Book Image

Android Studio 3.5 Development Essentials - Java Edition

By : Neil Smyth
Book Image

Android Studio 3.5 Development Essentials - Java Edition

By: Neil Smyth

Overview of this book

Android applications have become an important part of our daily lives and lots of effort goes into developing an Android application. This book will help you to build you own Android applications using Java. Android Studio 3.5 Development Essentials – Java Edition first teaches you to install Android development and test environment on different operating systems. Next, you will create an Android app and a virtual device in Android Studio, and install an Android application on emulator. You will test apps on physical Android devices, then study Android Studio code editor and constraint layout, Android architecture, the anatomy of an Android app, and Android activity state changes. The book then covers advanced topics such as views and widgets implementation, multi-window support integration, and biometric authentication, and finally, you will learn to upload your app to Google Play console and handle the build process with Gradle. By the end of this book, you will have gained enough knowledge to develop powerful Android applications using Java.
Table of Contents (86 chapters)
86
Index

73.6 Checking for Microphone Availability

Attempting to record audio on a device without a microphone will cause the Android system to throw an exception. It is vital, therefore, that the code check for the presence of a microphone before making such an attempt. There are a number of ways of doing this, including checking for the physical presence of the device. An easier approach, and one that is more likely to work on different Android devices, is to ask the Android system if it has a package installed for a particular feature. This involves creating an instance of the Android PackageManager class and then making a call to the object’s hasSystemFeature() method. PackageManager.FEATURE_MICROPHONE is the feature of interest in this case.

For the purposes of this example, we will create a method named hasMicrophone() that may be called upon to check for the presence of a microphone. Within the Project tool window, locate and double-click on the MainActivity.java file and modify...