DroidFS/app/src/main/res/layout/activity_text_editor.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:orientation="vertical">

    <include android:id="@+id/toolbar" layout="@layout/toolbar"/>

    <HorizontalScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fillViewport="true">

        <ScrollView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:fillViewport="true">

            <EditText
                android:id="@+id/text_editor"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:gravity="top"
                android:textSize="15sp"
                android:background="@null"
                android:padding="5dp"/>

        </ScrollView>

    </HorizontalScrollView>

</LinearLayout>