CustomView on top of ImageView with action on longtouch draw clickable circle saved in database

Question

I have an ImageView and on top of that, I have a CustomView which extends ImageView. ImageView is in BgPicture class handled by fragment class. But in CustomView I want to perform long touch which will show drop-down menu ( or something like it ) and after selected choose will save data with position into a database and draw a circle in touched position. If someone clicks in an existing circle I also want to show him some options and not allowing to create a new circle. I am not sure if I used the right approach for this task. Below will provide my code I came so far. Would anyone point me in the right direction? Also how to perform long touch?

XML:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/bg_picture_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

<ImageView
    android:id="@+id/bg_picture"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:layout_marginBottom="8dp"
    android:layout_marginEnd="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    android:clickable="true"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.492"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:srcCompat="@drawable/picture" />

<si.result.vehiclecheck.layouts.views.CustomView
    android:id="@+id/custom_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

BgPicture:

@EFragment ( R.layout.bg_picture )
public class BgPicture extends Fragment {

    private String regNumber;

    @ViewById( R.id.bg_picture )
    ImageView picture;


    @AfterViews
    void startBgPicture() {
        Bundle arguments = getArguments();
        if( arguments != null ) {
            regNumber = arguments.getString( "REG_NUMBER" );
        }
    }

    @Override
    public void setMenuVisibility(final boolean visible) {
        super.setMenuVisibility(visible);
        if (visible) {
            EventBus.getDefault().post( new MessageEvent( regNumber ) 
         );
        }
    }
}

CustomView:

@EView
public class CustomView extends 
android.support.v7.widget.AppCompatImageView {

private String regNum = "";
private List<Elements> elementsList;

public CustomView( Context context ) {
    super( context );
}
public CustomView( Context context, AttributeSet attrs) {
    super(context, attrs);
}
public CustomView(Context context, AttributeSet attrs, int 
defStyleAttr) {
    super(context, attrs, defStyleAttr);
}

@Subscribe( threadMode = ThreadMode.BACKGROUND )
public void onMessageEvent( MessageEvent event ) {
    this.regNum = event.message;
    getPositions();
}


// Its still in main thread
@Background
void getPositions() {
    AppDatabase database = Room.databaseBuilder(
        getContext(),
        AppDatabase.class, "PositionsData"
    ).allowMainThreadQueries().build();
    elementsList = database.positionDataDao().getElementsByNum( regNum 
    );
    database.close();
    invalidate();
}

@Override
protected void onDraw( Canvas canvas ) {
    super.onDraw( canvas );

    Paint paint = new Paint();
    paint.setColor( Color.GREEN );

    if( elementsList != null ) {
        for( Elements el : elementsList ) {
            canvas.drawCircle( el.getX(), el.getY(), 50, paint );
        }
    }
}

@Override
protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    EventBus.getDefault().register( this );
}

@Override
protected void onDetachedFromWindow() {
    EventBus.getDefault().unregister(this);
    super.onDetachedFromWindow();
}

// TODO in background
@Background
void writeIntoDB( String regNum, String type, float x, float y ) {
    AppDatabase database = Room.databaseBuilder(
            getContext(),
            AppDatabase.class, "PositionsData"
    ).allowMainThreadQueries().build();
    Elements el = new Elements( regNum, false, type, x, y );
    database.positionDataDao().insertNewElement( el );
    database.close();
    getPositions();
}

@Override
public boolean onTouchEvent( MotionEvent event ) {
    if( event.getAction() == MotionEvent.ACTION_DOWN ) {
        if( elementsList != null ) {
            for( Elements el : elementsList ) {
                if( Math.sqrt(Math.pow(event.getX() - el.getX(), 2) +                           
                    Math.pow(event.getY() - el.getY(), 2)) <= 50 ) {
                    return true;
                }
            }
        }
        writeIntoDB( regNum,"C", event.getX(), event.getY() );
        invalidate();
        return true;
    }
    if( event.getAction() == MotionEvent.ACTION_UP ) {
        System.out.println("ACTION UP");
        return true;
    }
    return false;
}
}