Book Image

Android Application Development Cookbook - Second Edition

By : Kyle Mew
Book Image

Android Application Development Cookbook - Second Edition

By: Kyle Mew

Overview of this book

The Android OS has the largest installation base of any operating system in the world; there has never been a better time to learn Android development to write your own applications, or to make your own contributions to the open source community! This “cookbook” will make it easy for you to jump to a topic of interest and get what you need to implement the feature in your own application. If you are new to Android and learn best by “doing,” then this book will provide many topics of interest. Starting with the basics of Android development, we move on to more advanced concepts, and we’ll guide you through common tasks developers struggle to solve. The first few chapters cover the basics including Activities, Layouts, Widgets, and the Menu. From there, we cover fragments and data storage (including SQLite), device sensors, the camera, and GPS. Then we move on more advanced topics such as graphics and animation (including OpenGL), multi-threading with AsyncTask, and Internet functionality with Volley. We’ll also demonstrate Google Maps and Google Cloud Messaging (also known as Push Notifications) using the Google API Library. Finally, we’ll take a look at several online services designed especially for Android development. Take your application big-time with full Internet web services without having to become a server admin by leveraging the power of Backend as a Service (BaaS) providers.
Table of Contents (23 chapters)
Android Application Development Cookbook Second Edition
Credits
Disclaimer
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Listening for click and long-press events


Almost every application needs to recognize and respond to basic events such as clicks and long-presses. It's so basic, in most of the recipes, we use the XML onClick attribute, but the more advanced listeners require setting up through code.

Android provides an Event Listener interface for receiving a single notification when certain actions occur, as shown in the following list:

  • onClick(): It's called when a View is pressed

  • onLongClick(): It's called when the View is long-pressed

  • onFocusChange(): It's called when the user navigates to or from the View

  • onKey(): It's called when a hardware key is pressed or released

  • onTouch(): It's called when a touch event occurs

This recipe will demonstrate responding to the click event, as well as the long-press event.

Getting ready

Create a new project in Android Studio and call it: PressEvents. Use the default Phone & Tablet options and select Empty Activity when prompted for the Activity Type.

How to do it....