Simple example of usage of RxBleCustomOperation — create an Observable that emits the Bluetooth GATT object

CustomOperationExample.java

package net.grlewis.cufftest;

import android.bluetooth.BluetoothGatt;

import com.polidea.rxandroidble2.RxBleCustomOperation;
import com.polidea.rxandroidble2.internal.connection.RxBleGattCallback;

import io.reactivex.Observable;
import io.reactivex.Scheduler;
import io.reactivex.annotations.NonNull;

public class GetGattOperation implements RxBleCustomOperation<BluetoothGatt> {
    
    private BluetoothGatt gatt;
    
    // How this works:
    
    // You call rxBleConnection.queue( <instance of this class> )
    // It returns an Observable<T>--call it Observable A
    
    // The queue manager calls the .asObservable() method below,
    // which returns another Observable<T>--call it Observable B
    // It is placed in the queue for execution
    
    // When it's time to run this operation, ConnectionOperationQueue will
    // subscribe to Observable B (here, Observable.just( bluetoothGatt ))
    
    // Emissions from this Observable B (here, the bluetoothGatt) are forwarded to the Observable A returned by the .queue() method
    
    // Instances can be queued and received via a subscription to Observable A:
    // rxBleConnection.queue( new GetGattOperation() ).subscribe( gatt -> {} );
    
    
    @Override  // returns "Observable B" (see above) 
    public @NonNull Observable<BluetoothGatt> asObservable( BluetoothGatt bluetoothGatt,
                                                            RxBleGattCallback rxBleGattCallback,
                                                            Scheduler scheduler) throws Throwable {
        
        gatt = bluetoothGatt;
        return Observable.just( bluetoothGatt );  // return Observable B (emits Gatt then completes)
    }
    
    
    public BluetoothGatt getGatt( ) {
        return gatt;
    }
    
}

In line 39, could I set native callback? something like this rxBleGattCallback.setNativeCallback(bluetoothGattCallback)

I have this
private val bluetoothGattCallback = object : BluetoothGattCallback() {
override fun onCharacteristicChanged(gatt: BluetoothGatt?, characteristic: BluetoothGattCharacteristic?) {
super.onCharacteristicChanged(gatt, characteristic)
Timber.e("CHARACTERISTIC CHANGED")
}
}