title: GridSplitter with button for pinning like behavior
body: <p>I'm looking to extend the GridSplitter in some way to add a button which when click expands or collapses the control to one of the specified sides of the splitter.</p>
  
  <p>I've found <a href="http://shemesh.wordpress.com/2010/07/10/silverlight-gridsplitter-with-a-collapse%C2%A0button-%E2%80%93-best/" rel="nofollow noreferrer">a solution that works for Silverlight 4</a> but I need this to work for standard WPF in .NET 3.5 which means that the GridSplitter doesn't implement the Visual State Manager stuff that is used in Shemesh's solution. Other than it won't work for WPF in .NET 3.5 I think Shemesh's solutions is probably exactly what I'm looking for with smooth animated transitions and remembering the last expanded size upon expanding from a collapsed state.</p>
  
  <p>Anybody have any examples of this being done in regular WPF?</p>