activity_teacher.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_teacher"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.darshanbshah.odsystem.TeacherActivity">

    <Button
        android:text="Logout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button2"
        android:onClick="signOut"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true" />

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/button2"
        android:layout_alignParentStart="true">

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

            <ListView
                android:layout_width="match_parent"
                android:layout_height="800dp"
                android:id="@+id/listView">

            </ListView>

        </LinearLayout>
    </ScrollView>
</RelativeLayout>