Table view under navigation bar after tab change - ios

Question

I have an app with two tabs, each one containing a table view. The whole is wrapped in a UINavigationController. Here is my storyboard:
When I run my app, the first tab is OK:
But on the second one, the table view starts under the navigation bar:
Even worse, when I rotate the screen from the second tab, the second tab is now OK, but the first isn't any more, the table view has an extra margin top:
If I rotate back to portrait from the first tab, I return to the initial state (first tab OK, second tab with table view starting under the navigation bar). In fact, each time I rotate the screen, the displayed tab is OK after the rotation, but the other one isn't.
It seems that I need to do something when my views are shown after a tab change, and that thing seems to be done when the screen rotates, but what is it??
EDIT: I forgot to mention that I don't want to uncheck the "Extend Edges: Under Top/Bottom Bars" checkboxes, because I want my table views to scroll under the nav and tab bars.

Answer 1

OK, I got it: first uncheck "Adjust Scroll View Insets" on the UITabBarController, and then add this code on each UITableViewController:
override func viewWillAppear(animated: Bool) {
// Call super:
super.viewWillAppear(animated);
// Update the table view insets:
updateTableViewInsets();
}
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
// Animate:
coordinator.animateAlongsideTransition({ (UIViewControllerTransitionCoordinatorContext) -> Void in
// Update the table view insets:
self.updateTableViewInsets();
}, completion: { (UIViewControllerTransitionCoordinatorContext) -> Void in })
// Call super:
super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
}
private func updateTableViewInsets() {
// Get the bars height:
let navigationBarHeight = self.navigationController!.navigationBar.frame.size.height;
let statusBarHeight = UIApplication.sharedApplication().statusBarFrame.size.height;
let tabBarHeight = self.tabBarController!.tabBar.frame.size.height;
// Create the insets:
let insets: UIEdgeInsets = UIEdgeInsetsMake(navigationBarHeight + statusBarHeight, 0, tabBarHeight, 0);
// Update the insets:
self.tableView.scrollIndicatorInsets = insets;
self.tableView.contentInset = insets;
}
Now I'm handling the insets myself, and everything is smooth. That should work out of the box IMHO, though...
EDIT: It works out of the box with iOS 9, Apple have probably fixed the bug. The code above works with iOS 8 & 9 (and maybe lower, I didn't try).