Converted dogs module from Epoxy to data binding (#272)

I wanted to give data binding a shot for my Droidcon NYC talk for a few reasons: I was curious. As I talk to people, a lot of people think that using MvRx requires Epoxy. It doesn't, it just happens to work really well with it. I think it adds to much overhead for the talk and scares/overwhelms people. It turns out that it's really awesome and is also super compatible with MvRx. P.S. I still ❤Epoxy
airbnb · Aug 30, 2019 · c0d9db3 · c0d9db3
1 parent e24b385
commit c0d9db3
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Showing 40 changed files with 505 additions and 468 deletions.
diff --git a/counter/build.gradle b/counter/build.gradle
@@ -21,8 +21,6 @@ dependencies {
     implementation 'androidx.core:core-ktx:1.0.2'
     implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
-    implementation "androidx.navigation:navigation-fragment-ktx:$navVersion"
-    implementation "androidx.navigation:navigation-ui-ktx:$navVersion"
 
     testImplementation 'junit:junit:4.12'
     testImplementation project(':testing')

diff --git a/counter/src/main/java/com/airbnb/mvrx/counter/CounterFragment.kt b/counter/src/main/java/com/airbnb/mvrx/counter/CounterFragment.kt
@@ -4,15 +4,12 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.navigation.fragment.findNavController
-import androidx.transition.Fade
 import com.airbnb.mvrx.BaseMvRxFragment
 import com.airbnb.mvrx.MvRxState
 import com.airbnb.mvrx.PersistState
 import com.airbnb.mvrx.activityViewModel
 import com.airbnb.mvrx.withState
 import kotlinx.android.synthetic.main.fragment_counter.counterText
-import kotlinx.android.synthetic.main.fragment_counter.nextButton
 
 data class CounterState(@PersistState val count: Int = 0) : MvRxState
 
@@ -25,20 +22,11 @@ class CounterFragment : BaseMvRxFragment() {
 
     private val viewModel: CounterViewModel by activityViewModel()
 
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        enterTransition = Fade()
-    }
-
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
         return inflater.inflate(R.layout.fragment_counter, container, false)
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        nextButton.setOnClickListener {
-            findNavController().navigate(R.id.counterFragment)
-        }
-
         counterText.setOnClickListener {
             viewModel.incrementCount()
         }

diff --git a/counter/src/main/res/layout/activity_counter.xml b/counter/src/main/res/layout/activity_counter.xml
@@ -1,21 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout 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"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:orientation="vertical"
     tools:context=".CounterActivity">
 
     <fragment
         android:id="@+id/nav_host_fragment"
-        android:name="androidx.navigation.fragment.NavHostFragment"
-        android:layout_width="0dp"
+        android:name="com.airbnb.mvrx.counter.CounterFragment"
+        android:layout_width="match_parent"
         android:layout_height="0dp"
-        app:defaultNavHost="true"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintLeft_toLeftOf="parent"
-        app:layout_constraintRight_toRightOf="parent"
-        app:layout_constraintTop_toTopOf="parent"
-        app:navGraph="@navigation/nav_graph" />
+        android:layout_weight="1" />
 
-</androidx.constraintlayout.widget.ConstraintLayout>
+</LinearLayout>
diff --git a/counter/src/main/res/layout/fragment_counter.xml b/counter/src/main/res/layout/fragment_counter.xml
@@ -12,12 +12,4 @@
         android:textSize="48dp"
         tools:text="12" />
 
-    <Button
-        android:id="@+id/nextButton"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_gravity="bottom|center_horizontal"
-        android:layout_marginBottom="16dp"
-        android:text="Next Counter" />
-
 </FrameLayout>
diff --git a/counter/src/main/res/navigation/nav_graph.xml b/counter/src/main/res/navigation/nav_graph.xml
diff --git a/dogs/build.gradle b/dogs/build.gradle
@@ -13,6 +13,10 @@ android {
         versionCode 1
         versionName "1.0"
     }
+
+    dataBinding {
+        enabled = true
+    }
 }
 
 dependencies {
@@ -25,7 +29,6 @@ dependencies {
     implementation "androidx.navigation:navigation-fragment-ktx:$navVersion"
     implementation "androidx.navigation:navigation-ui-ktx:$navVersion"
     implementation("com.airbnb.android:epoxy:$epoxyVersion") { exclude group: 'com.android.support' }
-    kapt "com.airbnb.android:epoxy-processor:$epoxyVersion"
     implementation "com.squareup.moshi:moshi-kotlin:$moshiVersion"
     kapt "com.squareup.moshi:moshi-kotlin-codegen:$moshiVersion"
     implementation 'com.squareup.picasso:picasso:2.5.2'

diff --git a/dogs/src/main/AndroidManifest.xml b/dogs/src/main/AndroidManifest.xml
@@ -6,13 +6,13 @@
 
     <application
         android:allowBackup="true"
-        android:name=".app.DogApplication"
+        android:name=".DogApplication"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-        <activity android:name=".app.DogsActivity">
+        <activity android:name=".DogsActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

diff --git a/dogs/src/main/java/com/airbnb/mvrx/dogs/AdoptionFragment.kt b/dogs/src/main/java/com/airbnb/mvrx/dogs/AdoptionFragment.kt
@@ -6,31 +6,19 @@ import android.view.View
 import android.view.ViewGroup
 import com.airbnb.mvrx.BaseMvRxFragment
 import com.airbnb.mvrx.activityViewModel
-import com.airbnb.mvrx.dogs.app.withModels
-import com.airbnb.mvrx.dogs.views.dogRow
-import com.airbnb.mvrx.dogs.views.titleRow
+import com.airbnb.mvrx.dogs.databinding.AdoptionFragmentBinding
 import com.airbnb.mvrx.withState
-import kotlinx.android.synthetic.main.fragment_adoption.dogsRecyclerView
 
 class AdoptionFragment : BaseMvRxFragment() {
     private val viewModel: DogViewModel by activityViewModel()
+    private lateinit var binding: AdoptionFragmentBinding
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
-        return inflater.inflate(R.layout.fragment_adoption, container, false)
+        binding = AdoptionFragmentBinding.inflate(inflater, container, false)
+        return binding.root
     }
 
     override fun invalidate() = withState(viewModel) { state ->
-        dogsRecyclerView.withModels {
-            titleRow {
-                id("title")
-                title(R.string.meet_your_dog)
-            }
-            state.adoptionRequest()?.let { dog ->
-                dogRow {
-                    id(dog.id)
-                    dog(dog)
-                }
-            }
-        }
+        binding.dog = state.adoptionRequest()
     }
 }
diff --git a/dogs/src/main/java/com/airbnb/mvrx/dogs/DogAdapter.kt b/dogs/src/main/java/com/airbnb/mvrx/dogs/DogAdapter.kt
@@ -0,0 +1,25 @@
+package com.airbnb.mvrx.dogs
+
+import android.view.ViewGroup
+import androidx.recyclerview.widget.ListAdapter
+import com.airbnb.mvrx.dogs.data.Dog
+import com.airbnb.mvrx.dogs.databinding.DogRowBinding
+import com.airbnb.mvrx.dogs.utils.LayoutViewHolder
+import com.airbnb.mvrx.dogs.views.DogsFragmentHandler
+import com.airbnb.mvrx.dogs.views.HashItemCallback
+
+class DogViewHolder(parent: ViewGroup) : LayoutViewHolder(parent, R.layout.dog_row) {
+    val binding = DogRowBinding.bind(itemView)
+}
+
+class DogAdapter(private val fragment: DogsFragmentHandler) : ListAdapter<Dog, DogViewHolder>(HashItemCallback()) {
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): DogViewHolder {
+        return DogViewHolder(parent).apply {
+            binding.handler = fragment
+        }
+    }
+
+    override fun onBindViewHolder(holder: DogViewHolder, position: Int) {
+        holder.binding.dog = getItem(position)
+    }
+}
diff --git a/...om/airbnb/mvrx/dogs/app/DogApplication.kt → ...va/com/airbnb/mvrx/dogs/DogApplication.kt b/...om/airbnb/mvrx/dogs/app/DogApplication.kt → ...va/com/airbnb/mvrx/dogs/DogApplication.kt
@@ -1,4 +1,4 @@
-package com.airbnb.mvrx.dogs.app
+package com.airbnb.mvrx.dogs
 
 import android.app.Application
 import com.airbnb.mvrx.dogs.data.DogRepository

diff --git a/dogs/src/main/java/com/airbnb/mvrx/dogs/DogDetailFragment.kt b/dogs/src/main/java/com/airbnb/mvrx/dogs/DogDetailFragment.kt
@@ -9,45 +9,35 @@ import com.airbnb.mvrx.BaseMvRxFragment
 import com.airbnb.mvrx.MvRx
 import com.airbnb.mvrx.activityViewModel
 import com.airbnb.mvrx.args
+import com.airbnb.mvrx.dogs.databinding.DogDetailFragmentBinding
+import com.airbnb.mvrx.dogs.views.DogDetailFragmentHandler
 import com.airbnb.mvrx.withState
-import com.squareup.picasso.Picasso
-import kotlinx.android.synthetic.main.fragment_dog_detail.breedsView
-import kotlinx.android.synthetic.main.fragment_dog_detail.descriptionView
-import kotlinx.android.synthetic.main.fragment_dog_detail.image
-import kotlinx.android.synthetic.main.fragment_dog_detail.loveButton
-import kotlinx.android.synthetic.main.fragment_dog_detail.nameView
 
-class DogDetailFragment : BaseMvRxFragment() {
+class DogDetailFragment : BaseMvRxFragment(), DogDetailFragmentHandler {
 
     private val viewModel: DogViewModel by activityViewModel()
     private val dogId: Long by args()
 
+    private lateinit var binding: DogDetailFragmentBinding
+
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
-        return inflater.inflate(R.layout.fragment_dog_detail, container, false)
+        binding = DogDetailFragmentBinding.inflate(inflater, container, false)
+        binding.handler = this
+        return binding.root
     }
 
-    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        loveButton.setOnClickListener {
-            viewModel.loveDog(dogId)
-            findNavController().popBackStack()
-        }
+    override fun onLoveClicked() {
+        viewModel.loveDog(dogId)
+        findNavController().popBackStack()
     }
 
     override fun invalidate() = withState(viewModel) { state ->
-        val dog = state.dog(dogId) ?: throw IllegalStateException("Cannot find dog with id $dogId")
-        Picasso.with(requireContext())
-            .load(dog.imageUrl)
-            .into(image)
-        nameView.text = dog.name
-        breedsView.text = dog.breeds
-        descriptionView.text = dog.description
+        binding.dog = state.dog(dogId) ?: error("Cannot find dog with id $dogId")
     }
 
     companion object {
-        fun arg(dogId: Long): Bundle {
-            val args = Bundle()
-            args.putLong(MvRx.KEY_ARG, dogId)
-            return args
+        fun arg(dogId: Long) = Bundle().apply {
+            putLong(MvRx.KEY_ARG, dogId)
         }
     }
 }
diff --git a/dogs/src/main/java/com/airbnb/mvrx/dogs/DogViewModel.kt b/dogs/src/main/java/com/airbnb/mvrx/dogs/DogViewModel.kt
@@ -2,20 +2,17 @@ package com.airbnb.mvrx.dogs
 
 import com.airbnb.mvrx.MvRxViewModelFactory
 import com.airbnb.mvrx.ViewModelContext
-import com.airbnb.mvrx.dogs.app.DogApplication
-import com.airbnb.mvrx.dogs.app.MvRxViewModel
 import com.airbnb.mvrx.dogs.data.DogRepository
+import com.airbnb.mvrx.dogs.utils.MvRxViewModel
 import io.reactivex.schedulers.Schedulers
 
 class DogViewModel(
-    state: DogState,
+    initialState: DogState,
     private val dogRepository: DogRepository
-) : MvRxViewModel<DogState>(state) {
+) : MvRxViewModel<DogState>(initialState) {
 
     init {
-        dogRepository.getDogs()
-            .subscribeOn(Schedulers.io())
-            .execute { copy(dogs = it) }
+        dogRepository.getDogs().execute { copy(dogs = it) }
     }
 
     fun loveDog(dogId: Long) = setState { copy(lovedDogId = dogId) }

diff --git a/.../com/airbnb/mvrx/dogs/app/DogsActivity.kt → ...java/com/airbnb/mvrx/dogs/DogsActivity.kt b/.../com/airbnb/mvrx/dogs/app/DogsActivity.kt → ...java/com/airbnb/mvrx/dogs/DogsActivity.kt
@@ -1,13 +1,12 @@
-package com.airbnb.mvrx.dogs.app
+package com.airbnb.mvrx.dogs
 
 import android.os.Bundle
 import com.airbnb.mvrx.BaseMvRxActivity
-import com.airbnb.mvrx.dogs.R
 
 class DogsActivity : BaseMvRxActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        setContentView(R.layout.activity_dogs)
+        setContentView(R.layout.dogs_activity)
     }
 }
diff --git a/dogs/src/main/java/com/airbnb/mvrx/dogs/DogsFragment.kt b/dogs/src/main/java/com/airbnb/mvrx/dogs/DogsFragment.kt
@@ -4,56 +4,37 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.core.view.isVisible
 import androidx.navigation.fragment.findNavController
 import com.airbnb.mvrx.BaseMvRxFragment
-import com.airbnb.mvrx.Fail
-import com.airbnb.mvrx.Loading
-import com.airbnb.mvrx.Uninitialized
 import com.airbnb.mvrx.activityViewModel
-import com.airbnb.mvrx.dogs.app.withModels
-import com.airbnb.mvrx.dogs.views.dogRow
+import com.airbnb.mvrx.dogs.data.Dog
+import com.airbnb.mvrx.dogs.databinding.DogsFragmentBinding
+import com.airbnb.mvrx.dogs.views.DogsFragmentHandler
 import com.airbnb.mvrx.withState
-import kotlinx.android.synthetic.main.fragment_dogs.adoptButton
-import kotlinx.android.synthetic.main.fragment_dogs.dogsRecyclerView
-import kotlinx.android.synthetic.main.fragment_dogs.loadingAnimation
 
-class DogsFragment : BaseMvRxFragment() {
+class DogsFragment : BaseMvRxFragment(), DogsFragmentHandler {
 
     private val viewModel: DogViewModel by activityViewModel()
+    private lateinit var bindings: DogsFragmentBinding
+    private val adapter = DogAdapter(this)
 
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        viewModel.asyncSubscribe(DogState::adoptionRequest, onSuccess = {
-            findNavController().navigate(R.id.action_dogs_to_adoption)
-        })
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        bindings = DogsFragmentBinding.inflate(inflater, container, false)
+        bindings.dogsRecyclerView.adapter = adapter
+        bindings.handler = this
+        return bindings.root
     }
 
-    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
-        return inflater.inflate(R.layout.fragment_dogs, container, false)
+    override fun onDogClicked(dog: Dog) {
+        findNavController().navigate(R.id.action_dogs_to_dogDetail, DogDetailFragment.arg(dog.id))
     }
 
-    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        adoptButton.setOnClickListener {
-            viewModel.adoptLovedDog()
-        }
+    override fun adoptLovedDog() {
+        viewModel.adoptLovedDog()
+        findNavController().navigate(R.id.action_dogs_to_adoption)
     }
 
     override fun invalidate() = withState(viewModel) { state ->
-        loadingAnimation.isVisible = state.dogs is Loading || state.adoptionRequest is Loading
-
-        adoptButton.isVisible = state.lovedDog != null
-        adoptButton.text = getString(R.string.adopt_dog, state.lovedDog?.name)
-
-        dogsRecyclerView.isVisible = state.adoptionRequest is Uninitialized || state.adoptionRequest is Fail
-        dogsRecyclerView.withModels {
-            state.dogs()?.forEach { dog ->
-                dogRow {
-                    id(dog.id)
-                    dog(dog)
-                    clickListener { _ -> findNavController().navigate(R.id.action_dogs_to_dogDetail, DogDetailFragment.arg(dog.id)) }
-                }
-            }
-        }
+        bindings.state = state
     }
 }