Merge pull request #22 from msfjarvis/pagination-prep

app/build.gradle

@@ -1,5 +1,4 @@
 plugins {
-    id 'kotlin-android'
     id 'kotlin-kapt'
     id 'dagger.hilt.android.plugin'
 }
@@ -45,17 +44,24 @@ android {
 
 tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).configureEach {
     kotlinOptions {
-        freeCompilerArgs += ["-Xallow-jvm-ir-dependencies", "-Xskip-prerelease-check", "-Xopt-in=kotlin.RequiresOptIn"]
+        freeCompilerArgs += [
+                "-Xallow-jvm-ir-dependencies",
+                "-Xskip-prerelease-check",
+                "-Xopt-in=kotlin.RequiresOptIn",
+                "-Xopt-in=kotlinx.coroutines.ExperimentalCoroutinesApi",
+        ]
     }
 }
 
 dependencies {
 
-    kapt "com.google.dagger:hilt-android-compiler:$hilt_version"
+    kapt "com.google.dagger:hilt-android-compiler:$hilt_dagger_version"
+    kapt "androidx.hilt:hilt-compiler:$hilt_androidx_version"
     implementation(project(":data"))
     implementation(project(":lobsters-api"))
     implementation(project(":model"))
     implementation 'androidx.core:core-ktx:1.5.0-alpha03'
+    implementation 'androidx.activity:activity-ktx:1.2.0-alpha08'
     implementation 'androidx.appcompat:appcompat:1.3.0-alpha02'
     implementation "androidx.compose.foundation:foundation:$compose_version"
     implementation "androidx.compose.foundation:foundation-layout:$compose_version"
@@ -67,10 +73,14 @@ dependencies {
     implementation "androidx.compose.ui:ui-text:$compose_version"
     implementation "androidx.compose.ui:ui-text-android:$compose_version"
     implementation "androidx.compose.ui:ui-unit:$compose_version"
+    implementation "androidx.hilt:hilt-lifecycle-viewmodel:$hilt_androidx_version"
+    implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version"
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
     implementation "androidx.ui:ui-tooling:$compose_version"
     implementation 'com.google.android.material:material:1.3.0-alpha02'
-    implementation "com.google.dagger:hilt-android:$hilt_version"
-    androidTestImplementation "com.google.dagger:hilt-android-testing:$hilt_version"
+    implementation "com.google.dagger:hilt-android:$hilt_dagger_version"
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"
+    androidTestImplementation "com.google.dagger:hilt-android-testing:$hilt_dagger_version"
     testImplementation 'junit:junit:4.13'
     androidTestImplementation "androidx.ui:ui-test:$compose_version"
     coreLibraryDesugaring "com.android.tools:desugar_jdk_libs:1.0.10"

app/src/main/java/dev/msfjarvis/lobsters/MainActivity.kt

@@ -1,25 +1,24 @@
 package dev.msfjarvis.lobsters
 
 import android.os.Bundle
+import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.Text
-import androidx.compose.foundation.lazy.LazyColumnFor
+import androidx.compose.foundation.lazy.LazyColumnForIndexed
 import androidx.compose.material.Scaffold
 import androidx.compose.material.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.Providers
 import androidx.compose.runtime.ambientOf
-import androidx.compose.runtime.mutableStateListOf
-import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.collectAsState
 import androidx.compose.ui.platform.setContent
 import androidx.compose.ui.res.stringResource
 import dagger.hilt.android.AndroidEntryPoint
 import dev.msfjarvis.lobsters.api.LobstersApi
-import dev.msfjarvis.lobsters.model.LobstersPost
+import dev.msfjarvis.lobsters.data.LobstersViewModel
 import dev.msfjarvis.lobsters.ui.LobstersItem
 import dev.msfjarvis.lobsters.ui.LobstersTheme
 import dev.msfjarvis.lobsters.urllauncher.UrlLauncher
-import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 val UrlLauncherAmbient = ambientOf<UrlLauncher> { error("Needs to be provided") }
@@ -28,18 +27,14 @@ val UrlLauncherAmbient = ambientOf<UrlLauncher> { error("Needs to be provided")
 class MainActivity : AppCompatActivity() {
   @Inject lateinit var urlLauncher: UrlLauncher
   @Inject lateinit var apiClient: LobstersApi
+  private val viewModel: LobstersViewModel by viewModels()
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     setContent {
       Providers(UrlLauncherAmbient provides urlLauncher) {
         LobstersTheme {
-          val coroutineScope = rememberCoroutineScope()
-          val posts = mutableStateListOf<LobstersPost>()
-          coroutineScope.launch {
-            posts.addAll(apiClient.getHottestPosts())
-          }
-          LobstersApp(posts)
+          LobstersApp(viewModel)
         }
       }
     }
@@ -48,14 +43,19 @@ class MainActivity : AppCompatActivity() {
 
 @Composable
 fun LobstersApp(
-  items: List<LobstersPost>,
+  viewModel: LobstersViewModel
 ) {
   val urlLauncher = UrlLauncherAmbient.current
+  val state = viewModel.posts.collectAsState()
+  val lastIndex = state.value.lastIndex
 
   Scaffold(
     topBar = { TopAppBar({ Text(text = stringResource(R.string.app_name)) }) },
     bodyContent = {
-      LazyColumnFor(items) { item ->
+      LazyColumnForIndexed(state.value) { index, item ->
+        if (lastIndex == index) {
+          viewModel.getMorePosts()
+        }
         LobstersItem(item) { post ->
           urlLauncher.launch(post.url)
         }

app/src/main/java/dev/msfjarvis/lobsters/data/LobstersViewModel.kt

@@ -0,0 +1,30 @@
+package dev.msfjarvis.lobsters.data
+
+import androidx.hilt.lifecycle.ViewModelInject
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import dev.msfjarvis.lobsters.api.LobstersApi
+import dev.msfjarvis.lobsters.model.LobstersPost
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.launch
+
+
+class LobstersViewModel @ViewModelInject constructor(
+  private val lobstersApi: LobstersApi,
+) : ViewModel() {
+  private var apiPage = 1
+  private val _posts = MutableStateFlow<List<LobstersPost>>(emptyList())
+  val posts: StateFlow<List<LobstersPost>> get() = _posts
+
+  init {
+    getMorePosts()
+  }
+
+  fun getMorePosts() {
+    viewModelScope.launch {
+      _posts.value += lobstersApi.getHottestPosts(apiPage)
+      apiPage += 1
+    }
+  }
+}

app/src/main/java/dev/msfjarvis/lobsters/di/PersistenceModule.kt

@@ -0,0 +1,22 @@
+package dev.msfjarvis.lobsters.di
+
+import android.content.Context
+import androidx.room.Room
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.components.ActivityComponent
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dev.msfjarvis.lobsters.data.source.PostsDatabase
+
+@Module
+@InstallIn(ActivityComponent::class)
+object PersistenceModule {
+
+  @Provides
+  fun providePostsDatabase(@ApplicationContext context: Context): PostsDatabase {
+    return Room.databaseBuilder(context, PostsDatabase::class.java, "posts.db")
+      .fallbackToDestructiveMigration()
+      .build()
+  }
+}

build.gradle

@@ -2,9 +2,13 @@
 buildscript {
     ext {
         compose_version = '1.0.0-alpha03'
+        coroutines_version = '1.3.9'
         dagger_version = '2.29.1'
-        hilt_version = '2.29-alpha'
+        hilt_androidx_version = '1.0.0-alpha02'
+        hilt_dagger_version = '2.29-alpha'
         kotlin_version = '1.4.10'
+        lifecycle_version = '2.3.0-alpha07'
+        moshi_version = '1.9.3'
         room_version = '2.3.0-alpha02'
     }
     repositories {
@@ -14,7 +18,7 @@ buildscript {
     dependencies {
         classpath "com.android.tools.build:gradle:4.2.0-alpha12"
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-        classpath "com.google.dagger:hilt-android-gradle-plugin:$hilt_version"
+        classpath "com.google.dagger:hilt-android-gradle-plugin:$hilt_dagger_version"
     }
 }
 
@@ -35,6 +39,7 @@ subprojects {
     } else {
         apply plugin: 'com.android.library'
     }
+    apply plugin: 'kotlin-android'
     android {
         compileSdkVersion 30
 
@@ -49,6 +54,13 @@ subprojects {
             targetCompatibility JavaVersion.VERSION_1_8
         }
     }
+    configurations.all {
+        resolutionStrategy {
+            force "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
+            force "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
+            force "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"
+        }
+    }
     tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).configureEach {
         kotlinOptions {
             jvmTarget = '1.8'

data/build.gradle

@@ -1,10 +1,12 @@
 plugins {
-    id 'kotlin-android'
     id 'kotlin-kapt'
 }
 
 dependencies {
+    implementation project(":model")
     kapt "androidx.room:room-compiler:$room_version"
     api "androidx.room:room-runtime:$room_version"
-    api "androidx.room:room-ktx:$room_version"
+    implementation "androidx.room:room-ktx:$room_version"
+    implementation "com.squareup.moshi:moshi:$moshi_version"
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
 }

data/src/main/java/dev/msfjarvis/lobsters/data/source/LobstersApiTypeConverters.kt

@@ -0,0 +1,63 @@
+package dev.msfjarvis.lobsters.data.source
+
+import androidx.room.TypeConverter
+import com.squareup.moshi.Moshi
+import dev.msfjarvis.lobsters.model.KeybaseSignature
+import dev.msfjarvis.lobsters.model.KeybaseSignatureJsonAdapter
+import dev.msfjarvis.lobsters.model.LobstersPost
+import dev.msfjarvis.lobsters.model.LobstersPostJsonAdapter
+import dev.msfjarvis.lobsters.model.Submitter
+import dev.msfjarvis.lobsters.model.SubmitterJsonAdapter
+
+object LobstersApiTypeConverters {
+  private val moshi = Moshi.Builder().build()
+  private const val SEPARATOR = ","
+
+  @TypeConverter
+  @JvmStatic
+  fun toSubmitterUser(value: String?): Submitter? {
+    return value?.let { SubmitterJsonAdapter(moshi).fromJson(value) }
+  }
+
+  @TypeConverter
+  @JvmStatic
+  fun fromSubmitterUser(value: Submitter?): String? {
+    return value?.let { SubmitterJsonAdapter(moshi).toJson(value) }
+  }
+
+  @TypeConverter
+  @JvmStatic
+  fun toKeybaseSignature(value: String?): KeybaseSignature? {
+    return value?.let { KeybaseSignatureJsonAdapter(moshi).fromJson(value) }
+  }
+
+  @TypeConverter
+  @JvmStatic
+  fun fromKeybaseSignature(value: KeybaseSignature?): String? {
+    return value?.let { KeybaseSignatureJsonAdapter(moshi).toJson(value) }
+  }
+
+  @TypeConverter
+  @JvmStatic
+  fun toLobstersPost(value: String?): LobstersPost? {
+    return value?.let { LobstersPostJsonAdapter(moshi).fromJson(value) }
+  }
+
+  @TypeConverter
+  @JvmStatic
+  fun fromLobstersPost(value: LobstersPost?): String? {
+    return value?.let { LobstersPostJsonAdapter(moshi).toJson(value) }
+  }
+
+  @TypeConverter
+  @JvmStatic
+  fun toTagList(value: String?): List<String>? {
+    return value?.split(SEPARATOR)
+  }
+
+  @TypeConverter
+  @JvmStatic
+  fun fromTagList(value: List<String>?): String? {
+    return value?.joinToString(SEPARATOR)
+  }
+}

data/src/main/java/dev/msfjarvis/lobsters/data/source/PostsDao.kt

@@ -0,0 +1,23 @@
+package dev.msfjarvis.lobsters.data.source
+
+import androidx.room.Dao
+import androidx.room.Delete
+import androidx.room.Insert
+import androidx.room.Query
+import dev.msfjarvis.lobsters.model.LobstersPost
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+abstract class PostsDao {
+  @Query("SELECT * FROM lobsters_posts")
+  abstract fun loadPosts(): Flow<List<LobstersPost>>
+
+  @Insert
+  abstract suspend fun insertPosts(vararg posts: LobstersPost)
+
+  @Delete
+  abstract suspend fun deletePosts(vararg posts: LobstersPost)
+
+  @Query("DELETE FROM lobsters_posts")
+  abstract suspend fun deleteAllPosts()
+}

data/src/main/java/dev/msfjarvis/lobsters/data/source/PostsDatabase.kt

@@ -0,0 +1,21 @@
+package dev.msfjarvis.lobsters.data.source
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import androidx.room.TypeConverters
+import dev.msfjarvis.lobsters.model.LobstersPost
+
+@Database(
+  entities = [
+    LobstersPost::class,
+  ],
+  version = 1,
+  exportSchema = false,
+)
+@TypeConverters(
+  LobstersApiTypeConverters::class,
+  DateTimeTypeConverters::class,
+)
+abstract class PostsDatabase : RoomDatabase() {
+  abstract fun postsDao(): PostsDao
+}

lobsters-api/build.gradle

@@ -1,5 +1,4 @@
 plugins {
-    id 'kotlin-android'
     id 'kotlin-kapt'
 }
 

lobsters-api/src/main/java/dev/msfjarvis/lobsters/api/LobstersApi.kt

@@ -2,8 +2,9 @@ package dev.msfjarvis.lobsters.api
 
 import dev.msfjarvis.lobsters.model.LobstersPost
 import retrofit2.http.GET
+import retrofit2.http.Query
 
 interface LobstersApi {
   @GET("hottest.json")
-  suspend fun getHottestPosts(): List<LobstersPost>
+  suspend fun getHottestPosts(@Query("page") page: Int): List<LobstersPost>
 }

lobsters-api/src/test/java/dev/msfjarvis/lobsters/api/LobstersApiTest.kt

@@ -27,7 +27,7 @@ class LobstersApiTest {
 
   @Test
   fun `api gets correct number of items`() = runBlocking {
-    val posts = apiClient.getHottestPosts()
+    val posts = apiClient.getHottestPosts(1)
     assertEquals(25, posts.size)
   }
 

model/build.gradle

@@ -1,10 +1,8 @@
 plugins {
-    id 'kotlin-android'
     id 'kotlin-kapt'
 }
 
 dependencies {
-    def moshi_version = "1.9.3"
     api "androidx.room:room-runtime:$room_version"
     kapt "com.squareup.moshi:moshi-kotlin-codegen:$moshi_version"
     implementation "com.squareup.moshi:moshi:$moshi_version"

model/src/main/java/dev/msfjarvis/lobsters/model/Submitter.kt

@@ -13,7 +13,7 @@ class Submitter(
   val about: String,
   @Json(name = "is_moderator")
   val isModerator: Boolean,
-  val karma: Long,
+  val karma: Long = 0,
   @Json(name = "avatar_url")
   val avatarUrl: String,
   @Json(name = "invited_by_user")