Spark column layout

Im currently working on an application, which contains lots of forms - Flex has already lots of tools to make forms, but i found complicated (you need to skin form items,lots of embedded containers), and slow for lot of displayed items. In Spark a single form item; for example a label and a text input creates 9 UIComponents - just look at the source of FormItemSkin.
I needed a simple way to create forms, so i made a layout that makes it easy to display forms, and its fast. The result is ColumnLayout, a custom layout, where one can set column sizes (either in percent or with fixed values), and its items get layed out according to these values. It can do a few extra stuff too: You can specify fixed row height (by default row height is the largest row element), vertical aligment of elements in rows, and padding values.

An example:



Download source.

Spark Datefield and Datechooser

The spark framework was released with Flex 4.0, and it still does not have a spark-only datefield and datechooser. I found, that in most of my projects the MX Alert, datechooser & datefield were the only MX components. Tink has made a really good Alert for Spark, and Alex Harui has made a Spark datechooser, which functions almost OK, but its skin is very ugly.

So i decided to make a usable DateChooser from Alex's component - after a while i found out, that i needed to rewrite most of the source.
So with this component you'll be able to get rid of the MX framework, making the size of your application several hundred KBs smaller. And it functions on mobile too (i guess... havent tested it).
I have only implemented a few functions from the MX component (for example you cant select a range or you cant use styles) - but on the good side the code is really simple, so you will have an easy time to extend it.
An example:



Download source.

Animated radial data visualization

I've been freelancing lately, and while looking around for data visualization techniques i found a really nice one. The animation technique was published some years ago (youtube video), and i think was used in some Gnutella clients (anyone remember those? :) ). I looked around and did not found a nicely working and free implementation for Flash, so i made one. You can check it out at link

Function plotter

I made this little function plotter app to help me with some research i was doing at the university. It can be used as an app, which can plot two arbitrary functions simultaneously, each with 3 adjustable variables.

The technical part if you're interested(AKA what is a Hodgkin-Huxley equation?):
It plots for me Hodgkin-Huxley activation and inactivation curves. A little explanation: The Hodgkin-Huxley formalism is a way to describe how neurons transmit signals. Neurons transmit signals by electric impulses. There is always a voltage difference between the interior and the exterior of the cell(called membrane potential). If i change this potential somewhere, this temporary change will spread across the cell's surface, like a wave. The mechanisms responsible for this process are molecules in the cell membrane(called ion channels), which can open to let ions flow trough, which causes change in the membrane potential. There are tons of different ion channels, but most of them can be described with the Hodgkin-Huxley formalism. These curves describe how much will be these channels open ( 0-closed; 1-fully open) at different membrane potential values. To make things more complicated each ion channel is modeled by 2 curves (activation and inactivation) and the product at a current membrane potential value will be the actual channel activity. Note, that this is a really simplified description (for example these channels have time-dependence too), if you want to really understand the concept i recommend reading on Wikipedia or Scholaropedia about this topic.

Tileset ripper

Im now working on a roguelike game as a hobby project,(well, since 1/2 year, its my neverending project :) ) , and i havent found any good programs on the net to get tiles from images, so i made one in Flex. Flex as a platform is not optimal for this task, because of lots of number crunching, but as long as you dont try to rip tiles from a 3000x2000 pixels image, it will work well.

Slider with 2 thumbs for flex 4

For a project i needed a slider with 2 draggable thumbnails and a fixed middle track. It has a separate skin file, so skinning should be easy.
I havent seen one for flex 4, so i made one:





download source

hai

I will post here stuff about the projects i do mostly on my free time.
In the near future these things will be mostly Flex 4 and actionscript related.