diff --git a/app/src/main/java/info/nightscout/androidaps/plugins/constraints/objectives/activities/ObjectivesExamDialog.kt b/app/src/main/java/info/nightscout/androidaps/plugins/constraints/objectives/activities/ObjectivesExamDialog.kt
index e44135eb45..97da62bbac 100644
--- a/app/src/main/java/info/nightscout/androidaps/plugins/constraints/objectives/activities/ObjectivesExamDialog.kt
+++ b/app/src/main/java/info/nightscout/androidaps/plugins/constraints/objectives/activities/ObjectivesExamDialog.kt
@@ -6,6 +6,7 @@ import android.view.View
 import android.view.ViewGroup
 import dagger.android.support.DaggerDialogFragment
 import info.nightscout.androidaps.R
+import info.nightscout.androidaps.databinding.ObjectivesExamFragmentBinding
 import info.nightscout.androidaps.plugins.bus.RxBusWrapper
 import info.nightscout.androidaps.plugins.constraints.objectives.events.EventObjectivesUpdateGui
 import info.nightscout.androidaps.plugins.constraints.objectives.objectives.Objective
@@ -15,28 +16,36 @@ import info.nightscout.androidaps.utils.DateUtil
 import info.nightscout.androidaps.utils.T
 import info.nightscout.androidaps.utils.ToastUtils
 import info.nightscout.androidaps.utils.resources.ResourceHelper
-import kotlinx.android.synthetic.main.objectives_exam_fragment.*
 import javax.inject.Inject
 
 class ObjectivesExamDialog : DaggerDialogFragment() {
+
     @Inject lateinit var rxBus: RxBusWrapper
     @Inject lateinit var resourceHelper: ResourceHelper
     @Inject lateinit var dateUtil: DateUtil
 
     companion object {
+
         var objective: Objective? = null
     }
 
     private var currentTask = 0
 
+    private var _binding: ObjectivesExamFragmentBinding? = null
+
+    // This property is only valid between onCreateView and
+    // onDestroyView.
+    private val binding get() = _binding!!
+
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
-                              savedInstanceState: Bundle?): View? {
+                              savedInstanceState: Bundle?): View {
         // load data from bundle
         (savedInstanceState ?: arguments)?.let { bundle ->
             currentTask = bundle.getInt("currentTask", 0)
         }
 
-        return inflater.inflate(R.layout.objectives_exam_fragment, container, false)
+        _binding = ObjectivesExamFragmentBinding.inflate(inflater, container, false)
+        return binding.root
     }
 
     override fun onStart() {
@@ -55,13 +64,21 @@ class ObjectivesExamDialog : DaggerDialogFragment() {
         bundle.putInt("currentTask", currentTask)
     }
 
+    @Synchronized
+    override fun onDestroyView() {
+        super.onDestroyView()
+        _binding = null
+    }
+
+    @Synchronized
     fun updateGui() {
+        if (_binding == null) return
         objective?.let { objective ->
             val task: ExamTask = objective.tasks[currentTask] as ExamTask
-            objectives_exam_name.setText(task.task)
-            objectives_exam_question.setText(task.question)
+            binding.examName.setText(task.task)
+            binding.examQuestion.setText(task.question)
             // Options
-            objectives_exam_options.removeAllViews()
+            binding.examOptions.removeAllViews()
             task.options.forEach {
                 val cb = it.generate(context)
                 if (task.answered) {
@@ -69,19 +86,19 @@ class ObjectivesExamDialog : DaggerDialogFragment() {
                     if (it.isCorrect)
                         cb.isChecked = true
                 }
-                objectives_exam_options.addView(cb)
+                binding.examOptions.addView(cb)
             }
             // Hints
-            objectives_exam_hints.removeAllViews()
+            binding.examHints.removeAllViews()
             for (h in task.hints) {
-                objectives_exam_hints.addView(h.generate(context))
+                binding.examHints.addView(h.generate(context))
             }
             // Disabled to
-            objectives_exam_disabledto.text = resourceHelper.gs(R.string.answerdisabledto, dateUtil.timeString(task.disabledTo))
-            objectives_exam_disabledto.visibility = if (task.isEnabledAnswer) View.GONE else View.VISIBLE
+            binding.examDisabledto.text = resourceHelper.gs(R.string.answerdisabledto, dateUtil.timeString(task.disabledTo))
+            binding.examDisabledto.visibility = if (task.isEnabledAnswer) View.GONE else View.VISIBLE
             // Buttons
-            objectives_exam_verify.isEnabled = !task.answered && task.isEnabledAnswer
-            objectives_exam_verify.setOnClickListener {
+            binding.examVerify.isEnabled = !task.answered && task.isEnabledAnswer
+            binding.examVerify.setOnClickListener {
                 var result = true
                 for (o in task.options) {
                     val option: Option = o as Option
@@ -95,26 +112,26 @@ class ObjectivesExamDialog : DaggerDialogFragment() {
                 updateGui()
                 rxBus.send(EventObjectivesUpdateGui())
             }
-            close.setOnClickListener { dismiss() }
-            objectives_exam_reset.setOnClickListener {
+            binding.close.setOnClickListener { dismiss() }
+            binding.examReset.setOnClickListener {
                 task.answered = false
                 //task.disabledTo = 0
                 updateGui()
                 rxBus.send(EventObjectivesUpdateGui())
             }
-            objectives_back_button.isEnabled = currentTask != 0
-            objectives_back_button.setOnClickListener {
+            binding.backButton.isEnabled = currentTask != 0
+            binding.backButton.setOnClickListener {
                 currentTask--
                 updateGui()
             }
-            objectives_next_button.isEnabled = currentTask != objective.tasks.size - 1
-            objectives_next_button.setOnClickListener {
+            binding.nextButton.isEnabled = currentTask != objective.tasks.size - 1
+            binding.nextButton.setOnClickListener {
                 currentTask++
                 updateGui()
             }
 
-            objectives_next_unanswered_button.isEnabled = !objective.isCompleted
-            objectives_next_unanswered_button.setOnClickListener {
+            binding.nextUnansweredButton.isEnabled = !objective.isCompleted
+            binding.nextUnansweredButton.setOnClickListener {
                 for (i in (currentTask + 1) until objective.tasks.size) {
                     if (!objective.tasks[i].isCompleted) {
                         currentTask = i
diff --git a/app/src/main/res/layout/objectives_exam_fragment.xml b/app/src/main/res/layout/objectives_exam_fragment.xml
index 2fe02877bd..1a8f2f84e4 100644
--- a/app/src/main/res/layout/objectives_exam_fragment.xml
+++ b/app/src/main/res/layout/objectives_exam_fragment.xml
@@ -12,38 +12,38 @@
         android:layout_margin="10dp">
 
         <LinearLayout
-            android:id="@+id/objectives_exam_options"
+            android:id="@+id/exam_options"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_marginTop="16dp"
             android:orientation="vertical"
-            app:layout_constraintTop_toBottomOf="@+id/objectives_exam_hint"
+            app:layout_constraintTop_toBottomOf="@+id/exam_hint"
             tools:layout_editor_absoluteX="3dp">
 
         </LinearLayout>
 
         <LinearLayout
-            android:id="@+id/objectives_exam_hints"
+            android:id="@+id/exam_hints"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_marginTop="16dp"
             android:layout_marginBottom="10dp"
             android:orientation="vertical"
-            app:layout_constraintTop_toBottomOf="@+id/objectives_exam_options"
+            app:layout_constraintTop_toBottomOf="@+id/exam_options"
             tools:layout_editor_absoluteX="3dp" />
 
         <LinearLayout
-            android:id="@+id/objectives_buttons"
+            android:id="@+id/buttons"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_marginTop="8dp"
             android:background="#3C3C3C"
             android:orientation="horizontal"
             android:padding="4dp"
-            app:layout_constraintTop_toBottomOf="@+id/objectives_exam_disabledto">
+            app:layout_constraintTop_toBottomOf="@+id/exam_disabledto">
 
             <Button
-                android:id="@+id/objectives_exam_reset"
+                android:id="@+id/exam_reset"
                 style="@style/Widget.AppCompat.Button.Borderless.Colored"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
@@ -63,7 +63,7 @@
                 android:text="@string/close" />
 
             <Button
-                android:id="@+id/objectives_exam_verify"
+                android:id="@+id/exam_verify"
                 style="@style/Widget.AppCompat.Button.Borderless.Colored"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
@@ -72,26 +72,26 @@
         </LinearLayout>
 
         <TextView
-            android:id="@+id/objectives_exam_question"
+            android:id="@+id/exam_question"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginTop="16dp"
             android:text="Question"
             android:textAppearance="@style/TextAppearance.AppCompat.Medium"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/objectives_exam_name" />
+            app:layout_constraintTop_toBottomOf="@id/exam_name" />
 
         <TextView
-            android:id="@+id/objectives_exam_hint"
+            android:id="@+id/exam_hint"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginTop="16dp"
             android:text="@string/objectives_hint"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/objectives_exam_question" />
+            app:layout_constraintTop_toBottomOf="@id/exam_question" />
 
         <TextView
-            android:id="@+id/objectives_exam_name"
+            android:id="@+id/exam_name"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:text="Name"
@@ -101,7 +101,7 @@
             app:layout_constraintTop_toTopOf="parent" />
 
         <TextView
-            android:id="@+id/objectives_exam_disabledto"
+            android:id="@+id/exam_disabledto"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginTop="8dp"
@@ -109,10 +109,10 @@
             android:textColor="#FF5722"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@+id/objectives_exam_hints" />
+            app:layout_constraintTop_toBottomOf="@+id/exam_hints" />
 
         <LinearLayout
-            android:id="@+id/objectives_navigation"
+            android:id="@+id/navigation"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_marginTop="2dp"
@@ -120,10 +120,10 @@
             android:orientation="horizontal"
             android:padding="4dp"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@+id/objectives_buttons">
+            app:layout_constraintTop_toBottomOf="@+id/buttons">
 
             <Button
-                android:id="@+id/objectives_back_button"
+                android:id="@+id/back_button"
                 style="@style/Widget.AppCompat.Button.Borderless.Colored"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
@@ -136,14 +136,14 @@
                 android:text="" />
 
             <Button
-                android:id="@+id/objectives_next_button"
+                android:id="@+id/next_button"
                 style="@style/Widget.AppCompat.Button.Borderless.Colored"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:text="@string/next_button" />
 
             <Button
-                android:id="@+id/objectives_next_unanswered_button"
+                android:id="@+id/next_unanswered_button"
                 style="@style/Widget.AppCompat.Button.Borderless.Colored"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"