Fix part of #632: Replace LanguageSelectionAdapter with BindableAdapter

app/src/main/java/org/oppia/android/app/options/AudioLanguageFragmentPresenter.kt

@@ -5,11 +5,20 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import org.oppia.android.app.recyclerview.BindableAdapter
+import org.oppia.android.app.topic.practice.TopicPracticeViewModel
+import org.oppia.android.app.topic.practice.practiceitemviewmodel.TopicPracticeSubtopicViewModel
+import org.oppia.android.app.viewmodel.ViewModelProvider
 import org.oppia.android.databinding.AudioLanguageFragmentBinding
+import org.oppia.android.databinding.LanguageItemsBinding
+import org.oppia.android.databinding.TopicPracticeSubtopicBinding
 import javax.inject.Inject
 
 /** The presenter for [AudioLanguageFragment]. */
-class AudioLanguageFragmentPresenter @Inject constructor(private val fragment: Fragment) {
+class AudioLanguageFragmentPresenter @Inject constructor(
+  private val fragment: Fragment,
+  private val viewModelProvider: ViewModelProvider<LanguageSelectionViewModel>
+) {
 
   private lateinit var prefSummaryValue: String
   private lateinit var languageSelectionAdapter: LanguageSelectionAdapter
@@ -25,12 +34,13 @@ class AudioLanguageFragmentPresenter @Inject constructor(private val fragment: F
       container,
       /* attachToRoot= */ false
     )
+    binding.viewModel = getLanguageSelectionViewModel()
     prefSummaryValue = prefValue
     languageSelectionAdapter = LanguageSelectionAdapter(prefKey) {
       updateAudioLanguage(it)
     }
     binding.audioLanguageRecyclerView.apply {
-      adapter = languageSelectionAdapter
+      adapter = createRecyclerViewAdapter()
     }
 
     binding.audioLanguageToolbar?.setNavigationOnClickListener {
@@ -40,7 +50,7 @@ class AudioLanguageFragmentPresenter @Inject constructor(private val fragment: F
       (fragment.activity as AudioLanguageActivity).setResult(REQUEST_CODE_AUDIO_LANGUAGE, intent)
       (fragment.activity as AudioLanguageActivity).finish()
     }
-    createAdapter()
+//    createAdapter()
     return binding.root
   }
 
@@ -69,4 +79,42 @@ class AudioLanguageFragmentPresenter @Inject constructor(private val fragment: F
     languageSelectionAdapter.setLanguageList(languageList)
     languageSelectionAdapter.setDefaultLanguageSelected(prefSummaryValue = prefSummaryValue)
   }
+
+  private fun createRecyclerViewAdapter(): BindableAdapter<LanguageItemViewModel> {
+    return BindableAdapter.MultiTypeBuilder
+      .newBuilder<LanguageItemViewModel, ViewType> { viewModel ->
+        ViewType.VIEW_TYPE_LANGUAGE
+      }
+      .registerViewDataBinder(
+        viewType = ViewType.VIEW_TYPE_LANGUAGE,
+        inflateDataBinding = LanguageItemsBinding::inflate,
+        setViewModel = this::bindSkillView,
+        transformViewModel = {it as LanguageSelectionViewModel}
+      ).build()
+  }
+
+  private fun bindSkillView(
+    binding: TopicPracticeSubtopicBinding,
+    model: TopicPracticeSubtopicViewModel
+  ) {
+    binding.viewModel = model
+//    binding.isChecked = selectedSubtopicIdList.contains(model.subtopic.subtopicId)
+//    binding.subtopicCheckBox.setOnCheckedChangeListener { _, isChecked ->
+//      if (isChecked) {
+//        subtopicSelected(model.subtopic.subtopicId, model.subtopic.skillIdsList)
+//      } else {
+//        subtopicUnselected(model.subtopic.subtopicId, model.subtopic.skillIdsList)
+//      }
+//    }
+  }
+
+
+  private enum class ViewType {
+    VIEW_TYPE_LANGUAGE
+  }
+
+  private fun getLanguageSelectionViewModel() : LanguageSelectionViewModel {
+    return viewModelProvider.getForFragment(fragment, LanguageSelectionViewModel::class.java)
+  }
+
 }

app/src/main/java/org/oppia/android/app/options/LanguageItemViewModel.kt

@@ -0,0 +1,5 @@
+package org.oppia.android.app.options
+
+import org.oppia.android.app.viewmodel.ObservableViewModel
+
+class LanguageItemViewModel(val language: String): ObservableViewModel()

app/src/main/java/org/oppia/android/app/options/LanguageSelectionViewModel.kt

@@ -0,0 +1,26 @@
+package org.oppia.android.app.options
+
+import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.LiveData
+import org.oppia.android.app.fragment.FragmentScope
+import org.oppia.android.app.viewmodel.ObservableViewModel
+import javax.inject.Inject
+
+@FragmentScope
+class LanguageSelectionViewModel @Inject constructor(
+  val activity: AppCompatActivity
+) :ObservableViewModel() {
+
+  var audioLanguagesList = listOf<LanguageItemViewModel>(
+    LanguageItemViewModel("No Audio"),
+    LanguageItemViewModel("English"),
+    LanguageItemViewModel("French"),
+    LanguageItemViewModel("Hindi"),
+    LanguageItemViewModel("Chinese")
+  )
+
+
+  val recyclerViewAudioList: List<LanguageItemViewModel> by lazy {
+    audioLanguagesList
+  }
+}

app/src/main/res/layout/audio_language_fragment.xml

@@ -2,6 +2,12 @@
 <layout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto">
 
+  <data>
+    <variable
+      name="viewModel"
+      type="org.oppia.android.app.options.LanguageSelectionViewModel"/>
+  </data>
+
   <androidx.constraintlayout.widget.ConstraintLayout
     android:layout_width="match_parent"
     android:layout_height="match_parent">
@@ -45,6 +51,7 @@
         android:clipToPadding="false"
         android:overScrollMode="never"
         android:paddingBottom="132dp"
+        app:list="@{viewModel.recyclerViewAudioList}"
         android:scrollbars="none"
         app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
         app:layout_constraintBottom_toBottomOf="parent"

app/src/main/res/layout/language_items.xml

@@ -1,10 +1,12 @@
 <layout xmlns:android="http://schemas.android.com/apk/res/android">
 
   <data>
-
     <variable
       name="languageString"
       type="CharSequence" />
+    <variable
+      name="viewModel"
+      type="org.oppia.android.app.options.LanguageItemViewModel" />
   </data>
 
   <LinearLayout
@@ -24,6 +26,7 @@
       android:layout_marginStart="24dp"
       android:layout_marginEnd="24dp"
       android:clickable="false"
+      android:checked="true"
       android:minWidth="20dp"
       android:minHeight="20dp" />
 
@@ -33,7 +36,7 @@
       android:layout_height="wrap_content"
       android:layout_marginEnd="24dp"
       android:fontFamily="sans-serif"
-      android:text="@{languageString}"
+      android:text="@{viewModel.language}"
       android:textColor="@color/oppiaPrimaryText"
       android:textSize="16sp" />
   </LinearLayout>