Book Image

Android Programming for Beginners - Third Edition

By : John Horton
Book Image

Android Programming for Beginners - Third Edition

By: John Horton

Overview of this book

Do you want to make a career in programming but don’t know where to start? Do you have a great idea for an app but don't know how to make it a reality? Or are you worried that you’ll have to learn Java programming to become an Android developer? Look no further! This new and expanded third edition of Android Programming for Beginners will be your guide to creating Android applications from scratch. The book starts by introducing you to all the fundamental concepts of programming in an Android context, from the basics of Java to working with the Android API. You’ll learn with the help of examples that use up-to-date API classes and are created within Android Studio, the official Android development environment that helps supercharge your mobile application development process. After a crash course on the key programming concepts, you’ll explore Android programming and get to grips with creating applications with a professional-standard UI using fragments and storing user data with SQLite. This Android Java book also shows you how you can make your apps multilingual, draw on the screen with a finger, and work with graphics, sound, and animations. By the end of this Android programming book, you'll be ready to start building your own custom applications in Android and Java.
Table of Contents (30 chapters)

Building a precise UI with ConstraintLayout

Open the ConstraintLayout that was autogenerated when we created the project. It is probably open already in a tab at the top of the editor. If not, it will be in the res/layout folder. The filename is activity_main.xml.

Inspect the XML in the Code tab and note that it is empty, apart from a TextView that says Hello World. Switch back to the Design tab, left-click the TextView to select it, and tap the Delete key to get rid of it.

Now, we can build ourselves a simple yet intricate UI. The ConstraintLayout is most useful when you want to position parts of your UI very precisely and/or relative to the other parts and not just in a linear fashion.

Adding a CalendarView

To get started, look in the Widgets category of the palette and find the CalendarView. Drag and drop the CalendarView near the top and horizontally central. As you drag the CalendarView around, notice that it jumps/snaps to some locations.

Also, notice the subtle...