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OpenLayers 2.10 Beginner's Guide

OpenLayers 2.10 Beginner's Guide

4.2 (9)
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OpenLayers 2.10 Beginner's Guide

OpenLayers 2.10 Beginner's Guide

4.2 (9)

Overview of this book

Table of Contents (18 chapters)
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OpenLayers 2.10
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Time for Action – setting zoom levels and maxExtent


  1. Create your map object, by specifying the numZoomLevels and adding a PanZoomBar control. We'll also set the numZoomLevels property to 8, meaning that only eight zoom levels will be available. Lastly, we'll set the maxExtent property to include just a subset of the world, like the following:

    map = new OpenLayers.Map('map_element', {
      controls: [
        new OpenLayers.Control.Navigation(),
        new OpenLayers.Control.PanZoomBar(),
        new OpenLayers.Control.LayerSwitcher()
      ],
      numZoomLevels: 8,
      maxExtent: new OpenLayers.Bounds(-100, -30, 40, 30)
    });
  2. Open up the page, and you should see something like this:

What Just Happened?

Our map has only eight zoom levels and a maximum extent of (-100, -30, 40, 30). You must have noticed that the map started at a zoom level that is zoomed in a couple of times. This is mainly due to the fact that the furthest out zoom level would show more than the maximum extent of the map. Let's quickly talk about...

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