i know this can be done by not putting the focus rectangle on any of the folders in a directory but it's better if there's another menu item or button or the likes of the two that when pressed will show all the sizes of the folders in a directory regardless of the position of the focus rectangle..
if you have selected multiple folders or files in a directory to copy, for example, but then you want to know first the sizes of all of the folders in that directory then you would have to put the focus rectangle to '...'or to any free space, press the 'calculate....'..then you if you want to continue what you want to do..you need to select again those files and folders!..if there's only a button or menu item that will show all of the folders sizes in that specific directory then there'll be no need to repeat the selection process..