From c193e9369815d23e5872ee04c414280ff5712d52 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Tue, 15 Oct 2019 17:47:50 +0530
Subject: [PATCH 01/16] fetching exploration id from exploration fragment

---
 .../player/exploration/ExplorationActivity.kt |  4 +++-
 .../ExplorationActivityPresenter.kt           | 10 ++++++---
 .../ExplorationFragmentPresenter.kt           | 21 ++++++++++++++++++-
 .../player/state/StateFragmentPresenter.kt    |  4 +++-
 .../main/res/layout/exploration_fragment.xml  |  7 ++-----
 5 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
index caf6374f3ed..5b24ae5a83b 100755
--- a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
+++ b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
@@ -12,11 +12,13 @@ const val EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY = "ExplorationActivity.expl
 class ExplorationActivity : InjectableAppCompatActivity() {
   @Inject
   lateinit var explorationActivityPresenter: ExplorationActivityPresenter
+  var explorationId: String = ""
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     activityComponent.inject(this)
-    explorationActivityPresenter.handleOnCreate()
+    explorationId = intent.getStringExtra(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY)
+    explorationActivityPresenter.handleOnCreate(explorationId)
   }
 
   companion object {
diff --git a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivityPresenter.kt b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivityPresenter.kt
index 0541e00e35b..f80d15a0978 100755
--- a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivityPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivityPresenter.kt
@@ -1,20 +1,24 @@
 package org.oppia.app.player.exploration
 
+import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import org.oppia.app.R
 import org.oppia.app.activity.ActivityScope
-import org.oppia.app.home.HomeFragment
 import javax.inject.Inject
 
 /** The controller for [ExplorationActivity]. */
 @ActivityScope
 class ExplorationActivityPresenter @Inject constructor(private val activity: AppCompatActivity) {
-  fun handleOnCreate() {
+  fun handleOnCreate(explorationId: String) {
     activity.setContentView(R.layout.exploration_activity)
     if (getExplorationFragment() == null) {
+      val explorationFragment = ExplorationFragment()
+      val args = Bundle()
+      args.putString(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY, explorationId)
+      explorationFragment.arguments = args
       activity.supportFragmentManager.beginTransaction().add(
         R.id.exploration_fragment_placeholder,
-        ExplorationFragment()
+        explorationFragment
       ).commitNow()
     }
   }
diff --git a/app/src/main/java/org/oppia/app/player/exploration/ExplorationFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/exploration/ExplorationFragmentPresenter.kt
index 8fc0223f7fa..a7c6ef7a828 100755
--- a/app/src/main/java/org/oppia/app/player/exploration/ExplorationFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/exploration/ExplorationFragmentPresenter.kt
@@ -1,11 +1,14 @@
 package org.oppia.app.player.exploration
 
+import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import org.oppia.app.R
 import org.oppia.app.databinding.ExplorationFragmentBinding
 import org.oppia.app.fragment.FragmentScope
+import org.oppia.app.player.state.StateFragment
 import javax.inject.Inject
 
 /** The controller for [ExplorationFragment]. */
@@ -14,6 +17,22 @@ class ExplorationFragmentPresenter @Inject constructor(
   private val fragment: Fragment
 ) {
   fun handleCreateView(inflater: LayoutInflater, container: ViewGroup?): View? {
-    return ExplorationFragmentBinding.inflate(inflater, container, /* attachToRoot= */ false).root
+    val binding = ExplorationFragmentBinding.inflate(inflater, container, /* attachToRoot= */ false).root
+
+    if (getStateFragment() == null) {
+      val stateFragment = StateFragment()
+      val args = Bundle()
+      args.putString(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY, fragment.arguments!!.getString(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY))
+      stateFragment.arguments = args
+      fragment.childFragmentManager.beginTransaction().add(
+        R.id.state_fragment_placeholder,
+        stateFragment
+      ).commitNow()
+    }
+    return binding
+  }
+
+  private fun getStateFragment(): StateFragment? {
+    return fragment.childFragmentManager.findFragmentById(R.id.state_fragment_placeholder) as StateFragment?
   }
 }
diff --git a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
index 45a30923e1a..83b9acc80c8 100755
--- a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
@@ -12,6 +12,7 @@ import org.oppia.app.fragment.FragmentScope
 import org.oppia.app.model.CellularDataPreference
 import org.oppia.app.model.EphemeralState
 import org.oppia.app.player.audio.CellularDataDialogFragment
+import org.oppia.app.player.exploration.EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY
 import org.oppia.app.viewmodel.ViewModelProvider
 import org.oppia.domain.audio.CellularDialogController
 import org.oppia.domain.exploration.ExplorationProgressController
@@ -33,6 +34,7 @@ class StateFragmentPresenter @Inject constructor(
 
   private var showCellularDataDialog = true
   private var useCellularData = false
+  private var explorationId: String = ""
 
   fun handleCreateView(inflater: LayoutInflater, container: ViewGroup?): View? {
     cellularDialogController.getCellularDataPreference()
@@ -49,7 +51,7 @@ class StateFragmentPresenter @Inject constructor(
       it.stateFragment = fragment as StateFragment
       it.viewModel = getStateViewModel()
     }
-
+    explorationId = fragment.arguments!!.getString(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY)
     subscribeToCurrentState()
 
     return binding.root
diff --git a/app/src/main/res/layout/exploration_fragment.xml b/app/src/main/res/layout/exploration_fragment.xml
index 231f8162b38..618f7f3da10 100755
--- a/app/src/main/res/layout/exploration_fragment.xml
+++ b/app/src/main/res/layout/exploration_fragment.xml
@@ -5,16 +5,13 @@
   <androidx.constraintlayout.widget.ConstraintLayout
     android:layout_width="match_parent"
     android:layout_height="match_parent">
-
-    <fragment
-      android:id="@+id/state_fragment"
-      class="org.oppia.app.player.state.StateFragment"
+    <FrameLayout
+      android:id="@+id/state_fragment_placeholder"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       app:layout_constraintBottom_toBottomOf="parent"
       app:layout_constraintEnd_toEndOf="parent"
       app:layout_constraintStart_toStartOf="parent"
       app:layout_constraintTop_toTopOf="parent" />
-
   </androidx.constraintlayout.widget.ConstraintLayout>
 </layout>

From 33ddb3352d17dda435849687504c2adc76e18329 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Tue, 15 Oct 2019 17:54:04 +0530
Subject: [PATCH 02/16] added framelayout for audiofragment

---
 .../oppia/app/player/state/StateFragmentPresenter.kt   |  9 +++++++++
 app/src/main/res/layout/state_fragment.xml             | 10 +++-------
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
index 83b9acc80c8..8b11b8bdca5 100755
--- a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
@@ -1,5 +1,6 @@
 package org.oppia.app.player.state
 
+import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
@@ -7,10 +8,12 @@ import androidx.fragment.app.Fragment
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.Observer
 import androidx.lifecycle.Transformations
+import org.oppia.app.R
 import org.oppia.app.databinding.StateFragmentBinding
 import org.oppia.app.fragment.FragmentScope
 import org.oppia.app.model.CellularDataPreference
 import org.oppia.app.model.EphemeralState
+import org.oppia.app.player.audio.AudioFragment
 import org.oppia.app.player.audio.CellularDataDialogFragment
 import org.oppia.app.player.exploration.EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY
 import org.oppia.app.viewmodel.ViewModelProvider
@@ -52,11 +55,17 @@ class StateFragmentPresenter @Inject constructor(
       it.viewModel = getStateViewModel()
     }
     explorationId = fragment.arguments!!.getString(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY)
+
+    getAudioFragment()
     subscribeToCurrentState()
 
     return binding.root
   }
 
+  private fun getAudioFragment(): AudioFragment? {
+    return fragment.childFragmentManager.findFragmentById(R.id.audio_fragment_placeholder) as AudioFragment?
+  }
+
   fun handleAudioClick() {
     if (showCellularDataDialog) {
       setAudioFragmentVisible(false)
diff --git a/app/src/main/res/layout/state_fragment.xml b/app/src/main/res/layout/state_fragment.xml
index d1cff627ed7..c72a00d28fa 100755
--- a/app/src/main/res/layout/state_fragment.xml
+++ b/app/src/main/res/layout/state_fragment.xml
@@ -14,7 +14,8 @@
   <androidx.constraintlayout.widget.ConstraintLayout
     android:layout_width="match_parent"
     android:layout_height="match_parent">
-    <LinearLayout
+    <FrameLayout
+      android:id="@+id/audio_fragment_placeholder"
       android:layout_width="0dp"
       android:layout_height="wrap_content"
       android:layout_marginStart="24dp"
@@ -23,12 +24,7 @@
       app:layout_constraintEnd_toEndOf="parent"
       app:layout_constraintStart_toStartOf="parent"
       app:layout_constraintTop_toTopOf="parent">
-      <fragment
-        android:id="@+id/audio_fragment"
-        class="org.oppia.app.player.audio.AudioFragment"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"/>
-    </LinearLayout>
+    </FrameLayout>
     <Button
       android:id="@+id/dummy_audio_button"
       android:layout_width="wrap_content"

From 0eae2606265a19cf0752cd05e41d2ff57d58793a Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Tue, 15 Oct 2019 18:00:20 +0530
Subject: [PATCH 03/16] Update StateFragmentPresenter.kt

---
 .../java/org/oppia/app/player/state/StateFragmentPresenter.kt    | 1 -
 1 file changed, 1 deletion(-)

diff --git a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
index 8b11b8bdca5..530ebc9519d 100755
--- a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
@@ -55,7 +55,6 @@ class StateFragmentPresenter @Inject constructor(
       it.viewModel = getStateViewModel()
     }
     explorationId = fragment.arguments!!.getString(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY)
-
     getAudioFragment()
     subscribeToCurrentState()
 

From 84877d6a09d3ca2c0831d9d633d693b2003db888 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 10:39:05 +0530
Subject: [PATCH 04/16] Update StateFragmentPresenter.kt

---
 .../org/oppia/app/player/state/StateFragmentPresenter.kt     | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
index 530ebc9519d..15284e9c3ed 100755
--- a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
@@ -55,7 +55,10 @@ class StateFragmentPresenter @Inject constructor(
       it.viewModel = getStateViewModel()
     }
     explorationId = fragment.arguments!!.getString(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY)
-    getAudioFragment()
+
+    if (getAudioFragment() == null) {
+      fragment.childFragmentManager.beginTransaction().add(R.id.audio_fragment_placeholder, AudioFragment()).commitNow()
+    }
     subscribeToCurrentState()
 
     return binding.root

From dd7e392d8c6f19b1e5f3e875bcf1a2e4121eb0c7 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 10:41:09 +0530
Subject: [PATCH 05/16] Update ExplorationActivity.kt

---
 .../org/oppia/app/player/exploration/ExplorationActivity.kt     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
index 5b24ae5a83b..53358fbf029 100755
--- a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
+++ b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
@@ -12,7 +12,7 @@ const val EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY = "ExplorationActivity.expl
 class ExplorationActivity : InjectableAppCompatActivity() {
   @Inject
   lateinit var explorationActivityPresenter: ExplorationActivityPresenter
-  var explorationId: String = ""
+  lateinit var explorationId: String = ""
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)

From 73d05d273093fbc29a0a50dea3c1213fadf62088 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 10:41:55 +0530
Subject: [PATCH 06/16] Update ExplorationActivity.kt

---
 .../org/oppia/app/player/exploration/ExplorationActivity.kt     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
index 53358fbf029..6e5508f7392 100755
--- a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
+++ b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivity.kt
@@ -12,7 +12,7 @@ const val EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY = "ExplorationActivity.expl
 class ExplorationActivity : InjectableAppCompatActivity() {
   @Inject
   lateinit var explorationActivityPresenter: ExplorationActivityPresenter
-  lateinit var explorationId: String = ""
+  private lateinit var explorationId : String
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)

From fb3cc39f5d9c4f5cb2dfd6d00154fe9d62bd8af0 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 10:42:33 +0530
Subject: [PATCH 07/16] Update StateFragmentPresenter.kt

---
 .../java/org/oppia/app/player/state/StateFragmentPresenter.kt   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
index 15284e9c3ed..267fca29609 100755
--- a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
@@ -37,7 +37,7 @@ class StateFragmentPresenter @Inject constructor(
 
   private var showCellularDataDialog = true
   private var useCellularData = false
-  private var explorationId: String = ""
+  private lateinit var explorationId: String 
 
   fun handleCreateView(inflater: LayoutInflater, container: ViewGroup?): View? {
     cellularDialogController.getCellularDataPreference()

From 22f33c02d0f44c3e2a243e2f2c288a1d659b203a Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 11:01:38 +0530
Subject: [PATCH 08/16] Update StateFragmentPresenter.kt

---
 .../java/org/oppia/app/player/state/StateFragmentPresenter.kt   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
index 267fca29609..570ea99169a 100755
--- a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
@@ -37,7 +37,7 @@ class StateFragmentPresenter @Inject constructor(
 
   private var showCellularDataDialog = true
   private var useCellularData = false
-  private lateinit var explorationId: String 
+  private lateinit var explorationId: String
 
   fun handleCreateView(inflater: LayoutInflater, container: ViewGroup?): View? {
     cellularDialogController.getCellularDataPreference()

From ebe2c42c8b2fb0b826c0f35e62ad9bdec076366f Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 11:49:37 +0530
Subject: [PATCH 09/16] corrected audio fragment implementation

---
 .../player/state/StateFragmentPresenter.kt    | 46 ++++++++++++-------
 .../oppia/app/player/state/StateViewModel.kt  |  8 +---
 app/src/main/res/layout/state_fragment.xml    |  4 +-
 3 files changed, 33 insertions(+), 25 deletions(-)

diff --git a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
index 570ea99169a..a1c0ea3501e 100755
--- a/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/state/StateFragmentPresenter.kt
@@ -1,6 +1,5 @@
 package org.oppia.app.player.state
 
-import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
@@ -24,6 +23,7 @@ import org.oppia.util.logging.Logger
 import javax.inject.Inject
 
 private const val TAG_CELLULAR_DATA_DIALOG = "CELLULAR_DATA_DIALOG"
+private const val TAG_AUDIO_FRAGMENT = "AUDIO_FRAGMENT"
 
 /** The presenter for [StateFragment]. */
 @FragmentScope
@@ -37,7 +37,7 @@ class StateFragmentPresenter @Inject constructor(
 
   private var showCellularDataDialog = true
   private var useCellularData = false
-  private lateinit var explorationId: String
+  private var explorationId: String? = null
 
   fun handleCreateView(inflater: LayoutInflater, container: ViewGroup?): View? {
     cellularDialogController.getCellularDataPreference()
@@ -56,36 +56,35 @@ class StateFragmentPresenter @Inject constructor(
     }
     explorationId = fragment.arguments!!.getString(EXPLORATION_ACTIVITY_TOPIC_ID_ARGUMENT_KEY)
 
-    if (getAudioFragment() == null) {
-      fragment.childFragmentManager.beginTransaction().add(R.id.audio_fragment_placeholder, AudioFragment()).commitNow()
-    }
     subscribeToCurrentState()
 
     return binding.root
   }
 
-  private fun getAudioFragment(): AudioFragment? {
-    return fragment.childFragmentManager.findFragmentById(R.id.audio_fragment_placeholder) as AudioFragment?
-  }
-
   fun handleAudioClick() {
     if (showCellularDataDialog) {
-      setAudioFragmentVisible(false)
+      showHideAudioFragment(false)
       showCellularDataDialogFragment()
     } else {
-      setAudioFragmentVisible(useCellularData)
+      if (useCellularData) {
+        showHideAudioFragment(getAudioFragment() == null)
+      } else {
+        showHideAudioFragment(false)
+      }
     }
   }
 
   fun handleEnableAudio(saveUserChoice: Boolean) {
-    setAudioFragmentVisible(true)
-    if (saveUserChoice)
+    showHideAudioFragment(true)
+    if (saveUserChoice) {
       cellularDialogController.setAlwaysUseCellularDataPreference()
+    }
   }
 
   fun handleDisableAudio(saveUserChoice: Boolean) {
-    if (saveUserChoice)
+    if (saveUserChoice) {
       cellularDialogController.setNeverUseCellularDataPreference()
+    }
   }
 
   private fun showCellularDataDialogFragment() {
@@ -101,8 +100,23 @@ class StateFragmentPresenter @Inject constructor(
     return viewModelProvider.getForFragment(fragment, StateViewModel::class.java)
   }
 
-  fun setAudioFragmentVisible(isVisible: Boolean) {
-    getStateViewModel().setAudioFragmentVisible(isVisible)
+  private fun getAudioFragment(): Fragment? {
+    return fragment.childFragmentManager.findFragmentByTag(TAG_AUDIO_FRAGMENT)
+  }
+
+  private fun showHideAudioFragment(isVisible: Boolean) {
+    if (isVisible) {
+      if (getAudioFragment() == null) {
+        fragment.childFragmentManager.beginTransaction().add(
+          R.id.audio_fragment_placeholder, AudioFragment(),
+          TAG_AUDIO_FRAGMENT
+        ).commitNow()
+      }
+    } else {
+      if (getAudioFragment() != null) {
+        fragment.childFragmentManager.beginTransaction().remove(getAudioFragment()!!).commitNow()
+      }
+    }
   }
 
   private fun subscribeToCurrentState() {
diff --git a/app/src/main/java/org/oppia/app/player/state/StateViewModel.kt b/app/src/main/java/org/oppia/app/player/state/StateViewModel.kt
index 5af8d2ac519..9d0f34d87d6 100644
--- a/app/src/main/java/org/oppia/app/player/state/StateViewModel.kt
+++ b/app/src/main/java/org/oppia/app/player/state/StateViewModel.kt
@@ -7,10 +7,4 @@ import javax.inject.Inject
 
 /** [ViewModel] for state-fragment. */
 @FragmentScope
-class StateViewModel @Inject constructor() : ViewModel() {
-  var isAudioFragmentVisible = ObservableField<Boolean>(false)
-
-  fun setAudioFragmentVisible(isVisible: Boolean) {
-    isAudioFragmentVisible.set(isVisible)
-  }
-}
+class StateViewModel @Inject constructor() : ViewModel() {}
diff --git a/app/src/main/res/layout/state_fragment.xml b/app/src/main/res/layout/state_fragment.xml
index c72a00d28fa..e56779576e2 100755
--- a/app/src/main/res/layout/state_fragment.xml
+++ b/app/src/main/res/layout/state_fragment.xml
@@ -20,7 +20,6 @@
       android:layout_height="wrap_content"
       android:layout_marginStart="24dp"
       android:layout_marginEnd="24dp"
-      android:visibility="@{viewModel.isAudioFragmentVisible? View.VISIBLE: View.GONE}"
       app:layout_constraintEnd_toEndOf="parent"
       app:layout_constraintStart_toStartOf="parent"
       app:layout_constraintTop_toTopOf="parent">
@@ -38,6 +37,7 @@
       app:layout_constraintBottom_toBottomOf="parent"
       app:layout_constraintEnd_toEndOf="parent"
       app:layout_constraintStart_toStartOf="parent"
-      app:layout_constraintTop_toTopOf="parent"/>
+      app:layout_constraintTop_toTopOf="parent"
+    />
   </androidx.constraintlayout.widget.ConstraintLayout>
 </layout>

From 9142d7803d7b349bb07b8b25615c104a6b41cef6 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 12:05:58 +0530
Subject: [PATCH 10/16] Update StateFragmentTest.kt

---
 .../java/org/oppia/app/player/state/StateFragmentTest.kt         | 1 +
 1 file changed, 1 insertion(+)

diff --git a/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt b/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
index ef3a1e7d0fa..c3e9861bd69 100644
--- a/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
+++ b/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
@@ -26,6 +26,7 @@ import org.oppia.util.threading.BackgroundDispatcher
 import org.oppia.util.threading.BlockingDispatcher
 import javax.inject.Singleton
 
+// TODO(#239) : Updated this implementation to creating or removing the AudioFragment only when needed.
 /** Tests for [StateFragment]. */
 @RunWith(AndroidJUnit4::class)
 class StateFragmentTest {

From ea939ec41019434e02f9c46a82c4d5a49d537e17 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 12:06:06 +0530
Subject: [PATCH 11/16] Update StateFragmentTest.kt

---
 .../java/org/oppia/app/player/state/StateFragmentTest.kt        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt b/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
index c3e9861bd69..0d244dd2736 100644
--- a/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
+++ b/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
@@ -26,7 +26,7 @@ import org.oppia.util.threading.BackgroundDispatcher
 import org.oppia.util.threading.BlockingDispatcher
 import javax.inject.Singleton
 
-// TODO(#239) : Updated this implementation to creating or removing the AudioFragment only when needed.
+// TODO(#239): Updated this implementation to creating or removing the AudioFragment only when needed.
 /** Tests for [StateFragment]. */
 @RunWith(AndroidJUnit4::class)
 class StateFragmentTest {

From e2b4ba9de806cbe870b909b9ae2573863e434770 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 12:08:39 +0530
Subject: [PATCH 12/16] Update StateFragmentTest.kt

---
 .../java/org/oppia/app/player/state/StateFragmentTest.kt        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt b/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
index 0d244dd2736..c507f225cf2 100644
--- a/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
+++ b/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
@@ -26,7 +26,7 @@ import org.oppia.util.threading.BackgroundDispatcher
 import org.oppia.util.threading.BlockingDispatcher
 import javax.inject.Singleton
 
-// TODO(#239): Updated this implementation to creating or removing the AudioFragment only when needed.
+// TODO(#239): Update testcases to creating or removing the AudioFragment only when needed.
 /** Tests for [StateFragment]. */
 @RunWith(AndroidJUnit4::class)
 class StateFragmentTest {

From dee3fa7ccfa09f3e4adb20ee00f61fbfdcd52603 Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 12:10:10 +0530
Subject: [PATCH 13/16] Update StateFragmentTest.kt

---
 .../java/org/oppia/app/player/state/StateFragmentTest.kt        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt b/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
index c507f225cf2..3749e259d70 100644
--- a/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
+++ b/app/src/sharedTest/java/org/oppia/app/player/state/StateFragmentTest.kt
@@ -26,7 +26,7 @@ import org.oppia.util.threading.BackgroundDispatcher
 import org.oppia.util.threading.BlockingDispatcher
 import javax.inject.Singleton
 
-// TODO(#239): Update testcases to creating or removing the AudioFragment only when needed.
+// TODO(#239): AudioFragment implementation has been updated in PR #238 and because of which these audio-related test cases are failing.
 /** Tests for [StateFragment]. */
 @RunWith(AndroidJUnit4::class)
 class StateFragmentTest {

From 58b25768484ebcb6e2d6040edabd7bfe98d72bed Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 12:11:08 +0530
Subject: [PATCH 14/16] Update ExplorationActivityPresenter.kt

---
 .../app/player/exploration/ExplorationActivityPresenter.kt      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivityPresenter.kt b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivityPresenter.kt
index f80d15a0978..94faaf4371c 100755
--- a/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivityPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/exploration/ExplorationActivityPresenter.kt
@@ -6,7 +6,7 @@ import org.oppia.app.R
 import org.oppia.app.activity.ActivityScope
 import javax.inject.Inject
 
-/** The controller for [ExplorationActivity]. */
+/** The Presenter for [ExplorationActivity]. */
 @ActivityScope
 class ExplorationActivityPresenter @Inject constructor(private val activity: AppCompatActivity) {
   fun handleOnCreate(explorationId: String) {

From b231e4cb02a507494df58e05d4e2d4d2aca7c15b Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 12:11:31 +0530
Subject: [PATCH 15/16] Update ExplorationFragmentPresenter.kt

---
 .../app/player/exploration/ExplorationFragmentPresenter.kt      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/src/main/java/org/oppia/app/player/exploration/ExplorationFragmentPresenter.kt b/app/src/main/java/org/oppia/app/player/exploration/ExplorationFragmentPresenter.kt
index a7c6ef7a828..7e13a8dcad5 100755
--- a/app/src/main/java/org/oppia/app/player/exploration/ExplorationFragmentPresenter.kt
+++ b/app/src/main/java/org/oppia/app/player/exploration/ExplorationFragmentPresenter.kt
@@ -11,7 +11,7 @@ import org.oppia.app.fragment.FragmentScope
 import org.oppia.app.player.state.StateFragment
 import javax.inject.Inject
 
-/** The controller for [ExplorationFragment]. */
+/** The presenter for [ExplorationFragment]. */
 @FragmentScope
 class ExplorationFragmentPresenter @Inject constructor(
   private val fragment: Fragment

From fee9aa62217b135cdab57725d3102f4964bf685c Mon Sep 17 00:00:00 2001
From: veena <veena14cs@gmail.com>
Date: Wed, 16 Oct 2019 12:13:29 +0530
Subject: [PATCH 16/16] Update state_fragment.xml

---
 app/src/main/res/layout/state_fragment.xml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/app/src/main/res/layout/state_fragment.xml b/app/src/main/res/layout/state_fragment.xml
index e56779576e2..4c30178d521 100755
--- a/app/src/main/res/layout/state_fragment.xml
+++ b/app/src/main/res/layout/state_fragment.xml
@@ -22,8 +22,7 @@
       android:layout_marginEnd="24dp"
       app:layout_constraintEnd_toEndOf="parent"
       app:layout_constraintStart_toStartOf="parent"
-      app:layout_constraintTop_toTopOf="parent">
-    </FrameLayout>
+      app:layout_constraintTop_toTopOf="parent"/>
     <Button
       android:id="@+id/dummy_audio_button"
       android:layout_width="wrap_content"