Add java document in BluetoothCallback

 * UI to receive events from {@link BluetoothEventManager}.

 */

public interface BluetoothCallback {

    /**

     * It will be called when the state of the local Bluetooth adapter has been changed.

     * It is listening {@link android.bluetooth.BluetoothAdapter#ACTION_STATE_CHANGED}.

     * For example, Bluetooth has been turned on or off.

     *

     * @param bluetoothState the current Bluetooth state, the possible values are:

     * {@link android.bluetooth.BluetoothAdapter#STATE_OFF},

     * {@link android.bluetooth.BluetoothAdapter#STATE_TURNING_ON},

     * {@link android.bluetooth.BluetoothAdapter#STATE_ON},

     * {@link android.bluetooth.BluetoothAdapter#STATE_TURNING_OFF}.

     */

    void onBluetoothStateChanged(int bluetoothState);

    /**

     * It will be called when the local Bluetooth adapter has started

     * or finished the remote device discovery process.

     * It is listening {@link android.bluetooth.BluetoothAdapter#ACTION_DISCOVERY_STARTED} and

     * {@link android.bluetooth.BluetoothAdapter#ACTION_DISCOVERY_FINISHED}.

     *

     * @param started indicate the current process is started or finished.

     */

    void onScanningStateChanged(boolean started);

    /**

     * It will be called in following situations:

     * 1. In scanning mode, when a new device has been found.

     * 2. When a profile service is connected and existing connected devices has been found.

     * This API only invoked once for each device and all devices will be cached in

     * {@link CachedBluetoothDeviceManager}.

     *

     * @param cachedDevice the Bluetooth device.

     */

    void onDeviceAdded(CachedBluetoothDevice cachedDevice);

    /**

     * It will be called when a remote device that was

     * found in the last discovery and is not found in the current discovery.

     * It is listening {@link android.bluetooth.BluetoothDevice#ACTION_DISAPPEARED}

     *

     * @param cachedDevice the Bluetooth device.

     */

    void onDeviceDeleted(CachedBluetoothDevice cachedDevice);

    /**

     * It will be called when bond state of a remote device is changed.

     * It is listening {@link android.bluetooth.BluetoothDevice#ACTION_BOND_STATE_CHANGED}

     *

     * @param cachedDevice the Bluetooth device.

     * @param bondState the Bluetooth device bond state, the possible values are:

     * {@link android.bluetooth.BluetoothDevice#BOND_NONE},

     * {@link android.bluetooth.BluetoothDevice#BOND_BONDING},

     * {@link android.bluetooth.BluetoothDevice#BOND_BONDED}.

     */

    void onDeviceBondStateChanged(CachedBluetoothDevice cachedDevice, int bondState);

    /**

     * It will be called in following situations:

     * 1. When the adapter is not connected to any profiles of any remote devices

     * and it attempts a connection to a profile.

     * 2. When the adapter disconnects from the last profile of the last device.

     * It is listening {@link android.bluetooth.BluetoothAdapter#ACTION_CONNECTION_STATE_CHANGED}

     *

     * @param cachedDevice the Bluetooth device.

     * @param state the Bluetooth device connection state, the possible values are:

     * {@link android.bluetooth.BluetoothAdapter#STATE_DISCONNECTED},

     * {@link android.bluetooth.BluetoothAdapter#STATE_CONNECTING},

     * {@link android.bluetooth.BluetoothAdapter#STATE_CONNECTED},

     * {@link android.bluetooth.BluetoothAdapter#STATE_DISCONNECTING}.

     */

    void onConnectionStateChanged(CachedBluetoothDevice cachedDevice, int state);

    /**

     * It will be called when device been set as active for {@code bluetoothProfile}

     * It is listening in following intent:

     * {@link android.bluetooth.BluetoothA2dp#ACTION_ACTIVE_DEVICE_CHANGED}

     * {@link android.bluetooth.BluetoothHeadset#ACTION_ACTIVE_DEVICE_CHANGED}

     * {@link android.bluetooth.BluetoothHearingAid#ACTION_ACTIVE_DEVICE_CHANGED}

     *

     * @param activeDevice the active Bluetooth device.

     * @param bluetoothProfile the profile of active Bluetooth device.

     */

    void onActiveDeviceChanged(CachedBluetoothDevice activeDevice, int bluetoothProfile);

    /**

     * It will be called in following situations:

     * 1. When the call state on the device is changed.

     * 2. When the audio connection state of the A2DP profile is changed.

     * It is listening in following intent:

     * {@link android.bluetooth.BluetoothHeadset#ACTION_AUDIO_STATE_CHANGED}

     * {@link android.telephony.TelephonyManager#ACTION_PHONE_STATE_CHANGED}

     */

    void onAudioModeChanged();

    /**

     * It will be called when one of the bluetooth device profile connection state is changed.

     *

     * @param cachedDevice the active Bluetooth device.

     * @param state the BluetoothProfile connection state, the possible values are:

     * {@link android.bluetooth.BluetoothProfile#STATE_CONNECTED},

     * {@link android.bluetooth.BluetoothProfile#STATE_CONNECTING},

     * {@link android.bluetooth.BluetoothProfile#STATE_DISCONNECTED},

     * {@link android.bluetooth.BluetoothProfile#STATE_DISCONNECTING}.

     * @param bluetoothProfile the BluetoothProfile id.

     */

    default void onProfileConnectionStateChanged(CachedBluetoothDevice cachedDevice,

            int state, int bluetoothProfile) {

    }