Navigation Bar doesn't come back once it hides (swipe)

Question

I created a ViewController with TableView inside it and embedded it a NavigationController. I also set the constraints. On Swipe down, Navigation Bar hides. Everything seems fine.

The only problem is that on Swipe Up, the Navigation Bar doesn't come back.

If I use the same TableView with a TableViewController instead of ViewController (embedded from the same Navigation Controller), the Navigation Bar does comes back.

For the ones wondering why I don't just go with the TableViewController, because I need to uncheck Adjust Scroll View Insets for some disturbing bug.

it seems like this same issue http://stackoverflow.com/q/24710258/4975761 — wj2061, Apr 09 '16 at 06:16
Possible duplicate of [Setting navigationController.hidesBarsOnSwipe = YES never shows my navbar again](https://stackoverflow.com/questions/26524395/setting-navigationcontroller-hidesbarsonswipe-yes-never-shows-my-navbar-again) — Brittany, Mar 23 '18 at 02:45

score 3 · Accepted Answer · answered Apr 09 '16 at 17:14

3

To solve the issue, I used scrollViewWillEndDragging and detected Going Down & Going Up

func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {

   if targetContentOffset.memory.y < scrollView.contentOffset.y {
       // UP
   } else {
       // DOWN
   }
}

answered Apr 09 '16 at 17:14

senty

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If you test for negative velocity, you can set a threshold speed to make the NavBar reappear. That way the user can control when the NavBar appears. – Bob Wakefield Oct 16 '16 at 16:12

score 1 · Answer 2 · answered Jun 05 '19 at 20:32

Here's my solution, based on senty's answer:

func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {

    let draggDelta = scrollView.contentOffset.y - targetContentOffset.pointee.y

    let hiddenContentHeight = spreadsheetView.contentSize.height - spreadsheetView.frame.height - 1

    if 0 < draggDelta && targetContentOffset.pointee.y < hiddenContentHeight || (targetContentOffset.pointee.y == 0 && scrollView.contentOffset.y < 0) {

        // Shows Navigation Bar
        navigationController?.setNavigationBarHidden(false, animated: true)
    }
}

Navigation Bar doesn't come back once it hides (swipe)

2 Answers2

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