Collapsible Toolbar - Make Fragment Footer Always Visible in Android

I had the same requirement for my one of apps. I just did workaround.
Add your required layout in tab layout:

<android.support.design.widget.CoordinatorLayout       xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:app="http://schemas.android.com/apk/res-auto"   android:id="@+id/main_content"   android:layout_width="match_parent"   android:layout_height="match_parent">    <android.support.design.widget.AppBarLayout        android:id="@+id/appbar"        android:layout_width="match_parent"        android:layout_height="256dp"        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">        <android.support.design.widget.CollapsingToolbarLayout            android:id="@+id/collapsing_toolbar"            android:layout_width="match_parent"            contentScrim="?attr/colorPrimary"            android:layout_height="match_parent"            app:layout_scrollFlags="scroll|exitUntilCollapsed">            <ImageView                android:id="@+id/profile_image"                android:layout_width="match_parent"                android:layout_height="match_parent"                android:fitsSystemWindows="true"                android:scaleType="centerCrop"                android:contentDescription="@string/profile_photo"                app:layout_collapseMode="none"/>            <android.support.v7.widget.Toolbar                android:id="@+id/toolbar"                android:layout_width="match_parent"                android:layout_height="?attr/actionBarSize"                app:layout_collapseMode="pin">                <ImageView                    android:id="@+id/toolbarEdit"                    android:layout_width="wrap_content"                    android:layout_height="wrap_content"                    android:layout_gravity="end"                    android:contentDescription="@string/block"                    android:paddingEnd="20dp"                    android:paddingStart="5dp"                    app:srcCompat="@drawable/ic_icon_edit" />            </android.support.v7.widget.Toolbar>        </android.support.design.widget.CollapsingToolbarLayout>    </android.support.design.widget.AppBarLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="fill_parent"        android:orientation="vertical"        app:layout_behavior="@string/appbar_scrolling_view_behavior">        <android.support.design.widget.TabLayout            android:id="@+id/myProfileTabs"            android:layout_width="match_parent"            android:layout_height="?attr/actionBarSize"            android:layout_gravity="bottom"            app:tabContentStart="72dp"            app:tabGravity="fill"            app:tabMode="scrollable" />        <android.support.v4.view.ViewPager            android:id="@+id/myProfileViewpager"            android:layout_width="match_parent"            android:layout_height="match_parent"            app:layout_behavior="@string/appbar_scrolling_view_behavior" />    </LinearLayout>    <-- Your required layout -->    <LinearLayout        android:id="@+id/tab123"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_gravity="bottom"        android:gravity="bottom"        android:orientation="horizontal"        android:visibility="gone"        android:weightSum="4">        <EditText            android:id="@+id/inputMsg"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="3"            android:paddingLeft="6dp"            android:paddingRight="6dp" />        <Button            android:id="@+id/btnSend"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_weight="1"            android:text="send" />    </LinearLayout></android.support.design.widget.CoordinatorLayout>

Add following code in your Tab activity:

TabLayout tabLayout;    tabLayout = (TabLayout) findViewById(R.id.tabs);tabLayout.setupWithViewPager(viewPager);//add your viewpager to TabLayout tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {    @Override    public void onTabSelected(TabLayout.Tab tab) {        viewPager.setCurrentItem(tab.getPosition());        LinearLayout l=(LinearLayout) findViewById(R.id.tab123);        final EditText text=(EditText) findViewById(R.id.inputMsg);        Button send=(Button) findViewById(R.id.btnSend);        if (tab.getPosition() == 0) {            l.setVisibility(View.GONE);            System.out.println("About tab");        } else if (tab.getPosition() == 1) {            l.setVisibility(View.VISIBLE);            System.out.println("Posts tab");            send.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    String msg = null;                    msg = text.getText().toString(); //get input                    // Perform your desired task.                }            });        } else if (tab.getPosition() == 2) {            l.setVisibility(View.VISIBLE);            System.out.println("Gallery tab");            send.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    String msg = null;                    msg = text.getText().toString(); //get input                    //Perform your desired task.                }            });        }    }    @Override    public void onTabUnselected(TabLayout.Tab tab) {    }    @Override    public void onTabReselected(TabLayout.Tab tab) {    }});