Change interactivePopGestureRecognizer direction - ios

Question

My app supports both English and Arabic. interactivePopGestureRecognizer works properly when using English, ie on swiping from left to right, it pops viewController. But when i am using arabic, I have changed the semanticContentAttribute from right to left.
if([[[NSUserDefaults standardUserDefaults] objectForKey:#"LanguageCode"] isEqualToString:#"en"])
{
[[UIView appearance] setSemanticContentAttribute:UISemanticContentAttributeForceLeftToRight]; //View for English language
}
else
{
[[UIView appearance] setSemanticContentAttribute:UISemanticContentAttributeForceRightToLeft]; //mirror view for Arabic language
}
But the interactivePopGestureRecogniser is still from left to right. How can I change the direction of interactivePopGestureRecogniser such that it supports Arabic? I want to swipe from right to left to pop view controller on using Arabic language.

Answer 1

I found the solution for it after searching long time, if someone seeks.
The previous answer may cause the UI to hang / freeze.
The reason that the UI freezes / hangs is because the UINavigationController is missing a check for the root view controller when the gesture is executed on the root view. There a few ways to fix that, the following is what I did.
You should subclass UINavigationController, this is the right way to go and add implement as followed:
class RTLNavController: UINavigationController, UINavigationControllerDelegate, UIGestureRecognizerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Adding swipe to pop viewController
self.interactivePopGestureRecognizer?.isEnabled = true
self.interactivePopGestureRecognizer?.delegate = self
// UINavigationControllerDelegate
self.delegate = self
}
func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
navigationController.view.semanticContentAttribute = UIView.isRightToLeft() ? .forceRightToLeft : .forceLeftToRight
navigationController.navigationBar.semanticContentAttribute = UIView.isRightToLeft() ? .forceRightToLeft : .forceLeftToRight
}
// Checking if the viewController is last, if not disable the gesture
func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if self.viewControllers.count > 1 {
return true
}
return false
}
}
extension UIView {
static func isRightToLeft() -> Bool {
return UIView.appearance().semanticContentAttribute == .forceRightToLeft
}
}
Resources:
Original question:
Slide gesture with custom back button freezes the root view controller
The answer is used for the solution:
https://stackoverflow.com/a/27683249/1138498
Other solution which may work better (But it's in Objective-C):
https://stackoverflow.com/a/28364126/1138498

Answer 2

After a lot of trials, the only solution worked for me was this:
Swift 3:
extension UIViewController {
open override func awakeFromNib() {
super.awakeFromNib()
navigationController?.view.semanticContentAttribute = .forceRightToLeft
navigationController?.navigationBar.semanticContentAttribute = .forceRightToLeft
}
}
You can exclude the semantic attribute for certain types like:
UIView.appearance(whenContainedInInstancesOf: [UITableViewCell.self]).semanticContentAttribute = .forceLeftToRight