Thunderhead Explorer

The Holistic micro-architecture framework for building RIAs and RMAs (Rich Mobile Applications) "borrows" from Robotlegs , PureMVC , Cairngorm , SWIZ ,  AS3Signals and the SpringFramework . Each has one or two things that I really like about it, but what I wanted is to bring all these things into one simple, very lightweight framework that enables me to quickly and more importantly methodically build mobile, web and desktop applications. This Holistic API is designed to work on top of either the Flex web or mobile framework and takes advantage of the Flex compiler, environment and lifecycle. Several "design patterns" are utilized in the API, such as Model-View-Controller , Loose Coupling, Locator , Usage of Interface, Delegation , Dependency Injection , Separation of Concerns and Inversion Of Control , not sure if some of latter are pure design patterns per GoF , but bear with me :-) One thing that is heavily relied on, is programming to convention versus progr...

So… Google introduced an offline feature to their mobile mapping application, enabling you to view map tiles when you are disconnected from the network. This is pretty neat and very useful now that local storage is so “abundant” on mobile devices. In this post, I would like to show you how to use the mobile device local storage for offline tile retrieval using the ArcGIS API for Flex . When we built the API, we always had the vision of extensibility to enable people to do things that we did not think about. One of then was to enable the control of the URL from where the tiles will be retrieved. A while back, I did such an implementation using Amazon S3 . So, I rehashed that code using Adobe AIR File capabilities. The demo application that I am featuring here operates in two modes; an online mode and an offline mode. In the online mode, I keep a set all downloaded tiles for a particular viewing session. Before I go offline, I download the map server metadata and all the visited tile...

So the Flex Spark architecture promotes the separation of a component model/controller from its view, or in Flex lingo, its skin. Here is the PITA process that I go throughout when creating a skinnable component manually: I create an ActionScript class (the host component) that subclasses SkinnableComponent. I define and annotate the skin parts. I try to define the skin part types to be as high as possible in the class hierarchy. What I mean by that is instead of defining a part to be of type Button, I make it of type ButtonBase. I override the partAdded function and add all the event listeners for each part, as event handling should be done in the host component not in the skin. I override the partRemoved function and remove all the added event listeners, as I want to be a “good citizen”. I create a subclass of Skin and associate it with the host component. I add the skin parts and any graphic elements to make it “pretty”. I “ClassReference” the skin to its host component as ...

The ArcGIS API for Flex is pretty amazing and very powerful, but it is very GIS centric. Flex Programmers have to know for example the difference between mercator and geographical coordinates systems and have to understand the concepts of map layers, etc…. Programmers just want to put dots on maps at a specific latitude and longitude. This is very easy to do say for example using the google map API and folks have been asking for something like that for a while. So, I am please to tell you about an open source project that we have launched on github that is exactly that. A simple mapping API that is based on the core API to enable Flex developers to build mapping applications. The idea to open source the project is to let you see how some high level functions are implemented using the low level API. Here is a quick sample: <?xml version="1.0" encoding="utf-8"?> <s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s=...

At this year's DevSummit , I did a couple of demo theater presentations. One of them was about hacking the Microsoft Kinect using the Flash platform in a mapping application. Here is a video. Kinect is a very successful and important product for Microsoft. And if you ever played with it using an XBox, you will understand why it is a very neat piece of technology. Now, have you see the movie " Minority Report " ? Remember in the beginning of the movie when Tom Cruise step up to a console and started waving his hands to manipulate images ( video )? One of the gestures that most fascinated me was the one where he twisted his wrist while his fingers were pretending to grab a baseball size object. That twisting gesture moved a sequence of images through time. Twist to the right and the sequence moves forward in time. Twist to the left and the sequence moves back in time. In the movie, he went back and forth to detect a pattern in that time sequence. Now, wouldn't be c...