1## 3.10\. Accessibility 2 3Android provides an accessibility layer that helps users with disabilities to 4navigate their devices more easily. In addition, Android provides platform APIs 5that enable accessibility service implementations to receive callbacks for user 6and system events and generate alternate feedback mechanisms, such as 7text-to-speech, haptic feedback, and trackball/d-pad navigation. 8 9If device implementations support third-party accessibility services, they: 10 11* [C-1-1] MUST provide an implementation of the Android accessibility 12 framework as described in the [accessibility APIs]( 13 http://developer.android.com/reference/android/view/accessibility/package-summary.html) 14 SDK documentation. 15* [C-1-2] MUST generate accessibility events and deliver the appropriate 16 `AccessibilityEvent` to all registered [`AccessibilityService`]( 17 http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html) 18 implementations as documented in the SDK. 19* [C-1-3] MUST honor the `android.settings.ACCESSIBILITY_SETTINGS` intent to 20 provide a user-accessible mechanism to enable and disable the third-party 21 accessibility services alongside the preloaded accessibility services. 22* [C-1-4] MUST add a button in the system's navigation bar allowing the user 23 to control the accessibility service when the enabled accessibility services 24 declare the [`AccessibilityServiceInfo.FLAG_REQUEST_ACCESSIBILITY_BUTTON`]( 25 https://developer.android.com/reference/android/accessibilityservice/AccessibilityServiceInfo.html#FLAG%5FREQUEST%5FACCESSIBILITY%5FBUTTON) 26 . Note that for device implementations with no system navigation bar, this 27 requirement is not applicable, but device implementations SHOULD provide a 28 user affordance to control these accessibility services. 29 30 31If device implementations include preloaded accessibility services, they: 32 33* [C-2-1] MUST implement these preloaded accessibility services as [Direct Boot Aware]( 34 https://developer.android.com/reference/android/content/pm/ComponentInfo.html#directBootAware) 35 apps when the data storage is encrypted with File Based Encryption (FBE). 36* SHOULD provide a mechanism in the out-of-box setup flow for users to enable 37 relevant accessibility services, as well as options to adjust the font size, 38 display size and magnification gestures. 39