Precision focus control within the Spark DataGrid

So, in preparation for my MAX 360Flex Unconference presentation on Tues Oct 4th at 2pm (http://www.360flex.com/blog/2011/08/360max-the-schedule-2/) I've put together this demo about how to get precision focus control within the Spark Datagrid.

In this example you can see:

• Set focus to first editable item
• Tab through occasionally editable fields
• Focus with a mixture of multiple occasionally editable fields within a record
• Focus on a particular data item
• Focus using Tab, Shift+Tab, Arrows, and Page-Up and Page-Down
• Remove Focus
• Focus by clicking on a row

(Note, I've left the "disabled" cells editable, as I'm only changing the alpha. This is so that you can see that even if you click in to the non-editable fields directly, that the editing sessions (via the "Dashboard") doesn't get set)

view source

The slide deck for the preso will be coming soon.

DataGrids performance tests

 So my mission is to try to performance test the 3 Flex grids. mx:DataGrid, s:DataGrid and mx:AdvancedDataGrid.

I feel like my tests are incorrect and looking to you to point out my flaws.

Each grid has the same dataprovider and columns defined. I'm only using the default renderers
I have a StopWatch class, that will getTimer() from a start() method, until the next Event.RENDER from the grid under test.
I remove the data provider by setting it to null.
Once the screen is blank, I start the stopwatch and add the dataprovider.

The average of these tests over ten samples is:

Spark DataGrid: 207 ms
mx DataGrid: 176ms
AdvancedDataGrid: 171ms

I feel like my testing method is invalid, as I don't trust that

   1. The ADG is the fastest at rendering
   2. Spark is the worst at rendering
   3. That the difference in rendering between the 3 grids is negligible

Anyone to offer any insight?