Look4Sat-BA7OPF/app/src/main/res/layout/dialog_sources.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/sources_root"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/greyDark"
    android:padding="4dp">

    <TextView
        android:id="@+id/sources_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="6dp"
        android:text="@string/sources_title"
        android:textSize="16sp"
        app:layout_constraintHorizontal_chainStyle="spread_inside"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/sources_warning"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="4dp"
        android:gravity="center"
        android:text="@string/sources_https"
        android:textSize="16sp"
        app:layout_constraintStart_toStartOf="@+id/sources_title"
        app:layout_constraintTop_toBottomOf="@+id/sources_title" />

    <ImageButton
        android:id="@+id/sources_btn_add"
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:backgroundTint="@color/greySurface"
        android:contentDescription="@string/placeholder"
        android:src="@drawable/ic_add"
        app:layout_constraintBottom_toBottomOf="@+id/sources_warning"
        app:layout_constraintDimensionRatio="h,1:1"
        app:layout_constraintEnd_toEndOf="@+id/sources_recycler"
        app:layout_constraintTop_toTopOf="@+id/sources_title" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/sources_recycler"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="4dp"
        android:layout_marginEnd="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/sources_warning">

    </androidx.recyclerview.widget.RecyclerView>

    <Button
        android:id="@+id/sources_btn_neg"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="4dp"
        android:backgroundTint="@color/greySurface"
        android:text="@string/btn_cancel"
        android:textAllCaps="false"
        android:textColor="@color/themeLight"
        app:layout_constraintBaseline_toBaselineOf="@+id/sources_btn_pos"
        app:layout_constraintHorizontal_chainStyle="spread_inside"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:id="@+id/sources_btn_pos"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="4dp"
        android:layout_marginEnd="4dp"
        android:layout_marginBottom="4dp"
        android:backgroundTint="@color/greySurface"
        android:text="@string/btn_update"
        android:textAllCaps="false"
        android:textColor="@color/themeLight"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/sources_recycler" />

</androidx.constraintlayout.widget.ConstraintLayout>