The following is the first few sections of a chapter from The Busy Coder's Guide to Android Development, plus headings for the remaining major sections, to give you an idea about the content of the chapter.
As developers, we are very used to creating apps that are designed to be navigated by touch, with users tapping on widgets and related windows to supply input.
However, not all Android devices have touchscreens, and not all Android users use touchscreens.
Internationalization (i18n) and localization (L10n) give you opportunities to expand your user base to audiences beyond your initial set, based on language. Similarly, you can expand your user base by offering support for non-touchscreen input and output. Long-term, the largest user base of these features may be those with televisions augmented by Android, whether via Android TV, OUYA consoles, or whatever. Short-term, the largest user base of these features may be those for whom touchscreens are rarely a great option, such as the blind. Supporting those with unusual requirements for input and output is called accessibility (a11y), and represents a powerful way for you to help your app distinguish itself from competitors.
In this chapter, we will first examine how to better handle focus management, and then segue into examining what else, beyond supporting keyboard-based input, can be done in the area of accessibility.
Understanding this chapter requires that you have read the core chapters and are familiar with the concept of widgets having focus for user input.
To test focus management, you will need an environment that supports “arrow key” navigation. Here, “arrow key” also includes things like D-pads or trackballs – basically, anything that navigates by key events instead of by touch events.
DPad supporthardware property set to
Hence, even if the emulator will be insufficient for your needs, you should be able to set up a hardware test environment relatively inexpensively. Most modern Android devices support Bluetooth keyboards, and such keyboards frequently can be obtained at low relative cost.
For accessibility beyond merely focus control, you will certainly want to enable TalkBack, via the Accessibility area of the Settings app. This will cause Android to verbally announce what is on the screen, by means of its text-to-speech engine.
On Android 4.0 and higher devices, enabling Talkback will also optionally
enable “Explore by Touch”. This allows users to tap on items (e.g., icons in a
GridView) to have them read aloud via TalkBack, with a double-tap to actually
perform what ordinarily would require a single-tap without “Explore by Touch”.
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