title: Animate width WPF left sided
body: <p>I have a <code>Grid</code>which I'm able to animate the following way:</p>
  
  <p><img src="https://i.stack.imgur.com/TUphq.png" alt="Normal state image right"></p>
  
  <p>When I click on the image, I can animate the template of my button with a Storyboard to grow as much as I want as a result like this:</p>
  
  <p><img src="https://i.stack.imgur.com/R5nRL.png" alt="enter image description here"></p>
  
  <p>That would be the result more or less. The animation looks like this:</p>
  
  <pre><code> &lt;Storyboard x:Key="ExpandPanelRight"&gt;
      &lt;DoubleAnimation
          Storyboard.TargetName="ExpandablePanel"
          Storyboard.TargetProperty="Width"
          BeginTime="0:0:0"
          From="0" To="450" Duration="0:0:0.5"&gt;&lt;/DoubleAnimation&gt;
  &lt;/Storyboard&gt;
  </code></pre>
  
  <p>As you can see, no problem while growing the grid from left to right, but what I really want is the opposite: expand the Grid from right to left:</p>
  
  <p><img src="https://i.stack.imgur.com/lT5Qg.png" alt="enter image description here"></p>
  
  <p>How will it be?? I can't find the answer.</p>