A couple of weeks ago (well actually, back in September), I received an interesting email from Lyora MacRae of Adobe. To quote the email:
Thanks so much for reporting 3 or more bugs for Flex SDK. As a thanks for your hard work, we want to send you a free t-shirt we're designing with all the developers' names on it. Therefore, we need your shirt size and mailing address to include you!"
Yesterday, I was trying to write a custom hierarchical cursor class that implements the
IHierarchicalCollectionViewCursor
interface. But no matter what I tried, the
AdvancedDataGrid would not recognise my
implemented cursor class as being hierarchical. When I extended the
HierarchicalCollectionViewCursor
class, the AdvancedDataGrid would happily recognise it - even I overrode every single method and property... yet, as
soon as I switched the class to implement IHierarchicalCollectionViewCursor instead of extending
HierarchicalCollectionViewCursor the AdvancedDataGrid would break again.
Last night I received some pretty exciting (to me) news about something that's just been released on Adobe's pre-release site (which I am a member of)... unfortunately I can't say what it is yet (I've been sworn to secrecy), but it will likely help with a number of technical issues I'm currently facing in a major project at work, so I'm very happy with the timing! :)
At work, we've been having some significant performance issues with the Flex
AdvancedDataGrid control, so my boss has
begun a dialog with some of the AdvancedDataGrid control's developers over at Adobe. As part
of that dialog, my boss asked me to write a brief summary of the problem - which I've done. But it has occurred to me
that the problem description is likely to be very interesting to some people, so I've decided to publish it here too.
And so, here it is...
I'm currently sitting in (and posting from) the first Adobe AIR Camp in Australia... there's not much going on yet, but the day is young! :)
Currently, Andrew Spaulding is introducing Flex Builder 3... since I've been using it for some time now, this part's a little slow ;)
Okay, now he's talking about using transparent images for application chrome... getting interesting... better go now :)
In my last post I presented a simple way to customise the DataGridItemRenderer
class so the Flex DataGrid control would use the textRollOverColor and textSelectedColor styles correctly. But I
also noted that the solution would not fix the DataGrid header items... well, here's my solution to that problem.
First of all, it's worth noting that there are two main reasons why a custom DataGridItemRender is not adequate for
the DataGrid header items. The first reason is that the renderer's validateNow() method is almost never called for
header items, even though it also called correctly, and often, for the data items. And the second reason is this: the
validateNow() method (both the original version, and my custom version) depends on two DataGrid methods in order to
determine which text style to use. Those methods are isItemHighlighted() and isItemSelected(). However, neither of
those methods work for header items - they both always return false, making them of no use in determining text color for
header items.