Convert from Java Thread to Coroutines

MrBean355 · MrBean355 · commit cfd3a116b46d · 2019-10-13T09:34:25.000+02:00
diff --git a/build.gradle b/build.gradle
@@ -13,6 +13,7 @@ buildscript {
         dagger_version = '2.24'
         enhanced_adapter_version = '1.0.0'
         kotlin_version = '1.3.50'
+        coroutines_version = '1.3.2'
         retrofit_version = '2.6.1'
 
         // SDKs
diff --git a/dagger-2/src/main/java/com/github/mrbean355/android/dagger2/ui/ViewHeroesViewModel.kt b/dagger-2/src/main/java/com/github/mrbean355/android/dagger2/ui/ViewHeroesViewModel.kt
@@ -4,15 +4,18 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import com.github.mrbean355.android.dagger2.data.Hero
 import com.github.mrbean355.android.dagger2.data.HeroRepository
+import kotlinx.coroutines.Dispatchers.IO
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 class ViewHeroesViewModel @Inject constructor(private val repository: HeroRepository) {
 
     fun getHeroes(): LiveData<List<Hero>> {
         val liveData = MutableLiveData<List<Hero>>()
-        Thread {
+        GlobalScope.launch(context = IO) {
             liveData.postValue(repository.getHeroes())
-        }.start()
+        }
         return liveData
     }
 }
diff --git a/framework/build.gradle b/framework/build.gradle
@@ -17,6 +17,8 @@ android {
 
 dependencies {
     api "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    api "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
+    api "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"
     api "androidx.appcompat:appcompat:$appcompat_version"
     api "androidx.core:core-ktx:$core_version"
     api "androidx.recyclerview:recyclerview:$recyclerview_version"
diff --git a/framework/src/main/java/com/github/mrbean355/android/framework/PokemonRepository.kt b/framework/src/main/java/com/github/mrbean355/android/framework/PokemonRepository.kt
@@ -1,9 +1,12 @@
 package com.github.mrbean355.android.framework
 
 import androidx.annotation.MainThread
-import androidx.annotation.WorkerThread
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
+import kotlinx.coroutines.Dispatchers.IO
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 import retrofit2.Retrofit
 import retrofit2.converter.gson.GsonConverterFactory
 
@@ -15,9 +18,8 @@ class PokemonRepository {
             .create(PokemonService::class.java)
 
     /** Make a blocking service call to fetch all Pokemon. */
-    @WorkerThread
-    fun getAll(): List<Pokemon> {
-        Thread.sleep(1000) // emulate a long service call.
+    suspend fun getAll(): List<Pokemon> {
+        delay(1000) // emulate a long service call.
         val response = service.getAll().execute()
         val body = response.body()
         if (response.isSuccessful && body != null) {
@@ -30,9 +32,9 @@ class PokemonRepository {
     @MainThread
     fun getAllAsLiveData(): LiveData<List<Pokemon>> {
         val liveData = MutableLiveData<List<Pokemon>>()
-        Thread {
+        GlobalScope.launch(context = IO) {
             liveData.postValue(getAll())
-        }.start()
+        }
         return liveData
     }
 }
diff --git a/room/src/main/java/com/github/mrbean355/android/room/ViewPokemonActivity.kt b/room/src/main/java/com/github/mrbean355/android/room/ViewPokemonActivity.kt
@@ -9,6 +9,11 @@ import com.github.mrbean355.android.framework.PokemonRepository
 import com.github.mrbean355.android.room.db.PokemonDatabase
 import com.github.mrbean355.android.room.db.PokemonEntity
 import kotlinx.android.synthetic.main.activity_view_pokemon.*
+import kotlinx.coroutines.Dispatchers.IO
+import kotlinx.coroutines.Dispatchers.Main
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 /**
  * NOTE: All this logic should be moved out of the activity!
@@ -27,17 +32,17 @@ class ViewPokemonActivity : AppCompatActivity() {
     }
 
     private fun loadPokemon() {
-        Thread {
+        GlobalScope.launch(context = IO) {
             var items = loadFromDatabase()
             if (items.isEmpty()) {
                 items = loadFromService()
                 saveToDatabase(items)
             }
-            runOnUiThread {
+            withContext(Main) {
                 adapter.setItems(items)
                 progress_bar.visibility = View.GONE
             }
-        }.start()
+        }
     }
 
     private fun loadFromDatabase(): List<Pokemon> {
@@ -52,7 +57,7 @@ class ViewPokemonActivity : AppCompatActivity() {
         dao.insertAll(items.map { PokemonEntity(0, it.name, it.url) })
     }
 
-    private fun loadFromService(): List<Pokemon> {
+    private suspend fun loadFromService(): List<Pokemon> {
         return PokemonRepository().getAll()
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -9,6 +9,11 @@ import com.github.mrbean355.android.framework.PokemonRepository`
`9`	`9`	`import com.github.mrbean355.android.room.db.PokemonDatabase`
`10`	`10`	`import com.github.mrbean355.android.room.db.PokemonEntity`
`11`	`11`	`import kotlinx.android.synthetic.main.activity_view_pokemon.*`
	`12`	`+import kotlinx.coroutines.Dispatchers.IO`
	`13`	`+import kotlinx.coroutines.Dispatchers.Main`
	`14`	`+import kotlinx.coroutines.GlobalScope`
	`15`	`+import kotlinx.coroutines.launch`
	`16`	`+import kotlinx.coroutines.withContext`
`12`	`17`
`13`	`18`	`/**`
`14`	`19`	`* NOTE: All this logic should be moved out of the activity!`
`@@ -27,17 +32,17 @@ class ViewPokemonActivity : AppCompatActivity() {`
`27`	`32`	`}`
`28`	`33`
`29`	`34`	`private fun loadPokemon() {`
`30`		`- Thread {`
	`35`	`+ GlobalScope.launch(context = IO) {`
`31`	`36`	`var items = loadFromDatabase()`
`32`	`37`	`if (items.isEmpty()) {`
`33`	`38`	`items = loadFromService()`
`34`	`39`	`saveToDatabase(items)`
`35`	`40`	`}`
`36`		`- runOnUiThread {`
	`41`	`+ withContext(Main) {`
`37`	`42`	`adapter.setItems(items)`
`38`	`43`	`progress_bar.visibility = View.GONE`
`39`	`44`	`}`
`40`		`- }.start()`
	`45`	`+ }`
`41`	`46`	`}`
`42`	`47`
`43`	`48`	`private fun loadFromDatabase(): List<Pokemon> {`
`@@ -52,7 +57,7 @@ class ViewPokemonActivity : AppCompatActivity() {`
`52`	`57`	`dao.insertAll(items.map { PokemonEntity(0, it.name, it.url) })`
`53`	`58`	`}`
`54`	`59`
`55`		`- private fun loadFromService(): List<Pokemon> {`
	`60`	`+ private suspend fun loadFromService(): List<Pokemon> {`
`56`	`61`	`return PokemonRepository().getAll()`
`57`	`62`	`}`
`58`	`63`	`}`