Adding Floating Action Button (Kotlin)

The Floating Action Button (FAB) is a circular button that triggers primary action in your app's UI. This tutorial shows you how to add the FAB to your layout , customize some of its appearance , and respond to the button taps. We will show Snackbar on FAB click.
We will use Kotlin and Android Studio.
Minimum API: Android 2.1 is API level 7

Step 1: Create a new project OR Open your project

Step 2: Add design library in build.gradle(Module:app) under dependencies{...}

implementation 'com.android.support:design:27.1.0'

Step 3: Place an image in res>drawable folder

Step 4: Code

activity_main.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:layout_width="match_parent"android:layout_height="match_parent"tools:context=".MainActivity"><TextViewandroid:id="@+id/textView"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Click Floating Action Button to show Toast..."android:textStyle="bold"android:layout_centerVertical="true"android:layout_centerHorizontal="true"/><android.support.design.widget.FloatingActionButtonandroid:id="@+id/fab"android:layout_width="wrap_content"android:layout_height="wrap_content"android:src="@drawable/done"android:layout_margin="16dp"android:layout_alignParentBottom="true"android:layout_alignParentEnd="true"android:layout_alignParentRight="true" /></RelativeLayout>

MainActivity.kt

package com.blogspot.devofandroid.myapplicationimport android.support.design.widget.FloatingActionButtonimport android.support.v7.app.AppCompatActivityimport android.os.Bundleimport android.widget.Toastclass MainActivity : AppCompatActivity() {override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContentView(R.layout.activity_main)val mFab = findViewById<FloatingActionButton>(R.id.fab)mFab.setOnClickListener {Toast.makeText(this@MainActivity , "FAB is clicked..." , Toast.LENGTH_LONG).show()}}}

Step 5: Run Project

Output