Pop to root when double tap on Back button UINavigationBar - ios

Question

I'm testing an app and I discovered that when double tapping the back button, it automatically pops to root view controller of the navigation controller. There is no code anywhere that does this explicitly and I was wondering if this is the default behavior of the back button in a navigation controller.
I've tested the same thing in another app and the issue wasn't there, so the only thing that explains this is that something else is triggering that popToRoot and I can't figure out what.
Sorry, but I cannot post the code here. Just want your opinion on this.
Thanks in advance!

Answer 1

As I commented above at Glenns answer, dispatching the popViewController into the main thread might be a problem because it will be executed also when a double tap is recognized. Maybe this is a slightly more "stable" solution:
private func setupBackButton() {
let myBackButton = UIButton(type: .custom) // or whatever
// setup title, image etc.
let myCustomBackButtonItem = UIBarButtonItem(customView: myBackButton)
self.navigationItem.leftBarButtonItem = myCustomBackButtonItem
// Create gesture recognizers for single and double tap:
let singleRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.singleTap))
singleRecognizer.numberOfTapsRequired = 1
let doubleRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.doubleTap))
doubleRecognizer.numberOfTapsRequired = 2
// single tap should only fire if double tap is not recognized
singleRecognizer.require(toFail: doubleRecognizer)
myBackButton.addGestureRecognizer(singleRecognizer)
myBackButton.addGestureRecognizer(doubleRecognizer)
}
#objc private func singleTap() {
self.navigationController?.popViewController(animated: true)
}
#objc private func doubleTap() {
self.navigationController?.popToRootViewController(animated: true)
}

Answer 2

When I saw this question, I implemented the idea onto my current project, and it worked, thanks for this. So an idea to do this is have a custom back button. I could post the whole code to this but that would make it a spoonfeeding. Anyways, here goes the steps:
Make a UIButton and make it your custom back button UIBarButtonItem in your navigationController's navigationBar if you ever use one.
The selector would be obviously like this, don't mind much the code inside, cause this is taken out of my project, but you get the idea:
func back() {
if let navCon = self.navigationController {
navCon.popViewController(animated: true)
}
}
And for the double tap, you'll need a tapGesture for that. I have this one declared like so:
private lazy var doubleTapGesture: UITapGestureRecognizer = {
let gesture = UITapGestureRecognizer(target: self, action: #selector(self.doubleTap))
gesture.numberOfTapsRequired = 2
return gesture
}()
and add that to your button. Selector would be like this:
#objc private func doubleTap() {
self.navigationController?.popToRootViewController(animated: true)
}
VOILA! Works smoothly. Easy, right? I hope this helps!

Answer 3

Thank you for all your answers but my issue was that I DIDN'T want that behavior, my post was misinterpreted and I'm sorry for that.
Otherwise, I solved myself the problem. There was a subview added to navigation controller's navigation bar which was hidden up, below the bar. And somehow, that subView had interaction enabled even if it was below. So I disabled interaction when hidden. That's all.