title: How to execute some code when user switches to a nested tabsheet?
body: <p>I have a TPageCOntrol which has 3 TTabSheet and some of those have further TPageCOntrol which have a TTabSheet</p>
  
  <p>Sort of  </p>
  
  <pre><code>Page Control 1
    TabSheet 1
    TabSheet 2
      Page Control 2
        TabSheet 2a
        TabSheet 2b
    TabSheet 3
  </code></pre>
  
  <p>Now, whenever one of those tabsheets becomes visible to the user I want to execute some code, but I'm not sure which event to hook.</p>
  
  <p>For instance, if the user is looking at <code>TabSheet 1</code> and switches to <code>TabSheet 2</code> where <code>TabSheet 2a</code> is showing,  then I want to execute Tabsheet 2a's code, but I can't hook TabSheet 2a's OnEnter or OnShow.  And it isn't Page Control2's OnChange.</p>
  
  <p>In fact, all that I can see is to put a whole bunch of switch/case into Page Control 1's OnChange event ... is tehre a better way?</p>