We recently decided to try and incorporate Parchment into our app since it would suit our needs perfectly. We also added a collapsing header effect with it. So we first made a test project to test it out and just as we had refactored it into our own app we noticed a very strange bug that we just can't seem to pinpoint the problem with. At first we thought maybe its something in our own app but i opened up the test project and its there as well.
This GIF will show you the issue. Its even worse when we only have one tab/screen. It then even gets hard to scroll down for a refresh properly without triggering this issue.
Anyone have any idea as of why and where this might be happening ?
Sample code for the Parchment implementation:
private var pagingViewController = PagingViewController()
pagingViewController.dataSource = self
pagingViewController.register(PagingCustomCell.self, for: CustomPagingItem.self)
addChild(pagingViewController)
pagingViewController.borderOptions = .hidden
pagingViewController.menuItemSize = .selfSizing(estimatedWidth: 100, height: 40)
pagingViewController.indicatorClass = CustomIndicatorView.self
pagingViewController.indicatorOptions = .visible(
height: 32,
zIndex: -1,
spacing: .zero,
insets: UIEdgeInsets(top: 0, left: 0, bottom: 5, right: 0)
)
pagingViewController.indicatorColor = .purple
pagingViewController.collectionView.contentInset = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: 16)
view.addSubview(pagingViewController.view)
pagingViewController.backgroundColor = .clear
pagingViewController.didMove(toParent: self)
pagingViewController.view.translatesAutoresizingMaskIntoConstraints = false
pagingViewController.view.snp.makeConstraints { (m) in
m.top.equalTo(headerView.snp.bottom)
m.left.right.bottom.equalToSuperview()
}
// Put shadow beneath tabs for collapsing header
pagingViewController.collectionView.layer.masksToBounds = true
pagingViewController.collectionView.layer.shadowOffset = CGSize(width: 0, height: 1)
pagingViewController.collectionView.layer.shadowRadius = 1
pagingViewController.collectionView.layer.shadowOpacity = 0.3
extension ViewController: PagingViewControllerDataSource {
func numberOfViewControllers(in pagingViewController: PagingViewController) -> Int {
return pages.count
}
func pagingViewController(_: PagingViewController, viewControllerAt index: Int) -> UIViewController {
let currentVc = pages[index]
if let currentVc = currentVc {
return currentVc
} else {
let tableViewVC = TableViewController()
tableViewVC.innerTableViewScrollDelegate = self
pages[index] = tableViewVC
return tableViewVC
}
}
func pagingViewController(_: PagingViewController, pagingItemAt index: Int) -> PagingItem {
return CustomPagingItem(index: index, text: "View \(index+1)")
}
}
