uiscrollview-definition.swift

/// # UIKit basic implementation

open class UIScrollView : UIView, NSCoding, UIFocusItemScrollableContainer {
    open var contentOffset: CGPoint // default CGPointZero
    open var contentSize: CGSize // default CGSizeZero
    open var contentInset: UIEdgeInsets // default UIEdgeInsetsZero. add additional scroll area around content

    // all another code ...
}

/// # Article basic implementation

class SimpleScrollView: UIView {
    var contentView: UIView?
    var contentSize: CGSize
    var contentOffset: CGPoint
}

/// Source: [Как работает UIScrollView](https://medium.com/@esskeetit/как-работает-uiscrollview-2e7052032d97)

open class UIScrollView : UIView, NSCoding, UIFocusItemScrollableContainer {
    open var contentOffset: CGPoint // default CGPointZero
    open var contentSize: CGSize // default CGSizeZero
    open var contentInset: UIEdgeInsets // default UIEdgeInsetsZero. add additional scroll area around content

    // all another code ...
}