android-6-for-programmers-3rd

Configure Android Studio to Disallow Code Folding
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2. When the Welcome to Android Studio window appears, click Configure, then click
Settings to open the Default Settings window. If the Welcome to Android Studio
window does not appear, use the menus on Mac to select Android Studio > Preferences…
or on Windows/Linux to select File > Other Settings > Default Settings….
3. Expand the Editor > General node and select Appearance, then ensure that Show
line numbers is selected and click OK.
Configure Android Studio to Disallow Code Folding
By default, Android Studio’s code-folding feature is enabled. This feature collapses multiple
lines of code into a single line so you can focus on other aspects of the code. For example,
all the import statements in a Java source-code file can be collapsed into a single line
to hide them, or an entire method can be collapsed into a single line. You can expand these
lines if you need to look at the code in detail. We disabled this feature in our IDE. If you
wish to do so, follow the steps in the preceding section, then under Editor > General > Code
Folding uncheck Show code folding outline.
Android 6 SDK
This book’s code examples were written using Android 6. At the time of this writing, the
Android 6 SDK was bundled with Android Studio. As new Android versions are released,
the latest version will be bundled, which may prevent our apps from compiling properly.
When you work with this book, we recommend using Android 6. You can install prior
Android platform versions as follows:
1. Open Android Studio ( ).
2. When the Welcome to Android Studio window appears, click Configure, then click
SDK Manager to display the Android SDK manager. If a project window appears
rather than the Welcome to Android Studio window, you can access the Android
SDK manager via Tools > Android > SDK Manager.
3. In the SDK Platforms tab, check the versions of Android you wish to install, then
click Apply and OK. The IDE then downloads and installs the additional platform
versions. The IDE also will help you keep your installed versions up-to-date.
Creating Android Virtual Devices (AVDs)
The Android SDK’s Android emulator allows you to test apps on your computer rather
than on an Android device—this is essential, of course, if you do not have Android devices.
To do so, you create Android Virtual Devices (AVDs) that run in the emulator. The emulator
can be slow, so most Android developers prefer testing on actual devices. Also, the emulator
does not support various features, including phone calls, USB connections,
headphones and Bluetooth. For the latest emulator capabilities and limitations, visit
That page’s Using Hardware Acceleration section discusses features that can improve emulator
performance, such as using the computer’s graphics processing unit (GPU) to inhttp://developer.android.com/tools/devices/emulator.html