hopewise Is there an example about having a scroll container that would have vertical and horizontal scrollers at the same time?
If the total width and height of the container's children are larger than the view port width and height, you will be able to scroll both horizontally and vertically. There's nothing special to enable here. You just need big enough content, and it will work automatically.
hopewise Also, scrollers shall be disappeared when all children can be seen within the viewport, is this built in?
Yes, it is built in. By default, scroll bars will not display if the content isn't large enough to require scrolling. On the other hand, if you wanted scroll bars to display all of the time, you would need to set scrollPolicyX and/or scrollPolicyY to ON instead of AUTO. On desktop, ON means that scroll bars should always be displayed, but disabled when scrolling is not possible. AUTO means that scroll bars should be displayed only when required.