JSFiddle - React, Tailwind, and code Playground

HTML

<textarea>This is some content. It wraps.</textarea>

CSS

textarea {
  width: 4cm;   
}

JavaScript

$("textarea").keydown(function (evt) {
console.log(evt)
  cursor_position = evt.pageY - $('textarea').offset().top;
  if (cursor_position <= 15) {
    alert("first line");
  } else {
    alert("other line");
  }
});