38.7 Summary
The term Navigation within the context of an Android app user interface refers to the ability of a user to move back and forth between different screens. Once time consuming to implement and difficult to organize, Android Studio and the Navigation Architecture Component now make it easier to implement and manage navigation within Android app projects.
The different screens within an app are referred to as destinations and are usually represented by fragments or activities. All apps have a home destination which includes the screen displayed when the app first loads. The content area of this layout is replaced by a navigation host fragment which is swapped out for other destination fragments as the user navigates the app. The navigation path is defined by the navigation graph file consisting of destinations and the actions that connect them together with any arguments to be passed between destinations. Navigation is handled by navigation controllers which, in addition...