Book Image

Android Studio Arctic Fox Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio Arctic Fox Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Android Studio is an Integrated Development Environment based on the JetBrains IntelliJ IDEA. It offers developers a unique platform to design and develop Android apps using various developer tools. Fully updated for Android Studio Arctic Fox, the goal of this book is to teach the skills necessary to develop Android-based applications using the Kotlin programming language. This book begins with an outline of the steps necessary to set up an Android development and testing environment, followed by an introduction to programming in Kotlin which includes data types, control flow, functions, lambdas, and object-oriented programming. An overview of Android Studio covers areas such as tool windows, the code editor, and the layout editor tool. An introduction to the architecture of Android is followed by an in-depth look at the design of Android applications and user interfaces using the Android Studio environment. Early chapters detail Android architecture components such as view models, lifecycle management, Room database access, the Database Inspector, app navigation, live data, and data binding. More advanced topics such as intents are also covered, as are touch screen handling, gesture recognition, and the recording and playback of audio. This edition of the book also covers printing, transitions, cloud-based file storage, and foldable device support. The concepts of material design are also discussed in detail, including the use of floating action buttons, Snackbars, tabbed interfaces, card views, navigation drawers, and collapsing toolbars. Other key features of Android Studio Arctic Fox and Android taught in this book include the Layout Editor, the ConstraintLayout and ConstraintSet classes, MotionLayout Editor, view binding, constraint chains, barriers, and direct reply to notifications. Chapters also explore more advanced features of Android Studio such as app links, dynamic delivery, Gradle build configuration, and submitting apps to the Google Play developer console.
Table of Contents (93 chapters)
93
Index

73.2 Key Elements of Room Database Persistence

Before going into greater detail later in the chapter, it is first worth summarizing the key elements involved in working with SQLite databases using the Room persistence library:

73.2.1 Repository

As previously discussed, the repository module contains all of the code necessary for directly handling all data sources used by the app. This avoids the need for the UI controller and ViewModel to contain code that directly accesses sources such as databases or web services.

73.2.2 Room Database

The room database object provides the interface to the underlying SQLite database. It also provides the repository with access to the Data Access Object (DAO). An app should only have one room database instance which may then be used to access multiple database tables.

73.2.3 Data Access Object (DAO)

The DAO contains the SQL statements required by the repository to insert, retrieve and delete data within the SQLite database. These...