chinwag-android/app/src/main/res/layout/activity_login.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"
    android:gravity="center"
    android:orientation="vertical"
    tools:context="com.keylesspalace.tusky.LoginActivity">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fillViewport="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:orientation="vertical"
            android:padding="16dp">

            <ImageView
                android:layout_width="147dp"
                android:layout_height="160dp"
                android:layout_marginBottom="50dp"
                android:contentDescription="@null"
                android:src="@drawable/elephant_friend" />

            <LinearLayout
                android:id="@+id/loginInputLayout"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <android.support.design.widget.TextInputLayout
                    android:layout_width="250dp"
                    android:layout_height="wrap_content">

                    <android.support.design.widget.TextInputEditText
                        android:id="@+id/domainEditText"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:ems="10"
                        android:hint="@string/hint_domain"
                        android:inputType="textUri" />
                </android.support.design.widget.TextInputLayout>

                <Button
                    android:id="@+id/loginButton"
                    android:layout_width="250dp"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="6dp"
                    android:text="@string/action_login"
                    android:textColor="@android:color/white" />

                <TextView
                    android:id="@+id/whatsAnInstanceTextView"
                    android:layout_width="250dp"
                    android:layout_height="wrap_content"
                    android:paddingTop="6dp"
                    android:text="@string/link_whats_an_instance"
                    android:textAlignment="center" />
            </LinearLayout>

            <LinearLayout
                android:id="@+id/loginLoadingLayout"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:visibility="gone">

                <ProgressBar
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center" />

                <TextView
                    android:layout_width="250dp"
                    android:layout_height="wrap_content"
                    android:paddingTop="10dp"
                    android:text="@string/login_connection"
                    android:textAlignment="center" />
            </LinearLayout>

        </LinearLayout>
    </ScrollView>

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:layout_alignParentTop="true"
        android:background="@android:color/transparent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>