C H A P T E R 2

Container Views

Closing an Overview

Tapping the Close box has the same effect whether a view is displaying item detail or an overview—the application closes. Tapping a Close box in an overview does not switch to item detail.

Nonfunctional Scroll and Overview Controls

Some views scroll or display an overview, but not both. Rather than doing nothing when a user taps a nonfunctional scroll or overview control, a view should provide feedback. If a view that scrolls but doesn’t have an overview is frontmost and a user taps the Overview button, the view should notify the user with a message such as “This view does not have an overview.” Likewise, if a user taps a scroll arrow when a view that doesn’t scroll is frontmost, the view should notify the user with a message such as “This view does not scroll.” To avoid confusing users, don’t begin messages about not scrolling or not having an overview with “This application” unless the message applies to every one of the views in your application. Furthermore, better messages state the title of the view in place of the generic “This view” or “This application.

If the frontmost view has local scroll arrows but doesn’t respond to the universal scroll arrows and doesn’t let views behind it receive universal scroll arrow events, then the view should display a message that explains why the universal arrows don’t work or what the user must do to make them work. Under these circumstances a message such as “You must close this view to use the universal scroll arrows” is clearly more accurate than “This view does not scroll.”

No view has to receive taps on the Overview button and universal scroll arrows. If the frontmost view was not designated during application development to receive taps on those controls, the taps go to the next lower view that was so designated. For example, a slip or other auxiliary view can simply let its main view respond to the Overview button and the universal scroll arrows.

How Views Work

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Apple 2 manual Nonfunctional Scroll and Overview Controls, Closing an Overview
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2 specifications

The Apple II is a defining product in the history of personal computing, first introduced in 1977 by Apple Computer, Inc. Designed by Steve Wozniak, the Apple II was one of the first highly successful mass-produced microcomputer products and played a significant role in bringing personal computers into homes and schools.

One of the Apple II's standout features was its color graphics capability. It was one of the first personal computers to provide color output, thanks to its built-in video interface. The initial model supported a resolution of 280x192 pixels with a palette of 6 colors, which allowed for vibrant visuals that set it apart from contemporaries like the monochrome Altair 8800.

The Apple II was notable for its open architecture. This design allowed users to expand the computer's capabilities easily through a series of expansion slots. Users could add floppy disk drives, additional memory, and various peripheral devices, making the system highly adaptable to individual needs. This encouraged a thriving ecosystem of third-party hardware and software, which contributed to its popularity.

Another significant feature was its use of the 6502 microprocessor. This 8-bit CPU was not only affordable but also powerful for its time, allowing the Apple II to run various applications efficiently. Along with a built-in keyboard and an innovative plastic case that housed its components, the design was user-friendly and appealing.

The Apple II also introduced the concept of “bootable software” through the use of floppy disks. The disk operating system (DOS) allowed users to store and run multiple programs without having to reload software manually, providing a level of convenience that had not been widely available before. Key software like VisiCalc, the first spreadsheet program, helped boost sales, showcasing the Apple II's utility in business and education environments.

The computer was also well-known for its early adoption of BASIC programming language. Apple provided an operating system that supported Applesoft BASIC, which enabled users, including students, to write their programs, further fostering a community of developers.

In summary, the Apple II's color graphics, open architecture, powerful 6502 processor, innovative use of floppy disks, and support for BASIC programming made it a revolutionary product in its time. Its legacy laid the groundwork for future personal computers and established Apple as a leader in the burgeoning tech industry. The Apple II remains an iconic symbol of the early personal computing era, reflecting a generation's transition into a digitally connected world.
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