Book Image

OpenLayers 3: Beginner's Guide

By : Thomas Gratier, Paul Spencer, Erik Hazzard
Book Image

OpenLayers 3: Beginner's Guide

By: Thomas Gratier, Paul Spencer, Erik Hazzard

Overview of this book

<p>This book is a practical, hands-on guide that provides you with all the information you need to get started with mapping using the OpenLayers 3 library.</p> <p>The book starts off by showing you how to create a simple map. Through the course of the book, we will review each component needed to make a map in OpenLayers 3, and you will end up with a full-fledged web map application. You will learn the key role of each OpenLayers 3 component in making a map, and important mapping principles such as projections and layers. You will create your own data files and connect to backend servers for mapping. A key part of this book will also be dedicated to building a mapping application for mobile devices and its specific components.</p>
Table of Contents (22 chapters)
OpenLayers 3 Beginner's Guide
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Touch support in OpenLayers


One of the biggest differences between desktop and mobile web applications is how we interact with an application. On a desktop or laptop computer, we have a keyboard and a mouse or trackpad, and we point and click or click and drag things. On mobile devices though, there is no keyboard and no mouse pointer. Instead, we use our fingers, and we do things like touch, drag, and tap. We can also do more complicated things, such as pinching two fingers together or rotating two fingers, and we usually expect this to do something in an application. In mapping applications on touch devices, for instance, we might expect that dragging a finger will pan the map and pinching two fingers will zoom in or out.

OpenLayers provides touch support for us in the form of interactions—recall that we talked about interactions in Chapter 8, Interacting with Your Map. The touch-specific interactions are as follows:

  • ol.interaction.DragPan: This pans the map in response to one or more fingers...