Button back to return to mainActivity

app/src/main/java/com/example/quickmax/TaskActivity.kt

@@ -2,6 +2,7 @@ package com.example.quickmax
 
 import android.animation.ArgbEvaluator
 import android.animation.ValueAnimator
+import android.content.Intent
 import android.graphics.Color
 import android.os.Bundle
 import android.os.CountDownTimer
@@ -29,6 +30,7 @@ class TaskActivity : AppCompatActivity() {
         setUpAnswerButtons()
         timer.start()
         startProgressBarAnimation()
+        btn_back.setOnClickListener { startActivity(Intent(this@TaskActivity, MainActivity::class.java)) }
     }
 
     fun reload() {

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

@@ -8,7 +8,7 @@
     android:background="#DADADA"
     tools:context=".TaskActivity">
 
-    <androidx.constraintlayout.widget.ConstraintLayout
+    <LinearLayout
         android:id="@+id/layout_gradient"
         android:layout_width="0dp"
         android:layout_height="0dp"
@@ -20,18 +20,16 @@
         app:layout_constraintTop_toTopOf="parent">
 
         <ImageButton
-            android:id="@+id/imageButton"
+            android:id="@+id/btn_back"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginStart="8dp"
             android:layout_marginTop="8dp"
             android:background="@android:color/transparent"
             android:tint="@android:color/white"
-            app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toTopOf="parent"
             app:srcCompat="@drawable/ic_back" />
 
-    </androidx.constraintlayout.widget.ConstraintLayout>
+    </LinearLayout>
 
     <TextView
         android:id="@+id/tv_timer"