t would be nice if the Undo command supported ALL actions -- i'm thinking here of view-changing such as zooming, filtering, etc. Especially for new users (but sometimes not), one will occasionally do something that just “blows up” the view, and you don’t understand why or where you are. Panic sets in, you're afraid you lost some work, and you just want to Undo. Unfortunately in these cases, Undo does nothing.

What makes it a little worse, is that Undo is still available from the Edit menu. So it looks like you can use it. But then nothing happens, so you wonder if you still "undid" anything. If your view didn't change, but it still lets you "undo", does that it mean it "undid" the last change you made that wasn't a view change? You look in the Edit menu again and "Redo" is available, not grey...so maybe you should Redo now in case you lost info you entered? But clicking Redo doesn't do anything either, and it still doesn't become grey, so that means you really have no idea if you're at the middle or the end of your "undo chain". Now you have to not only get back to your previous view, but remember the last thing you typed and see if it's still there...

Therefore, i suggest:
- Undo not available (grey) if clicking it will do nothing
- Undo pops up feedback on what was actually undone (the black banner at the bottom of the screen), so you know if it did nothing, or made a change you can't see. This can be very vague, like "undid typing" "undid view change" "undid filter"
- The black banner should have a "show" link that will jump the current pane to wherever the undo happened.
- Similarly, "Redo" should be unavailable (grey) if there is nothing to redo (ie you are at the end of the available undo chain).