Hello Readers! In this post, we are going to learn how to create and use android floating action button programmatically in any android application. We will also learn to add floating action button in linearLayout programmatically in any application.

Output

Tutorialwing Dynamic Floating Action Button Output

Getting Started

At first, we will create an android application. Then, we will use floating action button widget in the application.

1. Creating New Project

Follow the steps below to create a new project. Please ignore the steps if you have already created a new project.

Now, we will modify xml and java file to use android floating action button programmatically.

2. Modify values folder

Open res/values/strings.xml file and add below code into it.

<resources>
	<string name="app_name">DynamicFloatingActionButton</string>
	<string name="message">Floating Action Button has been created dynamically. Click on it to see Toast message.</string>
</resources>

Open res/values/styles.xml file. Then, add below code into it.

<resources>

	<!-- Base application theme. -->
	<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
		<!-- Customize your theme here. -->
		<item name="colorPrimary">@color/colorPrimary</item>
		<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
		<item name="colorAccent">@color/colorAccent</item>
	</style>

	<style name="AppTheme.AppBarOverlay" parent="AppTheme">
	</style>

	<style name="AppTheme.PopupOverlay" parent="AppTheme">
	</style>

</resources>

3. Define main content xml file

Now, we will create and xml file, content_main.xml, in res/layout folder. This file contains code related to main ui in the application. Then, add below code into it.

<?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"
	app:layout_behavior="@string/appbar_scrolling_view_behavior"
	tools:showIn="@layout/activity_main">

	<TextView
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_centerInParent="true"
		android:layout_margin="40dp"
		android:text="@string/message"/>

</RelativeLayout>

Note – This is optional step. You may not need it based on your application structure.

4. Create Container for Floating Action Button Widget

Open res/layout/activity_main.xml file. Then, add below code into it.

<?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"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:fitsSystemWindows="true">

	<android.support.design.widget.AppBarLayout
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:theme="@style/AppTheme.AppBarOverlay">

		<android.support.v7.widget.Toolbar
			android:id="@+id/toolbar"
			android:layout_width="match_parent"
			android:layout_height="?android:attr/actionBarSize"
			android:background="@color/colorPrimary"
			app:popupTheme="@style/AppTheme.PopupOverlay"
			app:titleTextColor="@android:color/white"/>

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

	<include layout="@layout/content_main"/>

	<LinearLayout
		android:id="@+id/rootContainer"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:layout_gravity="bottom|end"
		android:orientation="vertical">

	</LinearLayout>

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

In activity_main.xml file, linearLayout with id rootContainer will act as container for the android floating action button created programmatically in the application. Other parts are just to show different other ui parts in the application. Now, we will create floating button dynamically and add it to linearLayout container.

5. Create Android Floating Action Button Programmatically / Dynamically

Open app/src/main/java/com.tutorialwing.dynamicfloatingactionbutton/MainActivity.java file and add below code into it.

package com.tutorialwing.dynamicfloatingactionbutton;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		Toolbar toolbar = findViewById(R.id.toolbar);
		setSupportActionBar(toolbar);

		FloatingActionButton floatingActionButton = new FloatingActionButton(this);

		LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
		layoutParams.setMargins(32, 32, 32, 32);
		floatingActionButton.setLayoutParams(layoutParams);
		floatingActionButton.setImageResource(android.R.drawable.ic_dialog_email);
		floatingActionButton.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View view) {
				// We are showing only toast message. However, you can do anything you need.
				Toast.makeText(getApplicationContext(), "You clicked Floating Action Button", Toast.LENGTH_SHORT).show();
			}
		});

		LinearLayout linearLayout = findViewById(R.id.rootContainer);
		if (linearLayout != null) {
			linearLayout.addView(floatingActionButton);
		}
	}
}

Here, we have created android floating action button programmatically. Then, we have set it’s layout params, click listener to show toast message when it is clicked, margins etc. Then, finally, we have added floating action button to linearLayout having id rootContainer.

Since AndroidManifest.xml file is very important in any android project. We are also going to see the content inside this file.

AndroidManifest.xml file

Code inside src/main/AndroidManifest.xml file would look like below –

<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.tutorialwing.dynamicfloatingactionbutton"
		  xmlns:android="http://schemas.android.com/apk/res/android">

	<application
		android:allowBackup="true"
		android:icon="@mipmap/ic_launcher"
		android:label="@string/app_name"
		android:roundIcon="@mipmap/ic_launcher_round"
		android:supportsRtl="true"
		android:theme="@style/AppTheme">
		<activity android:name=".MainActivity">
			<intent-filter>
				<action android:name="android.intent.action.MAIN"/>

				<category android:name="android.intent.category.LAUNCHER"/>
			</intent-filter>
		</activity>
	</application>

</manifest>

When we run the application, we will get output as shown above.

That’s the end of tutorial on Creating Android Floating Action Button Programmatically.