Book Image

Mastering OpenLayers 3

By : Gábor Farkas
Book Image

Mastering OpenLayers 3

By: Gábor Farkas

Overview of this book

OpenLayers 3 allows you to create stunning web mapping and WebGIS applications. It uses modern, cutting edge browser technologies. It is written with Closure Library, enabling you to build browser-independent applications without painful debugging ceremonies, which even have some limited fallback options for older browsers. With this guide, you will be introduced to the world of advanced web mapping and WebGIS. First, you will be introduced to the advanced features and functionalities available in OpenLayers 3. Next, you will be taken through the key points of creating custom applications with OpenLayers 3. You will then learn how to create the web mapping application of yours (or your company's) dream with this open source, expense-free, yet very powerful library. We’ll also show you how to make amazing looking thematic maps and create great effects with canvas manipulation. By the end of this book, you will have a strong command of web mapping and will be well on your way to creating amazing applications using OpenLayers 3.
Table of Contents (17 chapters)
Mastering OpenLayers 3
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Creating new interactions


Creating new interactions is a little different than creating new controls. Instead of using a single root class, we can use ol.interaction.Pointer and ol.interaction.Interaction. We will cover, in this chapter, why we should use the pointer class. In this example, called ch05_pointer, we will implement two custom interactions. One for removing features and one for dragging features. Firstly, we define some CSS rules for our new controls, as usual:

.toolbar .ol-removefeat button {
    background-image: url(../../res/button_removefeat.png);
}
.toolbar .ol-dragfeat button {
    background-image: url(../../res/button_dragfeat.png);
}

Understanding ol.interaction.Pointer

Before creating some custom interaction, let's discuss how the pointer interaction works and how we can utilize it for our needs. This simple class can be constructed with five different event handler functions. The handleEvent function overrides every other handler and allows us to freely decide what...