Making Weather-Like ScrollView

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• 유저가 빠르게 스크롤 할 때, 헤더의 높이를 조정하는 부분에서 매끄럽지 않은 부분이 발생하.
• 헤더의 폰트 크기 결정하기
• 푸터에는 버튼이 들어가야 하는데, 터치 이벤트가 전달이 되는지 아직 확인하지 않음

Problems

The UIScrollView, surrounded by the UIPageViewController, behaves like the above as the user scroll it.

It seems very easy and clear to implement, but there were several things to think about it.

• First, how is the header is shrunk as the user scroll upward?
• Second, how can the content be prevent from being scrolled until the header is completely shrunk?
• Third, how can they detect touch events, and make the content to be scrolled although the header and footer seems to not be contained in the scroll view?

Clue

• First of all, I made 'scroll view' like below code.

  class ViewController: UIViewController {
  	...
  	override func viewDidLoad() {
  		super.viewDidLoad()
  		...
  		scrollView.contentInset = UIEdgeInsets(top: contentStartingPoint, left: 0, bottom: footerHeight, right: 0)
  		scrollView.contentInsetAdjustmentBehavior = .never
  		...
  	}
  }

  If I didn't set contentInset properly, the header would cover the content area.

• I used the delegate method, named scrollViewDidScroll(_ scrollView: UIScrollView), for solving the first one.

  In this method, I calculated how far did the user scroll, then adjusted the header's height value.

• Actually the first solution solved the second one as soon as I solved that. I'll find the reason.

• To solve the last problem, I found one clue making the scroll view as the container (not the root view).

I added the scroll view into the root as the lowest child, then set the rest's zPosition to some higher value.

So, I was able to interact with the scroll view, although I touched the header or footer area.

But as you can see, the original weather app contains several buttons in the footer. I haven't solved it yet.