UIScrollView scrolling events detection

UIScrollViewExtension.swift

extension UIScrollView {
  
  //MARK: Normal Scrolling

  func didScrollBeyondTop(withThreshold minimum: CGFloat = 0) -> Bool {
    return contentOffset.y < -minimum
  }
  
  func didScrollBeyondBottom(withThreshold minimum: CGFloat = 0) -> Bool {
    if contentOffset.y <= 0 { return false } //Fixes UIRefreshControll initial state
    return contentOffset.y >= (contentSize.height - bounds.size.height) + minimum
  }
  
  func didScrollBeyondLeft(withThreshold minimum: CGFloat = 0) -> Bool {
    return contentOffset.x < -minimum
  }
  
  func didScrollBeyondRight(withThreshold minimum: CGFloat = 0) -> Bool {
    return contentOffset.x >= (contentSize.width - bounds.size.width) + minimum
  }
  
  //MARK: Paged Scrolling

  func didReachLastVerticalPage() -> Bool {
    return contentOffset.y >= (contentSize.height / frame.size.height - 1) * frame.size.height
  }
  
  func didReachLastHorizontalPage() -> Bool {
    return contentOffset.x >= (contentSize.width / frame.size.width - 1) * frame.size.width
  }
}