custom xtype widget migration from classic to touch ui

Hi all,

I'm having a use case where we have a custom xtype widget developed using ext.js for classic ui , which basically create a  dropdown and using listeners on selection of different options different data is populated in other fields from json data files stored on aem, now we want to migrate all component to touch ui , which doesn't support ext.js, hence is there any coral or granite api like ext.js to crete custom resourcetype like foundation coral  component which basically use init.jsp and render.jsp  or am i need to write all logic in different jsp  ? any leads will help