activityScan.axml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/layoutRoot"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.camera.view.PreviewView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/previewView"/>

    <LinearLayout
        android:id="@+id/topLayout"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/transparent"
        android:weightSum="1.0">

        <LinearLayout
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:paddingTop="10dp"
            android:paddingEnd="20dp"
            android:paddingBottom="10dp"
            android:paddingStart="20dp"
            android:background="#80000000"
            android:layout_weight="0.1">

            <com.google.android.material.textview.MaterialTextView
                android:text="@string/scanHelpPrimary"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:textAppearance="?attr/textAppearanceSubtitle1"
                android:textColor="@android:color/white"/>

        </LinearLayout>

        <LinearLayout
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="0.8"/>

        <LinearLayout
            android:id="@+id/bottomLayout"
            android:orientation="vertical"
            android:background="#80000000"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:paddingTop="10dp"
            android:paddingEnd="20dp"
            android:paddingBottom="10dp"
            android:paddingStart="20dp"
            android:layout_weight="0.1"
            android:layout_gravity="center">

            <com.google.android.material.textview.MaterialTextView
                android:text="@string/scanHelpSecondary"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:textAppearance="?attr/textAppearanceSubtitle1"
                android:textColor="@android:color/white"/>

            <com.google.android.material.button.MaterialButton
                android:text="@string/toggleFlash"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="20dp"
                android:id="@+id/buttonFlash"
                android:layout_gravity="bottom"
                style="@style/Widget.Material3.Button"/>

        </LinearLayout>
    </LinearLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>