Book Image

Android 9 Development Cookbook - Third Edition

By : Rick Boyer
Book Image

Android 9 Development Cookbook - Third Edition

By: Rick Boyer

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! With this extensively updated cookbook, you'll find solutions for working with the user interfaces, multitouch gestures, location awareness, web services, and device features such as the phone, camera, and accelerometer. You also get useful steps on packaging your app for the Android Market. Each recipe provides a clear solution and sample code you can use in your project from the outset. Whether you are writing your first app or your hundredth, this is a book that you will come back to time and time again, with its many tips and tricks on the rich features of Android Pie.
Table of Contents (24 chapters)
Title Page
Copyright and Credits
Dedication
About Packt
Contributors
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 recipes we use the XML onClick attribute, but more advanced listeners require to be set 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 a click event, as well as a long-press event.

Getting ready

Create a new project in Android Studio and call it PressEventsUse the default Phone & Tablet options and select Empty Activity on the Add an Activity to Mobile dialog.

How to do it...

Setting up to receive...