Navigator

A Navigator is basically a backstack manager. The only public API a Navigator has is setBackstack which takes in the new backstack.

All navigation operations are extension functions that just call setBackstack, check that page for an extensive list of already provided operations, or create your own.

To create a navigator:

val myNavigator = rememberNavigator()

A backstack can be empty, which is why we don't need to provide some initial key, but we can do so by providing initialKey:

@Parcelize
class HomeKey: NavigationKey

val myNavigator = rememberNavigator(initialKey = HomeKey())

Now we can use the Navigator to update our current backstack:

myNavigator.setBackstack(HomeKey().entry(), ProfileKey("MyProfileId").entry())

You can see we call .entry() inside our setBackstack call. This is because the back stack is not a list of NavigationKey but a list of BackstackEntry which is a unique entry of a given key inside our backstack, it simply provides a unique id for a given key, that way we can differentiate two keys of the same type inside our backstack. That id is later used for lifecycle management and state saving/restoration.

Next, we will learn how to tie a NavigationKey to a NavigationNode inside our Navigator using NavigatorConfig.