My favourite is Massimo's 2nd option. A floating tool over the page.
I don't like the expanding row idea, though. To me it looks clumsy.
Perhaps in its 'options' you can choose where it pops up? 1) Under the pointer/selection, 2) Center of screen, or 3) xy coords.
Maybe all popup tools could have the xy option?
For the record, I'm a mouse/kbd user.
I had to shout loud enough to get my theatre group let me buy a new led fixture; a touchscreen I'd have to scream my head off.