title: Use Reactive Extensions to harmonize & simplify Control.Enabled = true/false conditions?
body: <p>Is it possible, or more precisely how is it possible to use RX.Net to listen to a number and different variety of (WinForms) controls' .TextChanged/.RowsChanged/.SelectionChanged events and whenever one condition is fullfilled (ControlA.Text isn't empty, ControlB.RowsCount > 0 etc) enable that one DoSomething button.</p>
  
  <p>I am asking because currently we have a lengthy if/then statement in each of these events' handlers and maintaining them if the condition changes is, due to duplicate code, quite error prone and that's why, if possible, I think it would be nice to take the stream of events and put the condition in one place.</p>
  
  <p>Has anyone done that?</p>