android-ftp-server/app/src/main/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="16dp">

    <TextView
        android:id="@+id/titleTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Android FTP Server"
        android:textSize="24sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginTop="32dp" />

    <TextView
        android:id="@+id/statusTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Server Status: Stopped"
        android:textSize="16sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/titleTextView"
        android:layout_marginTop="24dp" />

    <TextView
        android:id="@+id/portTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Port: 2121"
        android:textSize="14sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/statusTextView"
        android:layout_marginTop="8dp" />

    <Button
        android:id="@+id/startButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Start Server"
        android:minWidth="150dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/portTextView"
        android:layout_marginTop="32dp" />

    <Button
        android:id="@+id/stopButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Stop Server"
        android:minWidth="150dp"
        android:enabled="false"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/startButton"
        android:layout_marginTop="16dp" />

    <View
        android:id="@+id/divider"
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="#CCCCCC"
        android:layout_marginTop="32dp"
        app:layout_constraintTop_toBottomOf="@id/stopButton"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <TextView
        android:id="@+id/settingsTitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Settings"
        android:textSize="20sp"
        android:textStyle="bold"
        android:layout_marginTop="24dp"
        app:layout_constraintTop_toBottomOf="@id/divider"
        app:layout_constraintStart_toStartOf="parent" />

    <TextView
        android:id="@+id/portLabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Port:"
        android:textSize="16sp"
        android:layout_marginTop="24dp"
        app:layout_constraintTop_toBottomOf="@id/settingsTitle"
        app:layout_constraintStart_toStartOf="parent" />

    <EditText
        android:id="@+id/portEditText"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:hint="2121"
        android:layout_marginStart="16dp"
        app:layout_constraintBaseline_toBaselineOf="@id/portLabel"
        app:layout_constraintStart_toEndOf="@id/portLabel"
        app:layout_constraintEnd_toEndOf="parent" />

    <TextView
        android:id="@+id/rootDirLabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Root Directory:"
        android:textSize="16sp"
        android:layout_marginTop="16dp"
        app:layout_constraintTop_toBottomOf="@id/portLabel"
        app:layout_constraintStart_toStartOf="parent" />

    <TextView
        android:id="@+id/rootDirPathTextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Not selected"
        android:textSize="14sp"
        android:layout_marginTop="8dp"
        android:padding="8dp"
        android:background="@android:color/darker_gray"
        android:ellipsize="start"
        android:singleLine="true"
        app:layout_constraintTop_toBottomOf="@id/rootDirLabel"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <Button
        android:id="@+id/selectDirButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Select Directory"
        android:layout_marginTop="8dp"
        app:layout_constraintTop_toBottomOf="@id/rootDirPathTextView"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:id="@+id/saveSettingsButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Save Settings"
        android:minWidth="150dp"
        android:layout_marginTop="24dp"
        app:layout_constraintTop_toBottomOf="@id/selectDirButton"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>
</ScrollView>