Paint tabs over the title bar

Hi Ralph,

The Ribbon doesn't have that capability at this time.  I will make a note of the suggestion.  The downside of it is that it would prevent usage of application icons, the QAT, contextual tabs, and tab panel items.  Those all have UI pieces that arrange in various places that would conflict.

Yes, this can only be done when no advanced Ribbon features are used, but it's not a problem for many applications.  Contextual tabs will still appear, but without group banners above them.

I managed to get the tabs painted over the title bar by overriding OnApplyTemplate() in the RibbonWindow code behind.  The only downside of this solution is that when the window is first displayed, the ribbon visibly jumps.  Not perfect, but works.

        public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();

            Dispatcher.BeginInvoke(new Action(() =>
            {
                if (Template.FindName("PART_TitleBar", this) is Grid titleBar)
                    Ribbon.Margin = new Thickness(0.0, -titleBar.ActualHeight, 0.0, 0.0);
            }), DispatcherPriority.Normal);
        }