title: IPad like overlay popup window
body: <p>how would one do an IPad like overlay window like this
  in WPF with XAML
  <img src="https://i.stack.imgur.com/EvPUC.png" alt="enter image description here"></p>
  
  <p>I thought about a toggle button to or an expander control.
  It would be nice if the panel is scaleable. 
  I have the most trouble with the centric overlay that has different size then the button itself.</p>
  
  <p>Any help, links or resources would be great. </p>