Interesting, never knew of those settings available by rightclicking the QlikView logo.
But I suspect this is not a solution either?
First, my real world problem (not the example above) had more than 3 values to start with and second, changing of those settings I suspect affect the client not the application, if that is correct one would have to change the setting for every user including when new users are introduced.
I suspect the problem is solveable by using a maceo triggered by the button but I don't want to go that way even though I have the knowledge how to do it.
From your initial question it sounds like you know up front that "B" is the only category that you want to be able to exclude at the click of a button.
If that is the case we can prepare a new field in the script that will help us.
example_stg:
LOAD * INLINE [
Year, Category, Value 2012, A, 1 2012, B, 2 2012, C, 3 2013, A, 4 2013, , 6 ];
example:
LOAD * ,if(Category<>'B','Category is Not B') as excludeB Resident example_stg;
DROP Table example_stg;
Then you can simply use a Listbox on the excludeB field (my preference) or you can create an action to put in a button or on a trigger.
The action would simply be Select Possible against excludeB.
You could do something quirky with calculated dimensions.
If you create a separate table just to hold a copy of the Category values you could then create a list box on it whose selections would become immune from mutual exclusivity issues with other selections.
This could then be used in a calculated dimension to determine whether or not to include the row. I've called it [Category NOT IN] in the example to get you the clarity you were after to make it obvious in the current selections box that things are being excluded. I also coloured the list box reddish to try and give a visual clue that it is treated differently.
The calculated dimension checks the selections and returns either 1 or Null() and is set to suppress nulls. It is also hidden.
This certainly works for this simple example but the logic would need to be propogated in other charts and so on in the report where the exclusion is to be applied. You also need to make sure you choose a big enough max values number in the GetFieldSelections function to cover all the possible selections else you would end up with weirdness when the selection switched to the 'NOT B,C' or 'X of Y' type of response.
This is probably more trouble than it is worth for more complicated or larger production reports so I'm just presenting it as a curiosity. Hopefully thought provoking though.
By the way, if you use the GetFieldSelections function you can specify a max values without needing to tinker with any global client settings.
