Revert "Fix #4, #70, #71, #86, #87: Introduce data module (#85)"

This reverts commit bda2f7c.

.gitignore

@@ -8,7 +8,6 @@
 /.idea/navEditor.xml
 /.idea/assetWizardSettings.xml
 app/build
-data/build
 domain/build
 model/build
 utility/build

app/build.gradle

@@ -1,27 +1,17 @@
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
-apply plugin: 'kotlin-kapt'
 
 android {
-  compileSdkVersion 28
+  compileSdkVersion 29
   buildToolsVersion "29.0.1"
   defaultConfig {
     applicationId "org.oppia.app"
-    minSdkVersion 19
+    minSdkVersion 16
     targetSdkVersion 28
     versionCode 1
     versionName "1.0"
     testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
-    // https://developer.android.com/training/testing/junit-runner#ato-gradle
-    testInstrumentationRunnerArguments clearPackageData: 'true'
-  }
-  compileOptions {
-    sourceCompatibility JavaVersion.VERSION_1_8
-    targetCompatibility JavaVersion.VERSION_1_8
-  }
-  kotlinOptions {
-    jvmTarget = JavaVersion.VERSION_1_8
   }
   buildTypes {
     release {
@@ -33,8 +23,6 @@ android {
     enabled = true
   }
   testOptions {
-    // https://developer.android.com/training/testing/junit-runner#ato-gradle
-    execution 'ANDROIDX_TEST_ORCHESTRATOR'
     unitTests {
       includeAndroidResources = true
     }
@@ -61,7 +49,6 @@ dependencies {
       'androidx.constraintlayout:constraintlayout:1.1.3',
       'androidx.core:core-ktx:1.0.2',
       'androidx.lifecycle:lifecycle-runtime-ktx:2.2.0-alpha03',
-      'com.google.dagger:dagger:2.24',
       "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version",
   )
   testImplementation(
@@ -78,18 +65,6 @@ dependencies {
       'androidx.test:runner:1.2.0',
       'com.google.truth:truth:0.43',
   )
-  androidTestUtil(
-      'androidx.test:orchestrator:1.2.0',
-  )
-  kapt(
-      'com.google.dagger:dagger-compiler:2.24'
-  )
-  kaptTest(
-      'com.google.dagger:dagger-compiler:2.24'
-  )
-  kaptAndroidTest(
-      'com.google.dagger:dagger-compiler:2.24'
-  )
   implementation project(":model")
   implementation project(":domain")
   implementation project(":utility")

app/src/main/AndroidManifest.xml

@@ -4,14 +4,13 @@
   package="org.oppia.app">
 
   <application
-    android:name=".application.OppiaApplication"
     android:allowBackup="true"
     android:icon="@mipmap/ic_launcher"
     android:label="@string/app_name"
     android:roundIcon="@mipmap/ic_launcher_round"
     android:supportsRtl="true"
     android:theme="@style/OppiaTheme">
-    <activity android:name="org.oppia.app.home.HomeActivity">
+    <activity android:name="org.oppia.app.HomeActivity">
       <intent-filter>
         <action android:name="android.intent.action.MAIN"/>
         <category android:name="android.intent.category.LAUNCHER"/>

app/src/main/java/org/oppia/app/HomeActivity.kt

@@ -0,0 +1,14 @@
+package org.oppia.app
+
+import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+
+/** The central activity for all users entering the app. */
+class HomeActivity : AppCompatActivity() {
+
+  override fun onCreate(savedInstanceState: Bundle?) {
+    super.onCreate(savedInstanceState)
+    setContentView(R.layout.home_activity)
+    supportFragmentManager.beginTransaction().add(R.id.home_fragment_placeholder, HomeFragment()).commitNow()
+  }
+}

app/src/main/java/org/oppia/app/HomeFragment.kt

@@ -0,0 +1,55 @@
+package org.oppia.app
+
+import android.os.Bundle
+import android.util.Log
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.fragment.app.Fragment
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Transformations
+import androidx.lifecycle.ViewModelProviders
+import org.oppia.app.databinding.HomeFragmentBinding
+import org.oppia.app.model.UserAppHistory
+import org.oppia.domain.UserAppHistoryController
+import org.oppia.util.data.AsyncResult
+
+/** Fragment that contains an introduction to the app. */
+class HomeFragment : Fragment() {
+  private val userAppHistoryController = UserAppHistoryController()
+
+  override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+    val binding = HomeFragmentBinding.inflate(inflater, container, /* attachToRoot= */ false)
+    val viewModel = getUserAppHistoryViewModel()
+    val appUserHistory = getUserAppHistory()
+    viewModel.userAppHistoryLiveData = appUserHistory
+    // NB: Both the view model and lifecycle owner must be set in order to correctly bind LiveData elements to
+    // data-bound view models.
+    binding.let {
+      it.viewModel = viewModel
+      it.lifecycleOwner = this
+    }
+
+    // TODO(#70): Mark that the user opened the app once it's persisted to disk.
+
+    return binding.root
+  }
+
+  private fun getUserAppHistoryViewModel(): UserAppHistoryViewModel {
+    return ViewModelProviders.of(this).get(UserAppHistoryViewModel::class.java)
+  }
+
+  private fun getUserAppHistory(): LiveData<UserAppHistory> {
+    // If there's an error loading the data, assume the default.
+    return Transformations.map(
+      userAppHistoryController.getUserAppHistory()
+    ) { result: AsyncResult<UserAppHistory> -> processUserAppHistoryResult(result) }
+  }
+
+  private fun processUserAppHistoryResult(appHistoryResult: AsyncResult<UserAppHistory>): UserAppHistory {
+    if (appHistoryResult.isFailure()) {
+      Log.e("HomeFragment", "Failed to retrieve user app history", appHistoryResult.error)
+    }
+    return appHistoryResult.getOrDefault(UserAppHistory.getDefaultInstance())
+  }
+}

app/src/main/java/org/oppia/app/UserAppHistoryViewModel.kt

@@ -0,0 +1,10 @@
+package org.oppia.app
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.ViewModel
+import org.oppia.app.model.UserAppHistory
+
+/** [ViewModel] for user app usage history. */
+class UserAppHistoryViewModel: ViewModel() {
+  var userAppHistoryLiveData: LiveData<UserAppHistory>? = null
+}