Accessing Activity components from non-activity class

Question

I am trying to obtain Accelerometer's raw data and show it on a TextView.

I have two classes: MainActivity and SensorActivity. I am new to Android development and I made SensorActivity class intentionally just to learn how non-activity class and activity class interact. To do so, I learned, by searching, that I need to pass the Context of the MainActivity, so that SensorActivity class can interact with the MainActivity. So, I tried as far as I could, but I seem to get stuck.

In initialize function, my effort to get an access to a TextView of MainActivity doesn't seem to work. I cannot even make the correct syntax. Codes snippets are provided below. If I could get any help, it would be appreciated, tremendously.

In MainActivity.java

public class MainActivity extends Activity{

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        SensorActivity sensorActivity = new SensorActivity(this);
        sensorActivity.initialize();
    }
}

In SensorActivity.java

public class SensorActivity implements SensorEventListener{

    Context mainActivityContext;
    private SensorManager mySensorManager = (SensorManager) mainActivityContext.getSystemService(Context.SENSOR_SERVICE);

    public SensorActivity (Context context){
        this.mainActivityContext = context;
    }
    ...
    protected void initialize(){
        ...
        TextView tv = (TextView) findViewById(R.id.default_text_view);
        ...
    }
}

Answer 1

Use Activity Context for accessing View from non Activity class as:

protected void initialize(Activity activity){
    ...
    TextView tv = (TextView)activity.findViewById(R.id.default_text_view);
    ...
}

because findViewById is method from Activity class instead of Context

Answer 2

Use Activity reference instead of Context it will work.