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BrailleDisplayController.BrailleDisplayCallback
public
static
interface
BrailleDisplayController.BrailleDisplayCallback
| android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback
|
Interface provided to BrailleDisplayController connection methods to
receive callbacks from the system.
Summary
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.
onDisconnected
public abstract void onDisconnected ()
Callback to observe when the currently connected Braille display is disconnected by the
system.
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. |
Content and code samples on this page are subject to the licenses described in the Content License. Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
Last updated 2025-02-10 UTC.
[null,null,["Last updated 2025-02-10 UTC."],[],[],null,["# BrailleDisplayController.BrailleDisplayCallback\n\nAdded in [API level 35](/guide/topics/manifest/uses-sdk-element#ApiLevels) \n\nBrailleDisplayController.BrailleDisplayCallback\n===============================================\n\n*** ** * ** ***\n\n[Kotlin](/reference/kotlin/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback \"View this page in Kotlin\") \\|Java\n\n\n`\npublic\nstatic\n\n\ninterface\nBrailleDisplayController.BrailleDisplayCallback\n`\n\n\n`\n\n\n`\n\n|------------------------------------------------------------------------------|\n| android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback |\n\n\u003cbr /\u003e\n\n*** ** * ** ***\n\nInterface provided to [BrailleDisplayController](/reference/android/accessibilityservice/BrailleDisplayController) connection methods to\nreceive callbacks from the system.\n\nSummary\n-------\n\n| ### Constants ||\n|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `int` | [FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND) A unique Braille display matching the requested properties could not be identified. |\n| `int` | [FLAG_ERROR_CANNOT_ACCESS](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#FLAG_ERROR_CANNOT_ACCESS) The system cannot access connected HID devices. |\n\n| ### Public methods ||\n|------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| ` abstract void` | ` `[onConnected](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#onConnected(byte[]))`(byte[] hidDescriptor) ` Callback to observe a successful Braille display connection. |\n| ` abstract void` | ` `[onConnectionFailed](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#onConnectionFailed(int))`(int errorFlags) ` Callback to observe a failed Braille display connection. |\n| ` abstract void` | ` `[onDisconnected](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#onDisconnected())`() ` Callback to observe when the currently connected Braille display is disconnected by the system. |\n| ` abstract void` | ` `[onInput](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#onInput(byte[]))`(byte[] input) ` Callback to observe input bytes from the currently connected Braille display. |\n\nConstants\n---------\n\n### FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND\n\nAdded in [API level 35](/guide/topics/manifest/uses-sdk-element#ApiLevels) \n\n```\npublic static final int FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND\n```\n\nA unique Braille display matching the requested properties could not be identified.\n\n\u003cbr /\u003e\n\nConstant Value:\n\n2\n(0x00000002)\n\n\n### FLAG_ERROR_CANNOT_ACCESS\n\nAdded in [API level 35](/guide/topics/manifest/uses-sdk-element#ApiLevels) \n\n```\npublic static final int FLAG_ERROR_CANNOT_ACCESS\n```\n\nThe system cannot access connected HID devices.\n\n\u003cbr /\u003e\n\nConstant Value:\n\n1\n(0x00000001)\n\n\nPublic methods\n--------------\n\n### onConnected\n\nAdded in [API level 35](/guide/topics/manifest/uses-sdk-element#ApiLevels) \n\n```\npublic abstract void onConnected (byte[] hidDescriptor)\n```\n\nCallback to observe a successful Braille display connection.\n\nThe provided HID report descriptor should be used to understand the input bytes\nreceived from the Braille display via [onInput(byte)](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#onInput(byte[])) and to prepare\nthe output sent to the Braille display via [BrailleDisplayController.write(byte)](/reference/android/accessibilityservice/BrailleDisplayController#write(byte[])).\n\n\u003cbr /\u003e\n\n| Parameters ||\n|-----------------|-------------------------------------------------------------------------------------------------|\n| `hidDescriptor` | `byte`: The HID report descriptor for this Braille display. This value cannot be `null`. \u003cbr /\u003e |\n\n**See also:**\n\n- [BrailleDisplayController.connect(BluetoothDevice, BrailleDisplayCallback)](/reference/android/accessibilityservice/BrailleDisplayController#connect(android.bluetooth.BluetoothDevice,%20android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback))\n- [BrailleDisplayController.connect(UsbDevice, BrailleDisplayCallback)](/reference/android/accessibilityservice/BrailleDisplayController#connect(android.hardware.usb.UsbDevice,%20android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback)) \n\n### onConnectionFailed\n\nAdded in [API level 35](/guide/topics/manifest/uses-sdk-element#ApiLevels) \n\n```\npublic abstract void onConnectionFailed (int errorFlags)\n```\n\nCallback to observe a failed Braille display connection.\n\n\u003cbr /\u003e\n\n| Parameters ||\n|--------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `errorFlags` | `int`: A bitmask of error codes for the connection failure. Value is either `0` or a combination of [FLAG_ERROR_CANNOT_ACCESS](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#FLAG_ERROR_CANNOT_ACCESS), and [FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND](/reference/android/accessibilityservice/BrailleDisplayController.BrailleDisplayCallback#FLAG_ERROR_BRAILLE_DISPLAY_NOT_FOUND) \u003cbr /\u003e |\n\n**See also:**\n\n- [BrailleDisplayController.connect(BluetoothDevice, BrailleDisplayCallback)](/reference/android/accessibilityservice/BrailleDisplayController#connect(android.bluetooth.BluetoothDevice,%20android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback))\n- [BrailleDisplayController.connect(UsbDevice, BrailleDisplayCallback)](/reference/android/accessibilityservice/BrailleDisplayController#connect(android.hardware.usb.UsbDevice,%20android.accessibilityservice.BrailleDisplayController.BrailleDisplayCallback)) \n\n### onDisconnected\n\nAdded in [API level 35](/guide/topics/manifest/uses-sdk-element#ApiLevels) \n\n```\npublic abstract void onDisconnected ()\n```\n\nCallback to observe when the currently connected Braille display is disconnected by the\nsystem.\n\n\u003cbr /\u003e\n\n### onInput\n\nAdded in [API level 35](/guide/topics/manifest/uses-sdk-element#ApiLevels) \n\n```\npublic abstract void onInput (byte[] input)\n```\n\nCallback to observe input bytes from the currently connected Braille display.\n\n\u003cbr /\u003e\n\n| Parameters ||\n|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `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`. \u003cbr /\u003e |"]]
