title: Create a pop-up menu with right click about an object
body: <p>I want to know if it is possible create a pop-up menu with right click in a web page using R-Shiny, and how create menu with submenus?</p>
  
  <p>I was testing with this code but does not work:</p>
  
  <pre><code>selectInput("variable", "Variable:",
          c(selectInput("variable1",Cylinders",c("cyl"="pm,"mmm"="jj"),
            "Transmission" = "am",
            "Gears" = "gear"))
  </code></pre>