Multiple Inter-Dependent ComboBoxes

[AGS94]

I have several inter-depednendent (key point) comboboxes as shown in the pic below and everything is working well, but I would like to improve on a couple of things.

Right now I have it set up such that anytime a change is made to a given CB you have 4 seconds (via a timer) to finish making your selections, after which ALL CB selections (including the one changes were being made to) are filtered accordingly.

Depending on how many options are chose from a given CB, four seconds is somewhat fast, other times it is a bit slow. In these "slow" instances I would like to prevent users from jumping to any of the other CBs until they have been filtered via the timer.

My thought is to use rectangles (with transluscent fill) that are visible only while the timer is running, thus preventing the user from interacting with a CB. The tricky part is, the same rectangle will immediately block the CB the user is making changes to.

With enough "if" statements, etc. I could make all of that work, but was wondering if someone had a better idea? Again, it is working but I want the user experience to be as clean as possible. 

[AGS94 · Accepted solution]

Went with the rectangle soltuion. Was pretty straightforward, but still not ideal.

It would be great if there was a property for when a user was done making their selections (triggered by selecting the "X" and/or by clicking outside the CB drodown). That would make things much easier and cleaner for the user.

Still interested to know if others are using inter-dependent filter selections (via CBs or ?) and if so, what approach they are taking.