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

38.6 Making the Toolbar Fragment Talk to the Activity

When the user touches the button in the toolbar fragment, the fragment class is going to need to get the text from the EditText view and the current value of the SeekBar and send them to the text fragment. As outlined in “An Introduction to Android Fragments”, fragments should not communicate with each other directly, instead using the activity in which they are embedded as an intermediary.

The first step in this process is to make sure that the toolbar fragment responds to the button being clicked. We also need to implement some code to keep track of the value of the SeekBar view. For the purposes of this example, we will implement these listeners within the ToolbarFragment class. Select the ToolbarFragment.kt file and modify it so that it reads as shown in the following listing:

package com.ebookfrenzy.fragmentexample

 

import android.os.Bundle

import androidx.fragment.app.Fragment

import...