Book Image

Android Studio 4.0 Development Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 4.0 Development Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Kotlin as an Android-compatible programming language is becoming increasingly popular. Fully updated for Android Studio 4.0, this book will teach you the skills necessary to develop Android-based applications using Kotlin. Starting with the basics, this book outlines the steps necessary to set up Android development and testing environments, and goes on to introduce you to programming in Kotlin. You’ll practice Java to Kotlin code conversion and explore data types, operators, expressions, loops, functions, as well as the basics of OOP in Kotlin. You’ll then learn about Android architecture components and advanced topics, such as intents, touchscreen handling, gesture recognition, multi-window support integration, and biometric authentication. As you make progress, you’ll explore Android Studio 4.0’s key features, including layout editor, direct reply notifications, and dynamic delivery. You’ll also delve into Android Jetpack and create a sample app project using ViewModel, the Android Jetpack component. Finally, you will upload your app to Google Play Console and model the build process using Gradle. By the end of this Android book, you’ll be fully prepared to develop applications using Android Studio 4.0 and Kotlin.
Table of Contents (97 chapters)
97
Index

30.4 Constraint Sets

While property settings are internal to view objects and dictate how a view appears and behaves, constraint sets are used to control how a view appears relative to its parent view and other sibling views. Every ConstraintLayout instance has associated with it a set of constraints that define how its child views are positioned and constrained.

The key to working with constraint sets in Kotlin code is the ConstraintSet class. This class contains a range of methods that allow tasks such as creating, configuring and applying constraints to a ConstraintLayout instance. In addition, the current constraints for a ConstraintLayout instance may be copied into a ConstraintSet object and used to apply the same constraints to other layouts (with or without modifications).

A ConstraintSet instance is created just like any other Kotlin object:

val set = ConstraintSet()

Once a constraint set has been created, methods can be called on the instance to perform a wide...