Introduction

By now you should be aware that Jetpack has a dedicated Jetpack Navigation library. This library allows you to define routes to move between screens in your app, rather than writing this functionality from scratch. In this reading, you will recap how to use navigation components to easily set up the navigation for the Little Lemon food ordering app. Before you begin, you may find it helpful to revisit the following lesson items about the principles of app navigation in the Creating the User Interface in Android course.

• Navigation in Compose

• NavHost and NavController

• Exercise: Create navigation in Compose

Jetpack navigation

The most used navigation for Android apps is based on the stack, which allows the user to navigate through a stack of screens and navigate back using a back button. When navigating to a screen, it is added at the top of the stack and presented to the user. When going back, screens are removed from the top of the stack.

These are some key elements of Jetpack navigation:

• NavController is responsible for navigating between destinations while keeping track and manipulating the back stack.

• NavGraph represents the collection of navigable destinations and navigation routes. It is provided to NavHost for building the navigation graph.

• NavHost serves as a container that takes the NavController as an input parameter and associates it with the NavGraph , which contains the destinations that can be navigated.

• Destination represents a navigation destination. Navigating to a destination is done using a NavController .

• The startDestination is the first screen that the user will encounter. The above components will allow navigation between various navigation destinations called screens and enable back-button navigation.

Conclusion

In this reading, you had the opportunity to revisit key concepts related to navigation as well as the key elements in the Jetpack Navigation library that you will use in your Little Lemon food ordering app.