TermApp/app/src/main/res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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">

    <TextView
        android:id="@+id/sample_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="66dp"
        android:layout_marginTop="80dp"
        android:text="Start"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/port" />

    <Button
        android:id="@+id/stop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="68dp"
        android:layout_marginTop="80dp"
        android:enabled="false"
        android:text="Stop"
        app:layout_constraintStart_toEndOf="@+id/start"
        app:layout_constraintTop_toBottomOf="@+id/port" />

    <EditText
        android:id="@+id/server"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="35dp"
        android:ems="10"
        android:inputType=""
        app:layout_constraintTop_toTopOf="parent"
        tools:layout_editor_absoluteX="114dp" />

    <EditText
        android:id="@+id/port"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="11dp"
        android:ems="10"
        android:inputType=""
        android:text="Name"
        app:layout_constraintTop_toBottomOf="@+id/server"
        tools:layout_editor_absoluteX="118dp" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Server"
        tools:layout_editor_absoluteX="16dp"
        tools:layout_editor_absoluteY="44dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Port"
        tools:layout_editor_absoluteX="19dp"
        tools:layout_editor_absoluteY="96dp" />

    <SurfaceView
        android:id="@+id/surfaceView"
        android:layout_width="411dp"
        android:layout_height="441dp"
        android:layout_marginStart="2dp"
        android:visibility="gone"
        app:layout_constraintStart_toStartOf="parent"
        tools:layout_editor_absoluteY="288dp" />

</android.support.constraint.ConstraintLayout>