RecyclerView inside a ScrollView/NestedScrollView does not scroll properly

Question

I have a layout which has a CardView and a FloatingActionButton associated with it. There is a list of replies below the CardView (which is a RecyclerView). Sometimes the CardViews' height is greater than the screen, so I have used layout_height="wrap_content" for the CardView and wrapped the whole LinearLayout inside a ScrollView.

However, this causes a problem(since it is a scrolling view inside a ScrollView) while scrolling the items of the RecyclerView. As suggested in some of the questions and answers posted, I have used both the NestedScrollView and the android:nestedScrollingEnabled="true" tag but the scrolling in the RecyclerView is still bad.

Here is my Layout file -

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    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.forum.reply.ReplyActivity">

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

        <android.support.v7.widget.Toolbar
            android:id="@+id/reply_toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorPrimary"
            android:minHeight="?attr/actionBarSize"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
            app:titleTextColor="@android:color/white"/>

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

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_margin="8dp"
                android:orientation="vertical">

                <android.support.v7.widget.CardView
                    android:id="@+id/topic_card"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:paddingBottom="@dimen/card_margin"
                    android:paddingLeft="@dimen/card_margin"
                    android:paddingRight="@dimen/card_margin"
                    android:paddingTop="@dimen/card_margin">

                    <LinearLayout
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:orientation="vertical"
                        android:paddingEnd="@dimen/card_margin"
                        android:paddingStart="@dimen/card_margin">

                        <android.support.v7.widget.AppCompatTextView
                            android:id="@+id/topic_title"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:layout_marginBottom="8dp"
                            android:layout_marginTop="8dp"
                            android:textAppearance="@style/TextAppearance.AppCompat.Title"/>

                        <android.support.v7.widget.AppCompatTextView
                            android:id="@+id/topic_content"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:textAppearance="@style/TextAppearance.AppCompat.Body1"/>
                    </LinearLayout>
                </android.support.v7.widget.CardView>

                <ProgressBar
                    android:id="@+id/reply_progressbar"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:indeterminate="true"
                    android:visibility="visible"/>

                <android.support.v7.widget.RecyclerView
                    android:id="@+id/list_of_replies"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:visibility="invisible"/>
            </LinearLayout>
        </ScrollView>
    </LinearLayout>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/reply_to_topic"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:clickable="true"
        android:src="@drawable/ic_reply_white_24dp"
        app:layout_anchor="@id/topic_card"
        app:layout_anchorGravity="bottom|right|end"/>

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

Here are some images -

Answer 1

When you have multiple scrolling Views in your layout (eg. RecyclerView + ScrollView) and when you scroll while in your recyclerView, the recyclerView scrolls with the parent Scrollview. this causes jitters in RecyclerView. You can avoid this jitter by the following.

You can add
android:nestedScrollingEnabled="false" to your RecyclerView in XML or
recyclerView.setNestedScrollingEnabled(false); to your RecyclerView in Java.

Answer 2

If you want to support devices older than api 21 then you should use

ViewCompat.setNestedScrollingEnabled(mRecyclerView, false);

in your Activity/Fragment