Book Image

Android Studio 4.0 Development Essentials - Java Edition

By : Neil Smyth
Book Image

Android Studio 4.0 Development Essentials - Java Edition

By: Neil Smyth

Overview of this book

Android rolls out frequent updates to meet the demands of the dynamic mobile market and to enable its developer community to lead advancements in application development. This book focuses on the updated features of Android Studio (the fully integrated development environment launched by Google) to build reliable Android applications using Java. The book starts by outlining the steps necessary to set up an Android development and testing environment. You’ll then learn how to create user interfaces with the help of Android Studio Layout Editor, XML files, and by writing the code in Java. The book introduces you to Android architecture components and advanced topics such as intents, touchscreen handling, gesture recognition, multi-window support integration, and biometric authentication, and lets you explore key features of Android Studio 4.0, including the layout editor, direct reply notifications, and dynamic delivery. You’ll also cover Android Jetpack in detail and create a sample app project using the ViewModel component. Finally, you’ll upload your app to the Google Play Console and handle the build process with Gradle. By the end of this book, you’ll have gained the skills necessary to develop applications using Android Studio 4.0 and Java.
Table of Contents (88 chapters)
88
Index

42.9 Modifying the onOptionsItemSelected() Method

When items are selected from the menu, the overridden onOptionsItemsSelected() method of the application’s activity will be called. The role of this method will be to identify which item was selected and change the background color of the layout view to the corresponding color. Locate and double-click on the app -> java -> com.ebookfrenzy.menuexample -> MainActivity file and modify the method as follows:

package com.ebookfrenzy.menuexample;

 

import com.google.android.material.floatingactionbutton.FloatingActionButton;

import com.google.android.material.snackbar.Snackbar;

import androidx.appcompat.app.AppCompatActivity;

import androidx.appcompat.widget.Toolbar;

import android.view.View;

import android.view.Menu;

import android.view.MenuItem;

import androidx.constraintlayout.widget.ConstraintLayout;

 

public class MainActivity extends AppCompatActivity {

.

.

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