Scroll view with Relative layout

Question

I am building a layout with scroll view and inside the scroll view, there is a relative layout. I want to place the FloatingActionButton on the bottom center of the layout, but I don't know what is happening.

This is my layout:

Here's my code below:

<?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="com.example.mani.fakecall.MainActivity">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

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

            <ImageButton
                android:id="@+id/display_image"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:background="@drawable/circular_image_button"
                android:src="@drawable/ic_add_white_24dp" />

            <EditText
                android:id="@+id/display_number"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="16dp"
                android:hint="@string/enter_number"
                android:inputType="number" />

            <EditText
                android:id="@+id/display_name"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="16dp"
                android:hint="@string/enter_name"
                android:inputType="textCapWords" />

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:layout_marginTop="16dp"
                android:elevation="8dp"
                android:text="@string/set_time" />

        </LinearLayout>

        <android.support.design.widget.FloatingActionButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            android:layout_margin="16dp"
            android:clickable="true"
            android:elevation="12dp"
            android:src="@drawable/ic_call_white_24dp"
            app:backgroundTint="@color/colorFab"
            app:elevation="0dp" />

    </RelativeLayout>

</ScrollView>

Answer 1

Your hierarchy will be like this

<RelativeLayout 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="com.example.mani.fakecall.MainActivity">

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

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

        <ImageButton
            android:id="@+id/display_image"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:background="@drawable/circular_image_button"
            android:src="@drawable/ic_add_white_24dp" />

        <EditText
            android:id="@+id/display_number"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:hint="@string/enter_number"
            android:inputType="number" />

        <EditText
            android:id="@+id/display_name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp"
            android:hint="@string/enter_name"
            android:inputType="textCapWords" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="16dp"
            android:elevation="8dp"
            android:text="@string/set_time" />

    </LinearLayout>


</ScrollView>


<android.support.design.widget.FloatingActionButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:layout_margin="16dp"
    android:clickable="true"
    android:elevation="12dp"
    android:src="@drawable/ic_add"
    app:backgroundTint="@color/colorAccent"
    app:elevation="0dp" />

</RelativeLayout>

edited