The endless repaint.

Yet another JavaFX App !

2010-05-25T13:43:00.000-07:00

Being a Java EE developer,I am always attracted towards the "grass on the other side" :P . I have been working on a JavaFX app, which tries to solve a typical engineering problem of loading cargo containers to a BeechCraft 1900C cargo airplane. Although the aircraft data and equations are taken from the authentic FAA weight and balance handbook (see Chapter 7 , page 60) , this application is not intended to be used for realtime cargo loading as it is just for JavaFX demo purposes and does not guarantee the accuracy of data and calculations. I must say again, being a newbie to the language its fun to learn JavaFX. Although I still regret not visiting Amy Fowlers blog post during the early stages of this app . Shown below is the screen-shot of the work done till date. Shown on the upper left side of the screen-shot are cargo containers which are supposed to be loaded on the horizontal cross section of Beechcraft main deck shown on the center-top. The parallel red blocks denotes left and right position of sections where cargo containers can be placed. Just below the red blocks is a scale which shows the section names and their distance in inches from a reference point referred as 'Datum' which in our case is aircraft's nose. So starting from Nose at 0 inches from datum , the tail of the aircraft is at 533 inches. The cargo containers are of different weights which can be seen by a mouse-hover tool-tip. User can drag these containers and place it on the aircraft's deck , which recalculates the center of gravity of the aircraft. The line chart on the lower right is Weight vs CG chart.It is actually combination or 3 overlapped line charts, One is in which the polygons are drawn, 2nd is with no data , but with X and Y axis on opposite sides, and the 3rd one contains just one yellow dot. The polygons drawn inside these charts are operational center of gravity limits defined by aircraft manufacturer. The yellow dot in the chart denotes the current center of gravity of the aircraft which gets updated when you place a container on the deck, The yellow dot(CG) should fall within these polygons (operational limits), otherwise the aircraft is either nose heavy or tail heavy. The data grid in the center is the XTableView control from JFXtras library (they have some nice controls and utilities for JavaFX). Parameters in this table are dynamically updated when the container is placed on the deck . The pie-chart on the lower left shows the total traffic weight of an aircraft by showing weight covered by each section of the deck. You can also click on these charts to get a larger view. Double click the dropped container to revert it back from the deck to the container panel. Just below the Main Deck is a JavaFx Toolbar component which contains normal and toogle buttons styled using an external CSS file. A user can revert back all the placed containers by clicking on the "Reset Containers" button. The animation on drag-drop can be toggled using the "Disable Animation" button on the toolbar. By default weight of each cargo containers can bee seen on the tool-tip displayed by the mouse-hover, optionally one can choose to quick view/hide weights on the containers by toggling the "View Weights" . Do check out the help and about buttons for more information about the application.

Launch Application | Checkout Source code

I am improving this application when ever I get free time and I will be updating the source code to JFxtras repository to ensure its compatibility with future releases of JavaFx Please let me know your valuable feedback.

My first experience with JavaFx Charts

2010-02-18T05:49:00.000-08:00

In one of my previous projects I was involved in developing a 2D line chart which shows the center of gravity of large cargo aircrafts like Airbus A380 and Boeing 747 etc .We used Java2D with more than a thousand lines of code and Richfaces paint2D to draw it as an image on a JSF web page .Being a newbie to the language, I was just wondering how much effort can it take to develop such a chart in JavaFx . I finally managed some time to try it out. So this chart is a Weight vs. Index chart where weight of the aircraft is on the y-axis and change in center of gravity index is on the x-axis. The polygons drawn inside the chart reflect the structural limits of an aircraft. If your current (index,weight) point falls outside these polygons in a certain condition, than the aircraft cannot fly because it is either nose-heavy or tail-heavy so it will crash.

I was able to create the chart shown in the image above with almost 105 lines of code excluding the data inputs,in almost 3 hours. JavaFX charting takes care of drawing axis and tickmarks, tickmark gaps, axis and axis-label gaps, scaling factors, title, legend attributes and many more things like anti-aliasing and drop shadows. You just need to bother about configuring it and providing the chart data.

Launch it here.

Download source code

Bye Bye Zembly :(

2009-11-21T12:55:00.000-08:00

This is in the memory of my favourite social programming platform Zembly which was an interesting attempt of Sun Microsystems making easy writing the applications for social platforms such as Facebook, Orkut, Meebo, OpenSocial and the iPhone by sharing services and widgets with the developer community. One of my blog post posted earlier this year, has a JavaFX Piano widget hosted on Zembly , and one of the JQuery games which I couldnt manage to finish :( . So far I dont know clearly why its being shut down, below is an excerpt from the mail which I received from Sun.

"We regret to inform you that on November 30th, 2009 we will be suspending this service.

More than three years ago, we started this project with the goal of making it easy to create next-generation Web apps. Our original tagline was "Build the web, using the web," and the ideas we were incubating around platform-mediated Web applications, Web API mashups, and social programming were brand new.

We learned a lot along the way. Your confidence and enthusiasm helped us improve the project and do amazing things that we never imagined when we began this journey.

Thank you to everyone who's been with us through the ups and downs. It's heartening to see that many of the best ideas pioneered in zembly have started to appear elsewhere. With your support, we're proud to have contributed to the DNA of the Web. "

All I want to say to the Zembly team is that,hats off to you people, you guys built an incredible social programming platform. I had learned a lot by cloning widgets contributed by you guys.

JavaFX 1.2+ Spring + Hibernate

2009-09-04T12:48:00.001-07:00

Related to discussions going on in BoJUG, I was tempted to develop a Proof-of-Concept for using JavaFX as view technology in a web application backed by spring and hibernate stack . Well Spring already provides remoting support for communicating to rich clients. Currently,spring supports four remoting technologies .
In my application, I am using Spring's HTTP Invoker which allows for Java serialization via HTTP, supporting any Java interface (just like the RMI invoker). The corresponding support classes are

1) org.springframework.remoting.httpinvoker.HttpInvokerProxyFactoryBean

is a factory bean for HTTP invoker proxies. It behaves like the proxied service when used as bean reference, exposing the specified service interface. Serializes remote invocation objects and deserializes remote invocation result objects.

2) org.springframework.remoting.httpinvoker.HttpInvokerServiceExporter

is an HTTP request handler that exports the specified service bean as HTTP invoker service endpoint, accessible via an HTTP invoker proxy.It deserializes remote invocation objects and serializes remote invocation result objects.

I started of with developing an application that fetches and displays employee data using JavaFX,Spring and Hibernate.
The whole application was developed as 2 separate Netbeans projects.

1)empFXClient : is a JavaFX application.
2)empRemote: is a web application that uses empFXClient as view by embedding it as an applet inside a web page.

You can browse the code for both the projects online here . If you have Netbeans 6.5 and/or an SVN client then you can check out both the netbeans projects locally from kenai using the following URL and play with it.

https://kenai.com/svn/fxspring~svn-repository (requires kenai registeration)

We require 2 config files on the server side
1)web.xml

contextConfigLocation
/WEB-INF/empapp-servlet.xml


org.springframework.web.context.ContextLoaderListener


empapp
org.springframework.web.servlet.DispatcherServlet
1


empapp
/empapp/*


30


index.jsp

2)empapp-servlet.xml






  
      
      
      
      
  
  
      
          
      
  
  
      
      
          
              com/empapp/persistence/Employee.hbm.xml
          
      
      
          
      hibernate.dialect=org.hibernate.dialect.MySQLDialect

Spring Http invoker uses Java serialization just like RMI, but provides the same ease of setup
as Caucho's HTTP-based Hessian and Burlap protocols. As springs api docs says "HTTP invoker is the recommended protocol for Java-to-Java remoting.
It is more powerful and more extensible than Hessian and Burlap, at the expense of being tied to Java. Nevertheless, it is as easy to set up as Hessian and Burlap, which is its main advantage compared to RMI".

There is a nice example available which shows integrating JavaFX with JBoss Seam/spring using Flamingo DS through Hessian protocol. http://java.dzone.com/articles/javafx-and-seam-flamingo

JavaFX and JQuery Widgets with Zembly

2009-05-15T13:26:00.001-07:00

Since, I attended the BOJUG meet on JavaFX in Dec 2008 ,I was very excited about trying it out. Finally I managed to get some time to work on it.I found it easy and fun to learn as it is almost like writing Java2D code in a more sophisticated form. I was looking out for ways to create something that can be shared across blogging and other social networking sites something like flash widgets but not in flash.Being a Java developer it looks very scary to me ;). Then almost a month and a half back I got to know about this new browser based social programming environment Zembly from Sun Microsystems. I was not fully aware of how these widgets are published simultaneously on various social networks.But after exploring Zembly I found creating these kind of widgets very easy and interesting.My interest dragged me to write these two small apps which are published on Blogger and iGoogle using Zembly.
Added below is a JavaFX piano which can be played through keyboard(use Keys:A,W,E,D,R,T,G,Y,U,J,I,O,L to play various piano keys) or through mouse.
I will be posting the link to download the FXPiano netbeans project very soon.

FXPiano

The (kind of) game widget added below uses jQuery for animation and effects.It is not yet fully completed.

Game(under development)

While working on both the apps I found zemblys JavaScript/CSS/(X)HTML editor support really good. It provides code completion on CTRL+Space just like netbeans . The default javascript editor also provides applet based syntax highliting. Apart from the default editor they also have Mozilla labs Bespin editor which is also light weight and provides awesome syntax highliting.

Zembly simply rocks because of some basic features like "Clone and Edit","Preview Widget" which allows you to clone ,play and preview any widget developed by somebody else. It helped beginners like me a lot. Moreover it provides many inbuilt templates like NewsTicker, FeedScroller, GoogleMapMaker,3D-PhotoCarousel,YouTube Video Player etc. which are ready to use vanilla templates ,all you need to do is just customize according to your requirement. Zembly is huge, I am yet to try developing full fledged FaceBook and Meebo Apps which I will be looking forward to do now.

Web browsers and RIAs

2008-11-22T03:13:00.000-08:00

With smart and good looking AJAX sites becoming more prevalent on the web . The only restriction for Ajax developers now is browser compatibility and when it comes to Internet Explorer 5 ,6 and 7 its has became a nightmare for Ajaxians . As Web 2.0 mainly relies on Ajax and complex JS libraries the speed of a web browser's JavaScript interpretation and rendering is becoming more and more important . According to various web benchmarks for w3 standards all of them shows IE slowest browser when it comes to JavaScript and CSS interpretation and rendering(http://acid3.acidtests.org , http://www2.webkit.org/perf/sunspider-0.9/sunspider.html). With Google and Yahoo having most of its stake with AJAX based applications these days , Microsoft has also turned a bit with AJAX implementation of Live.com and according to this post http://blogs.msdn.com/ie/archive/2006/08/28/728654.aspx they are also trying to improve their JScript engine due to world wide criticism of the browser. Anyways with powerful Javascript engines like Tracemonkey for FF3 , V8 for Chrome and Safari's SquirrelFish in the market , AJAX is never going to die.

But when it comes to RIAs I sometimes feel that web browsers like IE are not the best way to deliver the RIA experience . Also value addition of rich experience has got a bit overhead in loading these kind of applications on web browsers . But I hope that probably in future the line between web applications and desktop applications will surely vanish if we clearly understand the enormous powers of RIA platforms like Flex, Silverlight and JavaFX outside of web browsers.