CustomView

Class로 그리기

public class CustomView extends View {

    private Paint paint;

    public CustomView(Context context) {
        super(context);
        paint = new Paint();
        paint.setColor(Color.RED);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawRect(100, 100, 500, 200, paint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            Toast.makeText(super.getContext(), "MotionEvent.ACTION_DOWN:" +
                    event.getX() + "," + event.getY(), Toast.LENGTH_SHORT).show();
        }
        return super.onTouchEvent(event);
    }
}

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        CustomView myView=new CustomView(this);
        setContentView(myView);
    }
}

참조
https://www.youtube.com/watch?v=iNOltfj_40Y