BrailleDisplayController.BrailleDisplayCallback
public
static
interface
BrailleDisplayController.BrailleDisplayCallback
| android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback |
Interface provided to BrailleDisplayController connection methods to
receive callbacks from the system.
Summary
Constants | |
|---|---|
int |
FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND
A unique Braille display matching the requested properties could not be identified. |
int |
FLAG_ERROR_CANNOT_ACCESS
The system cannot access connected HID devices. |
Public methods | |
|---|---|
abstract
void
|
onConnected(byte[] hidDescriptor)
Callback to observe a successful Braille display connection. |
abstract
void
|
onConnectionFailed(int errorFlags)
Callback to observe a failed Braille display connection. |
abstract
void
|
onDisconnected()
Callback to observe when the currently connected Braille display is disconnected by the system. |
abstract
void
|
onInput(byte[] input)
Callback to observe input bytes from the currently connected Braille display. |
Constants
FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND
public static final int FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND
A unique Braille display matching the requested properties could not be identified.
Constant Value: 2 (0x00000002)
FLAG_ERROR_CANNOT_ACCESS
public static final int FLAG_ERROR_CANNOT_ACCESS
The system cannot access connected HID devices.
Constant Value: 1 (0x00000001)
Public methods
onConnected
public abstract void onConnected (byte[] hidDescriptor)
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(byte) and to prepare
the output sent to the Braille display via BrailleDisplayController.write(byte).
| Parameters | |
|---|---|
hidDescriptor |
byte: The HID report descriptor for this Braille display.
This value cannot be null. |
onConnectionFailed
public abstract void onConnectionFailed (int errorFlags)
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 FLAG_ERROR_CANNOT_ACCESS, and FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND |
onDisconnected
public abstract void onDisconnected ()
Callback to observe when the currently connected Braille display is disconnected by the system.
onInput
public abstract void onInput (byte[] input)
Callback to observe input bytes from the currently connected Braille display.
| Parameters | |
|---|---|
input |
byte: The input bytes from the Braille display, formatted according to the HID
report descriptor and the HIDRAW kernel driver.
This value cannot be null. |