AdvancedDataGrid (grouping) quick jump to row

I have a problem with the AdvancedDataGrid widget. When the dataProvider is an ArrayCollection (of arrays), the nth array (within the collection) is also the nth row within the grid, and I can jump and display the i-th row by scripting

adg.selectedIndex = i;
adg.scrollToIndex(i);

now, when I add a Grouping, the dataProvider ends up being a GroupingCollection2, and now the index in the dataprovider's source does not correspond to the index in the adg anymore (which is understandable, because it's being grouped).

How can I select and display a row in grouped data efficiently? Currently, I have to traverse the adg and compare each found item with its data attributes in order to find the correct index of the row within the adg, and jump to it like above. This process is very slow. Any thoughts?

edited later: We already used a caching object as Shaun suggests, but it still didn't compensate for the search times. In order to fully construct a sorting of a list of things (which this problem equates to, as the list is completely reordered by the grouping), you always have to know the entire set. In the end we didn't solve that problem. The project is over now. I will accept Shaun's answer if no 开发者_运维问答one knows a better way in three days.

Depending on what values your comparing against you can store the objects in a dictionary with the lookup using the property/properties that would be searched for, this way you have a constant time look-up for the object (no need to look at every single item). Say for example your using a property called id on an object then you can create an AS object like

var idLookup:Object = {};
for(myObject in objects)
    idLookup[myObject.id] = myObject;

//Say you want multiple properties
//idLookup[myObject.id]={};
//idLookup[myObject.id][myObject.otherProp] = myObject;

now say the user types in an id you go into the idLookup object at that id property and retrieve the object:

var myObject:Object = idLookup[userInput.text]; myAdg.expandItem(myObject, true);

now when you want to get an object by id you can just do http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/controls/AdvancedDataGrid.html#expandItem() I haven't done any thorough testing of this directly, but use a similar concept for doing quick look-ups for advanced filtering. Let me know if this helps at all or is going in the wrong direction. Also if you could clarify a bit more in terms of what types/number of values you need to lookup and if there's the possibility for multiple matches etc. I may be able to provide a better answer.

Good luck,

Shaun