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@Frank1234
Last active August 28, 2022 15:58
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/**
* Navigates only if this is safely possible; when this Fragment is still the current destination.
*/
fun Fragment.navigateSafe(
@IdRes resId: Int,
args: Bundle? = null,
navOptions: NavOptions? = null,
navigatorExtras: Navigator.Extras? = null
) {
if (mayNavigate()) findNavController().navigate(
resId, args,
navOptions, navigatorExtras
)
}
/**
* Navigates only if this is safely possible; when this Fragment is still the current destination.
*/
fun Fragment.navigateSafe(
deepLink: Uri,
navOptions: NavOptions? = null,
navigatorExtras: Navigator.Extras? = null
) {
if (mayNavigate()) findNavController().navigate(deepLink, navOptions, navigatorExtras)
}
/**
* Navigates only if this is safely possible; when this Fragment is still the current destination.
*/
fun Fragment.navigateSafe(directions: NavDirections, navOptions: NavOptions? = null) {
if (mayNavigate()) findNavController().navigate(directions, navOptions)
}
/**
* Navigates only if this is safely possible; when this Fragment is still the current destination.
*/
fun Fragment.navigateSafe(
directions: NavDirections,
navigatorExtras: Navigator.Extras
) {
if (mayNavigate()) findNavController().navigate(directions, navigatorExtras)
}
/**
* Returns true if the navigation controller is still pointing at 'this' fragment, or false if it already navigated away.
*/
fun Fragment.mayNavigate(): Boolean {
val navController = findNavController()
val destinationIdInNavController = navController.currentDestination?.id
// add tag_navigation_destination_id to your ids.xml so that it's unique:
val destinationIdOfThisFragment = view?.getTag(R.id.tag_navigation_destination_id) ?: destinationIdInNavController
// check that the navigation graph is still in 'this' fragment, if not then the app already navigated:
if (destinationIdInNavController == destinationIdOfThisFragment) {
view?.setTag(R.id.tag_navigation_destination_id, destinationIdOfThisFragment)
return true
} else {
Log.d("FragmentExtensions", "May not navigate: current destination is not the current fragment.")
return false
}
}
@bitvale
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bitvale commented Jul 28, 2021

This solution not working in this case: open a dialog fragment (for example BottomSheetFragment) from some HomeFragment and call navigateSafe(BottomSheetFragmentDirections.openSomeScreen()) from it. In this case navHostFragment?.childFragmentManager?.fragments?.get(0) returns HomeFragment and destinationIdInNavController is a HomeFragment id and destinationIdOfThisFragment is a dialog fragment id, destinationIdInNavController != destinationIdOfThisFragment and this action not working.

@Frank1234
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Author

That can be true, I have never needed this use case.

What would you expect, the screen in the background to navigate and the dialog/bottom sheet to stay in place? Is that what happens when you call the regular "navigate" function?

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