Script, IF sheet has AutoFilter criteria, to unfilter...

Is there a way I can write a script which can run based on criteria, IF the sheet is filtered, to unfilter, before processing the remainder of the script?

Or, better yet, it will do the following, IF the sheet is filtered:
* Remember what the filter settings are
* Run an ActiveSheet.ShowAllData
* Run the remainder of the macro
* Re-filter so the sheet is back to the way it was previously

And if the sheet was already unfiltered, just run the macro.