app/src/main/res/layout/activity_chat.xml
<?xml version="1.0" encoding="utf-8"?>
<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:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="@+id/camera"
android:layout_width="66dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentStart="true"
android:layout_marginStart="52dp"
android:text="Camera" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_margin="@dimen/fab_margin"
android:clickable="true"
android:tint="@android:color/white"
app:fabSize="mini"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:srcCompat="@android:drawable/ic_menu_send"
android:focusable="true" />
<android.support.design.widget.TextInputLayout
android:layout_width="187dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentStart="true"
android:layout_marginStart="125dp"
android:layout_toLeftOf="@id/fab">
<EditText
android:id="@+id/input"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint=" Type Here" />
</android.support.design.widget.TextInputLayout>
<ListView
android:id="@+id/list_of_messages"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@id/fab"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginBottom="16dp"
android:divider="@android:color/transparent"
android:dividerHeight="16dp"
android:smoothScrollbar="false"
android:transcriptMode="alwaysScroll"
android:stackFromBottom="true"/>
<Button
android:id="@+id/gallery"
android:layout_width="66dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentStart="true"
android:text="Gallery" />
</RelativeLayout>