Breaking Down the AndroidX Navigation Framework

Is the new Navigation Architecture Component worth investing your precisous time in? In this talk we’ll attempt to answer that by exploring its feature set and live coding examples.

In this talk we’ll cover the new Navigation Architecture Component that was announced at Google I/O 2018. We’ll explain why this is a very important change to how we should consider building Android applications going forward and go through the features of the component via live coding examples.

Transcript

1. Breaking Down the AndroidX Navigation Framework Jerrell Mardis @jerrellmardis Making Fragments Great Again Finally
2. Another Navigation Framework?
3. Pain Points…
4. {com.jerrellmardis.fragmentsareterrible/com.jerrellmardis.fragmentsareterrible.MainActivity}: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState at android.app.ActivityThread.callActivityOnStop(ActivityThread.java:4151) at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:4121) at android.app.ActivityThread.handleStopActivity(ActivityThread.java:4196) at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:192) at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:165) at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:142) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:6669) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858) Caused by: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState at androidx.fragment.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:2080) at androidx.fragment.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:2106) at androidx.fragment.app.BackStackRecord.commitInternal(BackStackRecord.java:683) at androidx.fragment.app.BackStackRecord.commit(BackStackRecord.java:637) at com.jerrellmardis.fragmentsareterrible.MainActivity.onStop(MainActivity.kt:25) at android.app.Instrumentation.callActivityOnStop(Instrumentation.java:1432) at android.app.Activity.performStop(Activity.java:7367) at android.app.ActivityThread.callActivityOnStop(ActivityThread.java:4143) at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:4121) at android.app.ActivityThread.handleStopActivity(ActivityThread.java:4196) at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:192) at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:165) at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:142) at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:6669) at java.lang.reflect.Method.invoke(Native Method)
5. view.findViewById<View>(R.id.go_button).setOnClickListener {s fragmentManager?.beginTransaction()?.apply {s val myFrag = ErrorProneFragment() add(R.id.fragment_container, myFrag, ErrorProneFragment::class.java.simpleName) setCustomAnimations(R.anim.blink, R.anim.blink) commit() }s }s
6. view.findViewById<View>(R.id.go_button).setOnClickListener {s fragmentManager?.beginTransaction()?.apply {s val myFrag = ErrorProneFragment() add(R.id.fragment_container, myFrag, ErrorProneFragment::class.java.simpleName) setCustomAnimations(R.anim.blink, R.anim.blink) commit() }s }s
7. view.findViewById<View>(R.id.go_button).setOnClickListener {s fragmentManager?.beginTransaction()?.apply {s val myFrag = ErrorProneFragment() add(R.id.fragment_container, myFrag, ErrorProneFragment::class.java.simpleName) setCustomAnimations(R.anim.blink, R.anim.blink) commit() }s }s
8. view.findViewById<View>(R.id.go_button).setOnClickListener {s fragmentManager?.beginTransaction()?.apply {s val myFrag = ErrorProneFragment() setCustomAnimations(R.anim.blink, R.anim.blink) add(R.id.fragment_container, myFrag, ErrorProneFragment::class.java.simpleName) commit() }s }s
9. view.findViewById<View>(R.id.go_button).setOnClickListener {s fragmentManager?.beginTransaction()?.apply {s val myFrag = ErrorProneFragment() setCustomAnimations(R.anim.blink, R.anim.blink) add(R.id.fragment_container, myFrag, ErrorProneFragment::class.java.simpleName) commit() }s }s
10. …More Pain Points Fragment Transactions are error prone Animating Fragments are difficult Managing the back-stack seems like a failure of the framework Managing Deep Links is not scalable Passing Arguments is not type-safe
11. More Pain Points… Fragment Transactions are error prone Animating Fragments are difficult Managing the back-stack seems like a failure of the framework Managing Deep Links is not scalable Passing Arguments is not type-safe
12. The Navigation Component Saves The Day
13. Navigation Provides Declarative approach Manages back-stack and up/back button behavior Reduces boilerplate code Simplifies creating Fragment animations Removes the need to write Fragment transactions Creates a type-safe way to pass Fragment arguments
14. Navigation Provides Declarative approach Manages back-stack and up/back button behavior Reduces boilerplate code Simplifies creating Fragment animations Removes the need to write Fragment transactions Creates a type-safe way to pass Fragment arguments
15. Navigation Provides Declarative approach Manages back-stack and up/back button behavior Reduces boilerplate code Simplifies creating Fragment animations Removes the need to write Fragment transactions Creates a type-safe way to pass Fragment arguments
16. Navigation Provides Declarative approach Manages back-stack and up/back button behavior Reduces boilerplate code Simplifies creating Fragment animations Removes the need to write Fragment transactions Creates a type-safe way to pass Fragment arguments
17. Navigation Provides Declarative approach Manages back-stack and up/back button behavior Reduces boilerplate code Simplifies creating Fragment animations Removes the need to write Fragment transactions Creates a type-safe way to pass Fragment arguments
18. Navigation Provides Declarative approach Manages back-stack and up/back button behavior Reduces boilerplate code Simplifies creating Fragment animations Removes the need to write Fragment transactions Creates a type-safe way to pass Fragment arguments
19. Navigation Provides Declarative approach Manages back-stack and up/back button behavior Reduces boilerplate code Simplifies creating Fragment animations Removes the need to write Fragment transactions Creates a type-safe way to pass Fragment arguments
20. Navigation Components Graph and Nested Graphs NavHost Destinations Actions
21. Navigation Components Graph and Nested Graphs NavHost Destinations Actions
22. Navigation Components Graph and Nested Graphs An XML file which describes the navigational structure
23. Navigation Components Graph and Nested Graphs NavHost Destinations Actions
24. Navigation Components NavHost NavHost is a container view which swaps Fragments in and out
25. Navigation Components Graph and Nested Graphs NavHost Destinations Actions
26. Navigation Components Destinations A Fragment, Activity or Nested Navigation Graph
27. Navigation Components Graph and Nested Graphs NavHost Destinations Actions
28. Navigation Components Actions Connects one destination to another Defines enter/exit behavior for destinations
29. Let’s Code
30. So Is It Useful?
31. Breaking Down the AndroidX Navigation Framework Jerrell Mardis @jerrellmardis Making Fragments Great Again Finally speakerdeck.com/jerrellmardis