Flex 4 Layouts and States

Question

Hi,
I've recently been thinking about how Layouts can use states and wanted to know what you guys think. I noticed that the way a skin's state is changed in Flex 4 (e.g. FxButtonSkin) is by calling invalidateProperties/invalidateSkinState, which leads to the commitProperties method. Then this method says in there:
if (skinStateIsDirty)
skin.currentState = getCurrentSkinState();
skinStateIsDirty = false;
This is awesome. But it also means the names of the states are hardcoded in the FxComponent class (i.e. in the FxButton class you have "disabled", "down"), which means you must name your skin states with those names, but that's not a big issue. What I was thinking, though, is that you could do the same thing with Layouts!
If I'm reading the code right, it looks like all of the layout manipulations are called through the FxContainer and subclasses. In the layout you have a bunch of items you want to manipulate, such as the FxList and it's embedded VerticalLayout and HorizontalLayout. If you could somehow have your FxContainer (e.g. FxList) get ahold of the names of your custom component's states (check out the comment I made on OpenFlux about possible CoverFlowLayout states), then it could "map" layout states to your layout items' states. So for the CoverFlow, if the item is the "selectedIndex" item (the one facing forward), then the FxContainer class could assign that layout state (selectedIndexState) to your component's state (selectedIndexState, where "I want my center coverflow item to now display some buttons or something"). You could do that by adding something like this to the FxContainer class:
if (componentStateIsDirty)
component.currentState = getCurrentLayoutState();
componentStateIsDirty = false;
That would be really, really powerful. The only issue I could see is in matching the names of your CustomLayout states to your Component's state. This could be done in the layout tag of a FxContainer component by adding a "mapToStates" method that accepts an Object/hash to map layout states to component states:
mapToStates((coverFlowSelectedItemState:myImageSelectedState, coverFlowZoomedState:myImageFullViewState, etc...))
This way, you could dynamically change the states of your component whenever they were in a specific position within the layout. This cuts out the need of having to figure out each and every time you create a new component "how" to change the state. The layout should take care of all that for you.
One other thing. If I wanted to change the FxList layout from Horizontal/Vertical to say CoverFlow, it seems like the layouts are hard coded into the Container class, in the list_keyDownHandler method. It seems like a more separated-out option would be to handle all that stuff in the Layout classes. Then for the FxList you could render it in any of an infinite number of ways. OpenFlux does this really well.
If layouts become this robust, the line between Flex and Flare, for example, is going to become really, really thin. Flex will be able to make some really intense data visualizations that automatically change the state of your component whenever it is in a specific state of the layout.
Any thoughts on this? Sorry it's so long.
I wrote more about the CoverFlowLayout idea, as well as how one might rewrite the FlexStore ProductCatalogPanel layout using a pattern like this, it's here: http://groups.google.com/group/openflux/browse_thread/thread/9670ecc48046fc4
Basically, skins go on components, layouts "go on" containers which have components, so the functionality should be similar. While the FxComponent changes the skin's state, the FxContainer changes the component state through the layout's state.
Best,
Lance

Answer 1

You already have a thread open about this. Whether or not it's state related, the jury is out.