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The previous chapter introduced the basic concepts of creating and modifying user interface layouts in Kotlin code using the ConstraintLayout and ConstraintSet classes. This chapter will put these concepts into practice by creating an example layout created entirely in Kotlin code and without using the Android Studio Layout Editor tool. Creating the Example Project in…

Until this point in the book, all user interface design tasks have been performed using the Android Studio Layout Editor tool, either in text or design mode. An alternative to writing XML resource files or using the Android Studio Layout Editor is to write Kotlin code to directly create, configure and manipulate the view objects…

While the design of layouts using the Android Studio Layout Editor tool greatly improves productivity, it is still possible to create XML layouts by manually editing the underlying XML. This chapter will introduce the basics of the Android XML layout file format. Manually Creating an XML Layout The structure of an XML layout file is…

The easiest and most productive way to design a user interface for an Android application is to use the Android Studio Layout Editor tool. This chapter will provide an overview of how to create a ConstraintLayout-based user interface using this approach. The exercise included in this chapter will also be used as an opportunity to…

The previous chapters have introduced the key features of the ConstraintLayout class and outlined the best practices for ConstraintLayout-based user interface design within the Android Studio Layout Editor. Although the concepts of ConstraintLayout chains and ratios were outlined in the chapter entitled A Guide to the Android ConstraintLayout, we have not yet addressed how to…

As mentioned more than once in previous chapters, Google has made significant changes to the Android Studio Layout Editor tool, many of which were made solely to support user interface layout design using ConstraintLayout. Now that the basic concepts of ConstraintLayout have been outlined in the previous chapter, this chapter will explore these concepts in…

As discussed in the chapter entitled Android Views, View Groups, and Layouts, Android provides several layout managers to design user interfaces. With Android 7, Google introduced a layout that addressed many of the shortcomings of the older layout managers. This layout, called ConstraintLayout, combines a simple, expressive, and flexible layout system with powerful features built…

It is challenging to think of an Android application concept that does not require some form of user interface. Most Android devices come equipped with a touch screen and keyboard (either virtual or physical), and taps and swipes are the primary interaction between the user and the application. Invariably these interactions take place through the…

With the possible exception of listening to streaming audio, a user’s interaction with an Android device is primarily visual and tactile. All of this interaction occurs through the user interfaces of the applications installed on the device, including both the built-in applications and any third-party applications installed by the user. Therefore, it should come as…

If the previous few chapters have achieved their objective, it should now be clearer as to the importance of saving and restoring the state of a user interface at particular points in the lifetime of an activity. In this chapter, we will extend the example application created in Android Activity State Changes Tutorial to demonstrate…