TIWComboBox + OnAsyncChange + ItemsHaveValues

[MJS@mjs.us]

C++ Builder 11.0 / IW 15.2.47

TIWComboBox ItemIndex is not always updated correctly. 

For example: TIWComboBox Items populated with

A=1
B=1
C=1
D=2

and ItemsHaveValues = true so that only Names[] values A, B, C, D are visible. 

When selecting:
A, ItemIndex == 0 // correct
B, ItemIndex == 0 // incorrect
C, ItemIndex == 0 // incorrect
D, ItemIndex == 3 // correct

The ItemIndex seems to be affected by the Values[] column. 

Desired behavior is for ItemIndex to be updated to the true selection offset regardless of the Items content.

Demo attached.

>>Before even testing it... values shouldn't be the same for different items.

I don't see any requirement for that in the way TStringList or TIWStringList work.  IWCombo may be designed that way but's it's a restriction that radically changes the behavior based on ItemsHaveValues=true or ItemsHaveValues=false.  I think with ItemsHaveValues=true the IWCombo should display only the Names[] strings, then give the correct ItemIndex when a selection of an item occurs so that the correct Values[] can be returned.  Right now an incorrect ItemIndex can be returned (note the property is named ItemIndex not  FirstUniqueValueIndex).


>>The value is the KEY of the list and there is no way to distinguish one from
>>the other if you have identical values for two different items.

You don't want to search just the Values[] to determine uniqueness but search for the whole NAME=VALUE string itself (the Item). 


>>If you want that 2 different items behave the same in your event handler, you
>>need to treat 1, 2 and 3 the same, not giving first, second and third item the
>>same value "1".

My use case:  IWCombBox populated with many 'ACCOUNT_NUM=COUNTYID' strings. COUNTYID can be mostly duplicates but not always. With ItemsHaveValues=true ACCOUNT_NUM displays, COUNTYID does not but I can apply it to the database query based on IWCombBox selection.  Seems like a reasonable use case.


>>Imagine a LookupComboBox (from VCL, not IW) where all KeyValues of the list have
>>the same value?

Those are two different components with their own functionality - don't think that's a good comparison.  I have a workaround implemented so not waiting on a fix but think this is a design flaw in IWComboBox.