The document discusses Android Jetpack Navigation and best practices for applying it. It introduces key concepts like destinations, actions, the NavController, safe args plugin, and deep linking. It emphasizes principles like using the back button and up button properly, defining a navigation graph with fragments/activities as destinations and connections as actions, navigating via the NavController, and passing arguments safely between destinations with the safe args plugin. The document concludes that following these practices helps developers build apps that apply navigation best practices.

2. Who I am - @mbonifazi
● Android developer since Eclair
● GDE...what else? A high carb
addicted
● I hate MS Office & Jira notifications
My best quote: Day by day is the best way

3. https://androiddevs.it/

4. Headlines
➔ How we were & are
● How we wanna be
● How we apply best practices

6. Google+: https://plus.google.com/+DianneHackborn/posts/FXCCYxepsDU

7. Activity
added in API level 1

8. val intent = Intent(this, DisplayMessageActivity::class.java).apply {
putExtra(EXTRA_MESSAGE, message)
}
startActivity(intent)

9. <activity
android:name="com.example.android.GizmosActivity"
android:label="@string/title_gizmos" >
<intent-filter android:label="@string/filter_view_http_gizmos">
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="https"
android:host="www.example.com"
android:pathPrefix="/gizmos" />
</intent-filter>

10. Fragment
added in API level 11
Deprecated since API level 28

11. companion object {
@JvmStatic
fun newInstance(param1: String, param2: String) =
BlankFragment().apply {
arguments = Bundle().apply {
putString(ARG_PARAM1, param1)
putString(ARG_PARAM2, param2)
}
}
}

12. val detailsFragment = DetailsFragment.newInstance(comic)
supportFragmentManager.beginTransaction()
.replace(R.id.root_layout, detailsFragment, "rageComicDetails")
.addToBackStack(null)
.commit()

13. Headlines
● How we were & are
➔ How we wanna be
● How we apply Best practices

14. Android Jetpack

17. Principles of Navigation

20. Back button Up button

22. def nav_version = "1.0.0-alpha05"
implementation "android.arch.navigation:navigation-fragment-ktx:$nav_version"
implementation "android.arch.navigation:navigation-ui-ktx:$nav_version"

26. <navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
app:startDestination="@+id/home_dest">
<!-- ...tags for fragments and activities here -->
</navigation>

27. Destinations

28. <fragment
android:id="@+id/flow_step_one_dest"
android:name=".navigation.FlowStepFragment"
tools:layout="@layout/flow_step_one_fragment">
</fragment>

30. <LinearLayout>
<androidx.appcompat.widget.Toolbar/>
<fragment
………...
android:id="@+id/my_nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
app:navGraph="@navigation/mobile_navigation"
app:defaultNavHost="true"
/>
<com.google.android.material.bottomnavigation.BottomNavigationView/>
</LinearLayout>

31. Action

33. <fragment
android:id="@+id/flow_step_one_dest"
android:name=".navigation.FlowStepFragment">
<action
android:id="@+id/next_action"
app:destination="@+id/flow_step_two_dest">
</action>
</fragment>

34. NavController

35. findNavController().navigate(R.id.flow_step_one_dest)

36. findNavController().navigate(R.id.nextAction)

37. val options = navOptions {
anim {
enter = R.anim.slide_in_right
exit = R.anim.slide_out_left
popEnter = R.anim.slide_in_left
popExit = R.anim.slide_out_right
}
}
view.findViewById<Button>(R.id.navigate_destination_button)?.setOnClickListener {
findNavController().navigate(R.id.flow_step_one_dest, null, options)
}

38. apply plugin: 'androidx.navigation.safeargs'

39. <fragment
android:id="@+id/flow_step_one_dest"
android:name="com.example.android.codelabs.navigation.FlowStepFragment"
tools:layout="@layout/flow_step_one_fragment">
<argument
android:name="flowStepNumber"
app:argType="integer"
android:defaultValue="1"/>
...
</fragment>

40. val flowStepNumber = arguments?.getInt("flowStepNumber")

41. val safeArgs = FlowStepFragmentArgs.fromBundle(arguments)
val flowStepNumber = safeArgs.flowStepNumber

42. Deep linking

43. <fragment
android:id="@+id/flow_step_one_dest"
android:name="com.example.android.codelabs.navigation.FlowStepFragment"
tools:layout="@layout/flow_step_one_fragment">
…..
<deepLink app:uri="www.example.com/{myarg}" />
</fragment>

44. <activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<nav-graph android:value="@navigation/mobile_navigation" />
</activity>

45. Headlines
● How we were & are
● How we wanna be
➔ How we apply best practices

47. References
● https://github.com/googlesamples/android-sunflower
● https://www.youtube.com/watch?v=2k8x8V77CrU
● https://www.youtube.com/watch?v=7p22cSzniBM
● https://developer.android.com/topic/libraries/architecture/navigation/
● https://bit.ly/2PNQbb7
Codelab: https://codelabs.developers.google.com/codelabs/android-navigation
matteobonifazi@gmail.com - @mbonifazi