CoordinatorLayout with RecyclerView and bottom-pinned EditText

Question

I'm developing a chat screen. It consists of CollapsingToolbarLayout for user profile image, RecyclerView for messages list and an edit box to send messages. I can't figure out if it's possible to pin edit box to the bottom screen and prevent it from scrolling with the rest of the screen?

I achieved almost what I want if I wrap CoordinatorLayout in a vertical LinearLayout and put EditText outside of CoordinatorLayout. However in this case keyboard behavior is detached from RecyclerView - it doesn't scroll up/down when you open keyboard.

If I try to put EditText inside CoordinatorLayout it scrolls out of screen, I don't know if there is any special Behavior I need to set for it

My Layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
   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/keyboard_listener"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical"
>

<android.support.design.widget.CoordinatorLayout
    android:id="@+id/coordinator"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    >

    <RecyclerView
       android:id="@android:id/list"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:clickable="true"
       android:clipToPadding="false"
       android:focusableInTouchMode="true"
       android:paddingBottom="20dp"
       android:scrollbarStyle="outsideOverlay"
       android:scrollbars="vertical"
       android:transcriptMode="normal"
       app:layout_behavior="@string/appbar_scrolling_view_behavior"
       />

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        >

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/screen_toolbar_container"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:contentScrim="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|exitUntilCollapsed|snap"
            app:titleEnabled="false"
            >

            <FrameLayout
                android:id="@+id/toolbar_fragment_container"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                />

            <Toolbar
                android:id="@+id/screen_toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="@android:color/transparent"
                android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
                app:layout_collapseMode="pin"
                />

        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>

        <EditText
            android:id="@+id/messageEditText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@null"
            android:hint="@string/send_hint"
            android:inputType="textCapSentences|textMultiLine"
            android:maxLength="2000"
            android:maxLines="4"
            android:padding="10dp"
            android:textSize="14sp"/>

</LinearLayout>

Answer 1

Add this in your EditText, my friend, just like a floatingActionButton

   app:layout_anchor="@id/your bottom view id"
   app:layout_anchorGravity="bottom|right|end"