iphone - iOS : WHO'S in charge of refreshing UI/Screen while UITableView's scrolling? -

iphone - iOS : WHO'S in charge of refreshing UI/Screen while UITableView's scrolling? -

i finding ways calculate fps what said here, holding thought when uitableview scrolls, drawrect: called frame frame. didn't.

the uitableview's drawrect: called once, not matter drag , downwards or set buttons on it. uitableview's superview , cells. uiviews' drawrect:s called 1 time each.

given drawrect: called once, in charge of refreshing ui/screen while uitableview's scrolling?

updated 1

i know uitableview's delegate & datasource responsible layout cells show. if tableview scrolls slightly? though delegate & datasource not called, screen's content still changed. on occasion, ui refresh on iphone screen? scrollview scrolled -> uikit -> gpu -> lcd screen?

this uitableview's datasource , delegate properties for. allow define in charge of setting ui , handling user interaction.

ios iphone uitableview uikit drawrect