Category: Java

The previous chapter described the Android Jetpack Navigation Component and how it integrates with the navigation graphing features of Android Studio to provide an easy way to implement navigation between the screens of an Android app. In this chapter, a new Android Studio project will be created that uses these navigation features to implement an…

Very few Android apps today consist of just a single screen. In reality, most apps comprise multiple screens through which the user navigates using screen gestures, button clicks, and menu selections. Before the introduction of Android Jetpack, implementing navigation within an app was largely a manual coding process with no easy way to view and…

The previous chapter provided an overview of lifecycle awareness and outlined the key classes and interfaces that make this possible within an Android app project. This chapter will build on this knowledge base by building an Android Studio project to highlight lifecycle awareness in action. Creating the Example Lifecycle Project Select the New Project quick…

The earlier chapter, Android App and Activity Lifecycles described the use of lifecycle methods to track lifecycle state changes within a UI controller such as an activity or fragment. One of the main problems with these methods is that they place the burden of handling lifecycle changes onto the UI controller. On the surface, this…

The preservation and restoration of app state is about presenting the user with continuity in appearance and behavior after an app is placed in the background. Users expect to be able to switch from one app to another and, on returning to the original app, find it in the exact state it was in before…

In the chapter entitled “Modern Android App Architecture with Jetpack”, we introduced the concept of Android Data Binding. We explained how it is used to directly connect the views in a user interface layout to the methods and data located in other objects within an app without the need to write code. This chapter will…

The previous chapter began building an app to conform to the recommended Jetpack architecture guidelines. These initial steps involved implementing the data model for the app user interface within a ViewModel instance. This chapter will further enhance the app design using the LiveData architecture component. Once LiveData support has been added to the project in…

The previous chapter introduced the fundamental concepts of Android Jetpack and outlined the basics of modern Android app architecture. Jetpack defines a set of recommendations describing how an Android app project should be structured while providing a set of libraries and components that make it easier to conform to these guidelines to develop reliable apps…

As outlined in the previous chapter, fragments provide a convenient mechanism for creating reusable modules of application functionality consisting of both sections of a user interface and the corresponding behavior. Once created, fragments can be embedded within activities. Having explored the general theory of fragments in the previous chapter, this chapter aims to create an…

As you progress through the chapters of this book, it will become increasingly evident that many of the design concepts behind the Android system were conceived to promote the reuse of and interaction between the different elements that make up an application. One such area that will be explored in this chapter involves using Fragments.…