title: Translucent banner across all the layouts in my Vaadin app, à la Vaadin Charts 2 Demo license?
body: <p>The new <a href="https://vaadin.com/add-ons/charts" rel="nofollow noreferrer">Vaadin Charts 2</a> add-on offers a time-limited trial license. </p>
  
  <p>During that trial period, your app launches with a translucent grey bar at the bottom of the UI (browser window/tab). The grey bar displays a bit of text. The grey bar also reacts to a user’s click (bar disappears). The bar remains in place on the UI even while I change my layouts underneath. </p>
  
  <p><img src="https://i.stack.imgur.com/mG9ln.png" alt="screen shot of Vaadin app’s tables obscured by floating translucent bar"></p>
  
  <p>I would like to provide exactly that same behavior within my own app. When urgent alerts are pending, I want to notify the user with a bar across the screen. I want to react when the user clicks that bar. I want that bar to appear and remain displayed regardless of what layouts are changing beneath the bar. </p>
  
  <p>Rather than have to have every layout manage some urgent-alert notification widget, I want just one widget (translucent bar) to float over the entire rest of the app. </p>
  
  <p>Is there some way to provide that app-wide bar on my own?</p>
  
  <p>To clarify, the more important part of the Question is is not the translucency of the bar. The more important part is: How to float this bar over any and all content in the UI. That Vaadin Charts "Using Evaluation License" remains displayed while underneath I change from a VerticalLayout to a GridLayout to a TabSheet. So, that’s the core of my Question, how to float a bar over the changing Layouts in that UI <strong>without making each Layout aware</strong> of the bar widget.</p>