BrailleDisplayCallback

interface BrailleDisplayCallback
android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback

Interface provided to BrailleDisplayController connection methods to receive callbacks from the system.

Summary

Constants
static Int

A unique Braille display matching the requested properties could not be identified.
static Int

The system cannot access connected HID devices.
Public methods
abstract Unit
onConnected(hidDescriptor: ByteArray)

Callback to observe a successful Braille display connection.
abstract Unit
onConnectionFailed(errorFlags: Int)

Callback to observe a failed Braille display connection.
abstract Unit

Callback to observe when the currently connected Braille display is disconnected by the system.
abstract Unit

Callback to observe input bytes from the currently connected Braille display.

Constants

FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND

Added in API level VanillaIceCream
static val FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND: Int

A unique Braille display matching the requested properties could not be identified.

Value: 2

FLAG_ERROR_CANNOT_ACCESS

Added in API level VanillaIceCream
static val FLAG_ERROR_CANNOT_ACCESS: Int

The system cannot access connected HID devices.

Value: 1

Public methods

onConnected

Added in API level VanillaIceCream
abstract fun onConnected(hidDescriptor: ByteArray): Unit

Callback to observe a successful Braille display connection.

The provided HID report descriptor should be used to understand the input bytes received from the Braille display via onInput and to prepare the output sent to the Braille display via write.

Parameters
hidDescriptor ByteArray: The HID report descriptor for this Braille display. This value cannot be null.

onConnectionFailed

Added in API level VanillaIceCream
abstract fun onConnectionFailed(errorFlags: Int): Unit

Callback to observe a failed Braille display connection.

Parameters
errorFlags Int: A bitmask of error codes for the connection failure. Value is either 0 or a combination of android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback#FLAG_ERROR_CANNOT_ACCESS, and android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback#FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND

onDisconnected

Added in API level VanillaIceCream
abstract fun onDisconnected(): Unit

Callback to observe when the currently connected Braille display is disconnected by the system.

onInput

Added in API level VanillaIceCream
abstract fun onInput(input: ByteArray): Unit

Callback to observe input bytes from the currently connected Braille display.

Parameters
input ByteArray: The input bytes from the Braille display, formatted according to the HID report descriptor and the HIDRAW kernel driver. This value cannot be null.