code: private void setupImageContainer() {
          Resources res = getResources();
          Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.grid);
          int cellH = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 22, res.getDisplayMetrics());
          bitmap = Bitmap.createScaledBitmap(bitmap, cellH, cellH, true);
  
          BitmapDrawable bitmapDrawable = new BitmapDrawable(res, bitmap);
          bitmapDrawable.setTileModeX(Shader.TileMode.REPEAT);
          bitmapDrawable.setTileModeY(Shader.TileMode.REPEAT);
          mImageContainer.setBackgroundDrawable(bitmapDrawable);
      }
docs: Setup image container