can use modal views when your application needs information before it can continue. A modal view is fairly simple to implement, but that doesn’t mean that you should use modal views too freely. You should rarely restrict the user’s actions by forcing the user into a mode.

View Position

When designing an application, you must decide where to position the application’s main view, ordinary slips, and palettes. The system takes care of positioning routing slips, status slips, notification alerts, and confirmation alerts. In making these decisions consider the type of view, its size in relation to the main view (or the screen), what other views you know will also be open, and how the view’s content relates to the other open views.

The positions at which views open affects the usability of your application and of the whole Newton device. Each view that opens may obscure part of the other views already open.

Equally important are users’ preferences. If a user moves a view, your application should maintain that position.

Position of a Main View

The initial position of a main view that fills the screen is obvious. Most smaller main views are centered horizontally but are off-center vertically. Usually there is about three times as much uncovered screen space below the view as above it. Some main views, such as the built-in Find and Assist views, are centered at the bottom edge of the visible screen area.

2-30 How Views Work