JSFiddle - React, Tailwind, and code Playground
HTML
<div id="paper1"></div>
JavaScript
var paper = Raphael("paper1", 250, 250);
var dialCenter = 125;
var dialRadius = 125;
var dialCircum = 2 * Math.PI * dialRadius;
var circle = paper.circle(dialCenter, dialCenter, dialRadius).attr({fill: "orange"});
paper.circle(125, 125, 10).attr({fill: "black", "stroke-width": 5, stroke: "purple"});
var needle = paper.path("M" + dialCenter.toString() + ' ' + dialCenter.toString() + ", L0,125").attr({stroke: '#ffff00', 'stroke-width': 6});
var centerCircle = paper.circle(125, 125, 10).attr({fill: "black", "stroke-width": 5, stroke: "purple"});
needle.data("id", 'needle1');
var degStep = 1;
var currentDeg = 1;
var mouseXPos, mouseYPos, mouseDir, mouseEv;
var needleSet = paper.set();
needleSet.push(needle);
var circSectorA = 360 / dialCircum;
var currSectorX = 0;
var currSectorY = 0;
moveNeedle = function (dx,dy,x,y,e) {
var mouseX = e.clientX;
var mouseY = e.clientY;
var needleA = Raphael.angle(dialCenter, dialCenter, needle.getPointAtLength(needle.getTotalLength())['x'], needle.getPointAtLength(needle.getTotalLength())['y']);
var newA = Raphael.angle(dialCenter, dialCenter, mouseX, mouseY);
var rotateAngle = (360 - needleA) + newA;
needle.transform('r' + rotateAngle + ",125,125");
}
var startDrag = function () {
// console.log(this);
}, dragger = moveNeedle
, endDrag = function () {
};
needleSet.drag(dragger, startDrag, endDrag);