Documentation

Modules

OpenScales is composed by different modules described bellow.

openscales-viewer

Type : SWF application

Flex application that can configure a map dynamically thanks to a xml file URL passed as configurationUrl flashvar parameter

openscales-core

Type : ActionScript 3 library

OpenScale core module that contains main classes like Map, Layer, Handler ...

Key classes

OpenScales is composed by the following key concepts :

  • Map : the map is the main class in OpenScales. A map allows to display one or more layers on a specified extent. Extent and zoom level can change based on user input like mouse or keyboard.

  • Layer : a layer is a mapping data sources, usually available on a specific extent and zoom level ranges. There is 2 main kinds of layer :
    • Feature layer : data are geometries like points or polygons with some attributes and style information
    • Raster layer : data are geolocalized pictures
  • Handler : handlers listen to user input (mouse, keyboard) to move the map, zoom, draw features, etc.

  • Controls : GUI components used to display buttons, sliders that allows to control the map

Software design

OpenScales use the Map as a bus event useful for communication between modules in a loosely coupled way. For example, if you want to display a popup when a user click on a KML point feature, add a SelectFeatureHandler on your map and do a map.addEventListener(FeatureEvent.FEATURE_SELECTED, onFeatureSelected) in your application. You will be able to display a popup that will show feature attributes in the popup content.

When building your OpenScales based application, you will usually do this : listen to OpenScales events (MapEvent, LayerEvent, FeatureEvent) and build your own functionalities within a custom Flex user interface. Check openscales-fx-examples for more code samples.

If you need to support a new kind of Layer, for example, you will usually extend existing class like Layer, Grid of FeatureLayer to implements what you need. Feel free to send a patch on openscales.org site if you think this functionality may be integrated in our codebase.

openscales-proj4as

Type : ActionScript 3 library

It is a Proj.4 port in ActionScript 3. It provides reprojection functionnalities used to display layers with different projections (EPSG:4326, EPSG:90013) on the same map.

openscales-geometry

Type : ActionScript 3 library

Geometry classes like Location or Polygon

openscales-fx

Type : Flex library

Since openscales-core is developed in pure ActionScript 3 for size and performance reasons, openscales-fx provide some Flex components and wrappers useful to build easily OpenScales based applications using the power of Flex components.

openscales-as-example

Type : ActionScript 3 application

Pure ActionScript 3 demo application.

openscales-fx-examples

Type : Flex application

Sample Flex demo intended to show code samples and functionalities to application developers.

openscales-kml-viewer

Type : AIR application

Desktop application demo build with AIR.

openscales-mobile-tracker

Type : AIR mobile application

Mobile application demo build with AIR. This example has been tested under Android 2.2 (Froyo) on a HTC Desire device. You will have to register on http://labs.adobe.com/technologies/air2/android/ and follow instructions from Developing_AIR_Apps_for_Android.pdf and AIR_Android_ReleaseNotes.pdf

To make android packages, run the following command and use “os” as password when asked cd bin-debug adt -package -target apk -storetype pkcs12 -keystore ../../openscales.p12 MobileTracker.apk MobileTracker-app.xml MobileTracker.swf adb install -r MobileTracker.apk