Jetpack Navigation Component

In this deck, I have gone through the jetpack navigation component, what it is how it works, what are its different parts and how they work in harmony to make it easy to navigate in android.

Transcript

1. Navigating in Android Kashif Mehmood Software Engineer at Markaz (YC-W22)
2. About Me • Kashif Mehmood • Software Engineer • Technical Writer • Speaker • Opensource Contributor • Markaz (YC-W22)
3. Fragments • Fragment represents a reusable portion of the app’s user interface. • Each has its own layout & lifecycle. • Cannot live on their own and must be hosted in another activity or fragment.
4. Fragments • Movement between fragments with navigation component • Single Activity architecture is preferred
5. Fragment Lifecycle
6. The Back stack Activity A Activity B Activity C
7. Fragment Back stack Fragment A Fragment B Fragment C Activity A
8. Creating a Fragment
9. PRINCIPLES OF NAVIGATION Apps should always have a fix starting point.
10. PRINCIPLES OF NAVIGATION Navigation state should be represented in LIFO manner.
11. PRINCIPLES OF NAVIGATION Up Button never exits your app.
12. PRINCIPLES OF NAVIGATION Up and back are equivalent within your app.
13. NAVIGATION COMPONENT • Collection of tools and Libraries that simplify navigation • Automatically handles back stack • Type safe argument passing • Simplified deep linking • Centralizes and Visualizes Navigation
14. PARTS OF NAVIGATION COMPONENT • Navigation graph • Nav Host Fragment • Nav Controller • Safe Arguments
15. NAVIGATION GRAPH • Visualizes Navigation • Centralizes Navigation • Handles Actions and Destinations • Handles Fragments and Activities
16. Works with XML and Visual Builder
17. NAV HOST FRAGMENT • Container for the Fragments • Area or host within the layout for self-contained navigation to occur • A window that swaps navigation destinations on screen
18. Destinations • Individual screens are known as Destinations, Activities/Fragments • Start destination is the first screen in the flow/graph.
19. NAV CONTROLLER • NavController manages navigation within a navhost. • Call navigate() and it will handle the rest. • Use findNavController() to get the nav controller
20. PASSING DATA BETWEEN FRAGMENTS Safe Args: • Gradle plugin that gives a much neater way to pass data. • Declare the arguments that we need to pass in nav graph. • Generates all the code you need. • Provides type safety and nullability. • Send arguments with Parcelable
21. VIEW MODEL • Does not get destroyed on configuration changes. • Has its own lifecycle. • Can be used to share data between fragments. • ViewModel and ActivityViewModel.
22. Thank You