title: Animating the addition of a string to a ListBox in FireMonkey
body: <p>The following code nicely animates adding a new string to the end of a ListBox</p>
  
  <pre><code>procedure TForm6.AddItem(s: string);
  var
    l : TListBoxItem;
    OldHeight : Single;
  begin
    l := TListBoxItem.Create(Self);
    l.Text := s;
    OldHeight := l.Height;
    l.Height := 0;
    l.Parent := ListBox1;
    l.Opacity := 0;
    l.AnimateFloat('height', OldHeight, 0.5);
    l.AnimateFloat('Opacity', 1, 0.5);
  end;
  </code></pre>
  
  <p>The item expands and fades in.  However I want to be able to add the string into an arbitrary location in the ListBox - actually at the current ItemIndex.
  Does anyone know how to do this?</p>