This document summarizes how to use the Conductor library to manage view stacks and transitions in Android apps. It discusses how Conductor handles activities, controllers, transitions, lifecycles, dependency injection, and testing. Key points include using Conductor to push and pop controllers to manage the view stack, creating custom transition animations, surviving configuration changes, integrating with architectures like MVVM, and testing controllers with Espresso. The presenter provides code examples and recommends Conductor for building view-based Android apps.

1. Say bye to Fragments with
Conductor & Kotlin
Miquel Beltran
Android Dev @ nebenan.de
@Miqubel

2. @Miqubel
Slides & Code:

3. @Miqubel

4. @Miqubel

5. Activity

6. Activity
Router
Activity
Router

7. Activity
Router
Controller 1
Controller 2
Controller 3
View

8. class MainActivity : AppCompatActivity() {
private lateinit var router: Router
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
router = Conductor.attachRouter(this,
controller_container,
savedInstanceState)
}
@Miqubel

9. <com.bluelinelabs.conductor.ChangeHandlerFrameLayout
android:id="@+id/controller_container"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
@Miqubel

10. class MainActivity : AppCompatActivity() {
private lateinit var router: Router
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
router = Conductor.attachRouter(this,
controller_container,
savedInstanceState)
if (!router.hasRootController()) {
router.setRoot(RouterTransaction.with(MainController()))
}
}
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11. Controller
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12. class SimpleController : Controller() {
override fun onCreateView(inflater: LayoutInflater,
container: ViewGroup): View {
val view = inflater.inflate(R.layout.controller_simple,
container, false)
// Do something with the view
return view
}
}
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13. @Miqubel

14. router.pushController(
RouterTransaction.with(
OtherSimpleController()
)
)
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15. override fun onBackPressed() {
if (!router.handleBack()) {
super.onBackPressed()
}
}
router.popCurrentController()
or
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16. Transitions
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17. @Miqubel

18. router.pushController(
RouterTransaction.with(DummyController())
.popChangeHandler(HorizontalChangeHandler())
.pushChangeHandler(HorizontalChangeHandler())
)
router.pushController(
RouterTransaction.with(DummyController())
.popChangeHandler(FadeChangeHandler())
.pushChangeHandler(FadeChangeHandler())
)
@Miqubel

19. class CustomChangeHandler : AnimatorChangeHandler() {
override fun getAnimator(
container: ViewGroup,
from: View?,
to: View?,
isPush: Boolean,
toAddedToContainer: Boolean): Animator {
val animator = AnimatorSet()
to?.let {
animator.play(
ObjectAnimator
.ofFloat(to, View.SCALE_X, 0f, 1f)
)
animator.play(
ObjectAnimator
.ofFloat(to, View.SCALE_Y, 0f, 1f)
)
}
return animator
}
}

20. @Miqubel

21. override fun getAnimator(…): Animator {
val animator = AnimatorSet()
to?.let {
animator.play(…)
// The "to" View has a child with id "image"
animator.play(
ObjectAnimator
.ofFloat(to.image, View.ROTATION, -360f, 1f)
)
}
return animator
}
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22. @Miqubel

23. Lifecycle
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24. New Controller
instance
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25. onCreateView
Controller is on top
Pushed to
Router
New Controller
instance
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26. onCreateView
onDestroyView
Controller is on top
Pop from
Router
Config
change.
etc.
New Controller
instance
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27. onCreateView
onDestroyView
Controller is on top
Controller
back on
top
New Controller
instance
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28. onCreateView
onDestroyView
Controller is on top
New Controller
instance
Removed
from Router
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❌

29. Controller
Class
Properties
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30. class MyController(val parameter: String) : Controller() {
override fun onCreateView(…): View {
val view = inflater.inflate(…)
view.textView.text = "My favorite city is $parameter"
return view
}
}
❌
DON’T!
@Miqubel

31. class MyController(bundle: Bundle) : Controller(bundle) {
constructor(parameter: String) : this(Bundle().apply {
putString(EXTRA_PARAMETER, parameter)
})
// Access arguments like class properties
private val parameter by lazy {
args.getString(EXTRA_PARAMETER)
}
//…
view.textView.text = "My favorite city is $parameter"
👍
@Miqubel

32. Accessing
Views
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33. fun changeText(text: String) {
// access to views with KAE
view?.run {
textView.text = text
}
}
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34. class MyController : Controller() {
// Warning! this will leak on onDestroyView
lateinit var textView: TextView
override fun onCreateView(…): View {
val view = inflater.inflate(…)
// Store a reference to the textView for later
textView = view.textView
return view
}
❌
DON’T!
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35. Conductor
&
Arch. Comp.
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36. model = ViewModelProviders
.of(activity as AppCompatActivity)
.get(MyViewModel::class.java)
model.getLiveData()
.observe(
activity as AppCompatActivity,
Observer<String> {
// Use the LiveData values
}
)
❌
DON’T!
@Miqubel

37. abstract class BaseViewModelController
: LifecycleController() {
private val viewModelStore = ViewModelStore()
fun viewModelProvider(factory): ViewModelProvider {
return ViewModelProvider(viewModelStore, factory)
}
}
@Miqubel
Ref: https://github.com/bluelinelabs/Conductor/pull/405

38. class ViewModelController
: BaseViewModelController() {
model = viewModelProvider()
.get(MyViewModel::class.java)
model.getLiveData()
.observe(this, Observer<String> {
//…
})
👍
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39. Dependency
Injection
(Dagger)
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40. class MyDaggerController : Controller() {
@Inject
lateinit var value: String
override fun onCreateView(…): View {
val view = inflater.inflate(…)
(activity!!.application as App).component.inject(this)
return view
}
}
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41. Testing
Controllers
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42. @RunWith(AndroidJUnit4::class)
class TestableControllerEspressoTest {
@get:Rule
val activity = ActivityTestRule<TestActivity>(
TestActivity::class.java
)
}
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43. @RunWith(AndroidJUnit4::class)
class TestableControllerEspressoTest {
@get:Rule
val activity = ActivityTestRule…
val controller = TestableController()
@Before
fun setUp() {
activity.runOnUiThread {
activity.activity.router.setRoot(
RouterTransaction.with(controller)
)
}
}
}
@Miqubel

44. @RunWith(AndroidJUnit4::class)
class TestableControllerEspressoTest {
//…
@Test
fun a_click_action() {
// Call to Controller methods directly
activity.runOnUiThread {
controller.onClickDoAction()
}
// Check views
onView(withId(R.id.textView))
.check(matches(withText(“Test is running")))
}
}
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45. Recap
@Miqubel
View based apps on Android

46. Recap
@Miqubel
View based apps on Android
Manage your view stack

47. Recap
@Miqubel
View based apps on Android
Manage your view stack
Nice transition animations

48. Recap
@Miqubel
View based apps on Android
Manage your view stack
Nice transition animations
Surviving configuration changes

49. Recap
@Miqubel
View based apps on Android
Manage your view stack
Nice transition animations
Surviving configuration changes
Compatible with pres. patterns

50. Recap
@Miqubel
View based apps on Android
Manage your view stack
Nice transition animations
Surviving configuration changes
Compatible with pres. patterns
Easy to test with Espresso

51. Library:
https://github.com/bluelinelabs/Conductor
Talk sample code:
https://github.com/miquelbeltran/conductor-talk-
demo
Ask Me Anything: @Miqubel
ありがとう!
/ˌɑɹiˈɡɑtoʊ/