How to disable the content when button was clicked

I need to disable the content or put an overlay in my project. I have a floating button when this floating button clicked I need to expand some images in the right corner(I did this part). Also, I need when the button clicked it needs to overlay the current content. the problem is I need custom code for that when button clicked it should overlay.

My content view

   <ContentView xmlns="http://xamarin.com/schemas/2014/forms"
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
     xmlns:customRenderes="clr-namespace:DipsDemoXaml.CustomRenderes;assembly=DipsDemoXaml"
     x:Class="DipsDemoXaml.Views.Page1"
     x:Name="navi">

<StackLayout >



        <customRenderes:NavigationImageButton Source="MenuSettings"                                                
                                                  x:Name="Button1"                                                        
                                                Margin="0"                                                       
                                                    IsVisible="{Binding Visibility1}"                                                                                                                                                                                                                                                                                                                       
            />

This is how I called this whenever I need that floating button

  <AbsoluteLayout>
   <views:Page1 AbsoluteLayout.LayoutFlags="PositionProportional"  AbsoluteLayout.LayoutBounds="1,1,-1,-1" ></views:Page1>
     </AbsoluteLayout>

I need to add an overlay also I cannot mess with all my pages so it should include in the ContentView page. How to do it, How to add a popup overlay in contentview