The Android Support Library offers a number of features that are not built into the framework.
Support libraries provide a range of different features:
- Backward-compatible versions of framework components.
- UI elements to implement the recommended Android layout patterns.
- Support for different form factors.
- Miscellaneous utility functions.
- Support libraries allow apps running on older versions of the Android platform to support features made available on newer versions of the platform.
- If the framework provides the necessary functionality, the support library calls on the framework to perform the task.
- If the app is running on an earlier version of Android, and the framework doesn’t expose the needed functionality, the support library may try to provide the functionality itself, or may act as a no-op.
- The app does not need to check the system version at run time. The app can rely on the support library class to do the appropriate system checks, and modify its behavior as necessary.
Support for General Layout Patterns
- Support libraries provide user interface elements not offered by the Android framework.
- ex) DrawerLayout, RecylcerView
- By using these support library classes, you can avoid having to reinvent the wheel.
- If your app has a particular user interface requirement, you can draw on existing code, which provides a user interface that users will already be familiar with.
- These elements also help you build an app that looks and feels like a part of the Android ecosystem.
Support for Different Form Factors
- The Android SDK provides libraries for a number of different form factors, such as TV and wearables.
- An app can depend on the appropriate support library to provide functionality across a wide range of platform versions, and can provide content on external screens, speakers, and other destination devices.
The Android Support Library provides backward-compatible utility functions. Apps can use these utility functions to provide an appropriate user experience across a wide range of Android system versions.
ex) support library permission methods behave appropriately depending on what platform version your app is running on. If the platform supports the runtime permissions model, these methods request the appropriate permission from the user; on platform versions that do not support the runtime permissions model, the methods check whether the appropriate permission was granted at install time.
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