Extended Floating Action Button Gist Files

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.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"
    android:background="#EDEEEF"
    tools:context=".MainActivity">

    <androidx.core.widget.NestedScrollView
        android:id="@+id/nestedScrollView"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <!-- Linear layout to contain 2 text view and button -->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <!-- showing random text 1 from strings.xml file -->
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />
            <include layout="@layout/scroll_item" />

        </LinearLayout>

    </androidx.core.widget.NestedScrollView>

    <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
        android:id="@+id/extendedFab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:layout_gravity="bottom|end"
        android:text="Compose"
        app:icon="@drawable/ic_edit"/>

</androidx.coordinatorlayout.widget.CoordinatorLayout>

ic_edit.xml

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="24dp"
    android:height="24dp"
    android:viewportWidth="24"
    android:viewportHeight="24"
    android:tint="?attr/colorControlNormal">
  <path
      android:fillColor="@android:color/white"
      android:pathData="M3,17.25V21h3.75L17.81,9.94l-3.75,-3.75L3,17.25zM20.71,7.04c0.39,-0.39 0.39,-1.02 0,-1.41l-2.34,-2.34c-0.39,-0.39 -1.02,-0.39 -1.41,0l-1.83,1.83 3.75,3.75 1.83,-1.83z"/>
</vector>

MainActivity.kt

package com.sriyank.mdccomponents

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import androidx.core.widget.NestedScrollView
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        nestedScrollView.setOnScrollChangeListener(NestedScrollView.OnScrollChangeListener { v, scrollX, scrollY, oldScrollX, oldScrollY ->
            if (scrollY > oldScrollY + 20 && extendedFab.isExtended) {     // Scroll Down
                extendedFab.shrink()
            }

            if(scrollY < oldScrollY - 20 && !extendedFab.isExtended) {      // Scroll Up
                extendedFab.extend()
            }

            if (scrollY == 0) {     // At the top
                extendedFab.extend()
            }
        })
    }

    private fun showToast(str: String) {
        Toast.makeText(this, str, Toast.LENGTH_SHORT).show()
    }
}

recycler-view-code-snippet.txt

    recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {

        override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
            super.onScrolled(recyclerView, dx, dy)

            // Scroll down
            if (dy > 20 && extendedFab.isExtended) {
                extendedFab.shrink()
            }

            // Scroll up
            if (dy < -20 && !extendedFab.isExtended) {
                extendedFab.extend()
            }

            // At the top
            if (!recyclerView.canScrollVertically(-1)) {
                extendedFab.extend()
            }
        }
    })

scroll_item.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginStart="1dp"
    android:layout_marginEnd="1dp"
    android:layout_marginBottom="2dp"
    android:padding="20dp"
    android:background="#EFEDED"
    android:text="Sample Row Item"
    android:textColor="@android:color/black"
    android:textSize="18sp" />