private void moveCenter(
      RectF rect, float x, float y, RectF bounds, int viewWidth, int viewHeight, float snapRadius) {
    float dx = x - rect.centerX();
    float dy = y - rect.centerY();
    if (rect.left + dx < 0
        || rect.right + dx > viewWidth
        || rect.left + dx < bounds.left
        || rect.right + dx > bounds.right) {
      dx /= 1.05f;
      mTouchOffset.x -= dx / 2;
    }
    if (rect.top + dy < 0
        || rect.bottom + dy > viewHeight
        || rect.top + dy < bounds.top
        || rect.bottom + dy > bounds.bottom) {
      dy /= 1.05f;
      mTouchOffset.y -= dy / 2;
    }
    rect.offset(dx, dy);
    snapEdgesToBounds(rect, bounds, snapRadius);
  }
Center move only changes the position of the crop window without changing the size.
core/src/main/java/com/theartofdev/edmodo/cropper/CropWindowMoveHandler.java