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

26. Android Touch and Multi-touch Event Handling

Most Android based devices use a touch screen as the primary interface between user and device. The previous chapter introduced the mechanism by which a touch on the screen translates into an action within a running Android application. There is, however, much more to touch event handling than responding to a single finger tap on a view object. Most Android devices can, for example, detect more than one touch at a time. Nor are touches limited to a single point on the device display. Touches can, of course, be dynamic as the user slides one or more points of contact across the surface of the screen.

Touches can also be interpreted by an application as a gesture. Consider, for example, that a horizontal swipe is typically used to turn the page of an eBook, or how a pinching motion can be used to zoom in and out of an image displayed on the screen.

This chapter will explain the handling of touches that involve motion and explore...