JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://openlayers.org/dev/OpenLayers.js"></script>
<div id="map"></div>

CSS

.customControl{
    left: 40px;
    background-color: red;
    padding:5px;
}
#map {
  width:100%; 
  height:512px;
}

JavaScript

// https://github.com/openlayers/openlayers/pull/590 

OpenLayers.Control.prototype.keepEvents = function(div) {
    this.keepEventsDiv = new OpenLayers.Events(this, div, null, true);
    // IN THIS CASE triggerButton IS NOT NECESSARY 
    var triggerButton = function (evt) { 
        var element = OpenLayers.Event.element(evt),
            buttonclick = this.map.events && 
                    this.map.events.extensions && 
                    this.map.events.extensions.buttonclick;        
        if (element && buttonclick) {
            element = buttonclick.getPressedButton(element);
            if (element && OpenLayers.Element.hasClass(element, "olButton")) {
                buttonclick.buttonClick(evt);
            }
        }
    };
    var listeners = {
        "mousedown": function (evt) {
            this.mousedown = true;
            triggerButton(evt);
            OpenLayers.Event.stop(evt, true);
        },
        "mousemove": function (evt) {
            if (this.mousedown) {
                OpenLayers.Event.stop(evt, true);
            }
        },
        "mouseup": function (evt) {
            if (this.mousedown) {
                this.mousedown = false;
                triggerButton(evt);
                OpenLayers.Event.stop(evt, true);
            }
        },
        "click": function (evt) {
            var element = OpenLayers.Event.element(evt);
            triggerButton(evt);
            OpenLayers.Event.stop(evt, true);
        },
        "mouseout": function (evt) {
            this.mousedown = false;
        },
        "dblclick": function (evt) {
            var element = OpenLayers.Event.element(evt);
            triggerButton(evt);
            OpenLayers.Event.stop(evt, true);
        },
        "touchstart": function (evt) {
            OpenLayers.Event.stop(evt, true);
        },
        scope: this
    };
    this.keepEventsDiv.on(listeners);
};

var customControl = OpenLayers.Class(OpenLayers.Control, {
    initialize :...