Android : Class as a Popup for Android App

I have:



MainActivity.java,

Food.java (with layout food.xml),

food.xml (in GridView)

In my MainActivity class, I have a button where I want a popup to show up after clicking it. I am able to show a xml file as a popup, or move screens to another class, but is there a way to show the Food.java class as the content of the popup?